From: David Howells <dhowells@redhat•com>
To: syzbot <syzbot+3538a6a72efa8b059c38@syzkaller•appspotmail.com>
Cc: dhowells@redhat•com, davem@davemloft•net, edumazet@google•com,
kuba@kernel•org, linux-afs@lists•infradead.org,
linux-kernel@vger•kernel.org, marc.dionne@auristor•com,
netdev@vger•kernel.org, pabeni@redhat•com,
syzkaller-bugs@googlegroups•com
Subject: Re: [syzbot] KASAN: use-after-free Read in rxrpc_lookup_local
Date: Tue, 06 Dec 2022 21:09:30 +0000 [thread overview]
Message-ID: <1265526.1670360970@warthog.procyon.org.uk> (raw)
In-Reply-To: <000000000000229f1505ef2b6159@google.com>
#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git master
rxrpc: Fix NULL deref in rxrpc_unuse_local()
Fix rxrpc_unuse_local() to get the debug_id *after* checking to see if
local is NULL.
Fixes: a2cf3264f331 ("rxrpc: Fold __rxrpc_unuse_local() into rxrpc_unuse_local()")
Reported-by: syzbot+3538a6a72efa8b059c38@syzkaller•appspotmail.com
Signed-off-by: David Howells <dhowells@redhat•com>
cc: Marc Dionne <marc.dionne@auristor•com>
cc: linux-afs@lists•infradead.org
---
net/rxrpc/local_object.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/rxrpc/local_object.c b/net/rxrpc/local_object.c
index 44222923c0d1..24ee585d9aaf 100644
--- a/net/rxrpc/local_object.c
+++ b/net/rxrpc/local_object.c
@@ -357,10 +357,11 @@ struct rxrpc_local *rxrpc_use_local(struct rxrpc_local *local,
*/
void rxrpc_unuse_local(struct rxrpc_local *local, enum rxrpc_local_trace why)
{
- unsigned int debug_id = local->debug_id;
+ unsigned int debug_id;
int r, u;
if (local) {
+ debug_id = local->debug_id;
r = refcount_read(&local->ref);
u = atomic_dec_return(&local->active_users);
trace_rxrpc_local(debug_id, why, r, u);
next prev parent reply other threads:[~2022-12-06 21:10 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-06 16:34 [syzbot] KASAN: use-after-free Read in rxrpc_lookup_local syzbot
2022-12-06 21:09 ` David Howells [this message]
2022-12-07 3:09 ` syzbot
2022-12-07 17:43 ` David Howells
2022-12-07 23:16 ` syzbot
2022-12-08 11:20 ` David Howells
2022-12-08 12:02 ` syzbot
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=1265526.1670360970@warthog.procyon.org.uk \
--to=dhowells@redhat$(echo .)com \
--cc=davem@davemloft$(echo .)net \
--cc=edumazet@google$(echo .)com \
--cc=kuba@kernel$(echo .)org \
--cc=linux-afs@lists$(echo .)infradead.org \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=marc.dionne@auristor$(echo .)com \
--cc=netdev@vger$(echo .)kernel.org \
--cc=pabeni@redhat$(echo .)com \
--cc=syzbot+3538a6a72efa8b059c38@syzkaller$(echo .)appspotmail.com \
--cc=syzkaller-bugs@googlegroups$(echo .)com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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