EXT4-fs warning (device loop4): ext4_expand_extra_isize_ea:2847: Unable to expand inode 11. Delete some EAs or run e2fsck. EXT4-fs (loop4): 1 truncate cleaned up EXT4-fs (loop4): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none. loop4: detected capacity change from 512 to 0 ====================================================== WARNING: possible circular locking dependency detected 6.14.0-syzkaller-13189-ge48e99b6edf4 #0 Not tainted ------------------------------------------------------ syz.4.240/6758 is trying to acquire lock: ffffffff90697fe8 (uevent_sock_mutex){+.+.}-{4:4}, at: uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline] ffffffff90697fe8 (uevent_sock_mutex){+.+.}-{4:4}, at: kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline] ffffffff90697fe8 (uevent_sock_mutex){+.+.}-{4:4}, at: kobject_uevent_env+0xb36/0x1870 lib/kobject_uevent.c:608 but task is already holding lock: ffff888142371428 (&q->q_usage_counter(io)#21){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x15/0x20 block/blk-mq.c:215 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&q->q_usage_counter(io)#21){++++}-{0:0}: blk_alloc_queue+0x619/0x760 block/blk-core.c:461 blk_mq_alloc_queue+0x179/0x290 block/blk-mq.c:4348 __blk_mq_alloc_disk+0x29/0x120 block/blk-mq.c:4395 loop_add+0x496/0xb70 drivers/block/loop.c:2067 loop_init+0x164/0x270 drivers/block/loop.c:2302 do_one_initcall+0x123/0x6e0 init/main.c:1257 do_initcall_level init/main.c:1319 [inline] do_initcalls init/main.c:1335 [inline] do_basic_setup init/main.c:1354 [inline] kernel_init_freeable+0x5c2/0x900 init/main.c:1567 kernel_init+0x1c/0x2b0 init/main.c:1457 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #1 (fs_reclaim){+.+.}-{0:0}: __fs_reclaim_acquire mm/page_alloc.c:4028 [inline] fs_reclaim_acquire+0x102/0x150 mm/page_alloc.c:4042 might_alloc include/linux/sched/mm.h:318 [inline] slab_pre_alloc_hook mm/slub.c:4102 [inline] slab_alloc_node mm/slub.c:4180 [inline] kmem_cache_alloc_node_noprof+0x57/0x3b0 mm/slub.c:4252 __alloc_skb+0x2b2/0x380 net/core/skbuff.c:658 alloc_skb include/linux/skbuff.h:1340 [inline] alloc_uevent_skb+0x7d/0x210 lib/kobject_uevent.c:289 uevent_net_broadcast_untagged lib/kobject_uevent.c:326 [inline] kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline] kobject_uevent_env+0xca4/0x1870 lib/kobject_uevent.c:608 kobject_synth_uevent+0x7d4/0x8a0 lib/kobject_uevent.c:207 bus_uevent_store+0x3d/0x90 drivers/base/bus.c:832 bus_attr_store+0x74/0xb0 drivers/base/bus.c:172 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x354/0x510 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x5bd/0x1180 fs/read_write.c:684 ksys_write+0x12a/0x240 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (uevent_sock_mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain kernel/locking/lockdep.c:3909 [inline] __lock_acquire+0x1173/0x1ba0 kernel/locking/lockdep.c:5235 lock_acquire kernel/locking/lockdep.c:5866 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:746 uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline] kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline] kobject_uevent_env+0xb36/0x1870 lib/kobject_uevent.c:608 loop_set_size drivers/block/loop.c:211 [inline] loop_set_size drivers/block/loop.c:208 [inline] loop_set_status+0x9c7/0xb90 drivers/block/loop.c:1306 loop_set_status64 drivers/block/loop.c:1415 [inline] lo_ioctl+0x729/0x26d0 drivers/block/loop.c:1582 blkdev_ioctl+0x277/0x6d0 block/ioctl.c:698 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: uevent_sock_mutex --> fs_reclaim --> &q->q_usage_counter(io)#21 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&q->q_usage_counter(io)#21); lock(fs_reclaim); lock(&q->q_usage_counter(io)#21); lock(uevent_sock_mutex); *** DEADLOCK *** 3 locks held by syz.4.240/6758: #0: ffff8880258d6b68 (&lo->lo_mutex){+.+.}-{4:4}, at: loop_set_status+0x2a/0xb90 drivers/block/loop.c:1275 #1: ffff888142371428 (&q->q_usage_counter(io)#21){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x15/0x20 block/blk-mq.c:215 #2: ffff888142371460 (&q->q_usage_counter(queue)#19){+.+.}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x15/0x20 block/blk-mq.c:215 stack backtrace: CPU: 1 UID: 0 PID: 6758 Comm: syz.4.240 Not tainted 6.14.0-syzkaller-13189-ge48e99b6edf4 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2079 check_noncircular+0x14c/0x170 kernel/locking/lockdep.c:2211 check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain kernel/locking/lockdep.c:3909 [inline] __lock_acquire+0x1173/0x1ba0 kernel/locking/lockdep.c:5235 lock_acquire kernel/locking/lockdep.c:5866 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:746 uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline] kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline] kobject_uevent_env+0xb36/0x1870 lib/kobject_uevent.c:608 loop_set_size drivers/block/loop.c:211 [inline] loop_set_size drivers/block/loop.c:208 [inline] loop_set_status+0x9c7/0xb90 drivers/block/loop.c:1306 loop_set_status64 drivers/block/loop.c:1415 [inline] lo_ioctl+0x729/0x26d0 drivers/block/loop.c:1582 blkdev_ioctl+0x277/0x6d0 block/ioctl.c:698 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f34fdd8d169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f34feb15038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f34fdfa5fa0 RCX: 00007f34fdd8d169 RDX: 00002000000000c0 RSI: 0000000000004c04 RDI: 0000000000000005 RBP: 00007f34fde0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f34fdfa5fa0 R15: 00007ffe91dcd808