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From: Jiri Benc <jbenc@redhat.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: netdev@vger.kernel.org, edumazet@google.com,
	Stephen Hemminger <stephen@networkplumber.org>,
	David Ahern <dsahern@kernel.org>
Subject: Re: [PATCH net] ipv6: fix race condition between ipv6_get_ifaddr and ipv6_del_addr
Date: Fri, 5 Apr 2024 13:47:31 +0200	[thread overview]
Message-ID: <20240405134731.5db239c0@griffin> (raw)
In-Reply-To: <3e90336c-6859-474c-aa1e-01ccc665ad49@gmail.com>

On Fri, 5 Apr 2024 13:31:52 +0200, Eric Dumazet wrote:
> refcount_t semantic should prevent this double transition to 0  ?

You're right. This was found in an old kernel where it manifested
by a crash. In not so ancient kernels there's a refcount_t WARN:

[  202.500654] refcount_t: addition on 0; use-after-free.
[  202.500665] WARNING: CPU: 0 PID: 1327 at lib/refcount.c:25 refcount_warn_saturate+0x74/0x110

I knew about that but I wrote the commit message on the old kernel and
when updating it I missed this spot. Sorry about that.

> Can you include a stack trace in the changelog ?

I don't think I have a stack trace from the latest net kernel; let me
get one.

> Otherwise patch looks good to me, thanks !
> 
> Reviewed-by: Eric Dumazet <edumazet@google.com>

Thanks for the review! v2 with the updated commit message coming on
Monday.

 Jiri


  reply	other threads:[~2024-04-05 11:47 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-05 10:54 [PATCH net] ipv6: fix race condition between ipv6_get_ifaddr and ipv6_del_addr Jiri Benc
2024-04-05 11:31 ` Eric Dumazet
2024-04-05 11:47   ` Jiri Benc [this message]
2024-04-06 19:51 ` David Ahern

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