* [PATCH net-next] ipv6/addrconf: ensure addrconf_verify_rtnl() has completed
@ 2022-02-16 18:20 Eric Dumazet
2022-02-17 3:25 ` David Ahern
2022-02-17 16:50 ` patchwork-bot+netdevbpf
0 siblings, 2 replies; 3+ messages in thread
From: Eric Dumazet @ 2022-02-16 18:20 UTC (permalink / raw)
To: David S . Miller, Jakub Kicinski
Cc: netdev, David Ahern, Eric Dumazet, Eric Dumazet, syzbot
From: Eric Dumazet <edumazet@google.com>
Before freeing the hash table in addrconf_exit_net(),
we need to make sure the work queue has completed,
or risk NULL dereference or UAF.
Thus, use cancel_delayed_work_sync() to enforce this.
We do not hold RTNL in addrconf_exit_net(), making this safe.
Fixes: 8805d13ff1b2 ("ipv6/addrconf: use one delayed work per netns")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
---
net/ipv6/addrconf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 57fbd6f03ff8d118e50d8aa6ea0ab938a1bb3cbc..44e164706340959b85f8f2d5d562caf8e37aea67 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -7187,7 +7187,7 @@ static void __net_exit addrconf_exit_net(struct net *net)
kfree(net->ipv6.devconf_all);
net->ipv6.devconf_all = NULL;
- cancel_delayed_work(&net->ipv6.addr_chk_work);
+ cancel_delayed_work_sync(&net->ipv6.addr_chk_work);
/*
* Check hash table, then free it.
*/
--
2.35.1.265.g69c8d7142f-goog
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH net-next] ipv6/addrconf: ensure addrconf_verify_rtnl() has completed
2022-02-16 18:20 [PATCH net-next] ipv6/addrconf: ensure addrconf_verify_rtnl() has completed Eric Dumazet
@ 2022-02-17 3:25 ` David Ahern
2022-02-17 16:50 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: David Ahern @ 2022-02-17 3:25 UTC (permalink / raw)
To: Eric Dumazet, David S . Miller, Jakub Kicinski
Cc: netdev, Eric Dumazet, syzbot
On 2/16/22 11:20 AM, Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@google.com>
>
> Before freeing the hash table in addrconf_exit_net(),
> we need to make sure the work queue has completed,
> or risk NULL dereference or UAF.
>
> Thus, use cancel_delayed_work_sync() to enforce this.
> We do not hold RTNL in addrconf_exit_net(), making this safe.
>
> Fixes: 8805d13ff1b2 ("ipv6/addrconf: use one delayed work per netns")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: syzbot <syzkaller@googlegroups.com>
> ---
> net/ipv6/addrconf.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
Reviewed-by: David Ahern <dsahern@kernel.org>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH net-next] ipv6/addrconf: ensure addrconf_verify_rtnl() has completed
2022-02-16 18:20 [PATCH net-next] ipv6/addrconf: ensure addrconf_verify_rtnl() has completed Eric Dumazet
2022-02-17 3:25 ` David Ahern
@ 2022-02-17 16:50 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: patchwork-bot+netdevbpf @ 2022-02-17 16:50 UTC (permalink / raw)
To: Eric Dumazet; +Cc: davem, kuba, netdev, dsahern, edumazet, syzkaller
Hello:
This patch was applied to netdev/net-next.git (master)
by Jakub Kicinski <kuba@kernel.org>:
On Wed, 16 Feb 2022 10:20:37 -0800 you wrote:
> From: Eric Dumazet <edumazet@google.com>
>
> Before freeing the hash table in addrconf_exit_net(),
> we need to make sure the work queue has completed,
> or risk NULL dereference or UAF.
>
> Thus, use cancel_delayed_work_sync() to enforce this.
> We do not hold RTNL in addrconf_exit_net(), making this safe.
>
> [...]
Here is the summary with links:
- [net-next] ipv6/addrconf: ensure addrconf_verify_rtnl() has completed
https://git.kernel.org/netdev/net-next/c/be6b41c15dc0
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-02-17 16:50 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-02-16 18:20 [PATCH net-next] ipv6/addrconf: ensure addrconf_verify_rtnl() has completed Eric Dumazet
2022-02-17 3:25 ` David Ahern
2022-02-17 16:50 ` patchwork-bot+netdevbpf
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).