From: Florian Westphal <fw@strlen.de>
To: Sabrina Dubroca <sd@queasysnail.net>
Cc: netdev@vger.kernel.org,
Steffen Klassert <steffen.klassert@secunet.com>,
syzbot+7ed9d47e15e88581dc5b@syzkaller.appspotmail.com
Subject: Re: [PATCH ipsec 1/2] xfrm: state: initialize state_ptrs earlier in xfrm_state_find
Date: Fri, 23 May 2025 20:05:00 +0200 [thread overview]
Message-ID: <aDC4zH_iZ5ss08uK@strlen.de> (raw)
In-Reply-To: <73c9e0ad005210c0813316008ec69fe3da1bd4ba.1748001837.git.sd@queasysnail.net>
Sabrina Dubroca <sd@queasysnail.net> wrote:
> In case of preemption, xfrm_state_look_at will find a different
> pcpu_id and look up states for that other CPU. If we matched a state
> for CPU2 in the state_cache while the lookup started on CPU1, we will
> jump to "found", but the "best" state that we got will be ignored and
> we will enter the "acquire" block. This block uses state_ptrs, which
> isn't initialized at this point.
Yep, I missed the "goto" and cc doesn't complain either.
> Let's initialize state_ptrs just after taking rcu_read_lock. This will
> also prevent a possible misuse in the future, if someone adjusts this
> function.
Thanks for fixing this bug.
Reviewed-by: Florian Westphal <fw@strlen.de>
next prev parent reply other threads:[~2025-05-23 18:05 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-23 15:11 [PATCH ipsec 0/2] xfrm: fixes for xfrm_state_find under preemption Sabrina Dubroca
2025-05-23 15:11 ` [PATCH ipsec 1/2] xfrm: state: initialize state_ptrs earlier in xfrm_state_find Sabrina Dubroca
2025-05-23 18:05 ` Florian Westphal [this message]
2025-05-23 15:11 ` [PATCH ipsec 2/2] xfrm: state: use a consistent pcpu_id " Sabrina Dubroca
2025-05-23 18:12 ` Florian Westphal
2025-05-26 6:28 ` Steffen Klassert
2025-05-26 13:57 ` Florian Westphal
2025-05-26 12:17 ` Steffen Klassert
2025-06-10 7:55 ` [PATCH ipsec 0/2] xfrm: fixes for xfrm_state_find under preemption Steffen Klassert
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