syzbot


divide error in tcp_reno_cong_avoid

Status: auto-obsoleted due to no activity on 2022/10/10 12:05
Subsystems: net
[Documentation on labels]
First crash: 1212d, last: 882d
Cause bisection: introduced by (bisect log) [no-op commit]:
commit da382875c616856b234790206fc80d51f66b3bc7
Author: Jiri Pirko <jiri@mellanox.com>
Date: Wed Aug 7 10:42:31 2019 +0000

  mlxsw: spectrum: Extend to support Spectrum-3 ASIC

Crash: divide error in tcp_reno_cong_avoid (log)
Repro: C syz .config
  
Fix bisection: failed (error log, bisect log)
  
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 divide error in tcp_reno_cong_avoid C error 1 745d 1146d 0/1 upstream: reported C repro on 2021/07/25 10:44
linux-4.19 divide error in tcp_reno_cong_avoid C error 1 1093d 1183d 0/1 upstream: reported C repro on 2021/06/18 06:10
Last patch testing requests (4)
Created Duration User Patch Repo Result
2022/10/10 07:30 19m retest repro upstream OK log
2022/10/09 20:30 17m retest repro upstream OK log
2022/10/02 03:30 18m retest repro upstream OK log
2022/09/23 06:30 19m retest repro upstream OK log
Fix bisection attempts (6)
Created Duration User Patch Repo Result
2022/03/18 23:38 10m bisect fix upstream error job log
2021/12/31 05:54 21m bisect fix upstream OK (0) job log log
2021/10/01 10:20 20m bisect fix upstream OK (0) job log log
2021/08/31 19:33 20m bisect fix upstream OK (0) job log log
2021/07/24 07:10 21m bisect fix upstream OK (0) job log log
2021/06/24 06:48 21m bisect fix upstream OK (0) job log log

Sample crash report:
divide error: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 3614 Comm: syz-executor380 Not tainted 5.17.0-rc8-syzkaller-00072-g97e9c8eb4bb1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:tcp_cong_avoid_ai net/ipv4/tcp_cong.c:420 [inline]
RIP: 0010:tcp_reno_cong_avoid+0x288/0x310 net/ipv4/tcp_cong.c:450
Code: ab 80 09 00 00 e8 18 76 bb f9 45 85 e4 0f 85 aa fe ff ff 5b 5d 41 5c 41 5d 41 5e e9 62 74 bb f9 e8 5d 74 bb f9 44 89 e0 31 d2 <f7> f5 41 01 c5 89 93 84 09 00 00 44 89 ab 80 09 00 00 e9 fb fe ff
RSP: 0018:ffffc900027876b0 EFLAGS: 00010246
RAX: 0000000000000011 RBX: ffff8880736a20c0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff87bc8133 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff87bc8035 R11: 0000000000000000 R12: 0000000000000011
R13: 0000000000000001 R14: 00000000ffffffff R15: ffff8880736a2a40
FS:  0000555556ccf300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020102000 CR3: 000000001d16d000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 tcp_cdg_cong_avoid+0x5d6/0x1600 net/ipv4/tcp_cdg.c:293
 tcp_cong_avoid net/ipv4/tcp_input.c:3133 [inline]
 tcp_cong_control net/ipv4/tcp_input.c:3490 [inline]
 tcp_ack+0x3766/0x5900 net/ipv4/tcp_input.c:3891
 tcp_rcv_established+0x5d9/0x1ff0 net/ipv4/tcp_input.c:5938
 tcp_v4_do_rcv+0x65e/0x980 net/ipv4/tcp_ipv4.c:1719
 sk_backlog_rcv include/net/sock.h:1037 [inline]
 __release_sock+0x134/0x3b0 net/core/sock.c:2779
 __sk_flush_backlog+0x22/0x30 net/core/sock.c:2799
 sk_flush_backlog include/net/sock.h:1127 [inline]
 tcp_sendmsg_locked+0x2836/0x2e20 net/ipv4/tcp.c:1294
 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1449
 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:725
 __sys_sendto+0x21c/0x320 net/socket.c:2040
 __do_sys_sendto net/socket.c:2052 [inline]
 __se_sys_sendto net/socket.c:2048 [inline]
 __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2048
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f7069a8c559
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 15 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd628436b8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f7069a8c559
RDX: 00000000fffffd46 RSI: 0000000020000240 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000001f4
R10: 00000000000081f4 R11: 0000000000000246 R12: 00007ffd628436e0
R13: 00007ffd628436f0 R14: 000000000000caaa R15: 00007ffd628436d0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:tcp_cong_avoid_ai net/ipv4/tcp_cong.c:420 [inline]
RIP: 0010:tcp_reno_cong_avoid+0x288/0x310 net/ipv4/tcp_cong.c:450
Code: ab 80 09 00 00 e8 18 76 bb f9 45 85 e4 0f 85 aa fe ff ff 5b 5d 41 5c 41 5d 41 5e e9 62 74 bb f9 e8 5d 74 bb f9 44 89 e0 31 d2 <f7> f5 41 01 c5 89 93 84 09 00 00 44 89 ab 80 09 00 00 e9 fb fe ff
RSP: 0018:ffffc900027876b0 EFLAGS: 00010246
RAX: 0000000000000011 RBX: ffff8880736a20c0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff87bc8133 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff87bc8035 R11: 0000000000000000 R12: 0000000000000011
R13: 0000000000000001 R14: 00000000ffffffff R15: ffff8880736a2a40
FS:  0000555556ccf300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7069b0f110 CR3: 000000001d16d000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	ab                   	stos   %eax,%es:(%rdi)
   1:	80 09 00             	orb    $0x0,(%rcx)
   4:	00 e8                	add    %ch,%al
   6:	18 76 bb             	sbb    %dh,-0x45(%rsi)
   9:	f9                   	stc
   a:	45 85 e4             	test   %r12d,%r12d
   d:	0f 85 aa fe ff ff    	jne    0xfffffebd
  13:	5b                   	pop    %rbx
  14:	5d                   	pop    %rbp
  15:	41 5c                	pop    %r12
  17:	41 5d                	pop    %r13
  19:	41 5e                	pop    %r14
  1b:	e9 62 74 bb f9       	jmpq   0xf9bb7482
  20:	e8 5d 74 bb f9       	callq  0xf9bb7482
  25:	44 89 e0             	mov    %r12d,%eax
  28:	31 d2                	xor    %edx,%edx
* 2a:	f7 f5                	div    %ebp <-- trapping instruction
  2c:	41 01 c5             	add    %eax,%r13d
  2f:	89 93 84 09 00 00    	mov    %edx,0x984(%rbx)
  35:	44 89 ab 80 09 00 00 	mov    %r13d,0x980(%rbx)
  3c:	e9                   	.byte 0xe9
  3d:	fb                   	sti
  3e:	fe                   	(bad)
  3f:	ff                   	.byte 0xff

