======================================================
WARNING: possible circular locking dependency detected
4.19.0-rc2+ #6 Not tainted
------------------------------------------------------
syz-executor2/5381 is trying to acquire lock:
000000002a40b02c (jbd2_handle){++++}, at: start_this_handle+0x581/0x1250 fs/jbd2/transaction.c:383

but task is already holding lock:
000000003ac09723 (fs_reclaim){+.+.}, at: fs_reclaim_acquire.part.97+0x0/0x30 mm/internal.h:79

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (fs_reclaim){+.+.}:
       __fs_reclaim_acquire mm/page_alloc.c:3728 [inline]
       fs_reclaim_acquire.part.97+0x24/0x30 mm/page_alloc.c:3739
       fs_reclaim_acquire+0x14/0x20 mm/page_alloc.c:3740
       slab_pre_alloc_hook mm/slab.h:418 [inline]
       slab_alloc mm/slab.c:3378 [inline]
       kmem_cache_alloc_trace+0x2d/0x750 mm/slab.c:3618
       kmalloc include/linux/slab.h:513 [inline]
       kzalloc include/linux/slab.h:707 [inline]
       smk_fetch.part.24+0x5a/0xf0 security/smack/smack_lsm.c:273
       smk_fetch security/smack/smack_lsm.c:3548 [inline]
       smack_d_instantiate+0x94e/0xea0 security/smack/smack_lsm.c:3502
       security_d_instantiate+0x5c/0xf0 security/security.c:1287
       d_instantiate+0x5e/0xa0 fs/dcache.c:1870
       shmem_mknod+0x189/0x1f0 mm/shmem.c:2812
       vfs_mknod+0x445/0x800 fs/namei.c:3719
       handle_create+0x1ff/0x730 drivers/base/devtmpfs.c:211
       handle drivers/base/devtmpfs.c:374 [inline]
       devtmpfsd+0x27f/0x4c0 drivers/base/devtmpfs.c:400
       kthread+0x35a/0x420 kernel/kthread.c:246
       ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413

-> #1 (&isp->smk_lock){+.+.}:
       __mutex_lock_common kernel/locking/mutex.c:925 [inline]
       __mutex_lock+0x166/0x1710 kernel/locking/mutex.c:1073
       mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
       smack_d_instantiate+0x136/0xea0 security/smack/smack_lsm.c:3369
       security_d_instantiate+0x5c/0xf0 security/security.c:1287
       d_instantiate_new+0x70/0x160 fs/dcache.c:1889
       ext4_add_nondir+0x81/0x90 fs/ext4/namei.c:2415
       ext4_symlink+0x752/0x1130 fs/ext4/namei.c:3162
       vfs_symlink+0x37a/0x5d0 fs/namei.c:4127
       do_symlinkat+0x242/0x2d0 fs/namei.c:4154
       __do_sys_symlink fs/namei.c:4173 [inline]
       __se_sys_symlink fs/namei.c:4171 [inline]
       __x64_sys_symlink+0x59/0x80 fs/namei.c:4171
       do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #0 (jbd2_handle){++++}:
       lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3901
       start_this_handle+0x5b8/0x1250 fs/jbd2/transaction.c:385
       jbd2__journal_start+0x3c9/0xa90 fs/jbd2/transaction.c:439
       __ext4_journal_start_sb+0x1a5/0x5f0 fs/ext4/ext4_jbd2.c:81
       __ext4_journal_start fs/ext4/ext4_jbd2.h:311 [inline]
       ext4_dirty_inode+0x62/0xc0 fs/ext4/inode.c:6021
       __mark_inode_dirty+0x7c3/0x1510 fs/fs-writeback.c:2129
       mark_inode_dirty_sync include/linux/fs.h:2072 [inline]
       iput+0x131/0xa90 fs/inode.c:1570
       dentry_unlink_inode+0x461/0x5e0 fs/dcache.c:374
       __dentry_kill+0x44c/0x7a0 fs/dcache.c:566
       shrink_dentry_list+0x32f/0x800 fs/dcache.c:1079
       prune_dcache_sb+0x12f/0x1c0 fs/dcache.c:1171
       super_cache_scan+0x270/0x480 fs/super.c:102
       do_shrink_slab+0x4cf/0xd00 mm/vmscan.c:536
       shrink_slab_memcg mm/vmscan.c:601 [inline]
       shrink_slab+0x6f9/0x8c0 mm/vmscan.c:674
       shrink_node+0x431/0x16b0 mm/vmscan.c:2735
       shrink_zones mm/vmscan.c:2964 [inline]
       do_try_to_free_pages+0x3e7/0x1290 mm/vmscan.c:3026
       try_to_free_pages+0x4d0/0xb90 mm/vmscan.c:3241
       __perform_reclaim mm/page_alloc.c:3769 [inline]
       __alloc_pages_direct_reclaim mm/page_alloc.c:3790 [inline]
       __alloc_pages_slowpath+0x993/0x2d80 mm/page_alloc.c:4191
       __alloc_pages_nodemask+0xa80/0xde0 mm/page_alloc.c:4390
       __alloc_pages include/linux/gfp.h:473 [inline]
       __alloc_pages_node include/linux/gfp.h:486 [inline]
       kmem_getpages mm/slab.c:1409 [inline]
       cache_grow_begin+0x91/0x8c0 mm/slab.c:2677
       fallback_alloc+0x203/0x2e0 mm/slab.c:3219
       ____cache_alloc_node+0x1c7/0x1e0 mm/slab.c:3287
       __do_cache_alloc mm/slab.c:3356 [inline]
       slab_alloc mm/slab.c:3384 [inline]
       kmem_cache_alloc+0x1f8/0x730 mm/slab.c:3552
       getname_flags+0xd0/0x5a0 fs/namei.c:140
       getname fs/namei.c:211 [inline]
       __do_sys_unlink fs/namei.c:4110 [inline]
       __se_sys_unlink fs/namei.c:4108 [inline]
       __x64_sys_unlink+0x35/0x50 fs/namei.c:4108
       do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

