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2021-04-07bpf, sockmap: Fix incorrect fwd_alloc accountingJohn Fastabend
Incorrect accounting fwd_alloc can result in a warning when the socket is torn down, [18455.319240] WARNING: CPU: 0 PID: 24075 at net/core/stream.c:208 sk_stream_kill_queues+0x21f/0x230 [...] [18455.319543] Call Trace: [18455.319556] inet_csk_destroy_sock+0xba/0x1f0 [18455.319577] tcp_rcv_state_process+0x1b4e/0x2380 [18455.319593] ? lock_downgrade+0x3a0/0x3a0 [18455.319617] ? tcp_finish_connect+0x1e0/0x1e0 [18455.319631] ? sk_reset_timer+0x15/0x70 [18455.319646] ? tcp_schedule_loss_probe+0x1b2/0x240 [18455.319663] ? lock_release+0xb2/0x3f0 [18455.319676] ? __release_sock+0x8a/0x1b0 [18455.319690] ? lock_downgrade+0x3a0/0x3a0 [18455.319704] ? lock_release+0x3f0/0x3f0 [18455.319717] ? __tcp_close+0x2c6/0x790 [18455.319736] ? tcp_v4_do_rcv+0x168/0x370 [18455.319750] tcp_v4_do_rcv+0x168/0x370 [18455.319767] __release_sock+0xbc/0x1b0 [18455.319785] __tcp_close+0x2ee/0x790 [18455.319805] tcp_close+0x20/0x80 This currently happens because on redirect case we do skb_set_owner_r() with the original sock. This increments the fwd_alloc memory accounting on the original sock. Then on redirect we may push this into the queue of the psock we are redirecting to. When the skb is flushed from the queue we give the memory back to the original sock. The problem is if the original sock is destroyed/closed with skbs on another psocks queue then the original sock will not have a way to reclaim the memory before being destroyed. Then above warning will be thrown sockA sockB sk_psock_strp_read() sk_psock_verdict_apply() -- SK_REDIRECT -- sk_psock_skb_redirect() skb_queue_tail(psock_other->ingress_skb..) sk_close() sock_map_unref() sk_psock_put() sk_psock_drop() sk_psock_zap_ingress() At this point we have torn down our own psock, but have the outstanding skb in psock_other. Note that SK_PASS doesn't have this problem because the sk_psock_drop() logic releases the skb, its still associated with our psock. To resolve lets only account for sockets on the ingress queue that are still associated with the current socket. On the redirect case we will check memory limits per 6fa9201a89898, but will omit fwd_alloc accounting until skb is actually enqueued. When the skb is sent via skb_send_sock_locked or received with sk_psock_skb_ingress memory will be claimed on psock_other. Fixes: 6fa9201a89898 ("bpf, sockmap: Avoid returning unneeded EAGAIN when redirecting to self") Reported-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/161731444013.68884.4021114312848535993.stgit@john-XPS-13-9370
2021-01-28skmsg: Make sk_psock_destroy() staticCong Wang
sk_psock_destroy() is a RCU callback, I can't see any reason why it could be used outside. Signed-off-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Jakub Sitnicki <jakub@cloudflare.com> Cc: Lorenz Bauer <lmb@cloudflare.com> Link: https://lore.kernel.org/bpf/20210127221501.46866-1-xiyou.wangcong@gmail.com
2020-11-18bpf, sockmap: Avoid failures from skb_to_sgvec when skb has frag_listJohn Fastabend
When skb has a frag_list its possible for skb_to_sgvec() to fail. This happens when the scatterlist has fewer elements to store pages than would be needed for the initial skb plus any of its frags. This case appears rare, but is possible when running an RX parser/verdict programs exposed to the internet. Currently, when this happens we throw an error, break the pipe, and kfree the msg. This effectively breaks the application or forces it to do a retry. Lets catch this case and handle it by doing an skb_linearize() on any skb we receive with frags. At this point skb_to_sgvec should not fail because the failing conditions would require frags to be in place. Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/160556576837.73229.14800682790808797635.stgit@john-XPS-13-9370
2020-11-18bpf, sockmap: Handle memory acct if skb_verdict prog redirects to selfJohn Fastabend
If the skb_verdict_prog redirects an skb knowingly to itself, fix your BPF program this is not optimal and an abuse of the API please use SK_PASS. That said there may be cases, such as socket load balancing, where picking the socket is hashed based or otherwise picks the same socket it was received on in some rare cases. If this happens we don't want to confuse userspace giving them an EAGAIN error if we can avoid it. To avoid double accounting in these cases. At the moment even if the skb has already been charged against the sockets rcvbuf and forward alloc we check it again and do set_owner_r() causing it to be orphaned and recharged. For one this is useless work, but more importantly we can have a case where the skb could be put on the ingress queue, but because we are under memory pressure we return EAGAIN. The trouble here is the skb has already been accounted for so any rcvbuf checks include the memory associated with the packet already. This rolls up and can result in unnecessary EAGAIN errors in userspace read() calls. Fix by doing an unlikely check and skipping checks if skb->sk == sk. Fixes: 51199405f9672 ("bpf: skb_verdict, support SK_PASS on RX BPF path") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/160556574804.73229.11328201020039674147.stgit@john-XPS-13-9370
2020-11-18bpf, sockmap: Avoid returning unneeded EAGAIN when redirecting to selfJohn Fastabend
If a socket redirects to itself and it is under memory pressure it is possible to get a socket stuck so that recv() returns EAGAIN and the socket can not advance for some time. This happens because when redirecting a skb to the same socket we received the skb on we first check if it is OK to enqueue the skb on the receiving socket by checking memory limits. But, if the skb is itself the object holding the memory needed to enqueue the skb we will keep retrying from kernel side and always fail with EAGAIN. Then userspace will get a recv() EAGAIN error if there are no skbs in the psock ingress queue. This will continue until either some skbs get kfree'd causing the memory pressure to reduce far enough that we can enqueue the pending packet or the socket is destroyed. In some cases its possible to get a socket stuck for a noticeable amount of time if the socket is only receiving skbs from sk_skb verdict programs. To reproduce I make the socket memory limits ridiculously low so sockets are always under memory pressure. More often though if under memory pressure it looks like a spurious EAGAIN error on user space side causing userspace to retry and typically enough has moved on the memory side that it works. To fix skip memory checks and skb_orphan if receiving on the same sock as already assigned. For SK_PASS cases this is easy, its always the same socket so we can just omit the orphan/set_owner pair. For backlog cases we need to check skb->sk and decide if the orphan and set_owner pair are needed. Fixes: 51199405f9672 ("bpf: skb_verdict, support SK_PASS on RX BPF path") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/160556572660.73229.12566203819812939627.stgit@john-XPS-13-9370
2020-11-18bpf, sockmap: Use truesize with sk_rmem_schedule()John Fastabend
We use skb->size with sk_rmem_scheduled() which is not correct. Instead use truesize to align with socket and tcp stack usage of sk_rmem_schedule. Suggested-by: Daniel Borkman <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/160556570616.73229.17003722112077507863.stgit@john-XPS-13-9370
2020-11-18bpf, sockmap: Ensure SO_RCVBUF memory is observed on ingress redirectJohn Fastabend
Fix sockmap sk_skb programs so that they observe sk_rcvbuf limits. This allows users to tune SO_RCVBUF and sockmap will honor them. We can refactor the if(charge) case out in later patches. But, keep this fix to the point. Fixes: 51199405f9672 ("bpf: skb_verdict, support SK_PASS on RX BPF path") Suggested-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/160556568657.73229.8404601585878439060.stgit@john-XPS-13-9370
2020-10-11bpf, sockmap: Allow skipping sk_skb parser programJohn Fastabend
Currently, we often run with a nop parser namely one that just does this, 'return skb->len'. This happens when either our verdict program can handle streaming data or it is only looking at socket data such as IP addresses and other metadata associated with the flow. The second case is common for a L3/L4 proxy for instance. So lets allow loading programs without the parser then we can skip the stream parser logic and avoid having to add a BPF program that is effectively a nop. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/160239297866.8495.13345662302749219672.stgit@john-Precision-5820-Tower
2020-10-11bpf, sockmap: Add memory accounting so skbs on ingress lists are visibleJohn Fastabend
Move skb->sk assignment out of sk_psock_bpf_run() and into individual callers. Then we can use proper skb_set_owner_r() call to assign a sk to a skb. This improves things by also charging the truesize against the sockets sk_rmem_alloc counter. With this done we get some accounting in place to ensure the memory associated with skbs on the workqueue are still being accounted for somewhere. Finally, by using skb_set_owner_r the destructor is setup so we can just let the normal skb_kfree logic recover the memory. Combined with previous patch dropping skb_orphan() we now can recover from memory pressure and maintain accounting. Note, we will charge the skbs against their originating socket even if being redirected into another socket. Once the skb completes the redirect op the kfree_skb will give the memory back. This is important because if we charged the socket we are redirecting to (like it was done before this series) the sock_writeable() test could fail because of the skb trying to be sent is already charged against the socket. Also TLS case is special. Here we wait until we have decided not to simply PASS the packet up the stack. In the case where we PASS the packet up the stack we already have an skb which is accounted for on the TLS socket context. For the parser case we continue to just set/clear skb->sk this is because the skb being used here may be combined with other skbs or turned into multiple skbs depending on the parser logic. For example the parser could request a payload length greater than skb->len so that the strparser needs to collect multiple skbs. At any rate the final result will be handled in the strparser recv callback. Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/160226867513.5692.10579573214635925960.stgit@john-Precision-5820-Tower
2020-10-11bpf, sockmap: Remove skb_orphan and let normal skb_kfree do cleanupJohn Fastabend
Calling skb_orphan() is unnecessary in the strp rcv handler because the skb is from a skb_clone() in __strp_recv. So it never has a destructor or a sk assigned. Plus its confusing to read because it might hint to the reader that the skb could have an sk assigned which is not true. Even if we did have an sk assigned it would be cleaner to simply wait for the upcoming kfree_skb(). Additionally, move the comment about strparser clone up so its closer to the logic it is describing and add to it so that it is more complete. Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/160226865548.5692.9098315689984599579.stgit@john-Precision-5820-Tower
2020-10-11bpf, sockmap: Remove dropped data on errors in redirect caseJohn Fastabend
In the sk_skb redirect case we didn't handle the case where we overrun the sk_rmem_alloc entry on ingress redirect or sk_wmem_alloc on egress. Because we didn't have anything implemented we simply dropped the skb. This meant data could be dropped if socket memory accounting was in place. This fixes the above dropped data case by moving the memory checks later in the code where we actually do the send or recv. This pushes those checks into the workqueue and allows us to return an EAGAIN error which in turn allows us to try again later from the workqueue. Fixes: 51199405f9672 ("bpf: skb_verdict, support SK_PASS on RX BPF path") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/160226863689.5692.13861422742592309285.stgit@john-Precision-5820-Tower
2020-10-11bpf, sockmap: Remove skb_set_owner_w wmem will be taken later from sendpageJohn Fastabend
The skb_set_owner_w is unnecessary here. The sendpage call will create a fresh skb and set the owner correctly from workqueue. Its also not entirely harmless because it consumes cycles, but also impacts resource accounting by increasing sk_wmem_alloc. This is charging the socket we are going to send to for the skb, but we will put it on the workqueue for some time before this happens so we are artifically inflating sk_wmem_alloc for this period. Further, we don't know how many skbs will be used to send the packet or how it will be broken up when sent over the new socket so charging it with one big sum is also not correct when the workqueue may break it up if facing memory pressure. Seeing we don't know how/when this is going to be sent drop the early accounting. A later patch will do proper accounting charged on receive socket for the case where skbs get enqueued on the workqueue. Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/160226861708.5692.17964237936462425136.stgit@john-Precision-5820-Tower
2020-10-11bpf, sockmap: On receive programs try to fast track SK_PASS ingressJohn Fastabend
When we receive an skb and the ingress skb verdict program returns SK_PASS we currently set the ingress flag and put it on the workqueue so it can be turned into a sk_msg and put on the sk_msg ingress queue. Then finally telling userspace with data_ready hook. Here we observe that if the workqueue is empty then we can try to convert into a sk_msg type and call data_ready directly without bouncing through a workqueue. Its a common pattern to have a recv verdict program for visibility that always returns SK_PASS. In this case unless there is an ENOMEM error or we overrun the socket we can avoid the workqueue completely only using it when we fall back to error cases caused by memory pressure. By doing this we eliminate another case where data may be dropped if errors occur on memory limits in workqueue. Fixes: 51199405f9672 ("bpf: skb_verdict, support SK_PASS on RX BPF path") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/160226859704.5692.12929678876744977669.stgit@john-Precision-5820-Tower
