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 003901F23CB; Sun, 24 Mar 2024 22:58:17 +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=1711321099; cv=none; b=QV9TLCMCEOtGnPYMHpj/FYpOKZ3rQ6r70IK4QrK/DvZUyqwg4bvTpDZlVHXQKzHgysXB8iH6b1TjXlJhyTRTiJn+0WSeIXW+6wd8RbGWgAw4YaaSO+P09z1zO041551b8Pi0YSpACVf5xU6duus9K5C7QCBQeqPXgaV7kTVe9zM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711321099; c=relaxed/simple; bh=lHXQ2K8+8QPy1rd/IpDoX2dRit57EmurvmqurFZMb7w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JpOgS+kRF7IFNu2Y+YYr5VlT5uBbFpOuoHhzyHYzjLXekNeJWTAFUut/tfOqLHt8jtpE8/SFOkgrOPEvm1rjAsMB7Ko1nWkquwzz87ioJjnsctWeSMSSYnKIoyvYu9WxubREf7BSKcl90//3kNzgy99MoAMzg1Xj6nFd4MCbN/g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DQURhXbq; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DQURhXbq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 11BF6C43390; Sun, 24 Mar 2024 22:58:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711321097; bh=lHXQ2K8+8QPy1rd/IpDoX2dRit57EmurvmqurFZMb7w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DQURhXbqiHL950laaFMWjBSh7Dj6A7sDyckd9irL1wS6l6D3ime2dTq03Ieo4QkxG yO5Vws6HPUxYorijoXIYNmGII2KccYMQnopVwV4LrCN4YoIDIveTehKdeeOBvFoEiF JTWySMrrMiHm1iyiy1+/2jX21gH/4fg4Px3BV6TbGyGJQMYwDq5ipKCtcexGgljUwo 94/QHTRPE+h93qp3fJve0mTBJ1+LwWYdk2rfGqW8nplipuuBZmxPmUHa/c+zCzbs9b G39RyTnlZZK/Zv5TRxQ70RjeJXU0lu72QaL+I5V0+TYe0NmSIfS+Uz1RnHHbfMxprl Ln1hau0FnMi5w== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Kuniyuki Iwashima , syzbot+12c506c1aae251e70449@syzkaller.appspotmail.com, Eric Dumazet , Paolo Abeni , Sasha Levin Subject: [PATCH 6.7 660/713] tcp: Fix refcnt handling in __inet_hash_connect(). Date: Sun, 24 Mar 2024 18:46:26 -0400 Message-ID: <20240324224720.1345309-661-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324224720.1345309-1-sashal@kernel.org> References: <20240324224720.1345309-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Kuniyuki Iwashima [ Upstream commit 04d9d1fc428ac9f581d55118d67e0cb546701feb ] syzbot reported a warning in sk_nulls_del_node_init_rcu(). The commit 66b60b0c8c4a ("dccp/tcp: Unhash sk from ehash for tb2 alloc failure after check_estalblished().") tried to fix an issue that an unconnected socket occupies an ehash entry when bhash2 allocation fails. In such a case, we need to revert changes done by check_established(), which does not hold refcnt when inserting socket into ehash. So, to revert the change, we need to __sk_nulls_add_node_rcu() instead of sk_nulls_add_node_rcu(). Otherwise, sock_put() will cause refcnt underflow and leak the socket. [0]: WARNING: CPU: 0 PID: 23948 at include/net/sock.h:799 sk_nulls_del_node_init_rcu+0x166/0x1a0 include/net/sock.h:799 Modules linked in: CPU: 0 PID: 23948 Comm: syz-executor.2 Not tainted 6.8.0-rc6-syzkaller-00159-gc055fc00c07b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 RIP: 0010:sk_nulls_del_node_init_rcu+0x166/0x1a0 include/net/sock.h:799 Code: e8 7f 71 c6 f7 83 fb 02 7c 25 e8 35 6d c6 f7 4d 85 f6 0f 95 c0 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc e8 1b 6d c6 f7 90 <0f> 0b 90 eb b2 e8 10 6d c6 f7 4c 89 e7 be 04 00 00 00 e8 63 e7 d2 RSP: 0018:ffffc900032d7848 EFLAGS: 00010246 RAX: ffffffff89cd0035 RBX: 0000000000000001 RCX: 0000000000040000 RDX: ffffc90004de1000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: 1ffff1100439ac26 R08: ffffffff89ccffe3 R09: 1ffff1100439ac28 R10: dffffc0000000000 R11: ffffed100439ac29 R12: ffff888021cd6140 R13: dffffc0000000000 R14: ffff88802a9bf5c0 R15: ffff888021cd6130 FS: 00007f3b823f16c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3b823f0ff8 CR3: 000000004674a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __inet_hash_connect+0x140f/0x20b0 net/ipv4/inet_hashtables.c:1139 dccp_v6_connect+0xcb9/0x1480 net/dccp/ipv6.c:956 __inet_stream_connect+0x262/0xf30 net/ipv4/af_inet.c:678 inet_stream_connect+0x65/0xa0 net/ipv4/af_inet.c:749 __sys_connect_file net/socket.c:2048 [inline] __sys_connect+0x2df/0x310 net/socket.c:2065 __do_sys_connect net/socket.c:2075 [inline] __se_sys_connect net/socket.c:2072 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2072 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7f3b8167dda9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3b823f10c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 00007f3b817abf80 RCX: 00007f3b8167dda9 RDX: 000000000000001c RSI: 0000000020000040 RDI: 0000000000000003 RBP: 00007f3b823f1120 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 000000000000000b R14: 00007f3b817abf80 R15: 00007ffd3beb57b8 Reported-by: syzbot+12c506c1aae251e70449@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=12c506c1aae251e70449 Fixes: 66b60b0c8c4a ("dccp/tcp: Unhash sk from ehash for tb2 alloc failure after check_estalblished().") Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20240308201623.65448-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/ipv4/inet_hashtables.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c index 9456bf9e2705b..7967ff7e02f79 100644 --- a/net/ipv4/inet_hashtables.c +++ b/net/ipv4/inet_hashtables.c @@ -1137,7 +1137,7 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row, sock_prot_inuse_add(net, sk->sk_prot, -1); spin_lock(lock); - sk_nulls_del_node_init_rcu(sk); + __sk_nulls_del_node_init_rcu(sk); spin_unlock(lock); sk->sk_hash = 0; -- 2.43.0