syzbot


WARNING in syscall_exit_to_user_mode

Status: fixed on 2020/11/16 12:12
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+7ffc7214b893651d52b8@syzkaller.appspotmail.com
Fix commit: a49145acfb97 fbmem: add margin check to fb_check_caps()
First crash: 1384d, last: 1352d
Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: WARNING in sysfs_warn_dup (log)
Repro: C syz .config
  
Fix bisection: fixed by (bisect log) :
commit a49145acfb975d921464b84fe00279f99827d816
Author: George Kennedy <george.kennedy@oracle.com>
Date: Tue Jul 7 19:26:03 2020 +0000

  fbmem: add margin check to fb_check_caps()

  
Discussions (1)
Title Replies (including bot) Last reply
WARNING in syscall_exit_to_user_mode 6 (8) 2020/11/11 11:11
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2020/11/08 14:34 2h46m bisect fix upstream job log (1)
2020/10/09 14:14 16m bisect fix upstream job log (0) log

Sample crash report:
------------[ cut here ]------------
syscall 56 left IRQs disabled
WARNING: CPU: 1 PID: 31467 at kernel/entry/common.c:245 syscall_exit_to_user_mode_prepare kernel/entry/common.c:245 [inline]
WARNING: CPU: 1 PID: 31467 at kernel/entry/common.c:245 syscall_exit_to_user_mode+0xc1/0x2e0 kernel/entry/common.c:263
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 31467 Comm: syz-executor465 Not tainted 5.9.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x198/0x1fd lib/dump_stack.c:118
 panic+0x347/0x7c0 kernel/panic.c:231
 __warn.cold+0x20/0x46 kernel/panic.c:600
 report_bug+0x1bd/0x210 lib/bug.c:198
 handle_bug+0x38/0x90 arch/x86/kernel/traps.c:234
 exc_invalid_op+0x14/0x40 arch/x86/kernel/traps.c:254
 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536
RIP: 0010:syscall_exit_to_user_mode_prepare kernel/entry/common.c:245 [inline]
RIP: 0010:syscall_exit_to_user_mode+0xc1/0x2e0 kernel/entry/common.c:263
Code: 58 00 48 8b 7c 24 20 5b 5d 41 5c 41 5d e9 97 f7 ff ff e8 72 88 85 f9 eb c6 0f 0b 48 63 f6 48 c7 c7 50 a9 6a 89 e8 61 c8 50 f9 <0f> 0b e8 b8 8e 85 f9 48 83 3d 28 b6 c1 01 00 0f 84 7d 01 00 00 fb
RSP: 0018:ffffc90003f27f30 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000004000 RCX: 0000000000000000
RDX: ffff8880a2ec6480 RSI: ffffffff815db9a7 RDI: fffff520007e4fd8
RBP: ffffc90003f27f58 R08: 0000000000000000 R09: ffffffff89bcb4a3
R10: 00000000000007db R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:287
RIP: 0033:0x44da49
Code: ff 48 85 f6 0f 84 a7 dc fb ff 48 83 ee 10 48 89 4e 08 48 89 3e 48 89 d7 4c 89 c2 4d 89 c8 4c 8b 54 24 08 b8 38 00 00 00 0f 05 <48> 85 c0 0f 8c 7e dc fb ff 74 01 c3 31 ed 48 f7 c7 00 00 01 00 75
RSP: 002b:00007f7349191db0 EFLAGS: 00000202 ORIG_RAX: 0000000000000038
RAX: 0000000000000000 RBX: 00007f7349192700 RCX: 000000000044da49
RDX: 00007f73491929d0 RSI: 00007f7349191db0 RDI: 00000000003d0f00
RBP: 00007ffe9e518280 R08: 00007f7349192700 R09: 00007f7349192700
R10: 00007f73491929d0 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ffe9e5181df R14: 00007f73491929c0 R15: 20c49ba5e353f7cf
Kernel Offset: disabled

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/09/07 10:35 upstream f4d51dffc6c0 abf9ba4f .config console log report syz C ci-upstream-kasan-gce-root
* Struck through repros no longer work on HEAD.