2020-10-11bpf, sockmap: Skb verdict SK_PASS to self already checked rmem limitsJohn Fastabend
For sk_skb case where skb_verdict program returns SK_PASS to continue to pass packet up the stack, the memory limits were already checked before enqueuing in skb_queue_tail from TCP side. So, lets remove the extra checks here. The theory is if the TCP stack believes we have memory to receive the packet then lets trust the stack and not double check the limits. In fact the accounting here can cause a drop if sk_rmem_alloc has increased after the stack accepted this packet, but before the duplicate check here. And worse if this happens because TCP stack already believes the data has been received there is no retransmit. Fixes: 51199405f9672 ("bpf: skb_verdict, support SK_PASS on RX BPF path") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/160226857664.5692.668205469388498375.stgit@john-Precision-5820-Tower
2020-09-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
We got slightly different patches removing a double word in a comment in net/ipv4/raw.c - picked the version from net. Simple conflict in drivers/net/ethernet/ibm/ibmvnic.c. Use cached values instead of VNIC login response buffer (following what commit 507ebe6444a4 ("ibmvnic: Fix use-after-free of VNIC login response buffer") did). Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-21net: sk_msg: Simplify sk_psock initializationLorenz Bauer
Initializing psock->sk_proto and other saved callbacks is only done in sk_psock_update_proto, after sk_psock_init has returned. The logic for this is difficult to follow, and needlessly complex. Instead, initialize psock->sk_proto whenever we allocate a new psock. Additionally, assert the following invariants: * The SK has no ULP: ULP does it's own finagling of sk->sk_prot * sk_user_data is unused: we need it to store sk_psock Protect our access to sk_user_data with sk_callback_lock, which is what other users like reuseport arrays, etc. do. The result is that an sk_psock is always fully initialized, and that psock->sk_proto is always the "original" struct proto. The latter allows us to use psock->sk_proto when initializing IPv6 TCP / UDP callbacks for sockmap. Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200821102948.21918-2-lmb@cloudflare.com
2020-06-28bpf, sockmap: RCU dereferenced psock may be used outside RCU blockJohn Fastabend
If an ingress verdict program specifies message sizes greater than skb->len and there is an ENOMEM error due to memory pressure we may call the rcv_msg handler outside the strp_data_ready() caller context. This is because on an ENOMEM error the strparser will retry from a workqueue. The caller currently protects the use of psock by calling the strp_data_ready() inside a rcu_read_lock/unlock block. But, in above workqueue error case the psock is accessed outside the read_lock/unlock block of the caller. So instead of using psock directly we must do a look up against the sk again to ensure the psock is available. There is an an ugly piece here where we must handle the case where we paused the strp and removed the psock. On psock removal we first pause the strparser and then remove the psock. If the strparser is paused while an skb is scheduled on the workqueue the skb will be dropped on the flow and kfree_skb() is called. If the workqueue manages to get called before we pause the strparser but runs the rcvmsg callback after the psock is removed we will hit the unlikely case where we run the sockmap rcvmsg handler but do not have a psock. For now we will follow strparser logic and drop the skb on the floor with skb_kfree(). This is ugly because the data is dropped. To date this has not caused problems in practice because either the application controlling the sockmap is coordinating with the datapath so that skbs are "flushed" before removal or we simply wait for the sock to be closed before removing it. This patch fixes the describe RCU bug and dropping the skb doesn't make things worse. Future patches will improve this by allowing the normal case where skbs are not merged to skip the strparser altogether. In practice many (most?) use cases have no need to merge skbs so its both a code complexity hit as seen above and a performance issue. For example, in the Cilium case we always set the strparser up to return sbks 1:1 without any merging and have avoided above issues. Fixes: e91de6afa81c1 ("bpf: Fix running sk_skb program types with ktls") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/159312679888.18340.15248924071966273998.stgit@john-XPS-13-9370
2020-06-28bpf, sockmap: RCU splat with redirect and strparser error or TLSJohn Fastabend
There are two paths to generate the below RCU splat the first and most obvious is the result of the BPF verdict program issuing a redirect on a TLS socket (This is the splat shown below). Unlike the non-TLS case the caller of the *strp_read() hooks does not wrap the call in a rcu_read_lock/unlock. Then if the BPF program issues a redirect action we hit the RCU splat. However, in the non-TLS socket case the splat appears to be relatively rare, because the skmsg caller into the strp_data_ready() is wrapped in a rcu_read_lock/unlock. Shown here, static void sk_psock_strp_data_ready(struct sock *sk) { struct sk_psock *psock; rcu_read_lock(); psock = sk_psock(sk); if (likely(psock)) { if (tls_sw_has_ctx_rx(sk)) { psock->parser.saved_data_ready(sk); } else { write_lock_bh(&sk->sk_callback_lock); strp_data_ready(&psock->parser.strp); write_unlock_bh(&sk->sk_callback_lock); } } rcu_read_unlock(); } If the above was the only way to run the verdict program we would be safe. But, there is a case where the strparser may throw an ENOMEM error while parsing the skb. This is a result of a failed skb_clone, or alloc_skb_for_msg while building a new merged skb when the msg length needed spans multiple skbs. This will in turn put the skb on the strp_wrk workqueue in the strparser code. The skb will later be dequeued and verdict programs run, but now from a different context without the rcu_read_lock()/unlock() critical section in sk_psock_strp_data_ready() shown above. In practice I have not seen this yet, because as far as I know most users of the verdict programs are also only working on single skbs. In this case no merge happens which could trigger the above ENOMEM errors. In addition the system would need to be under memory pressure. For example, we can't hit the above case in selftests because we missed having tests to merge skbs. (Added in later patch) To fix the below splat extend the rcu_read_lock/unnlock block to include the call to sk_psock_tls_verdict_apply(). This will fix both TLS redirect case and non-TLS redirect+error case. Also remove psock from the sk_psock_tls_verdict_apply() function signature its not used there. [ 1095.937597] WARNING: suspicious RCU usage [ 1095.940964] 5.7.0-rc7-02911-g463bac5f1ca79 #1 Tainted: G W [ 1095.944363] ----------------------------- [ 1095.947384] include/linux/skmsg.h:284 suspicious rcu_dereference_check() usage! [ 1095.950866] [ 1095.950866] other info that might help us debug this: [ 1095.950866] [ 1095.957146] [ 1095.957146] rcu_scheduler_active = 2, debug_locks = 1 [ 1095.961482] 1 lock held by test_sockmap/15970: [ 1095.964501] #0: ffff9ea6b25de660 (sk_lock-AF_INET){+.