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2019-09-20ipv6: fix a typo in fib6_rule_lookup()Eric Dumazet
Yi Ren reported an issue discovered by syzkaller, and bisected to the cited commit. Many thanks to Yi, this trivial patch does not reflect the patient work that has been done. Fixes: d64a1f574a29 ("ipv6: honor RT6_LOOKUP_F_DST_NOREF in rule lookup logic") Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Wei Wang <weiwan@google.com> Bisected-and-reported-by: Yi Ren <c4tren@gmail.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-07-18ipv6: Unlink sibling route in case of failureIdo Schimmel
When a route needs to be appended to an existing multipath route, fib6_add_rt2node() first appends it to the siblings list and increments the number of sibling routes on each sibling. Later, the function notifies the route via call_fib6_entry_notifiers(). In case the notification is vetoed, the route is not unlinked from the siblings list, which can result in a use-after-free. Fix this by unlinking the route from the siblings list before returning an error. Audited the rest of the call sites from which the FIB notification chain is called and could not find more problems. Fixes: 2233000cba40 ("net/ipv6: Move call_fib6_entry_notifiers up for route adds") Signed-off-by: Ido Schimmel <idosch@mellanox.com> Reported-by: Alexander Petrovskiy <alexpe@mellanox.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-24ip6_fib: Don't discard nodes with valid routing information in fib6_locate_1()Stefano Brivio
When we perform an inexact match on FIB nodes via fib6_locate_1(), longer prefixes will be preferred to shorter ones. However, it might happen that a node, with higher fn_bit value than some other, has no valid routing information. In this case, we'll pick that node, but it will be discarded by the check on RTN_RTINFO in fib6_locate(), and we might miss nodes with valid routing information but with lower fn_bit value. This is apparent when a routing exception is created for a default route: # ip -6 route list fc00:1::/64 dev veth_A-R1 proto kernel metric 256 pref medium fc00:2::/64 dev veth_A-R2 proto kernel metric 256 pref medium fc00:4::1 via fc00:2::2 dev veth_A-R2 metric 1024 pref medium fe80::/64 dev veth_A-R1 proto kernel metric 256 pref medium fe80::/64 dev veth_A-R2 proto kernel metric 256 pref medium default via fc00:1::2 dev veth_A-R1 metric 1024 pref medium # ip -6 route list cache fc00:4::1 via fc00:2::2 dev veth_A-R2 metric 1024 expires 593sec mtu 1500 pref medium fc00:3::1 via fc00:1::2 dev veth_A-R1 metric 1024 expires 593sec mtu 1500 pref medium # ip -6 route flush cache # node for default route is discarded Failed to send flush request: No such process # ip -6 route list cache fc00:3::1 via fc00:1::2 dev veth_A-R1 metric 1024 expires 586sec mtu 1500 pref medium Check right away if the node has a RTN_RTINFO flag, before replacing the 'prev' pointer, that indicates the longest matching prefix found so far. Fixes: 38fbeeeeccdb ("ipv6: prepare fib6_locate() for exception table") Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-24ipv6: Dump route exceptions if requestedStefano Brivio
Since commit 2b760fcf5cfb ("ipv6: hook up exception table to store dst cache"), route exceptions reside in a separate hash table, and won't be found by walking the FIB, so they won't be dumped to userspace on a RTM_GETROUTE message. This causes 'ip -6 route list cache' and 'ip -6 route flush cache' to have no function anymore: # ip -6 route get fc00:3::1 fc00:3::1 via fc00:1::2 dev veth_A-R1 src fc00:1::1 metric 1024 expires 539sec mtu 1400 pref medium # ip -6 route get fc00:4::1 fc00:4::1 via fc00:2::2 dev veth_A-R2 src fc00:2::1 metric 1024 expires 536sec mtu 1500 pref medium # ip -6 route list cache # ip -6 route flush cache # ip -6 route get fc00:3::1 fc00:3::1 via fc00:1::2 dev veth_A-R1 src fc00:1::1 metric 1024 expires 520sec mtu 1400 pref medium # ip -6 route get fc00:4::1 fc00:4::1 via fc00:2::2 dev veth_A-R2 src fc00:2::1 metric 1024 expires 519sec mtu 1500 pref medium because iproute2 lists cached routes using RTM_GETROUTE, and flushes them by listing all the routes, and deleting them with RTM_DELROUTE one by one. If cached routes are requested using the RTM_F_CLONED flag together with strict checking, or if no strict checking is requested (and hence we can't consistently apply filters), look up exceptions in the hash table associated with the current fib6_info in rt6_dump_route(), and, if present and not expired, add them to the dump. We might be unable to dump all the entries for a given node in a single message, so keep track of how many entries were handled for the current node in fib6_walker, and skip that amount in case we start from the same partially dumped node. When a partial dump restarts, as the starting node might change when 'sernum' changes, we have no guarantee that we need to skip the same amount of in-node entries. Therefore, we need two counters, and we need to zero the in-node counter if the node from which the dump is resumed differs. Note that, with the current version of iproute2, this only fixes the 'ip -6 route list cache': on a flush command, iproute2 doesn't pass RTM_F_CLONED and, due to this inconsistency, 'ip -6 route flush cache' is still unable to fetch the routes to be flushed. This will be addressed in a patch for iproute2. To flush cached routes, a procfs entry could be introduced instead: that's how it works for IPv4. We already have a rt6_flush_exception() function ready to be wired to it. However, this would not solve the issue for listing. Versions of iproute2 and kernel tested: iproute2 kernel 4.14.0 4.15.0 4.19.0 5.0.0 5.1.0 5.1.0, patched 3.18 list + + + + + + flush + + + + + + 4.4 list + + + + + + flush + + + + + + 4.9 list + + + + + + flush + + + + + + 4.14 list + + + + + + flush + + + + + + 4.15 list flush 4.19 list flush 5.0 list flush 5.1 list flush with list + + + + + + fix flush + + + + v7: - Explain usage of "skip" counters in commit message (suggested by David Ahern) v6: - Rebase onto net-next, use recently introduced nexthop walker - Make rt6_nh_dump_exceptions() a separate function (suggested by David Ahern) v5: - Use dump_routes and dump_exceptions from filter, ignore NLM_F_MATCH, update test results (flushing works with iproute2 < 5.0.0 now) v4: - Split NLM_F_MATCH and strict check handling in separate patches - Filter routes using RTM_F_CLONED: if it's not set, only return non-cached routes, and if it's set, only return cached routes: change requested by David Ahern and Martin Lau. This implies that iproute2 needs a separate patch to be able to flush IPv6 cached routes. This is not ideal because we can't fix the breakage caused by 2b760fcf5cfb entirely in kernel. However, two years have passed since then, and this makes it more tolerable v3: - More descriptive comment about expired exceptions in rt6_dump_route() - Swap return values of rt6_dump_route() (suggested by Martin Lau) - Don't zero skip_in_node in case we don't dump anything in a given pass (also suggested by Martin Lau) - Remove check on RTM_F_CLONED altogether: in the current UAPI semantic, it's just a flag to indicate the route was cloned, not to filter on routes v2: Add tracking of number of entries to be skipped in current node after a partial dump. As we restart from the same node, if not all the exceptions for a given node fit in a single message, the dump will not terminate, as suggested by Martin Lau. This is a concrete possibility, setting up a big number of exceptions for the same route actually causes the issue, suggested by David Ahern. Reported-by: Jianlin Shi <jishi@redhat.com> Fixes: 2b760fcf5cfb ("ipv6: hook up exception table to store dst cache") Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-24ipv6/route: Change return code of rt6_dump_route() for partial node dumpsStefano Brivio
In the next patch, we are going to add optional dump of exceptions to rt6_dump_route(). Change the return code of rt6_dump_route() to accomodate partial node dumps: we might dump multiple routes per node, and might be able to dump only a given number of them, so fib6_dump_node() will need to know how many routes have been dumped on partial dump, to restart the dump from the point where it was interrupted. Note that fib6_dump_node() is the only caller and already handles all non-negative return codes as success: those become -1 to signal that we're done with the node. If we fail, return 0, as we were unable to dump the single route in the node, but we're not done with it. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-24Revert "net/ipv6: Bail early if user only wants cloned entries"Stefano Brivio
This reverts commit 08e814c9e8eb5a982cbd1e8f6bd255d97c51026f: as we are preparing to fix listing and dumping of IPv6 cached routes, we need to allow RTM_F_CLONED as a flag to match routes against while dumping them. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-24fib_frontend, ip6_fib: Select routes or exceptions dump from RTM_F_CLONEDStefano Brivio
The following patches add back the ability to dump IPv4 and IPv6 exception routes, and we need to allow selection of regular routes or exceptions. Use RTM_F_CLONED as filter to decide whether to dump routes or exceptions: iproute2 passes it in dump requests (except for IPv6 cache flush requests, this will be fixed in iproute2) and this used to work as long as exceptions were stored directly in the FIB, for both IPv4 and IPv6. Caveat: if strict checking is not requested (that is, if the dump request doesn't go through ip_valid_fib_dump_req()), we can't filter on protocol, tables or route types. In this case, filtering on RTM_F_CLONED would be inconsistent: we would fix 'ip route list cache' by returning exception routes and at the same time introduce another bug in case another selector is present, e.g. on 'ip route list cache table main' we would return all exception routes, without filtering on tables. Keep this consistent by applying no filters at all, and dumping both routes and exceptions, if strict checking is not requested. iproute2 currently filters results anyway, and no unwanted results will be presented to the user. The kernel will just dump more data than needed. v7: No changes v6: Rebase onto net-next, no changes v5: New patch: add dump_routes and dump_exceptions flags in filter and simply clear the unwanted one if strict checking is enabled, don't ignore NLM_F_MATCH and don't set filter_set if NLM_F_MATCH is set. Skip filtering altogether if no strict checking is requested: selecting routes or exceptions only would be inconsistent with the fact we can't filter on tables. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-23ipv6: honor RT6_LOOKUP_F_DST_NOREF in rule lookup logicWei Wang
