stack segment fault in del_gendisk

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: eb4a5a5dbd5b ANDROID: ion heap: init ion heaps in subsys_i..
git tree: android12-5.4
console output: https://syzkaller.appspot.com/x/log.txt?x=13d5b7af300000
kernel config: https://syzkaller.appspot.com/x/.config?x=170af3624e04993e
dashboard link: https://syzkaller.appspot.com/bug?extid=50fb3546b9fcc451fe74
compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14cb33c4b00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14a9bbd8b00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+50fb35...@syzkaller.appspotmail.com

RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: 00007ffe63dd1ad0 R11: 0000000000000246 R12: 00007ffe63dd206c
R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000
---[ end trace 91a358f4873211c9 ]---
stack segment: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 304 Comm: syz-executor589 Tainted: G W 5.4.147-syzkaller-00036-geb4a5a5dbd5b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:kill_device drivers/base/core.c:3022 [inline]
RIP: 0010:device_del+0xa3/0xf60 drivers/base/core.c:3049
Code: 00 74 08 4c 89 e7 e8 cc 75 0e ff 48 89 1c 24 41 bf c8 00 00 00 4d 03 3c 24 4c 89 fd 48 c1 ed 03 48 b8 00 00 00 00 00 fc ff df <8a> 44 05 00 84 c0 0f 85 33 0e 00 00 45 0f b6 2f 44 89 eb 83 e3 01
RSP: 0018:ffff8881de34fce0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8881f0560070 RCX: 1ffff1103e0ac01b
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff8881de34fca0
RBP: 0000000000000019 R08: dffffc0000000000 R09: ffffed103bc69f95
R10: ffffed103bc69f95 R11: 0000000000000000 R12: ffff8881f05600d8
R13: 1ffff1103e0ac085 R14: ffff8881f0560110 R15: 00000000000000c8
FS: 0000555556448300(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fab84a84130 CR3: 00000001e2cab000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
del_gendisk+0x94f/0xb70 block/genhd.c:835
loop_remove drivers/block/loop.c:2189 [inline]
loop_control_ioctl+0x563/0x680 drivers/block/loop.c:2288
do_vfs_ioctl+0x6fb/0x15b0 fs/ioctl.c:47
ksys_ioctl fs/ioctl.c:742 [inline]
__do_sys_ioctl fs/ioctl.c:749 [inline]
__se_sys_ioctl fs/ioctl.c:747 [inline]
__x64_sys_ioctl+0xd4/0x110 fs/ioctl.c:747
do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fab84a13079
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:00007ffe63dd2058 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000006520 RCX: 00007fab84a13079
RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: 00007ffe63dd1ad0 R11: 0000000000000246 R12: 00007ffe63dd206c
R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace 91a358f4873211ca ]---
RIP: 0010:kill_device drivers/base/core.c:3022 [inline]
RIP: 0010:device_del+0xa3/0xf60 drivers/base/core.c:3049
Code: 00 74 08 4c 89 e7 e8 cc 75 0e ff 48 89 1c 24 41 bf c8 00 00 00 4d 03 3c 24 4c 89 fd 48 c1 ed 03 48 b8 00 00 00 00 00 fc ff df <8a> 44 05 00 84 c0 0f 85 33 0e 00 00 45 0f b6 2f 44 89 eb 83 e3 01
RSP: 0018:ffff8881de34fce0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8881f0560070 RCX: 1ffff1103e0ac01b
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff8881de34fca0
RBP: 0000000000000019 R08: dffffc0000000000 R09: ffffed103bc69f95
R10: ffffed103bc69f95 R11: 0000000000000000 R12: ffff8881f05600d8
R13: 1ffff1103e0ac085 R14: ffff8881f0560110 R15: 00000000000000c8
FS: 0000555556448300(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fab84a84130 CR3: 00000001e2cab000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 00 74 08 4c add %dh,0x4c(%rax,%rcx,1)
4: 89 e7 mov %esp,%edi
6: e8 cc 75 0e ff callq 0xff0e75d7
b: 48 89 1c 24 mov %rbx,(%rsp)
f: 41 bf c8 00 00 00 mov $0xc8,%r15d
15: 4d 03 3c 24 add (%r12),%r15
19: 4c 89 fd mov %r15,%rbp
1c: 48 c1 ed 03 shr $0x3,%rbp
20: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
27: fc ff df
* 2a: 8a 44 05 00 mov 0x0(%rbp,%rax,1),%al <-- trapping instruction
2e: 84 c0 test %al,%al
30: 0f 85 33 0e 00 00 jne 0xe69
36: 45 0f b6 2f movzbl (%r15),%r13d
3a: 44 89 eb mov %r13d,%ebx
3d: 83 e3 01 and $0x1,%ebx


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