+.}-{0:0}, at: tls_sw_recvmsg+0x13a/0x840 [tls] [ 1095.968568] [ 1095.968568] stack backtrace: [ 1095.975001] CPU: 1 PID: 15970 Comm: test_sockmap Tainted: G W 5.7.0-rc7-02911-g463bac5f1ca79 #1 [ 1095.977883] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 [ 1095.980519] Call Trace: [ 1095.982191] dump_stack+0x8f/0xd0 [ 1095.984040] sk_psock_skb_redirect+0xa6/0xf0 [ 1095.986073] sk_psock_tls_strp_read+0x1d8/0x250 [ 1095.988095] tls_sw_recvmsg+0x714/0x840 [tls] v2: Improve commit message to identify non-TLS redirect plus error case condition as well as more common TLS case. In the process I decided doing the rcu_read_unlock followed by the lock/unlock inside branches was unnecessarily complex. We can just extend the current rcu block and get the same effeective without the shuffling and branching. Thanks Martin! Fixes: e91de6afa81c1 ("bpf: Fix running sk_skb program types with ktls") Reported-by: Jakub Sitnicki <jakub@cloudflare.com> Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/159312677907.18340.11064813152758406626.stgit@john-XPS-13-9370
2020-06-01bpf: Fix running sk_skb program types with ktlsJohn Fastabend
KTLS uses a stream parser to collect TLS messages and send them to the upper layer tls receive handler. This ensures the tls receiver has a full TLS header to parse when it is run. However, when a socket has BPF_SK_SKB_STREAM_VERDICT program attached before KTLS is enabled we end up with two stream parsers running on the same socket. The result is both try to run on the same socket. First the KTLS stream parser runs and calls read_sock() which will tcp_read_sock which in turn calls tcp_rcv_skb(). This dequeues the skb from the sk_receive_queue. When this is done KTLS code then data_ready() callback which because we stacked KTLS on top of the bpf stream verdict program has been replaced with sk_psock_start_strp(). This will in turn kick the stream parser again and eventually do the same thing KTLS did above calling into tcp_rcv_skb() and dequeuing a skb from the sk_receive_queue. At this point the data stream is broke. Part of the stream was handled by the KTLS side some other bytes may have been handled by the BPF side. Generally this results in either missing data or more likely a "Bad Message" complaint from the kTLS receive handler as the BPF program steals some bytes meant to be in a TLS header and/or the TLS header length is no longer correct. We've already broke the idealized model where we can stack ULPs in any order with generic callbacks on the TX side to handle this. So in this patch we do the same thing but for RX side. We add a sk_psock_strp_enabled() helper so TLS can learn a BPF verdict program is running and add a tls_sw_has_ctx_rx() helper so BPF side can learn there is a TLS ULP on the socket. Then on BPF side we omit calling our stream parser to avoid breaking the data stream for the KTLS receiver. Then on the KTLS side we call BPF_SK_SKB_STREAM_VERDICT once the KTLS receiver is done with the packet but before it posts the msg to userspace. This gives us symmetry between the TX and RX halfs and IMO makes it usable again. On the TX side we process packets in this order BPF -> TLS -> TCP and on the receive side in the reverse order TCP -> TLS -> BPF. Discovered while testing OpenSSL 3.0 Alpha2.0 release. Fixes: d829e9c4112b5 ("tls: convert to generic sk_msg interface") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/159079361946.5745.605854335665044485.stgit@john-Precision-5820-Tower Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-06-01bpf: Refactor sockmap redirect code so its easy to reuseJohn Fastabend
We will need this block of code called from tls context shortly lets refactor the redirect logic so its easy to use. This also cleans up the switch stmt so we have fewer fallthrough cases. No logic changes are intended. Fixes: d829e9c4112b5 ("tls: convert to generic sk_msg interface") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/159079360110.5745.7024009076049029819.stgit@john-Precision-5820-Tower Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-02-24bpf: Use bpf_prog_run_pin_on_cpu() at simple call sites.David Miller
All of these cases are strictly of the form: preempt_disable(); BPF_PROG_RUN(...); preempt_enable(); Replace this with bpf_prog_run_pin_on_cpu() which wraps BPF_PROG_RUN() with: migrate_disable(); BPF_PROG_RUN(...); migrate_enable(); On non RT enabled kernels this maps to preempt_disable/enable() and on RT enabled kernels this solely prevents migration, which is sufficient as there is no requirement to prevent reentrancy to any BPF program from a preempting task. The only requirement is that the program stays on the same CPU. Therefore, this is a trivially correct transformation. The seccomp loop does not need protection over the loop. It only needs protection per BPF filter program [ tglx: Converted to bpf_prog_run_pin_on_cpu() ] Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200224145643.691493094@linutronix.de
2020-02-21net, sk_msg: Clear sk_user_data pointer on clone if taggedJakub Sitnicki
sk_user_data can hold a pointer to an object that is not intended to be shared between the parent socket and the child that gets a pointer copy on clone. This is the case when sk_user_data points at reference-counted object, like struct sk_psock. One way to resolve it is to tag the pointer with a no-copy flag by repurposing its lowest bit. Based on the bit-flag value we clear the child sk_user_data pointer after cloning the parent socket. The no-copy flag is stored in the pointer itself as opposed to externally, say in socket flags, to guarantee that the pointer and the flag are copied from parent to child socket in an atomic fashion. Parent socket state is subject to change while copying, we don't hold any locks at that time. This approach relies on an assumption that sk_user_data holds a pointer to an object aligned at least 2 bytes. A manual audit of existing users of rcu_dereference_sk_user_data helper confirms our assumption. Also, an RCU-protected sk_user_data is not likely to hold a pointer to a char value or a pathological case of "struct { char c; }". To be safe, warn when the flag-bit is set when setting sk_user_data to catch any future misuses. It is worth considering why clearing sk_user_data unconditionally is not an option. There exist users, DRBD, NVMe, and Xen drivers being among them, that rely on the pointer being copied when cloning the listening socket. Potentially we could distinguish these users by checking if the listening socket has been created in kernel-space via sock_create_kern, and hence has sk_kern_sock flag set. However, this is not the case for NVMe and Xen drivers, which create sockets without marking them as belonging to the kernel. Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200218171023.844439-3-jakub@cloudflare.com
2020-01-22net, sk_msg: Don't check if sock is locked when tearing down psockJakub Sitnicki
