======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.4.38/4521 is trying to acquire lock:
ffff888071f72950 (&f->sem){+.+.}-{3:3}, at: jffs2_do_clear_inode+0x5e/0x390 fs/jffs2/readinode.c:1419

but task is already holding lock:
ffffffff8cc07460 (fs_reclaim){+.+.}-{0:0}, at: shrink_all_memory+0x100/0x2e0 mm/vmscan.c:7513

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (fs_reclaim){+.+.}-{0:0}:
       __fs_reclaim_acquire mm/page_alloc.c:4749 [inline]
       fs_reclaim_acquire+0x6d/0x100 mm/page_alloc.c:4763
       might_alloc include/linux/sched/mm.h:271 [inline]
       slab_pre_alloc_hook+0x2a/0x300 mm/slab.h:710
       slab_alloc_node mm/slub.c:3279 [inline]
       slab_alloc mm/slub.c:3367 [inline]
       __kmem_cache_alloc_lru mm/slub.c:3374 [inline]
       kmem_cache_alloc+0x56/0x2f0 mm/slub.c:3383
       jffs2_do_read_inode+0x302/0x640 fs/jffs2/readinode.c:1372
       jffs2_iget+0x20f/0xc60 fs/jffs2/fs.c:277
       jffs2_do_fill_super+0x599/0xc50 fs/jffs2/fs.c:577
       mtd_get_sb+0xcb/0x2b0 drivers/mtd/mtdsuper.c:80
       mtd_get_sb_by_nr drivers/mtd/mtdsuper.c:111 [inline]
       get_tree_mtd+0x4e2/0x760 drivers/mtd/mtdsuper.c:181
       vfs_get_tree+0x88/0x270 fs/super.c:1573
       do_new_mount+0x247/0xa40 fs/namespace.c:3078
       do_mount fs/namespace.c:3421 [inline]
       __do_sys_mount fs/namespace.c:3629 [inline]
       __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&f->sem){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3095 [inline]
       check_prevs_add kernel/locking/lockdep.c:3214 [inline]
       validate_chain kernel/locking/lockdep.c:3830 [inline]
       __lock_acquire+0x2d18/0x7c40 kernel/locking/lockdep.c:5063
       lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5676
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x12d/0xae0 kernel/locking/mutex.c:747
       jffs2_do_clear_inode+0x5e/0x390 fs/jffs2/readinode.c:1419
       evict+0x4b6/0x8b0 fs/inode.c:705
       dispose_list fs/inode.c:738 [inline]
       prune_icache_sb+0x220/0x2d0 fs/inode.c:941
       super_cache_scan+0x335/0x430 fs/super.c:106
       do_shrink_slab+0x4f7/0xdb0 mm/vmscan.c:853
       shrink_slab_memcg mm/vmscan.c:922 [inline]
       shrink_slab+0x448/0x740 mm/vmscan.c:1001
       shrink_node_memcgs mm/vmscan.c:6154 [inline]
       shrink_node+0x6e5/0x2890 mm/vmscan.c:6183
       shrink_zones mm/vmscan.c:6424 [inline]
       do_try_to_free_pages+0x650/0x1980 mm/vmscan.c:6486
       shrink_all_memory+0x1a2/0x2e0 mm/vmscan.c:7517
       hibernate_preallocate_memory+0x3af/0xa90 kernel/power/snapshot.c:1823
       hibernation_snapshot+0xa0/0x3b0 kernel/power/hibernate.c:381
       hibernate+0x191/0x520 kernel/power/hibernate.c:765
       state_store+0x22b/0x290 kernel/power/main.c:641
       kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352
       call_write_iter include/linux/fs.h:2265 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x482/0x9a0 fs/read_write.c:584
       ksys_write+0x14d/0x260 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(fs_reclaim);
                               lock(&f->sem);
                               lock(fs_reclaim);
  lock(&f->sem);

