Re: [syzbot] [trace?] WARNING in check_buffer

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    69f80fef3153 Merge tag 'ata-7.3-rc7' of git://git.kernel.o..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=1266a715580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=fc812281b37d1115
dashboard link: https://syzkaller.appspot.com/bug?extid=eb74dca0d1eb3ec227a7
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
userspace arch: i386
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1666a715580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+eb74dca0d1eb3ec227a7@xxxxxxxxxxxxxxxxxxxxxxxxx

 0x90: [80897807093] delta:0 TIME EXTEND
 0x98:  [80897807093] delta:0 .
expected end:0xb0 last event actually ended at:0xb0
------------[ cut here ]------------
system_state != SYSTEM_BOOTING
WARNING: kernel/trace/ring_buffer.c:4783 at check_buffer.cold+0x1a2/0x1ef kernel/trace/ring_buffer.c:4783, CPU#2: syz-executor270/6036
Modules linked in:
CPU: 2 UID: 0 PID: 6036 Comm: syz-executor270 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:check_buffer.cold+0x1a2/0x1ef kernel/trace/ring_buffer.c:4783
Code: 03 0f b6 14 11 38 d0 7c 04 84 d2 75 5c 8b 2d cc 17 22 10 31 ff 89 ee e8 9f 78 e8 00 85 ed 0f 84 18 13 eb 00 e8 22 7e e8 00 90 <0f> 0b 90 e9 c3 10 eb 00 49 c7 c7 00 5e f6 8b e9 51 fe ff ff e8 38
RSP: 0000:ffffc900037cf9a0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 1ffff920006f9f3a RCX: 0000000000000002
RDX: ffff888021a98000 RSI: ffffffff812327ce RDI: ffff888021a98000
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000001 R12: 0000000000005c85
R13: ffff88801d6c4000 R14: ffff88801cf70000 R15: ffffffff8bf659a0
FS:  0000000000000000(0000) GS:ffff888096b52000(0063) knlGS:00000000f5e91b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f5e916d8 CR3: 0000000055cc8000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 __rb_reserve_next.constprop.0+0x486/0x1640 kernel/trace/ring_buffer.c:4873
 rb_reserve_next_event kernel/trace/ring_buffer.c:5010 [inline]
 ring_buffer_lock_reserve+0x49a/0x1220 kernel/trace/ring_buffer.c:5069
 __trace_buffer_lock_reserve kernel/trace/trace.h:1677 [inline]
 write_marker_to_buffer+0x88/0x5f0 kernel/trace/trace.c:5936
 tracing_mark_write+0x215/0x3b0 kernel/trace/trace.c:6322
 vfs_write+0x2aa/0x1050 fs/read_write.c:685
 ksys_write+0x1f8/0x250 fs/read_write.c:739
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline]
 do_int80_emulation+0x166/0x650 arch/x86/entry/syscall_32.c:166
 asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:598
RIP: 0023:0xf7ee27eb
Code: 57 56 53 8b 44 24 14 f6 00 08 75 23 8b 44 24 18 8b 5c 24 1c 8b 4c 24 20 8b 54 24 24 8b 74 24 28 8b 7c 24 2c 8b 6c 24 30 cd 80 <5b> 5e 5f 5d c3 5b 5e 5f 5d e9 57 dd ff ff 66 90 66 90 66 90 90 55
RSP: 002b:00000000f5e9161c EFLAGS: 00000246 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 00000000f7f2dde3
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess):
   0:	57                   	push   %rdi
   1:	56                   	push   %rsi
   2:	53                   	push   %rbx
   3:	8b 44 24 14          	mov    0x14(%rsp),%eax
   7:	f6 00 08             	testb  $0x8,(%rax)
   a:	75 23                	jne    0x2f
   c:	8b 44 24 18          	mov    0x18(%rsp),%eax
  10:	8b 5c 24 1c          	mov    0x1c(%rsp),%ebx
  14:	8b 4c 24 20          	mov    0x20(%rsp),%ecx
  18:	8b 54 24 24          	mov    0x24(%rsp),%edx
  1c:	8b 74 24 28          	mov    0x28(%rsp),%esi
  20:	8b 7c 24 2c          	mov    0x2c(%rsp),%edi
  24:	8b 6c 24 30          	mov    0x30(%rsp),%ebp
  28:	cd 80                	int    $0x80
* 2a:	5b                   	pop    %rbx <-- trapping instruction
  2b:	5e                   	pop    %rsi
  2c:	5f                   	pop    %rdi
  2d:	5d                   	pop    %rbp
  2e:	c3                   	ret
  2f:	5b                   	pop    %rbx
  30:	5e                   	pop    %rsi
  31:	5f                   	pop    %rdi
  32:	5d                   	pop    %rbp
  33:	e9 57 dd ff ff       	jmp    0xffffdd8f
  38:	66 90                	xchg   %ax,%ax
  3a:	66 90                	xchg   %ax,%ax
  3c:	66 90                	xchg   %ax,%ax
  3e:	90                   	nop
  3f:	55                   	push   %rbp


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