As John Fastabend reports [0], psock state tear-down can happen on receive path *after* unlocking the socket, if the only other psock user, that is sockmap or sockhash, releases its psock reference before tcp_bpf_recvmsg does so: tcp_bpf_recvmsg() psock = sk_psock_get(sk) <- refcnt 2 lock_sock(sk); ... sock_map_free() <- refcnt 1 release_sock(sk) sk_psock_put() <- refcnt 0 Remove the lockdep check for socket lock in psock tear-down that got introduced in 7e81a3530206 ("bpf: Sockmap, ensure sock lock held during tear down"). [0] https://lore.kernel.org/netdev/5e25dc995d7d_74082aaee6e465b441@john-XPS-13-9370.notmuch/ Fixes: 7e81a3530206 ("bpf: Sockmap, ensure sock lock held during tear down") Reported-by: syzbot+d73682fcf7fee6982fe3@syzkaller.appspotmail.com Suggested-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-15bpf: Sockmap, ensure sock lock held during tear downJohn Fastabend
The sock_map_free() and sock_hash_free() paths used to delete sockmap and sockhash maps walk the maps and destroy psock and bpf state associated with the socks in the map. When done the socks no longer have BPF programs attached and will function normally. This can happen while the socks in the map are still "live" meaning data may be sent/received during the walk. Currently, though we don't take the sock_lock when the psock and bpf state is removed through this path. Specifically, this means we can be writing into the ops structure pointers such as sendmsg, sendpage, recvmsg, etc. while they are also being called from the networking side. This is not safe, we never used proper READ_ONCE/WRITE_ONCE semantics here if we believed it was safe. Further its not clear to me its even a good idea to try and do this on "live" sockets while networking side might also be using the socket. Instead of trying to reason about using the socks from both sides lets realize that every use case I'm aware of rarely deletes maps, in fact kubernetes/Cilium case builds map at init and never tears it down except on errors. So lets do the simple fix and grab sock lock. This patch wraps sock deletes from maps in sock lock and adds some annotations so we catch any other cases easier. Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/bpf/20200111061206.8028-3-john.fastabend@gmail.com
2019-11-28net: skmsg: fix TLS 1.3 crash with full sk_msgJakub Kicinski
TLS 1.3 started using the entry at the end of the SG array for chaining-in the single byte content type entry. This mostly works: [ E E E E E E . . ] ^ ^ start end E < content type / [ E E E E E E C . ] ^ ^ start end (Where E denotes a populated SG entry; C denotes a chaining entry.) If the array is full, however, the end will point to the start: [ E E E E E E E E ] ^ start end And we end up overwriting the start: E < content type / [ C E E E E E E E ] ^ start end The sg array is supposed to be a circular buffer with start and end markers pointing anywhere. In case where start > end (i.e. the circular buffer has "wrapped") there is an extra entry reserved at the end to chain the two halves together. [ E E E E E E . . l ] (Where l is the reserved entry for "looping" back to front. As suggested by John, let's reserve another entry for chaining SG entries after the main circular buffer. Note that this entry has to be pointed to by the end entry so its position is not fixed. Examples of full messages: [ E E E E E E E E . l ] ^ ^ start end <---------------. [ E E . E E E E E E l ] ^ ^ end start Now the end will always point to an unused entry, so TLS 1.3 can always use it. Fixes: 130b392c6cd6 ("net: tls: Add tls 1.3 support") Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-21bpf: skmsg, fix potential psock NULL pointer dereferenceJohn Fastabend
Report from Dan Carpenter, net/core/skmsg.c:792 sk_psock_write_space() error: we previously assumed 'psock' could be null (see line 790) net/core/skmsg.c 789 psock = sk_psock(sk); 790 if (likely(psock && sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED))) Check for NULL 791 schedule_work(&psock->work); 792 write_space = psock->saved_write_space; ^^^^^^^^^^^^^^^^^^^^^^^^ 793 rcu_read_unlock(); 794 write_space(sk); Ensure psock dereference on line 792 only occurs if psock is not null. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-05net/tls: fix sk_msg trim on fallback to copy modeJakub Kicinski
sk_msg_trim() tries to only update curr pointer if it falls into the trimmed region. The logic, however, does not take into the account pointer wrapping that sk_msg_iter_var_prev() does nor (as John points out) the fact that msg->sg is a ring buffer. This means that when the message was trimmed completely, the new curr pointer would have the value of MAX_MSG_FRAGS - 1, which is neither smaller than any other value, nor would it actually be correct. Special case the trimming to 0 length a little bit and rework the comparison between curr and end to take into account wrapping. This bug caused the TLS code to not copy all of the message, if zero copy filled in fewer sg entries than memcopy would need. Big thanks to Alexander Potapenko for the non-KMSAN reproducer. v2: - take into account that msg->sg is a ring buffer (John). Link: https://lore.kernel.org/netdev/20191030160542.30295-1-jakub.kicinski@netronome.com/ (v1) Fixes: d829e9c4112b ("tls: convert to generic sk_msg interface") Reported-by: syzbot+f8495bff23a879a6d0bd@syzkaller.appspotmail.com Reported-by: syzbot+6f50c99e8f6194bf363f@syzkaller.appspotmail.com Co-developed-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-24net/core/skmsg: Delete an unnecessary check before the function call ↵Markus Elfring
“consume_skb” The consume_skb() function performs also input parameter validation. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-22bpf: sockmap/tls, close can race with map freeJohn Fastabend
When a map free is called and in parallel a socket is closed we have two paths that can potentially reset the socket prot ops, the bpf close() path and the map free path. This creates a problem with which prot ops should be used from the socket closed side. If the map_free side completes first then we want to call the original lowest level ops. However, if the tls path runs first we want to call the sockmap ops. Additionally there was no locking around prot updates in TLS code paths so the prot ops could be changed multiple times once from TLS path and again from sockmap side potentially leaving ops pointed at either TLS or sockmap when psock and/or tls context have already been destroyed. To fix this race first only update ops inside callback lock so that TLS, sockmap and lowest level all agree on prot state. Second and a ULP callback update() so that lower layers can inform the upper layer when they are being removed allowing the upper layer to reset prot ops. This gets us close to allowing sockmap and tls to be stacked in arbitrary order but will save that patch for *next trees. v4: - make sure we don't free things for device; - remove the checks which swap the callbacks back only if TLS is at the top. Reported-by: syzbot+06537213db7ba2745c4a@syzkaller.appspotmail.com Fixes: 02c558b2d5d6 ("bpf: sockmap, support for msg_peek in sk_msg with redirect ingress") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-14bpf: sockmap fix msg->sg.size account on ingress skbJohn Fastabend
