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authorEric Dumazet <edumazet@google.com>2019-04-13 17:32:21 -0700
committerDavid S. Miller <davem@davemloft.net>2019-04-14 13:43:17 -0700
commitc543cb4a5f07e09237ec0fc2c60c9f131b2c79ad (patch)
tree32ee6941cd47c6798e3499725fdeb59c4df2fcf2 /net
parented0de45a1008991fdaa27a0152befcb74d126a8b (diff)
ipv4: ensure rcu_read_lock() in ipv4_link_failure()
fib_compute_spec_dst() needs to be called under rcu protection. syzbot reported : WARNING: suspicious RCU usage 5.1.0-rc4+ #165 Not tainted include/linux/inetdevice.h:220 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by swapper/0/0: #0: 0000000051b67925 ((&n->timer)){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:170 [inline] #0: 0000000051b67925 ((&n->timer)){+.-.}, at: call_timer_fn+0xda/0x720 kernel/time/timer.c:1315 stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.1.0-rc4+ #165 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+0x172/0x1f0 lib/dump_stack.c:113 lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:5162 __in_dev_get_rcu include/linux/inetdevice.h:220 [inline] fib_compute_spec_dst+0xbbd/0x1030 net/ipv4/fib_frontend.c:294 spec_dst_fill net/ipv4/ip_options.c:245 [inline] __ip_options_compile+0x15a7/0x1a10 net/ipv4/ip_options.c:343 ipv4_link_failure+0x172/0x400 net/ipv4/route.c:1195 dst_link_failure include/net/dst.h:427 [inline] arp_error_report+0xd1/0x1c0 net/ipv4/arp.c:297 neigh_invalidate+0x24b/0x570 net/core/neighbour.c:995 neigh_timer_handler+0xc35/0xf30 net/core/neighbour.c:1081 call_timer_fn+0x190/0x720 kernel/time/timer.c:1325 expire_timers kernel/time/timer.c:1362 [inline] __run_timers kernel/time/timer.c:1681 [inline] __run_timers kernel/time/timer.c:1649 [inline] run_timer_softirq+0x652/0x1700 kernel/time/timer.c:1694 __do_softirq+0x266/0x95a kernel/softirq.c:293 invoke_softirq kernel/softirq.c:374 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:414 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x14a/0x570 arch/x86/kernel/apic/apic.c:1062 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 Fixes: ed0de45a1008 ("ipv4: recompile ip options in ipv4_link_failure") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Stephen Suryaputra <ssuryaextr@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/route.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 0206789bc2b7..88ce038dd495 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1185,14 +1185,20 @@ static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
static void ipv4_link_failure(struct sk_buff *skb)
{
- struct rtable *rt;
struct ip_options opt;
+ struct rtable *rt;
+ int res;
/* Recompile ip options since IPCB may not be valid anymore.
*/
memset(&opt, 0, sizeof(opt));
opt.optlen = ip_hdr(skb)->ihl*4 - sizeof(struct iphdr);
- if (__ip_options_compile(dev_net(skb->dev), &opt, skb, NULL))
+
+ rcu_read_lock();
+ res = __ip_options_compile(dev_net(skb->dev), &opt, skb, NULL);
+ rcu_read_unlock();
+
+ if (res)
return;
__icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt);