From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 333EB8468; Thu, 25 Jul 2024 14:49:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721918982; cv=none; b=uHBVkRu4W4WrAcz9YqQLEz7LJD8Tcm+Hx8owPASf1YQP3cr0eRihLGCfVIOl9Vw8WdgiD3LwAEBeRNbvgwjPECXxnq2EBCmjCH3uL6cWl9NnyAa/sxk94vPXo9biR4ahhj9OFGzi3Gl7DuDT0vv43BCYv0ppYWR/tKtl6UJa6u8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721918982; c=relaxed/simple; bh=EpLc/UjxtMC0L0J8esYSWmdDKrjM5Okt4NR5i+7tMUQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CzQSxgXJzVEHgqbsrn5X++XizgRFea2GxSy7PZf9qDuae4gTg9PNKUT88uQDLsigCqpZwm8BIaGxkK4t9vsZEvnV/G5jmNBuB2Vaj03TgFeM65Vt1br3PA27rQ7iyaSnnNPBLnCClO6hfz7FdSEsLdC1sAk+2YcVcnWybLtmOaw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=UWucvz2u; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="UWucvz2u" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B285CC116B1; Thu, 25 Jul 2024 14:49:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1721918982; bh=EpLc/UjxtMC0L0J8esYSWmdDKrjM5Okt4NR5i+7tMUQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UWucvz2uuEUWkYzxiUQcBsb2w74MKFmyNOLL2MvdYO4R2S3kYiwTPE1zhvzlrIFSP Jpus4kGyZdfgDqv8T47DkgFoIxAAlJsCJSV9r4O8dEG6f8DCliz1fIhmcMoyhGC8DA zN2mZ8d0tWehVhgji+hysc5qQGnRnDIyVuqLoMUs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+aa8c8ec2538929f18f2d@syzkaller.appspotmail.com, Jason Xing , Daniel Borkmann , John Fastabend , Ashwin Dayanand Kamat Subject: [PATCH 5.10 47/59] bpf, skmsg: Fix NULL pointer dereference in sk_psock_skb_ingress_enqueue Date: Thu, 25 Jul 2024 16:37:37 +0200 Message-ID: <20240725142735.037490902@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240725142733.262322603@linuxfoundation.org> References: <20240725142733.262322603@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jason Xing commit 6648e613226e18897231ab5e42ffc29e63fa3365 upstream. Fix NULL pointer data-races in sk_psock_skb_ingress_enqueue() which syzbot reported [1]. [1] BUG: KCSAN: data-race in sk_psock_drop / sk_psock_skb_ingress_enqueue write to 0xffff88814b3278b8 of 8 bytes by task 10724 on cpu 1: sk_psock_stop_verdict net/core/skmsg.c:1257 [inline] sk_psock_drop+0x13e/0x1f0 net/core/skmsg.c:843 sk_psock_put include/linux/skmsg.h:459 [inline] sock_map_close+0x1a7/0x260 net/core/sock_map.c:1648 unix_release+0x4b/0x80 net/unix/af_unix.c:1048 __sock_release net/socket.c:659 [inline] sock_close+0x68/0x150 net/socket.c:1421 __fput+0x2c1/0x660 fs/file_table.c:422 __fput_sync+0x44/0x60 fs/file_table.c:507 __do_sys_close fs/open.c:1556 [inline] __se_sys_close+0x101/0x1b0 fs/open.c:1541 __x64_sys_close+0x1f/0x30 fs/open.c:1541 do_syscall_64+0xd3/0x1d0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 read to 0xffff88814b3278b8 of 8 bytes by task 10713 on cpu 0: sk_psock_data_ready include/linux/skmsg.h:464 [inline] sk_psock_skb_ingress_enqueue+0x32d/0x390 net/core/skmsg.c:555 sk_psock_skb_ingress_self+0x185/0x1e0 net/core/skmsg.c:606 sk_psock_verdict_apply net/core/skmsg.c:1008 [inline] sk_psock_verdict_recv+0x3e4/0x4a0 net/core/skmsg.c:1202 unix_read_skb net/unix/af_unix.c:2546 [inline] unix_stream_read_skb+0x9e/0xf0 net/unix/af_unix.c:2682 sk_psock_verdict_data_ready+0x77/0x220 net/core/skmsg.c:1223 unix_stream_sendmsg+0x527/0x860 net/unix/af_unix.c:2339 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x140/0x180 net/socket.c:745 ____sys_sendmsg+0x312/0x410 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [inline] __sys_sendmsg+0x1e9/0x280 net/socket.c:2667 __do_sys_sendmsg net/socket.c:2676 [inline] __se_sys_sendmsg net/socket.c:2674 [inline] __x64_sys_sendmsg+0x46/0x50 net/socket.c:2674 do_syscall_64+0xd3/0x1d0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 value changed: 0xffffffff83d7feb0 -> 0x0000000000000000 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 10713 Comm: syz-executor.4 Tainted: G W 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Prior to this, commit 4cd12c6065df ("bpf, sockmap: Fix NULL pointer dereference in sk_psock_verdict_data_ready()") fixed one NULL pointer similarly due to no protection of saved_data_ready. Here is another different caller causing the same issue because of the same reason. So we should protect it with sk_callback_lock read lock because the writer side in the sk_psock_drop() uses "write_lock_bh(&sk->sk_callback_lock);". To avoid errors that could happen in future, I move those two pairs of lock into the sk_psock_data_ready(), which is suggested by John Fastabend. Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface") Reported-by: syzbot+aa8c8ec2538929f18f2d@syzkaller.appspotmail.com Signed-off-by: Jason Xing Signed-off-by: Daniel Borkmann Reviewed-by: John Fastabend Closes: https://syzkaller.appspot.com/bug?extid=aa8c8ec2538929f18f2d Link: https://lore.kernel.org/all/20240329134037.92124-1-kerneljasonxing@gmail.com Link: https://lore.kernel.org/bpf/20240404021001.94815-1-kerneljasonxing@gmail.com Signed-off-by: Ashwin Dayanand Kamat Signed-off-by: Greg Kroah-Hartman --- include/linux/skmsg.h | 2 ++ 1 file changed, 2 insertions(+) --- a/include/linux/skmsg.h +++ b/include/linux/skmsg.h @@ -407,10 +407,12 @@ static inline void sk_psock_put(struct s static inline void sk_psock_data_ready(struct sock *sk, struct sk_psock *psock) { + read_lock_bh(&sk->sk_callback_lock); if (psock->parser.enabled) psock->parser.saved_data_ready(sk); else sk->sk_data_ready(sk); + read_unlock_bh(&sk->sk_callback_lock); } static inline void psock_set_prog(struct bpf_prog **pprog,