This patch specifically converts the rule lookup logic to honor this flag and not release refcnt when traversing each rule and calling lookup() on each routing table. Similar to previous patch, we also need some special handling of dst entries in uncached list because there is always 1 refcnt taken for them even if RT6_LOOKUP_F_DST_NOREF flag is set. Signed-off-by: Wei Wang <weiwan@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-18ipv6: Stop sending in-kernel notifications for each nexthopIdo Schimmel
Both listeners - mlxsw and netdevsim - of IPv6 FIB notifications are now ready to handle IPv6 multipath notifications. Therefore, stop ignoring such notifications in both drivers and stop sending notification for each added / deleted nexthop. v2: * Remove 'multipath_rt' from 'struct fib6_entry_notifier_info' Signed-off-by: Ido Schimmel <idosch@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-18ipv6: Extend notifier info for multipath routesIdo Schimmel
Extend the IPv6 FIB notifier info with number of sibling routes being notified. This will later allow listeners to process one notification for a multipath routes instead of N, where N is the number of nexthops. Signed-off-by: Ido Schimmel <idosch@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-10ipv6: Handle all fib6_nh in a nexthop in fib6_drop_pcpu_fromDavid Ahern
Use nexthop_for_each_fib6_nh to walk all fib6_nh in a nexthop when dropping 'from' reference in pcpu routes. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Some ISDN files that got removed in net-next had some changes done in mainline, take the removals. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-04ipv6: Plumb support for nexthop object in a fib6_infoDavid Ahern
Add struct nexthop and nh_list list_head to fib6_info. nh_list is the fib6_info side of the nexthop <-> fib_info relationship. Since a fib6_info referencing a nexthop object can not have 'sibling' entries (the old way of doing multipath routes), the nh_list is a union with fib6_siblings. Add f6i_list list_head to 'struct nexthop' to track fib6_info entries using a nexthop instance. Update __remove_nexthop_fib to walk f6_list and delete fib entries using the nexthop. Add a few nexthop helpers for use when a nexthop is added to fib6_info: - nexthop_fib6_nh - return first fib6_nh in a nexthop object - fib6_info_nh_dev moved to nexthop.h and updated to use nexthop_fib6_nh if the fib6_info references a nexthop object - nexthop_path_fib6_result - similar to ipv4, select a path within a multipath nexthop object. If the nexthop is a blackhole, set fib6_result type to RTN_BLACKHOLE, and set the REJECT flag Update the fib6_info references to check for nh and take a different path as needed: - rt6_qualify_for_ecmp - if a fib entry uses a nexthop object it can NOT be coalesced with other fib entries into a multipath route - rt6_duplicate_nexthop - use nexthop_cmp if either fib6_info references a nexthop - addrconf (host routes), RA's and info entries (anything configured via ndisc) does not use nexthop objects - fib6_info_destroy_rcu - put reference to nexthop object - fib6_purge_rt - drop fib6_info from f6i_list - fib6_select_path - update to use the new nexthop_path_fib6_result when fib entry uses a nexthop object - rt6_device_match - update to catch use of nexthop object as a blackhole and set fib6_type and flags. - ip6_route_info_create - don't add space for fib6_nh if fib entry is going to reference a nexthop object, take a reference to nexthop object, disallow use of source routing - rt6_nlmsg_size - add space for RTA_NH_ID - add rt6_fill_node_nexthop to add nexthop data on a dump As with ipv4, most of the changes push existing code into the else branch of whether the fib entry uses a nexthop object. Update the nexthop code to walk f6i_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24ipv6: Make fib6_nh optional at the end of fib6_infoDavid Ahern
Move fib6_nh to the end of fib6_info and make it an array of size 0. Pass a flag to fib6_info_alloc indicating if the allocation needs to add space for a fib6_nh. The current code path always has a fib6_nh allocated with a fib6_info; with nexthop objects they will be separate. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24ipv6: Move exception bucket to fib6_nhDavid Ahern
Similar to the pcpu routes exceptions are really per nexthop, so move rt6i_exception_bucket from fib6_info to fib6_nh. To avoid additional increases to the size of fib6_nh for a 1-bit flag, use the lowest bit in the allocated memory pointer for the flushed flag. Add helpers for retrieving the bucket pointer to mask off the flag. The cleanup of the exception bucket is moved to fib6_nh_release. fib6_nh_flush_exceptions can now be called from 2 contexts: 1. deleting a fib entry 2. deleting a fib6_nh For 1., fib6_nh_flush_exceptions is called for a specific fib6_info that is getting deleted. All exceptions in the cache using the entry are deleted. For 2, the fib6_nh itself is getting destroyed so fib6_nh_flush_exceptions is called for a NULL fib6_info which means flush all entries. The pmtu.sh selftest exercises the affected code paths - from creating exceptions to cleaning them up on device delete. All tests pass without any rcu locking or memleak warnings. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24ipv6: Refactor fib6_drop_pcpu_fromDavid Ahern
