syzbot


KCSAN: data-race in __skb_try_recv_from_queue / unix_dgram_sendmsg

Status: fixed on 2020/02/18 14:31
Subsystems: net
[Documentation on labels]
Fix commit: 86b18aaa2b5b skbuff: fix a data race in skb_queue_len()
First crash: 1697d, last: 1594d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __skb_try_recv_from_queue / unix_dgram_sendmsg

write to 0xffff88809a499ce0 of 4 bytes by task 8248 on cpu 0:
 __skb_unlink include/linux/skbuff.h:2022 [inline]
 __skb_try_recv_from_queue+0x407/0x4e0 net/core/datagram.c:199
 __skb_try_recv_datagram+0xfa/0x2c0 net/core/datagram.c:269
 unix_dgram_recvmsg+0xfd/0xbf0 net/unix/af_unix.c:2061
 sock_recvmsg_nosec net/socket.c:873 [inline]
 ____sys_recvmsg+0x387/0x3a0 net/socket.c:2551
 ___sys_recvmsg+0xb2/0x100 net/socket.c:2595
 do_recvmmsg+0x19a/0x5c0 net/socket.c:2693
 __sys_recvmmsg+0x1ef/0x200 net/socket.c:2772
 __do_sys_recvmmsg net/socket.c:2795 [inline]
 __se_sys_recvmmsg net/socket.c:2788 [inline]
 __x64_sys_recvmmsg+0x89/0xb0 net/socket.c:2788
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88809a499ce0 of 4 bytes by task 8234 on cpu 1:
 unix_recvq_full net/unix/af_unix.c:194 [inline]
 unix_dgram_sendmsg+0xad0/0xdc0 net/unix/af_unix.c:1725
 sock_sendmsg_nosec net/socket.c:639 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:659
 ____sys_sendmsg+0x212/0x4d0 net/socket.c:2330
 ___sys_sendmsg+0xb5/0x100 net/socket.c:2384
 __sys_sendmmsg+0x123/0x350 net/socket.c:2474
 __do_sys_sendmmsg net/socket.c:2503 [inline]
 __se_sys_sendmmsg net/socket.c:2500 [inline]
 __x64_sys_sendmmsg+0x64/0x80 net/socket.c:2500
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8234 Comm: syz-executor.4 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (61):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/02/02 22:08 https://github.com/google/ktsan.git kcsan 245a43005292 93e5e335 .config console log report ci2-upstream-kcsan-gce
2020/02/01 12:01 https://github.com/google/ktsan.git kcsan 245a43005292 326d4c78 .config console log report ci2-upstream-kcsan-gce
2020/01/28 21:17 https://github.com/google/ktsan.git kcsan 245a43005292 c8e81ce4 .config console log report ci2-upstream-kcsan-gce
2020/01/28 03:51 https://github.com/google/ktsan.git kcsan 245a43005292 56cd6c9b .config console log report ci2-upstream-kcsan-gce
2020/01/25 15:51 https://github.com/google/ktsan.git kcsan 245a43005292 2e95ab33 .config console log report ci2-upstream-kcsan-gce
2020/01/24 02:03 https://github.com/google/ktsan.git kcsan 245a43005292 11ebf937 .config console log report ci2-upstream-kcsan-gce
2020/01/22 20:07 https://github.com/google/ktsan.git kcsan 245a43005292 3334d684 .config console log report ci2-upstream-kcsan-gce
2020/01/20 23:10 https://github.com/google/ktsan.git kcsan 245a43005292 8eda0b95 .config console log report ci2-upstream-kcsan-gce
2020/01/19 18:08 https://github.com/google/ktsan.git kcsan 245a43005292 0342f8c7 .config console log report ci2-upstream-kcsan-gce
2020/01/19 01:02 https://github.com/google/ktsan.git kcsan 245a43005292 bc8bc756 .config console log report ci2-upstream-kcsan-gce
2020/01/16 14:50 https://github.com/google/ktsan.git kcsan 245a43005292 3de7aabb .config console log report ci2-upstream-kcsan-gce