other info that might help us debug this:

Chain exists of:
  jbd2_handle --> &isp->smk_lock --> fs_reclaim

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(fs_reclaim);
                               lock(&isp->smk_lock);
                               lock(fs_reclaim);
  lock(jbd2_handle);

 *** DEADLOCK ***

3 locks held by syz-executor2/5381:
 #0: 000000003ac09723 (fs_reclaim){+.+.}, at: fs_reclaim_acquire.part.97+0x0/0x30 mm/internal.h:79
 #1: 000000006a9c1fb2 (shrinker_rwsem){++++}, at: shrink_slab_memcg mm/vmscan.c:578 [inline]
 #1: 000000006a9c1fb2 (shrinker_rwsem){++++}, at: shrink_slab+0x1d1/0x8c0 mm/vmscan.c:674
 #2: 00000000e7a85a29 (&type->s_umount_key#29){++++}, at: trylock_super+0x22/0x110 fs/super.c:412

stack backtrace:
CPU: 1 PID: 5381 Comm: syz-executor2 Not tainted 4.19.0-rc2+ #6
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113
 print_circular_bug.isra.33.cold.54+0x1bd/0x27d kernel/locking/lockdep.c:1222
 check_prev_add kernel/locking/lockdep.c:1862 [inline]
 check_prevs_add kernel/locking/lockdep.c:1975 [inline]
 validate_chain kernel/locking/lockdep.c:2416 [inline]
 __lock_acquire+0x33e4/0x4ec0 kernel/locking/lockdep.c:3412
 lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3901
 start_this_handle+0x5b8/0x1250 fs/jbd2/transaction.c:385
 jbd2__journal_start+0x3c9/0xa90 fs/jbd2/transaction.c:439
 __ext4_journal_start_sb+0x1a5/0x5f0 fs/ext4/ext4_jbd2.c:81
 __ext4_journal_start fs/ext4/ext4_jbd2.h:311 [inline]
 ext4_dirty_inode+0x62/0xc0 fs/ext4/inode.c:6021
 __mark_inode_dirty+0x7c3/0x1510 fs/fs-writeback.c:2129
 mark_inode_dirty_sync include/linux/fs.h:2072 [inline]
 iput+0x131/0xa90 fs/inode.c:1570
 dentry_unlink_inode+0x461/0x5e0 fs/dcache.c:374
 __dentry_kill+0x44c/0x7a0 fs/dcache.c:566
 shrink_dentry_list+0x32f/0x800 fs/dcache.c:1079
 prune_dcache_sb+0x12f/0x1c0 fs/dcache.c:1171
 super_cache_scan+0x270/0x480 fs/super.c:102
 do_shrink_slab+0x4cf/0xd00 mm/vmscan.c:536
 shrink_slab_memcg mm/vmscan.c:601 [inline]
 shrink_slab+0x6f9/0x8c0 mm/vmscan.c:674
 shrink_node+0x431/0x16b0 mm/vmscan.c:2735
 shrink_zones mm/vmscan.c:2964 [inline]
 do_try_to_free_pages+0x3e7/0x1290 mm/vmscan.c:3026
 try_to_free_pages+0x4d0/0xb90 mm/vmscan.c:3241
 __perform_reclaim mm/page_alloc.c:3769 [inline]
 __alloc_pages_direct_reclaim mm/page_alloc.c:3790 [inline]
 __alloc_pages_slowpath+0x993/0x2d80 mm/page_alloc.c:4191
 __alloc_pages_nodemask+0xa80/0xde0 mm/page_alloc.c:4390
 __alloc_pages include/linux/gfp.h:473 [inline]
 __alloc_pages_node include/linux/gfp.h:486 [inline]
 kmem_getpages mm/slab.c:1409 [inline]
 cache_grow_begin+0x91/0x8c0 mm/slab.c:2677
 fallback_alloc+0x203/0x2e0 mm/slab.c:3219
