diff options
| author | Andrey Ryabinin <aryabinin@virtuozzo.com> | 2017-02-22 12:35:27 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-02-22 16:14:07 -0500 |
| commit | ec7cb62d18d854ea09df8b7194e7e710985f8b9a (patch) | |
| tree | 0e548d50f40aef5ef9e961915355f0a74d1ce948 /net/dccp | |
| parent | 2618be7dccf8739b89e1906b64bd8d551af351e6 (diff) | |
net/dccp: fix use after free in tw_timer_handler()
DCCP doesn't purge timewait sockets on network namespace shutdown.
So, after net namespace destroyed we could still have an active timer
which will trigger use after free in tw_timer_handler():
BUG: KASAN: use-after-free in tw_timer_handler+0x4a/0xa0 at addr ffff88010e0d1e10
Read of size 8 by task swapper/1/0
Call Trace:
__asan_load8+0x54/0x90
tw_timer_handler+0x4a/0xa0
call_timer_fn+0x127/0x480
expire_timers+0x1db/0x2e0
run_timer_softirq+0x12f/0x2a0
__do_softirq+0x105/0x5b4
irq_exit+0xdd/0xf0
smp_apic_timer_interrupt+0x57/0x70
apic_timer_interrupt+0x90/0xa0
Object at ffff88010e0d1bc0, in cache net_namespace size: 6848
Allocated:
save_stack_trace+0x1b/0x20
kasan_kmalloc+0xee/0x180
kasan_slab_alloc+0x12/0x20
kmem_cache_alloc+0x134/0x310
copy_net_ns+0x8d/0x280
create_new_namespaces+0x23f/0x340
unshare_nsproxy_namespaces+0x75/0xf0
SyS_unshare+0x299/0x4f0
entry_SYSCALL_64_fastpath+0x18/0xad
Freed:
save_stack_trace+0x1b/0x20
kasan_slab_free+0xae/0x180
kmem_cache_free+0xb4/0x350
net_drop_ns+0x3f/0x50
cleanup_net+0x3df/0x450
process_one_work+0x419/0xbb0
worker_thread+0x92/0x850
kthread+0x192/0x1e0
ret_from_fork+0x2e/0x40
Add .exit_batch hook to dccp_v4_ops()/dccp_v6_ops() which will purge
timewait sockets on net namespace destruction and prevent above issue.
Fixes: f2bf415cfed7 ("mib: add net to NET_ADD_STATS_BH")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dccp')
| -rw-r--r-- | net/dccp/ipv4.c | 6 | ||||
| -rw-r--r-- | net/dccp/ipv6.c | 6 |
2 files changed, 12 insertions, 0 deletions
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c index b043ec833785..409d0cfd3447 100644 --- a/net/dccp/ipv4.c +++ b/net/dccp/ipv4.c @@ -1017,9 +1017,15 @@ static void __net_exit dccp_v4_exit_net(struct net *net) inet_ctl_sock_destroy(net->dccp.v4_ctl_sk); } +static void __net_exit dccp_v4_exit_batch(struct list_head *net_exit_list) +{ + inet_twsk_purge(&dccp_hashinfo, AF_INET); +} + static struct pernet_operations dccp_v4_ops = { .init = dccp_v4_init_net, .exit = dccp_v4_exit_net, + .exit_batch = dccp_v4_exit_batch, }; static int __init dccp_v4_init(void) diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c index cef60a4a2803..233b57367758 100644 --- a/net/dccp/ipv6.c +++ b/net/dccp/ipv6.c @@ -1075,9 +1075,15 @@ static void __net_exit dccp_v6_exit_net(struct net *net) inet_ctl_sock_destroy(net->dccp.v6_ctl_sk); } +static void __net_exit dccp_v6_exit_batch(struct list_head *net_exit_list) +{ + inet_twsk_purge(&dccp_hashinfo, AF_INET6); +} + static struct pernet_operations dccp_v6_ops = { .init = dccp_v6_init_net, .exit = dccp_v6_exit_net, + .exit_batch = dccp_v6_exit_batch, }; static int __init dccp_v6_init(void) |