Move the existing pcpu walk in fib6_drop_pcpu_from to a new helper, __fib6_drop_pcpu_from, that can be invoked per fib6_nh with a reference to the from entries that need to be evicted. If the passed in 'from' is non-NULL then only entries associated with that fib6_info are removed (e.g., case where fib entry is deleted); if the 'from' is NULL are entries are flushed (e.g., fib6_nh is deleted). For fib6_info entries with builtin fib6_nh (ie., current code) there is no change in behavior. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24ipv6: Move pcpu cached routes to fib6_nhDavid Ahern
rt6_info are specific instances of a fib entry and are tied to a device and gateway - ie., a nexthop. Before nexthop objects, IPv6 fib entries have separate fib6_info for each nexthop in a multipath route, so the location of the pcpu cache in the fib6_info struct worked. However, with nexthop objects a fib6_info can point to a set of nexthops (yet another alignment of ipv6 with ipv4). Accordingly, the pcpu cache needs to be moved to the fib6_nh struct so the cached entries are local to the nexthop specification used to create the rt6_info. Initialization and free of the pcpu entries moved to fib6_nh_init and fib6_nh_release. Change in location only, from fib6_info down to fib6_nh; no other functional change intended. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-22ipv6: export function to send route updatesDavid Ahern
Add fib6_rt_update to send RTM_NEWROUTE with NLM_F_REPLACE set. This helper will be used by the nexthop code to notify userspace of routes that are impacted when a nexthop config is updated via replace. This notification is needed for legacy apps that do not understand the new nexthop object. Apps that are nexthop aware can use the RTA_NH_ID attribute in the route notification to just ignore it. In the future this should be wrapped in a sysctl to allow OS'es that are fully updated to avoid the notificaton storm. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-22ipv6: Add hook to bump sernum for a route to stubsDavid Ahern
Add hook to ipv6 stub to bump the sernum up to the root node for a route. This is needed by the nexthop code when a nexthop config changes. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-16ipv6: prevent possible fib6 leaksEric Dumazet
At ipv6 route dismantle, fib6_drop_pcpu_from() is responsible for finding all percpu routes and set their ->from pointer to NULL, so that fib6_ref can reach its expected value (1). The problem right now is that other cpus can still catch the route being deleted, since there is no rcu grace period between the route deletion and call to fib6_drop_pcpu_from() This can leak the fib6 and associated resources, since no notifier will take care of removing the last reference(s). I decided to add another boolean (fib6_destroying) instead of reusing/renaming exception_bucket_flushed to ease stable backports, and properly document the memory barriers used to implement this fix. This patch has been co-developped with Wei Wang. Fixes: 93531c674315 ("net/ipv6: separate handling of FIB entries from dst based routes") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Wei Wang <weiwan@google.com> Cc: David Ahern <dsahern@gmail.com> Cc: Martin Lau <kafai@fb.com> Acked-by: Wei Wang <weiwan@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Three trivial overlapping conflicts. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-30ipv6: fix races in ip6_dst_destroy()Eric Dumazet
We had many syzbot reports that seem to be caused by use-after-free of struct fib6_info. ip6_dst_destroy(), fib6_drop_pcpu_from() and rt6_remove_exception() are writers vs rt->from, and use non consistent synchronization among themselves. Switching to xchg() will solve the issues with no possible lockdep issues. BUG: KASAN: user-memory-access in atomic_dec_and_test include/asm-generic/atomic-instrumented.h:747 [inline] BUG: KASAN: user-memory-access in fib6_info_release include/net/ip6_fib.h:294 [inline] BUG: KASAN: user-memory-access in fib6_info_release include/net/ip6_fib.h:292 [inline] BUG: KASAN: user-memory-access in fib6_drop_pcpu_from net/ipv6/ip6_fib.c:927 [inline] BUG: KASAN: user-memory-access in fib6_purge_rt+0x4f6/0x670 net/ipv6/ip6_fib.c:960 Write of size 4 at addr 0000000000ffffb4 by task syz-executor.1/7649 CPU: 0 PID: 7649 Comm: syz-executor.1 Not tainted 5.1.0-rc6+ #183 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 kasan_report.cold+0x5/0x40 mm/kasan/report.c:321 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x123/0x190 mm/kasan/generic.c:191 kasan_check_write+0x14/0x20 mm/kasan/common.c:108 atomic_dec_and_test include/asm-generic/atomic-instrumented.h:747 [inline] fib6_info_release include/net/ip6_fib.h:294 [inline] fib6_info_release include/net/ip6_fib.h:292 [inline] fib6_drop_pcpu_from net/ipv6/ip6_fib.c:927 [inline] fib6_purge_rt+0x4f6/0x670 net/ipv6/ip6_fib.c:960 fib6_del_route net/ipv6/ip6_fib.c:1813 [inline] fib6_del+0xac2/0x10a0 net/ipv6/ip6_fib.c:1844 fib6_clean_node+0x3a8/0x590 