 ____cache_alloc_node+0x1c7/0x1e0 mm/slab.c:3287
 __do_cache_alloc mm/slab.c:3356 [inline]
 slab_alloc mm/slab.c:3384 [inline]
 kmem_cache_alloc+0x1f8/0x730 mm/slab.c:3552
 getname_flags+0xd0/0x5a0 fs/namei.c:140
 getname fs/namei.c:211 [inline]
 __do_sys_unlink fs/namei.c:4110 [inline]
 __se_sys_unlink fs/namei.c:4108 [inline]
 __x64_sys_unlink+0x35/0x50 fs/namei.c:4108
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456de7
Code: 0f 1f 00 b8 58 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 9d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 7d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffd2030ad98 EFLAGS: 00000202 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000456de7
RDX: 00007ffd2030adb0 RSI: 00007ffd2030ae40 RDI: 00007ffd2030ae40
RBP: 0000000000000bdc R08: 0000000000000000 R09: 0000000000000010
R10: 000000000000000a R11: 0000000000000202 R12: 00007ffd2030bea0
R13: 000000000214f940 R14: 0000000000000000 R15: badc0ffeebadface
kobject: 'loop2' (000000001e4cda9d): kobject_uevent_env
kobject: 'loop2' (000000001e4cda9d): fill_kobj_path: path = '/devices/virtual/block/loop2'
syz-executor7 (32230) used greatest stack depth: 6040 bytes left
kobject: 'loop7' (0000000069343abd): kobject_uevent_env
kobject: 'loop7' (0000000069343abd): fill_kobj_path: path = '/devices/virtual/block/loop7'
kobject: 'kvm' (00000000d0ce116b): kobject_uevent_env
kobject: 'kvm' (00000000d0ce116b): fill_kobj_path: path = '/devices/virtual/misc/kvm'
kobject: 'loop2' (000000001e4cda9d): kobject_uevent_env
kobject: 'loop2' (000000001e4cda9d): fill_kobj_path: path = '/devices/virtual/block/loop2'
kobject: 'loop3' (00000000bf037997): kobject_uevent_env
syz-executor1 (32231) used greatest stack depth: 6008 bytes left
kobject: 'loop3' (00000000bf037997): fill_kobj_path: path = '/devices/virtual/block/loop3'
kobject: 'loop4' (00000000280751f6): kobject_uevent_env
kobject: 'loop4' (00000000280751f6): fill_kobj_path: path = '/devices/virtual/block/loop4'
kobject: 'loop5' (00000000ce0f49c1): kobject_uevent_env
kobject: 'loop5' (00000000ce0f49c1): fill_kobj_path: path = '/devices/virtual/block/loop5'
kobject: 'loop1' (0000000084ee7deb): kobject_uevent_env
kobject: 'loop1' (0000000084ee7deb): fill_kobj_path: path = '/devices/virtual/block/loop1'
kobject: 'loop4' (00000000280751f6): kobject_uevent_env
kobject: 'loop4' (00000000280751f6): fill_kobj_path: path = '/devices/virtual/block/loop4'
kobject: 'loop0' (000000006875a128): kobject_uevent_env
kobject: 'loop0' (000000006875a128): fill_kobj_path: path = '/devices/virtual/block/loop0'
kobject: 'loop3' (00000000bf037997): kobject_uevent_env
