[syzbot] [block?] INFO: task hung in read_cache_folio (6)

[syzbot <syzbot+9db0864859224b833108@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    92e3f6ef4ffb Merge branch 'for-next/core' into for-kernelci
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=142300d6580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a4a42e870a0b0ae0
dashboard link: https://syzkaller.appspot.com/bug?extid=9db0864859224b833108
compiler:       Debian clang version 22.1.6 (++20260514074242+fc4aad7b5db3-1~exp1~20260514074407.73), Debian LLD 22.1.6
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/75ce25b4a6ef/disk-92e3f6ef.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/14bda28d7d38/vmlinux-92e3f6ef.xz
kernel image: https://storage.googleapis.com/syzbot-assets/247283a18992/Image-92e3f6ef.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9db0864859224b833108@syzkaller.appspotmail.com

INFO: task udevd:6979 blocked
INFO: task udevd:6979 blocked in I/O wait for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:0     pid:6979  tgid:6979  ppid:4339   task_flags:0x400140 flags:0x00800011
Call trace:
 __switch_to+0x2b0/0x6e0 arch/arm64/kernel/process.c:810 (T)
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1c04/0x2db8 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0x13c/0x20c kernel/sched/core.c:7283
 io_schedule+0x1c/0xe0 kernel/sched/core.c:8110
 folio_wait_bit_common+0x6b8/0xa30 mm/filemap.c:1324
 folio_put_wait_locked mm/filemap.c:1493 [inline]
 do_read_cache_folio+0x23c/0x5a8 mm/filemap.c:4089
 read_cache_folio+0x68/0x88 mm/filemap.c:4139
 read_mapping_folio include/linux/pagemap.h:1017 [inline]
 read_part_sector+0xcc/0x708 block/partitions/core.c:724
 adfspart_check_POWERTEC+0x94/0x5b8 block/partitions/acorn.c:450
 check_partition block/partitions/core.c:143 [inline]
 blk_add_partitions block/partitions/core.c:591 [inline]
 bdev_disk_changed+0x6c4/0x11ec block/partitions/core.c:695
 blkdev_get_whole+0x15c/0x240 block/bdev.c:756
 bdev_open+0x2b4/0x880 block/bdev.c:965
 blkdev_open+0x2d4/0x408 block/fops.c:697
 do_dentry_open+0x5c4/0xfb8 fs/open.c:947
 vfs_open+0x44/0x2dc fs/open.c:1079
 do_open fs/namei.c:4699 [inline]
 path_openat+0x22d4/0x2b88 fs/namei.c:4858
 do_file_open+0x1c8/0x2e8 fs/namei.c:4887
 do_sys_openat2+0x114/0x1e8 fs/open.c:1364
 do_sys_open+0xac/0xdc fs/open.c:1370
 __do_sys_openat fs/open.c:1386 [inline]
 __se_sys_openat fs/open.c:1381 [inline]
 __arm64_sys_openat+0xa0/0xbc fs/open.c:1381
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736
 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffff800088bf70c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffff800088bf70c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffff800088bf70c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x4c/0x188 kernel/locking/lockdep.c:6775
2 locks held by pr/ttyAMA-1/41:
2 locks held by getty/4488:
 #0: ffff0000d43c90a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff8000923ab2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x348/0xf70 drivers/tty/n_tty.c:2211
1 lock held by udevd/6979:
 #0: ffff0000c7f2a350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xc4/0x880 block/bdev.c:953

=============================================



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