net/ipv6/ip6_fib.c:2006 fib6_walk_continue+0x495/0x900 net/ipv6/ip6_fib.c:1928 fib6_walk+0x9d/0x100 net/ipv6/ip6_fib.c:1976 fib6_clean_tree+0xe0/0x120 net/ipv6/ip6_fib.c:2055 __fib6_clean_all+0x118/0x2a0 net/ipv6/ip6_fib.c:2071 fib6_clean_all+0x2b/0x40 net/ipv6/ip6_fib.c:2082 rt6_sync_down_dev+0x134/0x150 net/ipv6/route.c:4057 rt6_disable_ip+0x27/0x5f0 net/ipv6/route.c:4062 addrconf_ifdown+0xa2/0x1220 net/ipv6/addrconf.c:3705 addrconf_notify+0x19a/0x2260 net/ipv6/addrconf.c:3630 notifier_call_chain+0xc7/0x240 kernel/notifier.c:93 __raw_notifier_call_chain kernel/notifier.c:394 [inline] raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:401 call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1753 call_netdevice_notifiers_extack net/core/dev.c:1765 [inline] call_netdevice_notifiers net/core/dev.c:1779 [inline] dev_close_many+0x33f/0x6f0 net/core/dev.c:1522 rollback_registered_many+0x43b/0xfd0 net/core/dev.c:8177 rollback_registered+0x109/0x1d0 net/core/dev.c:8242 unregister_netdevice_queue net/core/dev.c:9289 [inline] unregister_netdevice_queue+0x1ee/0x2c0 net/core/dev.c:9282 unregister_netdevice include/linux/netdevice.h:2658 [inline] __tun_detach+0xd5b/0x1000 drivers/net/tun.c:727 tun_detach drivers/net/tun.c:744 [inline] tun_chr_close+0xe0/0x180 drivers/net/tun.c:3443 __fput+0x2e5/0x8d0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x14a/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x90a/0x2fa0 kernel/exit.c:876 do_group_exit+0x135/0x370 kernel/exit.c:980 __do_sys_exit_group kernel/exit.c:991 [inline] __se_sys_exit_group kernel/exit.c:989 [inline] __x64_sys_exit_group+0x44/0x50 kernel/exit.c:989 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458da9 Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffeafc2a6a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000000000000001c RCX: 0000000000458da9 RDX: 0000000000412a80 RSI: 0000000000a54ef0 RDI: 0000000000000043 RBP: 00000000004be552 R08: 000000000000000c R09: 000000000004c0d1 R10: 0000000002341940 R11: 0000000000000246 R12: 00000000ffffffff R13: 00007ffeafc2a7f0 R14: 000000000004c065 R15: 00007ffeafc2a800 Fixes: a68886a69180 ("net/ipv6: Make from in rt6_info rcu protected") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: David Ahern <dsahern@gmail.com> Reviewed-by: David Ahern <dsahern@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Wei Wang <weiwan@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-23ipv6: convert fib6_ref to refcount_tEric Dumazet
We suspect some issues involving fib6_ref 0 -> 1 transitions might cause strange syzbot reports. Lets convert fib6_ref to refcount_t to catch them earlier. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Wei Wang <weiwan@google.com> Acked-by: Wei Wang <weiwan@google.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-23ipv6: broadly use fib6_info_hold() helperEric Dumazet
Instead of using atomic_inc(), prefer fib6_info_hold() so that upcoming refcount_t conversion is simpler. Only fib6_info_alloc() is using atomic_set() since we just allocated a new object. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Wei Wang <weiwan@google.com> Acked-by: Wei Wang <weiwan@google.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-23ipv6: fib6_info_destroy_rcu() cleanupEric Dumazet
We do not need to clear f6i->rt6i_exception_bucket right before freeing f6i. Note that f6i->rt6i_exception_bucket is properly protected by f6i->exception_bucket_flushed being set to one in rt6_flush_exceptions() under the protection of rt6_exception_lock. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Wei Wang <weiwan@google.com> Acked-by: Wei Wang <weiwan@google.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-17ipv6: Pass fib6_result to fib lookupsDavid Ahern
Change fib6_lookup and fib6_table_lookup to take a fib6_result and set f6i and nh rather than returning a fib6_info. For now both always return 0. A later patch set can make these more like the IPv4 counterparts and return EINVAL, EACCESS, etc based on fib6_type. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-08net: Replace nhc_has_gw with nhc_gw_familyDavid Ahern
Allow the gateway in a fib_nh_common to be from a different address family than the outer fib{6}_nh. To that end, replace nhc_has_gw with nhc_gw_family and update users of nhc_has_gw to check nhc_gw_family. Now nhc_family is used to know if the nh_common is part of a fib_nh or fib6_nh (used for container_of to get to route family specific data), and nhc_gw_family represents the address family for the gateway. Signed-off-by: David Ahern <dsahern@gmail.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-29ipv6: Rename fib6_nh entriesDavid Ahern
Rename fib6_nh entries that will be moved to a fib_nh_common struct. Specifically, the device, gateway, flags, and lwtstate are common with all nexthop definitions. In some places new temporary variables are declared or local variables renamed to maintain line lengths. Rename only; no functional change intended. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-29ipv6: Move gateway checks to a fib6_nh settingDavid Ahern