2020/01/15 16:58 https://github.com/google/ktsan.git kcsan 245a43005292 069a5a44 .config console log report ci2-upstream-kcsan-gce
2020/01/14 01:12 https://github.com/google/ktsan.git kcsan 245a43005292 32881205 .config console log report ci2-upstream-kcsan-gce
2020/01/12 12:43 https://github.com/google/ktsan.git kcsan 245a43005292 31290a45 .config console log report ci2-upstream-kcsan-gce
2020/01/10 19:56 https://github.com/google/ktsan.git kcsan 245a43005292 532ec44e .config console log report ci2-upstream-kcsan-gce
2020/01/10 06:57 https://github.com/google/ktsan.git kcsan 245a43005292 4de4e9f0 .config console log report ci2-upstream-kcsan-gce
2020/01/08 15:08 https://github.com/google/ktsan.git kcsan 245a43005292 ddc3e859 .config console log report ci2-upstream-kcsan-gce
2020/01/06 08:32 https://github.com/google/ktsan.git kcsan 245a43005292 438e1227 .config console log report ci2-upstream-kcsan-gce
2020/01/05 19:24 https://github.com/google/ktsan.git kcsan 245a43005292 d646e21f .config console log report ci2-upstream-kcsan-gce
2019/12/31 16:45 https://github.com/google/ktsan.git kcsan 245a43005292 25a0186e .config console log report ci2-upstream-kcsan-gce
2019/12/29 03:59 https://github.com/google/ktsan.git kcsan 245a43005292 af6b8ef8 .config console log report ci2-upstream-kcsan-gce
2019/12/19 07:39 https://github.com/google/ktsan.git kcsan 245a43005292 79b211f7 .config console log report ci2-upstream-kcsan-gce
2019/12/17 08:58 https://github.com/google/ktsan.git kcsan 245a43005292 d13d7958 .config console log report ci2-upstream-kcsan-gce
2019/12/11 04:18 https://github.com/google/ktsan.git kcsan ef798c30ba4e 101194eb .config console log report ci2-upstream-kcsan-gce
2019/12/09 16:38 https://github.com/google/ktsan.git kcsan ef798c30ba4e b31eda3d .config console log report ci2-upstream-kcsan-gce
2019/12/08 05:36 https://github.com/google/ktsan.git kcsan ef798c30ba4e 1508f453 .config console log report ci2-upstream-kcsan-gce
2019/12/06 21:48 https://github.com/google/ktsan.git kcsan ef798c30ba4e 85f26751 .config console log report ci2-upstream-kcsan-gce
2019/12/06 02:27 https://github.com/google/ktsan.git kcsan ef798c30ba4e 98b4ef2d .config console log report ci2-upstream-kcsan-gce
2019/12/05 09:53 https://github.com/google/ktsan.git kcsan ef798c30ba4e b2088328 .config console log report ci2-upstream-kcsan-gce
2019/12/03 07:38 https://github.com/google/ktsan.git kcsan ef798c30ba4e ab342da3 .config console log report ci2-upstream-kcsan-gce
2019/12/02 08:20 https://github.com/google/ktsan.git kcsan ef798c30ba4e f879db37 .config console log report ci2-upstream-kcsan-gce
2019/12/01 07:24 https://github.com/google/ktsan.git kcsan ef798c30ba4e a76bf83f .config console log report ci2-upstream-kcsan-gce
2019/11/30 00:38 https://github.com/google/ktsan.git kcsan ef798c30ba4e 4f7e1d0f .config console log report ci2-upstream-kcsan-gce
2019/11/29 07:03 https://github.com/google/ktsan.git kcsan ef798c30ba4e 76357d6f .config console log report ci2-upstream-kcsan-gce
2019/11/28 13:58 https://github.com/google/ktsan.git kcsan ef798c30ba4e 97264cb1 .config console log report ci2-upstream-kcsan-gce
2019/11/27 18:06 https://github.com/google/ktsan.git kcsan ef798c30ba4e 0d63f89c .config console log report ci2-upstream-kcsan-gce
