syzbot

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VFS: brelse: Trying to free free buffer
WARNING: CPU: 0 PID: 3603 at fs/buffer.c:1145 __brelse fs/buffer.c:1145 [inline]
WARNING: CPU: 0 PID: 3603 at fs/buffer.c:1145 brelse include/linux/buffer_head.h:326 [inline]
WARNING: CPU: 0 PID: 3603 at fs/buffer.c:1145 __invalidate_bh_lrus fs/buffer.c:1380 [inline]
WARNING: CPU: 0 PID: 3603 at fs/buffer.c:1145 invalidate_bh_lru+0xf8/0x1a0 fs/buffer.c:1393
Modules linked in:
CPU: 0 PID: 3603 Comm: syslogd Not tainted 6.1.118-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
RIP: 0010:__brelse fs/buffer.c:1145 [inline]
RIP: 0010:brelse include/linux/buffer_head.h:326 [inline]
RIP: 0010:__invalidate_bh_lrus fs/buffer.c:1380 [inline]
RIP: 0010:invalidate_bh_lru+0xf8/0x1a0 fs/buffer.c:1393
Code: 00 e8 bc 8e e0 ff f0 ff 0b eb 21 e8 b2 09 89 ff 41 80 3c 2e 00 75 26 eb 2c e8 a4 09 89 ff 48 c7 c7 a0 0d 1a 8b e8 a8 23 51 ff <0f> 0b 48 bd 00 00 00 00 00 fc ff df 41 80 3c 2e 00 74 08 4c 89 ff
RSP: 0018:ffffc90000007f38 EFLAGS: 00010046
RAX: ccdd1403be6a4200 RBX: ffff88807176b318 RCX: ffff88807d211dc0
RDX: 0000000000010000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff8152a88e R09: fffff52000000f49
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880b8e368f8
R13: 0000000000000000 R14: 1ffff110171c6d1f R15: ffff8880b8e368f8
FS:  00007f69623b8380(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe7e16ecb8 CR3: 00000000312c5000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __flush_smp_call_function_queue+0x2d9/0xd00 kernel/smp.c:641
 __sysvec_call_function_single+0xbb/0x360 arch/x86/kernel/smp.c:267
 instr_sysvec_call_function_single arch/x86/kernel/smp.c:262 [inline]
 sysvec_call_function_single+0x98/0xc0 arch/x86/kernel/smp.c:262
 </IRQ>
 <TASK>
 asm_sysvec_call_function_single+0x16/0x20 arch/x86/include/asm/idtentry.h:699
RIP: 0010:check_canary_byte mm/kfence/core.c:314 [inline]
RIP: 0010:for_each_canary mm/kfence/core.c:344 [inline]
RIP: 0010:kfence_guarded_free+0x2ca/0x7f0 mm/kfence/core.c:499
Code: dc 49 81 e4 00 f0 ff ff 4c 89 e7 48 89 de e8 4d 65 a8 ff 49 39 dc 73 70 4d 89 e6 4c 89 f0 48 c1 e8 03 0f b6 04 28 84 c0 75 4a <41> 0f b6 2e 44 89 f3 83 e3 07 81 f3 aa 00 00 00 89 df 89 ee e8 9d
RSP: 0018:ffffc9000324f930 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00000000000000a9 RCX: ffff88807d211dc0
RDX: 0000000000000000 RSI: 00000000000000a9 RDI: 00000000000000a9
RBP: dffffc0000000000 R08: ffffffff81e228b3 R09: fffffbfff2e7fb20
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88823bdcc000
R13: 1ffffffff2e7c4d2 R14: ffff88823bdcc5a4 R15: ffffffff973e2690
 __unix_dgram_recvmsg+0xcb3/0x1260 net/unix/af_unix.c:2507
 sock_recvmsg_nosec net/socket.c:1022 [inline]
 sock_recvmsg net/socket.c:1040 [inline]
 sock_read_iter+0x3b2/0x4b0 net/socket.c:1121
 call_read_iter include/linux/fs.h:2259 [inline]
 new_sync_read fs/read_write.c:389 [inline]
 vfs_read+0x88d/0xbf0 fs/read_write.c:470
 ksys_read+0x19c/0x2c0 fs/read_write.c:613
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f696250cb6a
Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffe9eff95f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f696250cb6a
RDX: 00000000000000ff RSI: 000055d4eeb9f950 RDI: 0000000000000000
RBP: 000055d4eeb9f910 R08: 0000000000000001 R09: 0000000000000000
R10: 00007f69626ab3a3 R11: 0000000000000246 R12: 000055d4eeb9f9a0
R13: 000055d4eeb9f950 R14: 0000000000000000 R15: 00007f69626e9a80
 </TASK>
----------------
Code disassembly (best guess):
   0:	dc 49 81             	fmull  -0x7f(%rcx)
   3:	e4 00                	in     $0x0,%al
   5:	f0 ff                	lock (bad)
   7:	ff 4c 89 e7          	decl   -0x19(%rcx,%rcx,4)
   b:	48 89 de             	mov    %rbx,%rsi
   e:	e8 4d 65 a8 ff       	call   0xffa86560
  13:	49 39 dc             	cmp    %rbx,%r12
  16:	73 70                	jae    0x88
  18:	4d 89 e6             	mov    %r12,%r14
  1b:	4c 89 f0             	mov    %r14,%rax
  1e:	48 c1 e8 03          	shr    $0x3,%rax
  22:	0f b6 04 28          	movzbl (%rax,%rbp,1),%eax
  26:	84 c0                	test   %al,%al
  28:	75 4a                	jne    0x74
* 2a:	41 0f b6 2e          	movzbl (%r14),%ebp <-- trapping instruction
  2e:	44 89 f3             	mov    %r14d,%ebx
  31:	83 e3 07             	and    $0x7,%ebx
  34:	81 f3 aa 00 00 00    	xor    $0xaa,%ebx
  3a:	89 df                	mov    %ebx,%edi
  3c:	89 ee                	mov    %ebp,%esi
  3e:	e8                   	.byte 0xe8
  3f:	9d                   	popf