The gateway setting is not per fib6_info entry but per-fib6_nh. Add a new fib_nh_has_gw flag to fib6_nh and convert references to RTF_GATEWAY to the new flag. For IPv6 address the flag is cheaper than checking that nh_gw is non-0 like IPv4 does. While this increases fib6_nh by 8-bytes, the effective allocation size of a fib6_info is unchanged. The 8 bytes is recovered later with a fib_nh_common change. Signed-off-by: David Ahern <dsahern@gmail.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-29ipv6: Create cleanup helper for fib6_nhDavid Ahern
Move the fib6_nh cleanup code to a new helper, fib6_nh_release. Signed-off-by: David Ahern <dsahern@gmail.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-02ipv6: Fix dump of specific table with strict checkingDavid Ahern
Dump of a specific table with strict checking enabled is looping. The problem is that the end of the table dump is not marked in the cb. When dumping a specific table, cb args 0 and 1 are not used (they are the hash index and entry with an hash table index when dumping all tables). Re-use args[0] to hold a 'done' flag for the specific table dump. Fixes: 13e38901d46ca ("net/ipv6: Plumb support for filtering route dumps") Reported-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-05ipv6: properly check return value in inet6_dump_all()Alexey Kodanev
Make sure we call fib6_dump_end() if it happens that skb->len is zero. rtnl_dump_all() can reset cb->args on the next loop iteration there. Fixes: 08e814c9e8eb ("net/ipv6: Bail early if user only wants cloned entries") Fixes: ae677bbb4441 ("net: Don't return invalid table id error when dumping all families") Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-24net: Don't return invalid table id error when dumping all familiesDavid Ahern
When doing a route dump across all address families, do not error out if the table does not exist. This allows a route dump for AF_UNSPEC with a table id that may only exist for some of the families. Do return the table does not exist error if dumping routes for a specific family and the table does not exist. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-16net/ipv6: Bail early if user only wants cloned entriesDavid Ahern
Similar to IPv4, IPv6 fib no longer contains cloned routes. If a user requests a route dump for only cloned entries, no sense walking the FIB and returning everything. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-16net: Enable kernel side filtering of route dumpsDavid Ahern
Update parsing of route dump request to enable kernel side filtering. Allow filtering results by protocol (e.g., which routing daemon installed the route), route type (e.g., unicast), table id and nexthop device. These amount to the low hanging fruit, yet a huge improvement, for dumping routes. ip_valid_fib_dump_req is called with RTNL held, so __dev_get_by_index can be used to look up the device index without taking a reference. From there filter->dev is only used during dump loops with the lock still held. Set NLM_F_DUMP_FILTERED in the answer_flags so the user knows the results have been filtered should no entries be returned. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-16net/ipv6: Plumb support for filtering route dumpsDavid Ahern
Implement kernel side filtering of routes by table id, egress device index, protocol, and route type. If the table id is given in the filter, lookup the table and call fib6_dump_table directly for it. Move the existing route flags check for prefix only routes to the new filter. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-16net: Add struct for fib dump filterDavid Ahern
Add struct fib_dump_filter for options on limiting which routes are returned in a dump request. The current list is table id, protocol, route type, rtm_flags and nexthop device index. struct net is needed to lookup the net_device from the index. Declare the filter for each route dump handler and plumb the new arguments from dump handlers to ip_valid_fib_dump_req. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-12Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts were easy to resolve using immediate context mostly, except the cls_u32.c one where I simply too the entire HEAD chunk. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-12net/ipv6: Add knob to skip DELROUTE message on device downDavid Ahern
Another difference between IPv4 and IPv6 is the generation of RTM_DELROUTE notifications when a device is taken down (admin down) or deleted. IPv4 does not generate a message for routes evicted by the down or delete; IPv6 does. A NOS at scale really needs to avoid these messages and have IPv4 and IPv6 behave similarly, relying on userspace to handle link notifications and evict the routes. At this point existing user behavior needs to be preserved. Since notifications are a global action (not per app) the only way to preserve existing behavior and allow the messages to be skipped is to add a new sysctl (net/ipv6/route/skip_notify_on_dev_down) which can be set to disable the notificatioons. IPv6 route code already supports the option to skip the message (it is used for multipath routes for example). Besides the new sysctl we need to pass the skip_notify setting through the generic fib6_clean and fib6_walk functions to fib6_clean_node and to set skip_notify on calls to __ip_del_rt for the addrconf_ifdown path. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-10net/ipv6: stop leaking percpu memory in fib6 infoMike Rapoport
The fib6_info_alloc() function allocates percpu memory to hold per CPU pointers to rt6_info, but this memory is never freed. Fix it. Fixes: a64efe142f5e ("net/ipv6: introduce fib6_info struct and helpers") Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-08rtnetlink: Update fib dumps for strict data checkingDavid Ahern
Add helper to check netlink message for route dumps. If the strict flag is set the dump request is expected to have an rtmsg struct as the header. All elements of the struct are expected to be 0 with the exception of rtm_flags (which is used by both ipv4 and ipv6 dumps) and no attributes can be appended. rtm_flags can only have RTM_F_CLONED and RTM_F_PREFIX set. Update inet_dump_fib, inet6_dump_fib, mpls_dump_routes, ipmr_rtm_dumproute, and ip6mr_rtm_dumproute to call this helper if strict data checking is enabled. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-04net: Move free of fib_metrics to helperDavid Ahern
Move the refcounting and potential free of dst metrics associated with a fib entry to a helper and use it in both ipv4 and ipv6. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-04net: common metrics init helper for FIB entriesDavid Ahern
Consolidate initialization of ipv4 and ipv6 metrics when fib entries are created into a single helper, ip_fib_metrics_init, that handles the call to ip_metrics_convert. If no metrics are defined for the fib entry, then the metrics is set to dst_default_metrics. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-02net/ipv6: Only update MTU metric if it setDavid Ahern
Jan reported a regression after an update to 4.18.5. In this case ipv6 default route is setup by systemd-networkd based on data from an RA. The RA contains an MTU of 1492 which is used when the route is first inserted but then systemd-networkd pushes down updates to the default route without the mtu set. Prior to the change to fib6_info, metrics such as MTU were held in the dst_entry and rt6i_pmtu in rt6_info contained an update to the mtu if any. ip6_mtu would look at rt6i_pmtu first and use it if set. If not, the value from the metrics is used if it is set and finally falling back to the idev value. After the fib6_info change metrics are contained in the fib6_info struct and there is no equivalent to rt6i_pmtu. To maintain consistency with the old behavior the new code should only reset the MTU in the metrics if the route update has it set. Fixes: d4ead6b34b67 ("net/ipv6: move metrics from dst to rt6_info") Reported-by: Jan Janssen <medhefgo@web.de> Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-20net/ipv6: Put lwtstate when destroying fib6_infoDavid Ahern
Prior to the introduction of fib6_info lwtstate was managed by the dst code. With fib6_info releasing lwtstate needs to be done when the struct is freed. Fixes: 93531c674315 ("net/ipv6: separate handling of FIB entries from dst based routes") Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-01Revert "net/ipv6: fix metrics leak"David S. Miller
This reverts commit df18b50448fab1dff093731dfd0e25e77e1afcd1. This change causes other problems and use-after-free situations as found by syzbot. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-30net/ipv6: fix metrics leakSabrina Dubroca
Since commit d4ead6b34b67 ("net/ipv6: move metrics from dst to rt6_info"), ipv6 metrics are shared and refcounted. rt6_set_from() assigns the rt->from pointer and increases the refcount on from's metrics. This reference is never released. Introduce the fib6_metrics_release() helper and use it to release the metrics. Fixes: d4ead6b34b67 ("net/ipv6: move metrics from dst to rt6_info") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-04net/ipv6: Revert attempt to simplify route replace and appendDavid Ahern
NetworkManager likes to manage linklocal prefix routes and does so with the NLM_F_APPEND flag, breaking attempts to simplify the IPv6 route code and by extension enable multipath routes with device only nexthops. Revert f34436a43092 and these followup patches: 6eba08c3626b ("ipv6: Only emit append events for appended routes"). ce45bded6435 ("mlxsw: spectrum_router: Align with new route replace logic") 53b562df8c20 ("mlxsw: spectrum_router: Allow appending to dev-only routes") Update the fib_tests cases to reflect the old behavior. Fixes: f34436a43092 ("net/ipv6: Simplify route replace and appending into multipath route") Signed-off-by: David Ahern <dsahern@gmail.com>
2018-06-20net/ipv6: respect rcu grace period before freeing fib6_infoEric Dumazet
