[v6.1] kernel BUG in put_mtd_device

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: a500ba24937a Linux 6.1.189
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17a6123e580000
kernel config: https://syzkaller.appspot.com/x/.config?x=ad298832474de60c
dashboard link: https://syzkaller.appspot.com/bug?extid=096edc3beb455034e7db
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e278ec6c88b0/disk-a500ba24.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e95551d48fd4/vmlinux-a500ba24.xz
kernel image: https://storage.googleapis.com/syzbot-assets/64269add15d8/Image-a500ba24.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+096edc...@syzkaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at drivers/mtd/mtdcore.c:1314!
Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 6264 Comm: mtd_probe Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2026
pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : __put_mtd_device drivers/mtd/mtdcore.c:1314 [inline]
pc : put_mtd_device+0x17c/0x180 drivers/mtd/mtdcore.c:1302
lr : __put_mtd_device drivers/mtd/mtdcore.c:1314 [inline]
lr : put_mtd_device+0x17c/0x180 drivers/mtd/mtdcore.c:1302
sp : ffff8000237e7a00
x29: ffff8000237e7a00 x28: 1fffe0001b4e7404 x27: dfff800000000000
x26: 0000000000002000 x25: 1fffe0001b4e7405 x24: 1fffe0001b4e7435
x23: dfff800000000000 x22: ffff0000d045a000 x21: dfff800000000000
x20: ffff0000e06ff628 x19: ffff0000d045a000 x18: 1fffe00033c1877e
x17: ffff80001641d000 x16: ffff800011bcac18 x15: 0000000000000000
x14: 0000000000000001 x13: 1ffff000046fcef4 x12: 0000000000000000
x11: ff0080000c599f74 x10: 0000000000000000 x9 : ffff80000c599f74
x8 : ffff0000da2a5400 x7 : ffff80000c599e2c x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff8000082d45f8
x2 : ffff0000da2a5400 x1 : ffff800012222f40 x0 : 0000000000000000
Call trace:
__put_mtd_device drivers/mtd/mtdcore.c:1314 [inline]
put_mtd_device+0x17c/0x180 drivers/mtd/mtdcore.c:1302
mtdchar_close+0x100/0x174 drivers/mtd/mtdchar.c:102
__fput+0x1b4/0x7b0 fs/file_table.c:320
____fput+0x20/0x30 fs/file_table.c:348
task_work_run+0x1f4/0x280 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0x54c/0x19ac kernel/exit.c:887
do_group_exit+0x198/0x238 kernel/exit.c:1030
__do_sys_exit_group kernel/exit.c:1041 [inline]
__se_sys_exit_group kernel/exit.c:1039 [inline]
__wake_up_parent+0x0/0x60 kernel/exit.c:1039
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x12c arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
Code: 9118a260 970d7cea 17ffffda 96fc6aef (d4210000)
---[ end trace 0000000000000000 ]---


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