 *** DEADLOCK ***

10 locks held by syz.4.38/4521:
 #0: ffff88801eb3aae8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
 #1: ffff88805382c460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
 #2: ffff888078e9e088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1d8/0x520 fs/kernfs/file.c:343
 #3: ffff888140a17008 (kn->active#63){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #3: ffff888140a17008 (kn->active#63){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x520 fs/kernfs/file.c:344
 #4: ffffffff8c9e2e28 (system_transition_mutex){+.+.}-{3:3}, at: lock_system_sleep+0x45/0x60 kernel/power/main.c:28
 #5: ffffffff8d3cf288 (device_hotplug_lock){+.+.}-{3:3}, at: hibernate+0x15d/0x520 kernel/power/hibernate.c:759
 #6: ffffffff8d226f28 (acpi_scan_lock){+.+.}-{3:3}, at: acpi_pm_start drivers/acpi/sleep.c:518 [inline]
 #6: ffffffff8d226f28 (acpi_scan_lock){+.+.}-{3:3}, at: acpi_hibernation_begin+0xc4/0x100 drivers/acpi/sleep.c:918
 #7: ffffffff8cc07460 (fs_reclaim){+.+.}-{0:0}, at: shrink_all_memory+0x100/0x2e0 mm/vmscan.c:7513
 #8: ffffffff8cbdba30 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab_memcg mm/vmscan.c:895 [inline]
 #8: ffffffff8cbdba30 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0x228/0x740 mm/vmscan.c:1001
 #9: ffff888076e520e0 (&type->s_umount_key#78){++++}-{3:3}, at: trylock_super fs/super.c:415 [inline]
 #9: ffff888076e520e0 (&type->s_umount_key#78){++++}-{3:3}, at: super_cache_scan+0x70/0x430 fs/super.c:79

stack backtrace:
CPU: 1 PID: 4521 Comm: syz.4.38 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3095 [inline]
 check_prevs_add kernel/locking/lockdep.c:3214 [inline]
 validate_chain kernel/locking/lockdep.c:3830 [inline]
 __lock_acquire+0x2d18/0x7c40 kernel/locking/lockdep.c:5063
 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5676
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x12d/0xae0 kernel/locking/mutex.c:747
 jffs2_do_clear_inode+0x5e/0x390 fs/jffs2/readinode.c:1419
 evict+0x4b6/0x8b0 fs/inode.c:705
 dispose_list fs/inode.c:738 [inline]
 prune_icache_sb+0x220/0x2d0 fs/inode.c:941
 super_cache_scan+0x335/0x430 fs/super.c:106
 do_shrink_slab+0x4f7/0xdb0 mm/vmscan.c:853
 shrink_slab_memcg mm/vmscan.c:922 [inline]
 shrink_slab+0x448/0x740 mm/vmscan.c:1001
 shrink_node_memcgs mm/vmscan.c:6154 [inline]
 shrink_node+0x6e5/0x2890 mm/vmscan.c:6183
 shrink_zones mm/vmscan.c:6424 [inline]
 do_try_to_free_pages+0x650/0x1980 mm/vmscan.c:6486
 shrink_all_memory+0x1a2/0x2e0 mm/vmscan.c:7517
 hibernate_preallocate_memory+0x3af/0xa90 kernel/power/snapshot.c:1823
 hibernation_snapshot+0xa0/0x3b0 kernel/power/hibernate.c:381
 hibernate+0x191/0x520 kernel/power/hibernate.c:765
 state_store+0x22b/0x290 kernel/power/main.c:641
 kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x482/0x9a0 fs/read_write.c:584
 ksys_write+0x14d/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa72b79e019
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa72c73b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fa72ba26090 RCX: 00007fa72b79e019
RDX: 0000000000000005 RSI: 0000200000000240 RDI: 0000000000000006
RBP: 00007fa72b83500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa72ba26128 R14: 00007fa72ba26090 R15: 00007ffdeb742f08
 </TASK>