syzbot reported use after free that is caused by fib6_info being freed without a proper RCU grace period. CPU: 0 PID: 1407 Comm: udevd Not tainted 4.17.0+ #39 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b9/0x294 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 __read_once_size include/linux/compiler.h:188 [inline] find_rr_leaf net/ipv6/route.c:705 [inline] rt6_select net/ipv6/route.c:761 [inline] fib6_table_lookup+0x12b7/0x14d0 net/ipv6/route.c:1823 ip6_pol_route+0x1c2/0x1020 net/ipv6/route.c:1856 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2082 fib6_rule_lookup+0x211/0x6d0 net/ipv6/fib6_rules.c:122 ip6_route_output_flags+0x2c5/0x350 net/ipv6/route.c:2110 ip6_route_output include/net/ip6_route.h:82 [inline] icmpv6_xrlim_allow net/ipv6/icmp.c:211 [inline] icmp6_send+0x147c/0x2da0 net/ipv6/icmp.c:535 icmpv6_send+0x17a/0x300 net/ipv6/ip6_icmp.c:43 ip6_link_failure+0xa5/0x790 net/ipv6/route.c:2244 dst_link_failure include/net/dst.h:427 [inline] ndisc_error_report+0xd1/0x1c0 net/ipv6/ndisc.c:695 neigh_invalidate+0x246/0x550 net/core/neighbour.c:892 neigh_timer_handler+0xaf9/0xde0 net/core/neighbour.c:978 call_timer_fn+0x230/0x940 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers+0x79e/0xc50 kernel/time/timer.c:1666 run_timer_softirq+0x4c/0x70 kernel/time/timer.c:1692 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 [inline] irq_exit+0x1d1/0x200 kernel/softirq.c:404 exiting_irq arch/x86/include/asm/apic.h:527 [inline] smp_apic_timer_interrupt+0x17e/0x710 arch/x86/kernel/apic/apic.c:1052 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863 </IRQ> RIP: 0010:strlen+0x5e/0xa0 lib/string.c:482 Code: 24 00 74 3b 48 bb 00 00 00 00 00 fc ff df 4c 89 e0 48 83 c0 01 48 89 c2 48 89 c1 48 c1 ea 03 83 e1 07 0f b6 14 1a 38 ca 7f 04 <84> d2 75 23 80 38 00 75 de 48 83 c4 08 4c 29 e0 5b 41 5c 5d c3 48 RSP: 0018:ffff8801af117850 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffff880197f53bd0 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff81c5b06c RDI: ffff880197f53bc0 RBP: ffff8801af117868 R08: ffff88019a976540 R09: 0000000000000000 R10: ffff88019a976540 R11: 0000000000000000 R12: ffff880197f53bc0 R13: ffff880197f53bc0 R14: ffffffff899e4e90 R15: ffff8801d91c6a00 strlen include/linux/string.h:267 [inline] getname_kernel+0x24/0x370 fs/namei.c:218 open_exec+0x17/0x70 fs/exec.c:882 load_elf_binary+0x968/0x5610 fs/binfmt_elf.c:780 search_binary_handler+0x17d/0x570 fs/exec.c:1653 exec_binprm fs/exec.c:1695 [inline] __do_execve_file.isra.35+0x16fe/0x2710 fs/exec.c:1819 do_execveat_common fs/exec.c:1866 [inline] do_execve fs/exec.c:1883 [inline] __do_sys_execve fs/exec.c:1964 [inline] __se_sys_execve fs/exec.c:1959 [inline] __x64_sys_execve+0x8f/0xc0 fs/exec.c:1959 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f1576a46207 Code: 77 19 f4 48 89 d7 44 89 c0 0f 05 48 3d 00 f0 ff ff 76 e0 f7 d8 64 41 89 01 eb d8 f7 d8 64 41 89 01 eb df b8 3b 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 02 f3 c3 48 8b 15 00 8c 2d 00 f7 d8 64 89 02 RSP: 002b:00007ffff2784568 EFLAGS: 00000202 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007f1576a46207 RDX: 0000000001215b10 RSI: 00007ffff2784660 RDI: 00007ffff2785670 RBP: 0000000000625500 R08: 000000000000589c R09: 000000000000589c R10: 0000000000000000 R11: 0000000000000202 R12: 0000000001215b10 R13: 0000000000000007 R14: 0000000001204250 R15: 0000000000000005 Allocated by task 12188: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kmem_cache_alloc_trace+0x152/0x780 mm/slab.c:3620 kmalloc include/linux/slab.h:513 [inline] kzalloc include/linux/slab.h:706 [inline] fib6_info_alloc+0xbb/0x280 net/ipv6/ip6_fib.c:152 ip6_route_info_create+0x782/0x2b50 net/ipv6/route.c:3013 ip6_route_add+0x23/0xb0 net/ipv6/route.c:3154 ipv6_route_ioctl+0x5a5/0x760 net/ipv6/route.c:3660 inet6_ioctl+0x100/0x1f0 net/ipv6/af_inet6.c:546 sock_do_ioctl+0xe4/0x3e0 net/socket.c:973 sock_ioctl+0x30d/0x680 net/socket.c:1097 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1cf/0x16f0 fs/ioctl.c:684 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701 __do_sys_ioctl fs/ioctl.c:708 [inline] __se_sys_ioctl fs/ioctl.c:706 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 1402: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xd9/0x260 mm/slab.c:3813 fib6_info_destroy+0x29b/0x350 net/ipv6/ip6_fib.c:207 fib6_info_release include/net/ip6_fib.h:286 [inline] __ip6_del_rt_siblings net/ipv6/route.c:3235 [inline] ip6_route_del+0x11c4/0x13b0 net/ipv6/route.c:3316 ipv6_route_ioctl+0x616/0x760 net/ipv6/route.c:3663 inet6_ioctl+0x100/0x1f0 net/ipv6/af_inet6.c:546 sock_do_ioctl+0xe4/0x3e0 net/socket.c:973 sock_ioctl+0x30d/0x680 net/socket.c:1097 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1cf/0x16f0 fs/ioctl.c:684 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701 __do_sys_ioctl fs/ioctl.c:708 [inline] __se_sys_ioctl fs/ioctl.c:706 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801b5df2580 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 8 bytes inside of 256-byte region [ffff8801b5df2580, ffff8801b5df2680) The buggy address belongs to the page: page:ffffea0006d77c80 count:1 mapcount:0 mapping:ffff8801da8007c0 index:0xffff8801b5df2e40 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea0006c5cc48 ffffea0007363308 ffff8801da8007c0 raw: ffff8801b5df2e40 ffff8801b5df2080 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801b5df2480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801b5df2500: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > ffff8801b5df2580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801b5df2600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801b5df2680: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb Fixes: a64efe142f5e ("net/ipv6: introduce fib6_info struct and helpers") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: David Ahern <dsahern@gmail.com> Reported-by: syzbot+9e6d75e3edef427ee888@syzkaller.appspotmail.com Acked-by: David Ahern <dsahern@gmail.com> Tested-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>