When converting a skb to msg->sg we forget to set the size after the latest ktls/tls code conversion. This patch can be reached by doing a redir into ingress path from BPF skb sock recv hook. Then trying to read the size fails. Fix this by setting the size. Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-14bpf: sockmap, only stop/flush strp if it was enabled at some pointJohn Fastabend
If we try to call strp_done on a parser that has never been initialized, because the sockmap user is only using TX side for example we get the following error. [ 883.422081] WARNING: CPU: 1 PID: 208 at kernel/workqueue.c:3030 __flush_work+0x1ca/0x1e0 ... [ 883.422095] Workqueue: events sk_psock_destroy_deferred [ 883.422097] RIP: 0010:__flush_work+0x1ca/0x1e0 This had been wrapped in a 'if (psock->parser.enabled)' logic which was broken because the strp_done() was never actually being called because we do a strp_stop() earlier in the tear down logic will set parser.enabled to false. This could result in a use after free if work was still in the queue and was resolved by the patch here, 1d79895aef18f ("sk_msg: Always cancel strp work before freeing the psock"). However, calling strp_stop(), done by the patch marked in the fixes tag, only is useful if we never initialized a strp parser program and never initialized the strp to start with. Because if we had initialized a stream parser strp_stop() would have been called by sk_psock_drop() earlier in the tear down process. By forcing the strp to stop we get past the WARNING in strp_done that checks the stopped flag but calling cancel_work_sync on work that has never been initialized is also wrong and generates the warning above. To fix check if the parser program exists. If the program exists then the strp work has been initialized and must be sync'd and cancelled before free'ing any structures. If no program exists we never initialized the stream parser in the first place so skip the sync/cancel logic implemented by strp_done. Finally, remove the strp_done its not needed and in the case where we are using the stream parser has already been called. Fixes: e8e3437762ad9 ("bpf: Stop the psock parser before canceling its work") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-03-07bpf: Stop the psock parser before canceling its workJakub Sitnicki
We might have never enabled (started) the psock's parser, in which case it will not get stopped when destroying the psock. This leads to a warning when trying to cancel parser's work from psock's deferred destructor: [ 405.325769] WARNING: CPU: 1 PID: 3216 at net/strparser/strparser.c:526 strp_done+0x3c/0x40 [ 405.326712] Modules linked in: [last unloaded: test_bpf] [ 405.327359] CPU: 1 PID: 3216 Comm: kworker/1:164 Tainted: G W 5.0.0 #42 [ 405.328294] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20180531_142017-buildhw-08.phx2.fedoraproject.org-1.fc28 04/01/2014 [ 405.329712] Workqueue: events sk_psock_destroy_deferred [ 405.330254] RIP: 0010:strp_done+0x3c/0x40 [ 405.330706] Code: 28 e8 b8 d5 6b ff 48 8d bb 80 00 00 00 e8 9c d5 6b ff 48 8b 7b 18 48 85 ff 74 0d e8 1e a5 e8 ff 48 c7 43 18 00 00 00 00 5b c3 <0f> 0b eb cf 66 66 66 66 90 55 89 f5 53 48 89 fb 48 83 c7 28 e8 0b [ 405.332862] RSP: 0018:ffffc900026bbe50 EFLAGS: 00010246 [ 405.333482] RAX: ffffffff819323e0 RBX: ffff88812cb83640 RCX: ffff88812cb829e8 [ 405.334228] RDX: 0000000000000001 RSI: ffff88812cb837e8 RDI: ffff88812cb83640 [ 405.335366] RBP: ffff88813fd22680 R08: 0000000000000000 R09: 000073746e657665 [ 405.336472] R10: 8080808080808080 R11: 0000000000000001 R12: ffff88812cb83600 [ 405.337760] R13: 0000000000000000 R14: ffff88811f401780 R15: ffff88812cb837e8 [ 405.338777] FS: 0000000000000000(0000) GS:ffff88813fd00000(0000) knlGS:0000000000000000 [ 405.339903] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 405.340821] CR2: 00007fb11489a6b8 CR3: 000000012d4d6000 CR4: 00000000000406e0 [ 405.341981] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 405.343131] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 405.344415] Call Trace: [ 405.344821] sk_psock_destroy_deferred+0x23/0x1b0 [ 405.345585] process_one_work+0x1ae/0x3e0 [ 405.346110] worker_thread+0x3c/0x3b0 [ 405.346576] ? pwq_unbound_release_workfn+0xd0/0xd0 [ 405.347187] kthread+0x11d/0x140 [ 405.347601] ? __kthread_parkme+0x80/0x80 [ 405.348108] ret_from_fork+0x35/0x40 [ 405.348566] ---[ end trace a4a3af4026a327d4 ]--- Stop psock's parser just before canceling its work. Fixes: 1d79895aef18 ("sk_msg: Always cancel strp work before freeing the psock") Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
An ipvlan bug fix in 'net' conflicted with the abstraction away of the IPV6 specific support in 'net-next'. Similarly, a bug fix for mlx5 in 'net' conflicted with the flow action conversion in 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-29sk_msg: Always cancel strp work before freeing the psockJakub Sitnicki
Despite having stopped the parser, we still need to deinitialize it by calling strp_done so that it cancels its work. Otherwise the worker thread can run after we have freed the parser, and attempt to access its workqueue resulting in a use-after-free: ================================================================== BUG: KASAN: use-after-free in pwq_activate_delayed_work+0x1b/0x1d0 Read of size 8 at addr ffff888069975240 by task kworker/u2:2/93 CPU: 0 PID: 93 Comm: kworker/u2:2 Not tainted 5.0.0-rc2-00335-g28f9d1a3d4fe-dirty #14 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-2.fc27 04/01/2014 Workqueue: (null) (kstrp) Call Trace: print_address_description+0x6e/0x2b0 ? pwq_activate_delayed_work+0x1b/0x1d0 kasan_report+0xfd/0x177 ? pwq_activate_delayed_work+0x1b/0x1d0 ? pwq_activate_delayed_work+0x1b/0x1d0 pwq_activate_delayed_work+0x1b/0x1d0 ? process_one_work+0x4aa/0x660 pwq_dec_nr_in_flight+0x9b/0x100 worker_thread+0x82/0x680 ? process_one_work+0x660/0x660 kthread+0x1b9/0x1e0 ? __kthread_create_on_node+0x250/0x250 ret_from_fork+0x1f/0x30 Allocated by task 111: sk_psock_init+0x3c/0x1b0 sock_map_link.isra.2+0x103/0x4b0 sock_map_update_common+0x94/0x270 sock_map_update_elem+0x145/0x160 __se_sys_bpf+0x152e/0x1e10 do_syscall_64+0xb2/0x3e0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 112: kfree+0x7f/0x140 process_one_work+0x40b/0x660 worker_thread+0x82/0x680 kthread+0x1b9/0x1e0 ret_from_fork+0x1f/0x30 The buggy address belongs to the object at ffff888069975180 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 192 bytes inside of 512-byte region [ffff888069975180, ffff888069975380) The buggy address belongs to the page: page:ffffea0001a65d00 count:1 mapcount:0 mapping:ffff88806d401280 index:0x0 compound_mapcount: 0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 dead000000000100 dead000000000200 ffff88806d401280 raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888069975100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888069975180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888069975200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888069975280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888069975300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Reported-by: Marek Majkowski <marek@cloudflare.com> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/netdev/CAJPywTLwgXNEZ2dZVoa=udiZmtrWJ0q5SuBW64aYs0Y1khXX3A@mail.gmail.com Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-01-17Optimize sk_msg_clone() by data merge to end dst sg entryVakul Garg
