------------[ cut here ]------------
VFS: brelse: Trying to free free buffer
WARNING: CPU: 1 PID: 4686 at fs/buffer.c:1235 __brelse fs/buffer.c:1235 [inline]
WARNING: CPU: 1 PID: 4686 at fs/buffer.c:1235 __brelse+0x6d/0xb0 fs/buffer.c:1229
Modules linked in:
CPU: 1 PID: 4686 Comm: udevd Not tainted 6.9.0-rc3-syzkaller-00208-g586b5dfb51b9 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:__brelse fs/buffer.c:1235 [inline]
RIP: 0010:__brelse+0x6d/0xb0 fs/buffer.c:1229
Code: 84 d2 75 52 44 8b 63 60 31 ff 44 89 e6 e8 9b 95 81 ff 45 85 e4 75 20 e8 b1 9a 81 ff 90 48 c7 c7 e0 17 1e 8b e8 f4 6e 44 ff 90 <0f> 0b 90 90 5b 5d 41 5c e9 96 9a 81 ff e8 91 9a 81 ff be 04 00 00
RSP: 0018:ffffc90000588f40 EFLAGS: 00010082
RAX: 0000000000000000 RBX: ffff88804f07b570 RCX: ffffffff81512be9
RDX: ffff8880260f2440 RSI: ffffffff81512bf6 RDI: 0000000000000001
RBP: ffff88804f07b5d0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88804f07b570 R14: dffffc0000000000 R15: ffffffff820cbbb0
FS:  00007fb72b918280(0000) GS:ffff88802c300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000f5e81000 CR3: 000000002166c000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 brelse include/linux/buffer_head.h:309 [inline]
 __invalidate_bh_lrus fs/buffer.c:1487 [inline]
 invalidate_bh_lru+0xa2/0x190 fs/buffer.c:1500
 csd_do_func kernel/smp.c:133 [inline]
 __flush_smp_call_function_queue+0x27a/0x8c0 kernel/smp.c:511
 __sysvec_call_function+0x8c/0x410 arch/x86/kernel/smp.c:262
 instr_sysvec_call_function arch/x86/kernel/smp.c:257 [inline]
 sysvec_call_function+0x90/0xb0 arch/x86/kernel/smp.c:257
 </IRQ>
 <TASK>
 asm_sysvec_call_function+0x1a/0x20 arch/x86/include/asm/idtentry.h:710
RIP: 0010:in_gate_area_no_mm+0x19/0x70 arch/x86/entry/vsyscall/vsyscall_64.c:345
Code: 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 41 54 45 31 e4 55 53 48 89 fb e8 dd bc 8d 00 8b 2d 97 27 21 0c <bf> 02 00 00 00 89 ee e8 ab b7 8d 00 83 fd 02 74 29 e8 c1 bc 8d 00
RSP: 0018:ffffc900033b7900 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 00007fb72b5165f4 RCX: ffffffff813caf4c
RDX: ffff8880260f2440 RSI: ffffffff81009923 RDI: 00007fb72b5165f4
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff817a3bd0 R14: ffffc900033b7a30 R15: ffff8880260f2440
 is_kernel_text include/linux/kallsyms.h:31 [inline]
 core_kernel_text kernel/extable.c:68 [inline]
 kernel_text_address+0x35/0x100 kernel/extable.c:99
 __kernel_text_address+0xd/0x40 kernel/extable.c:79
 unwind_get_return_address+0x7c/0xe0 arch/x86/kernel/unwind_orc.c:369
 arch_stack_walk+0xc1/0x170 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:240 [inline]
 __kasan_slab_free+0x11d/0x1a0 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2106 [inline]
 slab_free mm/slub.c:4280 [inline]
 kmem_cache_free+0x12e/0x380 mm/slub.c:4344
 putname+0x12e/0x170 fs/namei.c:273
 vfs_fstatat+0xbd/0x150 fs/stat.c:305
 __do_sys_newfstatat+0x98/0x120 fs/stat.c:468
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb72b5165f4
Code: 64 c7 00 09 00 00 00 83 c8 ff c3 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 00 00 00 00 41 89 ca b8 06 01 00 00 0f 05 <45> 31 c0 3d 00 f0 ff ff 76 10 48 8b 15 03 a8 0d 00 f7 d8 41 83 c8
RSP: 002b:00007ffd56c927e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 00005584f4021540 RCX: 00007fb72b5165f4
RDX: 00007ffd56c927f8 RSI: 00007ffd56c92c88 RDI: 00000000ffffff9c
RBP: 00007ffd56c92888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd56c92c88
R13: 00007ffd56c927f8 R14: 00005584f3ffc910 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess):
   0:	00 90 90 90 90 90    	add    %dl,-0x6f6f6f70(%rax)
   6:	90                   	nop
   7:	90                   	nop
   8:	90                   	nop
   9:	90                   	nop
   a:	90                   	nop
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	66 0f 1f 00          	nopw   (%rax)
  15:	41 54                	push   %r12
  17:	45 31 e4             	xor    %r12d,%r12d
  1a:	55                   	push   %rbp
  1b:	53                   	push   %rbx
  1c:	48 89 fb             	mov    %rdi,%rbx
  1f:	e8 dd bc 8d 00       	call   0x8dbd01
  24:	8b 2d 97 27 21 0c    	mov    0xc212797(%rip),%ebp        # 0xc2127c1
* 2a:	bf 02 00 00 00       	mov    $0x2,%edi <-- trapping instruction
  2f:	89 ee                	mov    %ebp,%esi
  31:	e8 ab b7 8d 00       	call   0x8db7e1
  36:	83 fd 02             	cmp    $0x2,%ebp
  39:	74 29                	je     0x64
  3b:	e8 c1 bc 8d 00       	call   0x8dbd01