syzbot


KCSAN: data-race in tcp_add_backlog / tcp_rcv_space_adjust (2)

Status: fixed on 2019/11/04 14:50
Subsystems: net
[Documentation on labels]
Fix commit: ebb3b78db7bf tcp: annotate sk->sk_rcvbuf lockless reads
First crash: 1743d, last: 1736d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in tcp_add_backlog / tcp_rcv_space_adjust net 18 1744d 1753d 0/27 closed as invalid on 2019/10/15 15:50

Sample crash report:
==================================================================
BUG: KCSAN: data-race in tcp_add_backlog / tcp_rcv_space_adjust

read to 0xffff88811eedb30c of 4 bytes by interrupt on cpu 1:
 tcp_add_backlog+0x43/0xcc0 net/ipv4/tcp_ipv4.c:1647
 tcp_v4_rcv+0x1a60/0x1bb0 net/ipv4/tcp_ipv4.c:1944
 ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204
 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:442 [inline]
 ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523
 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010
 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5124
 netif_receive_skb_internal+0x59/0x190 net/core/dev.c:5214
 napi_skb_finish net/core/dev.c:5677 [inline]
 napi_gro_receive+0x28f/0x330 net/core/dev.c:5710
 receive_buf+0x284/0x30b0 drivers/net/virtio_net.c:1061
 virtnet_receive drivers/net/virtio_net.c:1323 [inline]
 virtnet_poll+0x436/0x7d0 drivers/net/virtio_net.c:1428
 napi_poll net/core/dev.c:6392 [inline]
 net_rx_action+0x3ae/0xa90 net/core/dev.c:6460

write to 0xffff88811eedb30c of 4 bytes by task 7232 on cpu 0:
 tcp_rcv_space_adjust+0x40f/0x4c0 net/ipv4/tcp_input.c:651
 tcp_recvmsg+0xdaa/0x1a30 net/ipv4/tcp.c:2146
 inet_recvmsg+0xbb/0x250 net/ipv4/af_inet.c:838
 sock_recvmsg_nosec net/socket.c:871 [inline]
 sock_recvmsg net/socket.c:889 [inline]
 sock_recvmsg+0x92/0xb0 net/socket.c:885
 sock_read_iter+0x15f/0x1e0 net/socket.c:967
 call_read_iter include/linux/fs.h:1889 [inline]
 new_sync_read+0x389/0x4f0 fs/read_write.c:414
 __vfs_read+0xb1/0xc0 fs/read_write.c:427
 vfs_read fs/read_write.c:461 [inline]
 vfs_read+0x143/0x2c0 fs/read_write.c:446
 ksys_read+0xd5/0x1b0 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read fs/read_write.c:595 [inline]
 __x64_sys_read+0x4c/0x60 fs/read_write.c:595
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7232 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (18):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/10/22 23:08 https://github.com/google/ktsan.git kcsan 05f2236801fe 4ee855e7 .config console log report ci2-upstream-kcsan-gce
2019/10/22 19:47 https://github.com/google/ktsan.git kcsan 05f2236801fe 4ee855e7 .config console log report ci2-upstream-kcsan-gce
2019/10/22 15:01 https://github.com/google/ktsan.git kcsan 05f2236801fe 4ee855e7 .config console log report ci2-upstream-kcsan-gce
2019/10/22 02:42 https://github.com/google/ktsan.git kcsan 05f2236801fe c59a7cd8 .config console log report ci2-upstream-kcsan-gce
2019/10/21 00:12 https://github.com/google/ktsan.git kcsan 05f2236801fe 8c88c9c1 .config console log report ci2-upstream-kcsan-gce
2019/10/20 19:55 https://github.com/google/ktsan.git kcsan 05f2236801fe 8c88c9c1 .config console log report ci2-upstream-kcsan-gce
2019/10/20 16:24 https://github.com/google/ktsan.git kcsan 05f2236801fe 8c88c9c1 .config console log report ci2-upstream-kcsan-gce
2019/10/20 05:38 https://github.com/google/ktsan.git kcsan 05f2236801fe 8c88c9c1 .config console log report ci2-upstream-kcsan-gce
2019/10/19 11:22 https://github.com/google/ktsan.git kcsan 05f2236801fe 8c88c9c1 .config console log report ci2-upstream-kcsan-gce
2019/10/19 09:01 https://github.com/google/ktsan.git kcsan 05f2236801fe 8c88c9c1 .config console log report ci2-upstream-kcsan-gce
2019/10/19 02:32 https://github.com/google/ktsan.git kcsan 05f2236801fe 8c88c9c1 .config console log report ci2-upstream-kcsan-gce
2019/10/18 16:19 https://github.com/google/ktsan.git kcsan 05f2236801fe 8c88c9c1 .config console log report ci2-upstream-kcsan-gce
2019/10/18 08:15 https://github.com/google/ktsan.git kcsan 05f2236801fe 8c88c9c1 .config console log report ci2-upstream-kcsan-gce
2019/10/17 17:43 https://github.com/google/ktsan.git kcsan 05f2236801fe 8c88c9c1 .config console log report ci2-upstream-kcsan-gce
2019/10/17 07:50 https://github.com/google/ktsan.git kcsan a6311db074d9 8c88c9c1 .config console log report ci2-upstream-kcsan-gce
2019/10/17 00:51 https://github.com/google/ktsan.git kcsan a6311db074d9 8c88c9c1 .config console log report ci2-upstream-kcsan-gce
2019/10/16 22:24 https://github.com/google/ktsan.git kcsan a6311db074d9 8c88c9c1 .config console log report ci2-upstream-kcsan-gce
2019/10/16 03:50 https://github.com/google/ktsan.git kcsan e3d315561216 d4ea592f .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.