2019/11/26 23:33 https://github.com/google/ktsan.git kcsan ef798c30ba4e 1048481f .config console log report ci2-upstream-kcsan-gce
2019/11/23 05:09 https://github.com/google/ktsan.git kcsan 5863cc791e4c 598ca6c8 .config console log report ci2-upstream-kcsan-gce
2019/11/23 05:00 https://github.com/google/ktsan.git kcsan 5863cc791e4c 598ca6c8 .config console log report ci2-upstream-kcsan-gce
2019/11/21 02:37 https://github.com/google/ktsan.git kcsan 5863cc791e4c 8098ea0f .config console log report ci2-upstream-kcsan-gce
2019/11/19 10:53 https://github.com/google/ktsan.git kcsan 5863cc791e4c 432c7650 .config console log report ci2-upstream-kcsan-gce
2019/11/18 08:36 https://github.com/google/ktsan.git kcsan 5863cc791e4c d5696d51 .config console log report ci2-upstream-kcsan-gce
2019/11/16 10:13 https://github.com/google/ktsan.git kcsan 5863cc791e4c cdac920b .config console log report ci2-upstream-kcsan-gce
2019/11/12 13:09 https://github.com/google/ktsan.git kcsan 7f2955e0d056 048f2d49 .config console log report ci2-upstream-kcsan-gce
2019/11/10 21:58 https://github.com/google/ktsan.git kcsan 94c006602e13 dc438b91 .config console log report ci2-upstream-kcsan-gce
2019/11/07 15:42 https://github.com/google/ktsan.git kcsan 94c006602e13 f39aff9e .config console log report ci2-upstream-kcsan-gce
2019/11/06 14:40 https://github.com/google/ktsan.git kcsan 94c006602e13 da505f84 .config console log report ci2-upstream-kcsan-gce
2019/11/05 12:55 https://github.com/google/ktsan.git kcsan 94c006602e13 0f3ec414 .config console log report ci2-upstream-kcsan-gce
2019/11/05 00:50 https://github.com/google/ktsan.git kcsan 94c006602e13 76630fc9 .config console log report ci2-upstream-kcsan-gce
2019/11/04 15:10 https://github.com/google/ktsan.git kcsan 94c006602e13 18e12644 .config console log report ci2-upstream-kcsan-gce
2019/11/04 13:08 https://github.com/google/ktsan.git kcsan 05f2236801fe 18e12644 .config console log report ci2-upstream-kcsan-gce
2019/11/03 12:08 https://github.com/google/ktsan.git kcsan 05f2236801fe c9610487 .config console log report ci2-upstream-kcsan-gce
2019/11/03 02:47 https://github.com/google/ktsan.git kcsan 05f2236801fe d603afc9 .config console log report ci2-upstream-kcsan-gce
2019/11/01 20:31 https://github.com/google/ktsan.git kcsan 05f2236801fe 997ccc67 .config console log report ci2-upstream-kcsan-gce
2019/10/30 23:52 https://github.com/google/ktsan.git kcsan 05f2236801fe a41ca8fa .config console log report ci2-upstream-kcsan-gce
2019/10/29 06:24 https://github.com/google/ktsan.git kcsan 05f2236801fe 5ea87a66 .config console log report ci2-upstream-kcsan-gce
2019/10/26 12:13 https://github.com/google/ktsan.git kcsan 05f2236801fe 25bb509e .config console log report ci2-upstream-kcsan-gce
2019/10/26 03:26 https://github.com/google/ktsan.git kcsan 05f2236801fe 413926c5 .config console log report ci2-upstream-kcsan-gce
2019/10/25 12:39 https://github.com/google/ktsan.git kcsan 05f2236801fe 04ca72cd .config console log report ci2-upstream-kcsan-gce
2019/10/24 09:32 https://github.com/google/ktsan.git kcsan 05f2236801fe d01bb02a .config console log report ci2-upstream-kcsan-gce
2019/10/23 07:05 https://github.com/google/ktsan.git kcsan 05f2236801fe d0686497 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.