general protection fault in del_gendisk (5)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: fa7f6a5f56d9 Merge branch 'android12-5.10' into branch 'an..
git tree: android12-5.10-lts
console+strace: https://syzkaller.appspot.com/x/log.txt?x=17da04b2080000
kernel config: https://syzkaller.appspot.com/x/.config?x=30bf844d1a89de15
dashboard link: https://syzkaller.appspot.com/bug?extid=8fe1ba2605ff4383aca1
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1767ef34080000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13229782080000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8fe1ba...@syzkaller.appspotmail.com

RBP: 00007ffe5b36fd00 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000004
R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000
---[ end trace ab9e6fe86789591c ]---
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: 376 Comm: syz-executor330 Tainted: G W 5.10.118-syzkaller-00163-gfa7f6a5f56d9 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
RIP: 0010:kill_device drivers/base/core.c:3361 [inline]
RIP: 0010:device_del+0xdf/0xf00 drivers/base/core.c:3389
Code: 20 42 80 3c 28 00 74 08 48 89 df e8 9b 16 df fe 4c 89 7c 24 48 41 bf d0 00 00 00 48 89 5c 24 18 4c 03 3b 4d 89 fc 49 c1 ec 03 <43> 8a 04 2c 84 c0 0f 85 0d 0d 00 00 41 0f b6 1f 89 de 83 e6 01 31
RSP: 0018:ffffc90000b27b60 EFLAGS: 00010202
RAX: 1ffff110209b241a RBX: ffff888104d920d0 RCX: ffffffff8492a346
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffc90000b27ae0
RBP: ffffc90000b27c50 R08: dffffc0000000000 R09: fffff52000164f5d
R10: fffff52000164f5d R11: 1ffff92000164f5c R12: 000000000000001a
R13: dffffc0000000000 R14: ffff888104d92108 R15: 00000000000000d0
FS: 00005555556bd300(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2ae9ad7144 CR3: 0000000105fc4000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
del_gendisk+0xbf2/0xe20 block/genhd.c:953
loop_remove+0x46/0xb0 drivers/block/loop.c:2185
loop_control_ioctl+0x67f/0x740 drivers/block/loop.c:2284
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl+0x115/0x190 fs/ioctl.c:739
__x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:739
do_syscall_64+0x34/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f2ae9a7f0b9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 90 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe5b36fce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f2ae9a7f0b9
RDX: 000000000000000c RSI: 0000000000004c81 RDI: 0000000000000005
RBP: 00007ffe5b36fd00 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000004
R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace ab9e6fe86789591d ]---
RIP: 0010:kill_device drivers/base/core.c:3361 [inline]
RIP: 0010:device_del+0xdf/0xf00 drivers/base/core.c:3389
Code: 20 42 80 3c 28 00 74 08 48 89 df e8 9b 16 df fe 4c 89 7c 24 48 41 bf d0 00 00 00 48 89 5c 24 18 4c 03 3b 4d 89 fc 49 c1 ec 03 <43> 8a 04 2c 84 c0 0f 85 0d 0d 00 00 41 0f b6 1f 89 de 83 e6 01 31
RSP: 0018:ffffc90000b27b60 EFLAGS: 00010202
RAX: 1ffff110209b241a RBX: ffff888104d920d0 RCX: ffffffff8492a346
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffc90000b27ae0
RBP: ffffc90000b27c50 R08: dffffc0000000000 R09: fffff52000164f5d
R10: fffff52000164f5d R11: 1ffff92000164f5c R12: 000000000000001a
R13: dffffc0000000000 R14: ffff888104d92108 R15: 00000000000000d0
FS: 00005555556bd300(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2ae9ad7144 CR3: 0000000105fc4000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 20 42 80 and %al,-0x80(%rdx)
3: 3c 28 cmp $0x28,%al
5: 00 74 08 48 add %dh,0x48(%rax,%rcx,1)
9: 89 df mov %ebx,%edi
b: e8 9b 16 df fe callq 0xfedf16ab
10: 4c 89 7c 24 48 mov %r15,0x48(%rsp)
15: 41 bf d0 00 00 00 mov $0xd0,%r15d
1b: 48 89 5c 24 18 mov %rbx,0x18(%rsp)
20: 4c 03 3b add (%rbx),%r15
23: 4d 89 fc mov %r15,%r12
26: 49 c1 ec 03 shr $0x3,%r12
* 2a: 43 8a 04 2c mov (%r12,%r13,1),%al <-- trapping instruction
2e: 84 c0 test %al,%al
30: 0f 85 0d 0d 00 00 jne 0xd43
36: 41 0f b6 1f movzbl (%r15),%ebx
3a: 89 de mov %ebx,%esi
3c: 83 e6 01 and $0x1,%esi
3f: 31 .byte 0x31


---
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[syzbot]

syzbot has bisected this issue to:

commit bda49ad0602e5250a9d3dd61deda19d3e5615c54
Author: Bart Van Assche <bvana...@google.com>
Date: Mon Aug 2 17:05:29 2021 +0000

FROMGIT: loop: Select I/O scheduler 'none' from inside add_disk()

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=124fef82080000
start commit: fa7f6a5f56d9 Merge branch 'android12-5.10' into branch 'an..
git tree: android12-5.10-lts
final oops: https://syzkaller.appspot.com/x/report.txt?x=114fef82080000
console output: https://syzkaller.appspot.com/x/log.txt?x=164fef82080000

kernel config: https://syzkaller.appspot.com/x/.config?x=30bf844d1a89de15
dashboard link: https://syzkaller.appspot.com/bug?extid=8fe1ba2605ff4383aca1

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1767ef34080000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13229782080000

Reported-by: syzbot+8fe1ba...@syzkaller.appspotmail.com
Fixes: bda49ad0602e ("FROMGIT: loop: Select I/O scheduler 'none' from inside add_disk()")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection