bisecting fixing commit since 234d53d2bb60a9436a6d4d55bef1712613b79014
building syzkaller on c1132b49314d96788d6467f64e567faa31e8e063
testing commit 234d53d2bb60a9436a6d4d55bef1712613b79014
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: ee8a379bf5d6b07ca522284f49f8f8069818914a55fd0b74372e3bfc1be01cf7
all runs: crashed: general protection fault in del_gendisk
testing current HEAD 0347b16583990db22fff7b3faa6a9aacf4c7cbac
testing commit 0347b16583990db22fff7b3faa6a9aacf4c7cbac
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: 7086ce6671cab9eb8c633da90a43b1d2ca46df035878b9c50deba728869ce55f
all runs: crashed: general protection fault in del_gendisk
revisions tested: 2, total time: 20m33.906995361s (build: 14m7.007264704s, test: 5m34.860061287s)
the crash still happens on HEAD
commit msg: Merge 5.10.93 into android12-5.10-lts
crash: general protection fault in del_gendisk
RBP: 00007f5da2cefe8f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc0276374f R14: 00007f5da2c0c300 R15: 0000000000022000
---[ end trace f307833f6866bf99 ]---
general protection fault, probably for non-canonical address 0xdffffc000000001a: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000000d0-0x00000000000000d7]
CPU: 0 PID: 441 Comm: syz-executor.0 Tainted: G        W         5.10.93-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:kill_device drivers/base/core.c:3355 [inline]
RIP: 0010:device_del+0xe3/0xd00 drivers/base/core.c:3383
Code: c1 ea 03 80 3c 02 00 0f 85 c6 0a 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 63 68 49 8d bc 24 d0 00 00 00 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 06 0f 8e a7 09 00 00 41 0f b6 84 24 d0 00 00
RSP: 0018:ffffc90000a97ca0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff88810ec70068 RCX: ffffffff8420bec9
RDX: 000000000000001a RSI: 0000000000000008 RDI: 00000000000000d0
RBP: ffffc90000a97d58 R08: 0000000000000001 R09: ffffc90000a97c3f
R10: fffff52000152f87 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88810ec70108 R14: fffffbfff0c8b888 R15: 0000000000000008
FS:  00007f5da2c0c700(0000) GS:ffff8881f7200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5da2beb718 CR3: 00000001216fc000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 del_gendisk+0x5ef/0xa10 block/genhd.c:953
 loop_remove drivers/block/loop.c:2185 [inline]
 loop_control_ioctl drivers/block/loop.c:2284 [inline]
 loop_control_ioctl+0x30d/0x3d0 drivers/block/loop.c:2250
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x129/0x1a0 fs/ioctl.c:739
 do_syscall_64+0x32/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f5da2c95a39
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5da2c0c188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f5da2d98f60 RCX: 00007f5da2c95a39
RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003
RBP: 00007f5da2cefe8f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc0276374f R14: 00007f5da2c0c300 R15: 0000000000022000
Modules linked in:
---[ end trace f307833f6866bf9a ]---
RIP: 0010:kill_device drivers/base/core.c:3355 [inline]
RIP: 0010:device_del+0xe3/0xd00 drivers/base/core.c:3383
Code: c1 ea 03 80 3c 02 00 0f 85 c6 0a 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 63 68 49 8d bc 24 d0 00 00 00 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 06 0f 8e a7 09 00 00 41 0f b6 84 24 d0 00 00
RSP: 0018:ffffc90000a97ca0 EFLAGS: 00010202

RAX: dffffc0000000000 RBX: ffff88810ec70068 RCX: ffffffff8420bec9
RDX: 000000000000001a RSI: 0000000000000008 RDI: 00000000000000d0
RBP: ffffc90000a97d58 R08: 0000000000000001 R09: ffffc90000a97c3f
R10: fffff52000152f87 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88810ec70108 R14: fffffbfff0c8b888 R15: 0000000000000008
FS:  00007f5da2c0c700(0000) GS:ffff8881f7200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5da2beb718 CR3: 00000001216fc000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	c1 ea 03             	shr    $0x3,%edx
   3:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   7:	0f 85 c6 0a 00 00    	jne    0xad3
   d:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  14:	fc ff df
  17:	4c 8b 63 68          	mov    0x68(%rbx),%r12
  1b:	49 8d bc 24 d0 00 00 	lea    0xd0(%r12),%rdi
  22:	00
  23:	48 89 fa             	mov    %rdi,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	0f b6 04 02          	movzbl (%rdx,%rax,1),%eax <-- trapping instruction
  2e:	84 c0                	test   %al,%al
  30:	74 06                	je     0x38
  32:	0f 8e a7 09 00 00    	jle    0x9df
  38:	41                   	rex.B
  39:	0f                   	.byte 0xf
  3a:	b6 84                	mov    $0x84,%dh
  3c:	24 d0                	and    $0xd0,%al