kobject: 'loop3' (00000000bf037997): fill_kobj_path: path = '/devices/virtual/block/loop3'
kobject: 'loop6' (00000000a0fedeb1): kobject_uevent_env
kobject: 'loop6' (00000000a0fedeb1): fill_kobj_path: path = '/devices/virtual/block/loop6'
kobject: 'loop0' (000000006875a128): kobject_uevent_env
kobject: 'loop0' (000000006875a128): fill_kobj_path: path = '/devices/virtual/block/loop0'
kobject: 'loop2' (000000001e4cda9d): kobject_uevent_env
kobject: 'loop2' (000000001e4cda9d): fill_kobj_path: path = '/devices/virtual/block/loop2'
kobject: 'loop6' (00000000a0fedeb1): kobject_uevent_env
kobject: 'loop6' (00000000a0fedeb1): fill_kobj_path: path = '/devices/virtual/block/loop6'
kobject: 'loop7' (0000000069343abd): kobject_uevent_env
kobject: 'loop7' (0000000069343abd): fill_kobj_path: path = '/devices/virtual/block/loop7'
kobject: 'loop1' (0000000084ee7deb): kobject_uevent_env
kobject: 'loop1' (0000000084ee7deb): fill_kobj_path: path = '/devices/virtual/block/loop1'
kobject: 'loop2' (000000001e4cda9d): kobject_uevent_env
kobject: 'loop2' (000000001e4cda9d): fill_kobj_path: path = '/devices/virtual/block/loop2'
kobject: 'loop7' (0000000069343abd): kobject_uevent_env
kobject: 'loop7' (0000000069343abd): fill_kobj_path: path = '/devices/virtual/block/loop7'
kobject: 'loop4' (00000000280751f6): kobject_uevent_env
kobject: 'loop4' (00000000280751f6): fill_kobj_path: path = '/devices/virtual/block/loop4'
kobject: 'loop6' (00000000a0fedeb1): kobject_uevent_env
kobject: 'loop6' (00000000a0fedeb1): fill_kobj_path: path = '/devices/virtual/block/loop6'
kobject: 'loop5' (00000000ce0f49c1): kobject_uevent_env
kobject: 'loop5' (00000000ce0f49c1): fill_kobj_path: path = '/devices/virtual/block/loop5'
kobject: 'loop1' (0000000084ee7deb): kobject_uevent_env
kobject: 'loop1' (0000000084ee7deb): fill_kobj_path: path = '/devices/virtual/block/loop1'
kobject: 'loop4' (00000000280751f6): kobject_uevent_env
kobject: 'loop4' (00000000280751f6): fill_kobj_path: path = '/devices/virtual/block/loop4'
kobject: 'loop6' (00000000a0fedeb1): kobject_uevent_env
kobject: 'loop6' (00000000a0fedeb1): fill_kobj_path: path = '/devices/virtual/block/loop6'
kobject: 'loop1' (0000000084ee7deb): kobject_uevent_env
kobject: 'loop1' (0000000084ee7deb): fill_kobj_path: path = '/devices/virtual/block/loop1'
kobject: 'loop4' (00000000280751f6): kobject_uevent_env
kobject: 'loop4' (00000000280751f6): fill_kobj_path: path = '/devices/virtual/block/loop4'
syz-executor0 (32321) used greatest stack depth: 5656 bytes left
kobject: 'loop7' (0000000069343abd): kobject_uevent_env
kobject: 'loop7' (0000000069343abd): fill_kobj_path: path = '/devices/virtual/block/loop7'