Function sk_msg_clone has been modified to merge the data from source sg entry to destination sg entry if the cloned data resides in same page and is contiguous to the end entry of destination sk_msg. This improves kernel tls throughput to the tune of 10%. When the user space tls application calls sendmsg() with MSG_MORE, it leads to calling sk_msg_clone() with new data being cloned placed continuous to previously cloned data. Without this optimization, a new SG entry in the destination sk_msg i.e. rec->msg_plaintext in tls_clone_plaintext_msg() gets used. This leads to exhaustion of sg entries in rec->msg_plaintext even before a full 16K of allowable record data is accumulated. Hence we lose oppurtunity to encrypt and send a full 16K record. With this patch, the kernel tls can accumulate full 16K of record data irrespective of the size of data passed in sendmsg() with MSG_MORE. Signed-off-by: Vakul Garg <vakul.garg@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking updates from David Miller: 1) New ipset extensions for matching on destination MAC addresses, from Stefano Brivio. 2) Add ipv4 ttl and tos, plus ipv6 flow label and hop limit offloads to nfp driver. From Stefano Brivio. 3) Implement GRO for plain UDP sockets, from Paolo Abeni. 4) Lots of work from Michał Mirosław to eliminate the VLAN_TAG_PRESENT bit so that we could support the entire vlan_tci value. 5) Rework the IPSEC policy lookups to better optimize more usecases, from Florian Westphal. 6) Infrastructure changes eliminating direct manipulation of SKB lists wherever possible, and to always use the appropriate SKB list helpers. This work is still ongoing... 7) Lots of PHY driver and state machine improvements and simplifications, from Heiner Kallweit. 8) Various TSO deferral refinements, from Eric Dumazet. 9) Add ntuple filter support to aquantia driver, from Dmitry Bogdanov. 10) Batch dropping of XDP packets in tuntap, from Jason Wang. 11) Lots of cleanups and improvements to the r8169 driver from Heiner Kallweit, including support for ->xmit_more. This driver has been getting some much needed love since he started working on it. 12) Lots of new forwarding selftests from Petr Machata. 13) Enable VXLAN learning in mlxsw driver, from Ido Schimmel. 14) Packed ring support for virtio, from Tiwei Bie. 15) Add new Aquantia AQtion USB driver, from Dmitry Bezrukov. 16) Add XDP support to dpaa2-eth driver, from Ioana Ciocoi Radulescu. 17) Implement coalescing on TCP backlog queue, from Eric Dumazet. 18) Implement carrier change in tun driver, from Nicolas Dichtel. 19) Support msg_zerocopy in UDP, from Willem de Bruijn. 20) Significantly improve garbage collection of neighbor objects when the table has many PERMANENT entries, from David Ahern. 21) Remove egdev usage from nfp and mlx5, and remove the facility completely from the tree as it no longer has any users. From Oz Shlomo and others. 22) Add a NETDEV_PRE_CHANGEADDR so that drivers can veto the change and therefore abort the operation before the commit phase (which is the NETDEV_CHANGEADDR event). From Petr Machata. 23) Add indirect call wrappers to avoid retpoline overhead, and use them in the GRO code paths. From Paolo Abeni. 24) Add support for netlink FDB get operations, from Roopa Prabhu. 25) Support bloom filter in mlxsw driver, from Nir Dotan. 26) Add SKB extension infrastructure. This consolidates the handling of the auxiliary SKB data used by IPSEC and bridge netfilter, and is designed to support the needs to MPTCP which could be integrated in the future. 27) Lots of XDP TX optimizations in mlx5 from Tariq Toukan. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1845 commits) net: dccp: fix kernel crash on module load drivers/net: appletalk/cops: remove redundant if statement and mask bnx2x: Fix NULL pointer dereference in bnx2x_del_all_vlans() on some hw net/net_namespace: Check the return value of register_pernet_subsys() net/netlink_compat: Fix a missing check of nla_parse_nested ieee802154: lowpan_header_create check must check daddr net/mlx4_core: drop useless LIST_HEAD mlxsw: spectrum: drop useless LIST_HEAD net/mlx5e: drop useless LIST_HEAD iptunnel: Set tun_flags in the iptunnel_metadata_reply from src net/mlx5e: fix semicolon.cocci warnings staging: octeon: fix build failure with XFRM enabled net: Revert recent Spectre-v1 patches. can: af_can: Fix Spectre v1 vulnerability packet: validate address length if non-zero nfc: af_nfc: Fix Spectre v1 vulnerability phonet: af_phonet: Fix Spectre v1 vulnerability net: core: Fix Spectre v1 vulnerability net: minor cleanup in skb_ext_add() net: drop the unused helper skb_ext_get() ...
2018-12-26Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "The biggest RCU changes in this cycle were: - Convert RCU's BUG_ON() and similar calls to WARN_ON() and similar. - Replace calls of RCU-bh and RCU-sched update-side functions to their vanilla RCU counterparts. This series is a step towards complete removal of the RCU-bh and RCU-sched update-side functions. ( Note that some of these conversions are going upstream via their respective maintainers. ) - Documentation updates, including a number of flavor-consolidation updates from Joel Fernandes. - Miscellaneous fixes. - Automate generation of the initrd filesystem used for rcutorture testing. - Convert spin_is_locked() assertions to instead use lockdep. ( Note that some of these conversions are going upstream via their respective maintainers. ) - SRCU updates, especially including a fix from Dennis Krein for a bag-on-head-class bug. - RCU torture-test updates" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (112 commits) rcutorture: Don't do busted forward-progress testing rcutorture: Use 100ms buckets for forward-progress callback histograms rcutorture: Recover from OOM during forward-progress tests rcutorture: Print forward-progress test age upon failure rcutorture: Print time since GP end upon forward-progress failure rcutorture: Print histogram of CB invocation at OOM time rcutorture: Print GP age upon forward-progress failure rcu: Print per-CPU callback counts for forward-progress failures rcu: Account for nocb-CPU callback counts in RCU CPU stall warnings rcutorture: Dump grace-period diagnostics upon forward-progress OOM rcutorture: Prepare for asynchronous access to rcu_fwd_startat torture: Remove unnecessary "ret" variables rcutorture: Affinity forward-progress test to avoid housekeeping CPUs rcutorture: Break up too-long rcu_torture_fwd_prog() function rcutorture: Remove cbflood facility torture: Bring any extra CPUs online during kernel startup rcutorture: Add call_rcu() flooding forward-progress tests rcutorture/formal: Replace synchronize_sched() with synchronize_rcu() tools/kernel.h: Replace synchronize_sched() with synchronize_rcu() net/decnet: Replace rcu_barrier_bh() with rcu_barrier() ...