Crashes (15):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/03/20 02:53 upstream 97e9c8eb4bb1 e2d91b1d .config console log report syz C ci-upstream-kasan-gce-selinux-root divide error in tcp_reno_cong_avoid
2022/02/16 15:44 upstream c5d9ae265b10 8b9ca619 .config console log report syz C ci-upstream-kasan-gce-smack-root divide error in tcp_reno_cong_avoid
2021/08/01 10:25 upstream f3438b4c4e69 6c236867 .config console log report syz C ci-upstream-kasan-gce divide error in tcp_reno_cong_avoid
2021/05/25 06:48 upstream 1434a3127887 3c7fef33 .config console log report syz C ci-upstream-kasan-gce-smack-root divide error in tcp_reno_cong_avoid
2022/04/14 22:30 upstream b9b4c79e5830 b17b2923 .config console log report info ci-qemu-upstream divide error in tcp_reno_cong_avoid
2022/01/29 08:57 upstream df0001545b27 495e00c5 .config console log report info ci-upstream-kasan-gce divide error in tcp_reno_cong_avoid
2021/12/01 00:44 upstream 58e1100fdc59 80270552 .config console log report info ci-qemu-upstream divide error in tcp_reno_cong_avoid
2021/11/25 05:51 upstream 5f53fa508db0 545ab074 .config console log report info ci-upstream-kasan-gce divide error in tcp_reno_cong_avoid
2021/11/16 23:01 upstream 8ab774587903 cafff8b6 .config console log report info ci-upstream-kasan-gce divide error in tcp_reno_cong_avoid
2021/11/12 22:04 upstream 7246f4dcaccc 83f5c9b5 .config console log report info ci-upstream-kasan-gce-smack-root divide error in tcp_reno_cong_avoid
2021/11/06 16:08 upstream fe91c4725aee 4c1be0be .config console log report info ci-upstream-kasan-gce divide error in tcp_reno_cong_avoid
2021/10/22 11:05 upstream 2f111a6fd5b5 55f90bc6 .config console log report info ci-upstream-kasan-gce divide error in tcp_reno_cong_avoid
2021/07/25 11:29 upstream 6498f6151825 4d1b57d4 .config console log report info ci-upstream-kasan-gce-smack-root divide error in tcp_reno_cong_avoid
2021/05/25 04:03 upstream 1434a3127887 3c7fef33 .config console log report info ci-upstream-kasan-gce-smack-root divide error in tcp_reno_cong_avoid
2021/05/20 13:56 upstream c3d0e3fd41b7 c560a65d .config console log report info ci-upstream-kasan-gce-386 divide error in tcp_reno_cong_avoid
* Struck through repros no longer work on HEAD.