------------[ cut here ]------------
VFS: brelse: Trying to free free buffer
WARNING: CPU: 0 PID: 7951 at fs/buffer.c:1229 __brelse fs/buffer.c:1229 [inline]
WARNING: CPU: 0 PID: 7951 at fs/buffer.c:1229 __brelse+0x6d/0xb0 fs/buffer.c:1223
Modules linked in:
CPU: 0 UID: 0 PID: 7951 Comm: syz.5.671 Not tainted 6.13.0-rc5-syzkaller-00161-g63676eefb7a0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:__brelse fs/buffer.c:1229 [inline]
RIP: 0010:__brelse+0x6d/0xb0 fs/buffer.c:1223
Code: 84 d2 75 52 44 8b 63 60 31 ff 44 89 e6 e8 fb d5 79 ff 45 85 e4 75 20 e8 b1 d3 79 ff 90 48 c7 c7 e0 24 7f 8b e8 c4 0d 3a ff 90 <0f> 0b 90 90 5b 5d 41 5c e9 96 d3 79 ff e8 91 d3 79 ff be 04 00 00
RSP: 0018:ffffc90000007f40 EFLAGS: 00010082
RAX: 0000000000000000 RBX: ffff888054c6c740 RCX: ffffffff815a5139
RDX: ffff88805761da00 RSI: ffffffff815a5146 RDI: 0000000000000001
RBP: ffff888054c6c7a0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff888054c6c740 R14: dffffc0000000000 R15: ffffffff82204230
FS:  00007f3a2b0f46c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffca8c96fc0 CR3: 0000000079cf6000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 brelse include/linux/buffer_head.h:324 [inline]
 __invalidate_bh_lrus fs/buffer.c:1498 [inline]
 invalidate_bh_lru+0xa2/0x190 fs/buffer.c:1511
 csd_do_func kernel/smp.c:134 [inline]
 __flush_smp_call_function_queue+0x27d/0x8c0 kernel/smp.c:540
 __sysvec_call_function_single+0x8c/0x410 arch/x86/kernel/smp.c:271
 instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline]
 sysvec_call_function_single+0x9f/0xc0 arch/x86/kernel/smp.c:266
 </IRQ>
 <TASK>
 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:709
RIP: 0010:__might_sleep+0x33/0x170 kernel/sched/core.c:8675
Code: 00 00 fc ff df 41 54 65 4c 8b 25 38 b5 9b 7e 55 89 f5 53 48 89 fb 49 8d 7c 24 18 48 83 ec 10 48 89 fa 48 c1 ea 03 0f b6 14 02 <48> 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 d8 00 00 00 41
RSP: 0018:ffffc90002fc7a08 EFLAGS: 00000212
RAX: dffffc0000000000 RBX: ffffffff8bd18e00 RCX: ffffc9000e50f000
RDX: 0000000000000000 RSI: 00000000000000a2 RDI: ffff88805761da18
RBP: 00000000000000a2 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88805761da00
R13: ffffc90002fc7aa8 R14: ffffc90002fc7b90 R15: ffffc90002fc7aa8
 __might_fault+0x83/0x190 mm/memory.c:6748
 _inline_copy_from_user include/linux/uaccess.h:162 [inline]
 _copy_from_user+0x29/0xd0 lib/usercopy.c:18
 copy_from_user include/linux/uaccess.h:212 [inline]
 copy_msghdr_from_user+0x99/0x160 net/socket.c:2513
 recvmsg_copy_msghdr net/socket.c:2769 [inline]
 ___sys_recvmsg+0xdc/0x1a0 net/socket.c:2841
 do_recvmmsg+0x2f8/0x740 net/socket.c:2940
 __sys_recvmmsg net/socket.c:3014 [inline]
 __do_sys_recvmmsg net/socket.c:3037 [inline]
 __se_sys_recvmmsg net/socket.c:3030 [inline]
 __x64_sys_recvmmsg+0x239/0x290 net/socket.c:3030
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3a2a385d29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3a2b0f4038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f3a2a576080 RCX: 00007f3a2a385d29
RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000006
RBP: 00007f3a2a401b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f3a2a576080 R15: 00007ffd1a90fc08
 </TASK>
----------------
Code disassembly (best guess), 4 bytes skipped:
   0:	df 41 54             	filds  0x54(%rcx)
   3:	65 4c 8b 25 38 b5 9b 	mov    %gs:0x7e9bb538(%rip),%r12        # 0x7e9bb543
   a:	7e
   b:	55                   	push   %rbp
   c:	89 f5                	mov    %esi,%ebp
   e:	53                   	push   %rbx
   f:	48 89 fb             	mov    %rdi,%rbx
  12:	49 8d 7c 24 18       	lea    0x18(%r12),%rdi
  17:	48 83 ec 10          	sub    $0x10,%rsp
  1b:	48 89 fa             	mov    %rdi,%rdx
  1e:	48 c1 ea 03          	shr    $0x3,%rdx
  22:	0f b6 14 02          	movzbl (%rdx,%rax,1),%edx
* 26:	48 89 f8             	mov    %rdi,%rax <-- trapping instruction
  29:	83 e0 07             	and    $0x7,%eax
  2c:	83 c0 03             	add    $0x3,%eax
  2f:	38 d0                	cmp    %dl,%al
  31:	7c 08                	jl     0x3b
  33:	84 d2                	test   %dl,%dl
  35:	0f 85 d8 00 00 00    	jne    0x113
  3b:	41                   	rex.B