kobject: 'loop1' (0000000084ee7deb): kobject_uevent_env
kobject: 'loop1' (0000000084ee7deb): fill_kobj_path: path = '/devices/virtual/block/loop1'
kobject: 'loop3' (00000000bf037997): kobject_uevent_env
kobject: 'loop3' (00000000bf037997): fill_kobj_path: path = '/devices/virtual/block/loop3'
kobject: 'loop3' (00000000bf037997): kobject_uevent_env
kobject: 'loop3' (00000000bf037997): fill_kobj_path: path = '/devices/virtual/block/loop3'
kobject: 'loop1' (0000000084ee7deb): kobject_uevent_env
kobject: 'loop1' (0000000084ee7deb): fill_kobj_path: path = '/devices/virtual/block/loop1'
kobject: 'loop4' (00000000280751f6): kobject_uevent_env
kobject: 'loop4' (00000000280751f6): fill_kobj_path: path = '/devices/virtual/block/loop4'
kobject: 'loop5' (00000000ce0f49c1): kobject_uevent_env
kobject: 'loop5' (00000000ce0f49c1): fill_kobj_path: path = '/devices/virtual/block/loop5'
kobject: 'loop2' (000000001e4cda9d): kobject_uevent_env
kobject: 'loop2' (000000001e4cda9d): fill_kobj_path: path = '/devices/virtual/block/loop2'
kobject: 'loop4' (00000000280751f6): kobject_uevent_env
kobject: 'loop4' (00000000280751f6): fill_kobj_path: path = '/devices/virtual/block/loop4'
kobject: 'loop4' (00000000280751f6): kobject_uevent_env
kobject: 'loop4' (00000000280751f6): fill_kobj_path: path = '/devices/virtual/block/loop4'
kobject: 'loop7' (0000000069343abd): kobject_uevent_env
kobject: 'loop7' (0000000069343abd): fill_kobj_path: path = '/devices/virtual/block/loop7'
kobject: 'loop0' (000000006875a128): kobject_uevent_env
kobject: 'loop0' (000000006875a128): fill_kobj_path: path = '/devices/virtual/block/loop0'
kobject: 'loop6' (00000000a0fedeb1): kobject_uevent_env
kobject: 'loop6' (00000000a0fedeb1): fill_kobj_path: path = '/devices/virtual/block/loop6'
kobject: 'loop2' (000000001e4cda9d): kobject_uevent_env
kobject: 'loop2' (000000001e4cda9d): fill_kobj_path: path = '/devices/virtual/block/loop2'
kobject: 'loop5' (00000000ce0f49c1): kobject_uevent_env
kobject: 'loop5' (00000000ce0f49c1): fill_kobj_path: path = '/devices/virtual/block/loop5'
kobject: 'loop4' (00000000280751f6): kobject_uevent_env
kobject: 'loop4' (00000000280751f6): fill_kobj_path: path = '/devices/virtual/block/loop4'
kobject: 'loop2' (000000001e4cda9d): kobject_uevent_env
kobject: 'loop2' (000000001e4cda9d): fill_kobj_path: path = '/devices/virtual/block/loop2'
kobject: 'loop3' (00000000bf037997): kobject_uevent_env
kobject: 'loop3' (00000000bf037997): fill_kobj_path: path = '/devices/virtual/block/loop3'
kobject: 'loop4' (00000000280751f6): kobject_uevent_env
kobject: 'loop4' (00000000280751f6): fill_kobj_path: path = '/devices/virtual/block/loop4'