2018-12-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2018-12-21Prevent overflow of sk_msg in sk_msg_clone()Vakul Garg
Fixed function sk_msg_clone() to prevent overflow of 'dst' while adding pages in scatterlist entries. The overflow of 'dst' causes crash in kernel tls module while doing record encryption. Crash fixed by this patch. [ 78.796119] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 [ 78.804900] Mem abort info: [ 78.807683] ESR = 0x96000004 [ 78.810744] Exception class = DABT (current EL), IL = 32 bits [ 78.816677] SET = 0, FnV = 0 [ 78.819727] EA = 0, S1PTW = 0 [ 78.822873] Data abort info: [ 78.825759] ISV = 0, ISS = 0x00000004 [ 78.829600] CM = 0, WnR = 0 [ 78.832576] user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000bf8ee311 [ 78.839195] [0000000000000008] pgd=0000000000000000 [ 78.844081] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 78.849642] Modules linked in: tls xt_conntrack ipt_REJECT nf_reject_ipv4 ip6table_filter ip6_tables xt_CHECKSUM cpve cpufreq_conservative lm90 ina2xx crct10dif_ce [ 78.865377] CPU: 0 PID: 6007 Comm: openssl Not tainted 4.20.0-rc6-01647-g754d5da63145-dirty #107 [ 78.874149] Hardware name: LS1043A RDB Board (DT) [ 78.878844] pstate: 60000005 (nZCv daif -PAN -UAO) [ 78.883632] pc : scatterwalk_copychunks+0x164/0x1c8 [ 78.888500] lr : scatterwalk_copychunks+0x160/0x1c8 [ 78.893366] sp : ffff00001d04b600 [ 78.896668] x29: ffff00001d04b600 x28: ffff80006814c680 [ 78.901970] x27: 0000000000000000 x26: ffff80006c8de786 [ 78.907272] x25: ffff00001d04b760 x24: 000000000000001a [ 78.912573] x23: 0000000000000006 x22: ffff80006814e440 [ 78.917874] x21: 0000000000000100 x20: 0000000000000000 [ 78.923175] x19: 000081ffffffffff x18: 0000000000000400 [ 78.928476] x17: 0000000000000008 x16: 0000000000000000 [ 78.933778] x15: 0000000000000100 x14: 0000000000000001 [ 78.939079] x13: 0000000000001080 x12: 0000000000000020 [ 78.944381] x11: 0000000000001080 x10: 00000000ffff0002 [ 78.949683] x9 : ffff80006814c248 x8 : 00000000ffff0000 [ 78.954985] x7 : ffff80006814c318 x6 : ffff80006c8de786 [ 78.960286] x5 : 0000000000000f80 x4 : ffff80006c8de000 [ 78.965588] x3 : 0000000000000000 x2 : 0000000000001086 [ 78.970889] x1 : ffff7e0001b74e02 x0 : 0000000000000000 [ 78.976192] Process openssl (pid: 6007, stack limit = 0x00000000291367f9) [ 78.982968] Call trace: [ 78.985406] scatterwalk_copychunks+0x164/0x1c8 [ 78.989927] skcipher_walk_next+0x28c/0x448 [ 78.994099] skcipher_walk_done+0xfc/0x258 [ 78.998187] gcm_encrypt+0x434/0x4c0 [ 79.001758] tls_push_record+0x354/0xa58 [tls] [ 79.006194] bpf_exec_tx_verdict+0x1e4/0x3e8 [tls] [ 79.010978] tls_sw_sendmsg+0x650/0x780 [tls] [ 79.015326] inet_sendmsg+0x2c/0xf8 [ 79.018806] sock_sendmsg+0x18/0x30 [ 79.022284] __sys_sendto+0x104/0x138 [ 79.025935] __arm64_sys_sendto+0x24/0x30 [ 79.029936] el0_svc_common+0x60/0xe8 [ 79.033588] el0_svc_handler+0x2c/0x80 [ 79.037327] el0_svc+0x8/0xc [ 79.040200] Code: 6b01005f 54fff788 940169b1 f9000320 (b9400801) [ 79.046283] ---[ end trace 74db007d069c1cf7 ]--- Fixes: d829e9c4112b ("tls: convert to generic sk_msg interface") Signed-off-by: Vakul Garg <vakul.garg@nxp.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-20bpf: sk_msg, zap ingress queue on psock downJohn Fastabend
In addition to releasing any cork'ed data on a psock when the psock is removed we should also release any skb's in the ingress work queue. Otherwise the skb's eventually get free'd but late in the tear down process so we see the WARNING due to non-zero sk_forward_alloc. void sk_stream_kill_queues(struct sock *sk) { ... WARN_ON(sk->sk_forward_alloc); ... } Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-20bpf: sk_msg, fix socket data_ready eventsJohn Fastabend
When a skb verdict program is in-use and either another BPF program redirects to that socket or the new SK_PASS support is used the data_ready callback does not wake up application. Instead because the stream parser/verdict is using the sk data_ready callback we wake up the stream parser/verdict block. Fix this by adding a helper to check if the stream parser block is enabled on the sk and if so call the saved pointer which is the upper layers wake up function. This fixes application stalls observed when an application is waiting for data in a blocking read(). Fixes: d829e9c4112b ("tls: convert to generic sk_msg interface") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-20bpf: skb_verdict, support SK_PASS on RX BPF pathJohn Fastabend
Add SK_PASS verdict support to SK_SKB_VERDICT programs. Now that support for redirects exists we can implement SK_PASS as a redirect to the same socket. This simplifies the BPF programs and avoids an extra map lookup on RX path for simple visibility cases. Further, reduces user (BPF programmer in this context) confusion when their program drops skb due to lack of support. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-01net/core/skmsg: Replace call_rcu_sched() with call_rcu()Paul E. McKenney
Now that call_rcu()'s callback is not invoked until after all preempt-disable regions of code have completed (in addition to explicitly marked RCU read-side critical sections), call_rcu() can be used in place of call_rcu_sched(). This commit therefore makes that change. Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: <netdev@vger.kernel.org>
2018-10-15tls: convert to generic sk_msg interfaceDaniel Borkmann
Convert kTLS over to make use of sk_msg interface for plaintext and encrypted scattergather data, so it reuses all the sk_msg helpers and data structure which later on in a second step enables to glue this to BPF. This also allows to remove quite a bit of open coded helpers which are covered by the sk_msg API. Recent changes in kTLs 80ece6a03aaf ("tls: Remove redundant vars from tls record structure") and 4e6d47206c32 ("tls: Add support for inplace records encryption") changed the data path handling a bit; while we've kept the latter optimization intact, we had to undo the former change to better fit the sk_msg model, hence the sg_aead_in and sg_aead_out have been brought back and are linked into the sk_msg sgs. Now the kTLS record contains a msg_plaintext and msg_encrypted sk_msg each. In the original code, the zerocopy_from_iter() has been used out of TX but also RX path. For the strparser skb-based RX path, we've left the zerocopy_from_iter() in decrypt_internal() mostly untouched, meaning it has been moved into tls_setup_from_iter() with charging logic removed (as not used from RX). Given RX path is not based on sk_msg objects, we haven't pursued setting up a dummy sk_msg to call into sk_msg_zerocopy_from_iter(), but it could be an option to prusue in a later step. Joint work with John. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-15bpf, sockmap: convert to generic sk_msg interfaceDaniel Borkmann
Add a generic sk_msg layer, and convert current sockmap and later kTLS over to make use of it. While sk_buff handles network packet representation from netdevice up to socket, sk_msg handles data representation from application to socket layer. This means that sk_msg framework spans across ULP users in the kernel, and enables features such as introspection or filtering of data with the help of BPF programs that operate on this data structure. Latter becomes in particular useful for kTLS where data encryption is deferred into the kernel, and as such enabling the kernel to perform L7 introspection and policy based on BPF for TLS connections where the record is being encrypted after BPF has run and came to a verdict. In order to get there, first step is to transform open coding of scatter-gather list handling into a common core framework that subsystems can use. The code itself has been split and refactored into three bigger pieces: i) the generic sk_msg API which deals with managing the scatter gather ring, providing helpers for walking and mangling, transferring application data from user space into it, and preparing it for BPF pre/post-processing, ii) the plain sock map itself where sockets can be attached to or detached from; these bits are independent of i) which can now be used also without sock map, and iii) the integration with plain TCP as one protocol to be used for processing L7 application data (later this could e.g. also be extended to other protocols like UDP). The semantics are the same with the old sock map code and therefore no change of user facing behavior or APIs. While pursuing this work it also helped finding a number of bugs in the old sockmap code that we've fixed already in earlier commits. The test_sockmap kselftest suite passes through fine as well. Joint work with John. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>