From: Ido Schimmel <idosch@nvidia.com>
To: Kuniyuki Iwashima <kuniyu@google.com>
Cc: David Ahern <dsahern@kernel.org>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Simon Horman <horms@kernel.org>,
Kuniyuki Iwashima <kuni1840@gmail.com>,
netdev@vger.kernel.org, syzkaller <syzkaller@googlegroups.com>,
Yi Lai <yi1.lai@intel.com>
Subject: Re: [PATCH v1 net] ipmr: Call ipmr_fib_lookup() under RCU.
Date: Wed, 6 May 2026 17:50:55 +0300 [thread overview]
Message-ID: <20260506145055.GA704316@shredder> (raw)
In-Reply-To: <20260506065955.1695753-1-kuniyu@google.com>
On Wed, May 06, 2026 at 06:59:53AM +0000, Kuniyuki Iwashima wrote:
> Yi Lai reported RCU splat in reg_vif_xmit() below. [0]
>
> When CONFIG_IP_MROUTE_MULTIPLE_TABLES=n, ipmr_fib_lookup()
> uses rcu_dereference() without explicit rcu_read_lock().
>
> Although rcu_read_lock_bh() is already held by the caller
> __dev_queue_xmit(), lockdep requires explicit rcu_read_lock()
> for rcu_dereference().
>
> Let's move up rcu_read_lock() in reg_vif_xmit() to
> cover ipmr_fib_lookup().
[...]
> Fixes: b3b6babf4751 ("ipmr: Free mr_table after RCU grace period.")
> Reported-by: syzkaller <syzkaller@googlegroups.com>
> Reported-by: Yi Lai <yi1.lai@intel.com>
> Closes: https://lore.kernel.org/netdev/afrY34dLXNUboevf@ly-workstation/
> Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
next prev parent reply other threads:[~2026-05-06 14:51 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-06 6:59 [PATCH v1 net] ipmr: Call ipmr_fib_lookup() under RCU Kuniyuki Iwashima
2026-05-06 10:13 ` Eric Dumazet
2026-05-06 14:50 ` Ido Schimmel [this message]
2026-05-07 15:50 ` patchwork-bot+netdevbpf
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260506145055.GA704316@shredder \
--to=idosch@nvidia.com \
--cc=davem@davemloft.net \
--cc=dsahern@kernel.org \
--cc=edumazet@google.com \
--cc=horms@kernel.org \
--cc=kuba@kernel.org \
--cc=kuni1840@gmail.com \
--cc=kuniyu@google.com \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=syzkaller@googlegroups.com \
--cc=yi1.lai@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox