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 9FD581F8ADA; Tue, 17 Dec 2024 17:14:54 +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=1734455694; cv=none; b=C9Y19n1Nu0EnpHda8SmTW2H9+EHMNwmWU6AYFoUuJMlnsHuTUnUVU3aInutgI1Mv6M/mgaz9C2ytT827QHpca32repqg5Rxam3XXveo7S9bqEpX0bwa7avhY3jiGczpdb+peH55JYxBDV+LoCjRQYj9y7oQEcPRIPy1iL5TiKgA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734455694; c=relaxed/simple; bh=jXVHZVdKrsnU3V5+W2sNNraEaIgHqqxegrfAMErZ064=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oZQTb/4M9YiLKg0asi/3Xp2dOVSTianE9Od5paRvNnWJ5nYXc6lcPBAf2RMhJiGZPJTQKxqLgerJJBpbK+masTkfIxfsc9tRztzLlgYyZAiB0foBx9tEC0iyRq8rsupXI67cD5GMwhA80hmvdA6He+LH6TFyWuVbsZxcxUCl+xo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=NbcbKfbq; 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="NbcbKfbq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28619C4CED3; Tue, 17 Dec 2024 17:14:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1734455694; bh=jXVHZVdKrsnU3V5+W2sNNraEaIgHqqxegrfAMErZ064=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NbcbKfbqRE82k1nqA1XjdETQ6cR4UqgAwxkL5+nTN9DIAqk7ujGkAhL+/PYN7plIN c5PtCCYxac2tIS8riWZqruTEFysSkBWQBy22NU5/ItVvJucO9n3JErydgZ6d0YCFvw 7EpXnfnAnyc50ZLs+a12npKzH5JxE7lS20t77DnY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+46aa5474f179dacd1a3b@syzkaller.appspotmail.com, Eric Dumazet , Kuniyuki Iwashima , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 22/51] tipc: fix NULL deref in cleanup_bearer() Date: Tue, 17 Dec 2024 18:07:15 +0100 Message-ID: <20241217170521.204160057@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241217170520.301972474@linuxfoundation.org> References: <20241217170520.301972474@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit b04d86fff66b15c07505d226431f808c15b1703c ] syzbot found [1] that after blamed commit, ub->ubsock->sk was NULL when attempting the atomic_dec() : atomic_dec(&tipc_net(sock_net(ub->ubsock->sk))->wq_count); Fix this by caching the tipc_net pointer. [1] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] CPU: 0 UID: 0 PID: 5896 Comm: kworker/0:3 Not tainted 6.13.0-rc1-next-20241203-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events cleanup_bearer RIP: 0010:read_pnet include/net/net_namespace.h:387 [inline] RIP: 0010:sock_net include/net/sock.h:655 [inline] RIP: 0010:cleanup_bearer+0x1f7/0x280 net/tipc/udp_media.c:820 Code: 18 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 3c f7 99 f6 48 8b 1b 48 83 c3 30 e8 f0 e4 60 00 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00 74 08 48 89 df e8 1a f7 99 f6 49 83 c7 e8 48 8b 1b RSP: 0018:ffffc9000410fb70 EFLAGS: 00010206 RAX: 0000000000000006 RBX: 0000000000000030 RCX: ffff88802fe45a00 RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffc9000410f900 RBP: ffff88807e1f0908 R08: ffffc9000410f907 R09: 1ffff92000821f20 R10: dffffc0000000000 R11: fffff52000821f21 R12: ffff888031d19980 R13: dffffc0000000000 R14: dffffc0000000000 R15: ffff88807e1f0918 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000556ca050b000 CR3: 0000000031c0c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Fixes: 6a2fa13312e5 ("tipc: Fix use-after-free of kernel socket in cleanup_bearer().") Reported-by: syzbot+46aa5474f179dacd1a3b@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/67508b5f.050a0220.17bd51.0070.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20241204170548.4152658-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/tipc/udp_media.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c index 3f5a12b85b2d..f5bd75d931c1 100644 --- a/net/tipc/udp_media.c +++ b/net/tipc/udp_media.c @@ -811,6 +811,7 @@ static void cleanup_bearer(struct work_struct *work) { struct udp_bearer *ub = container_of(work, struct udp_bearer, work); struct udp_replicast *rcast, *tmp; + struct tipc_net *tn; list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) { dst_cache_destroy(&rcast->dst_cache); @@ -818,10 +819,14 @@ static void cleanup_bearer(struct work_struct *work) kfree_rcu(rcast, rcu); } + tn = tipc_net(sock_net(ub->ubsock->sk)); + dst_cache_destroy(&ub->rcast.dst_cache); udp_tunnel_sock_release(ub->ubsock); + + /* Note: could use a call_rcu() to avoid another synchronize_net() */ synchronize_net(); - atomic_dec(&tipc_net(sock_net(ub->ubsock->sk))->wq_count); + atomic_dec(&tn->wq_count); kfree(ub); } -- 2.39.5