loop0: detected capacity change from 0 to 32768 loop0: detected capacity change from 32768 to 32767 ====================================================== WARNING: possible circular locking dependency detected 6.16.0-rc1-syzkaller-g4774cfe3543a #0 Not tainted ------------------------------------------------------ syz.0.16/5894 is trying to acquire lock: ffffffff8f87a3e8 (uevent_sock_mutex){+.+.}-{4:4}, at: uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline] ffffffff8f87a3e8 (uevent_sock_mutex){+.+.}-{4:4}, at: kobject_uevent_net_broadcast+0x27e/0x560 lib/kobject_uevent.c:410 but task is already holding lock: ffff888000ea9e00 (&q->q_usage_counter(io)#17){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline] ffff888000ea9e00 (&q->q_usage_counter(io)#17){++++}-{0:0}, at: loop_set_status+0x227/0xaf0 drivers/block/loop.c:1239 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&q->q_usage_counter(io)#17){++++}-{0:0}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 blk_alloc_queue+0x538/0x620 block/blk-core.c:461 blk_mq_alloc_queue block/blk-mq.c:4396 [inline] __blk_mq_alloc_disk+0x162/0x340 block/blk-mq.c:4443 loop_add+0x41b/0xad0 drivers/block/loop.c:2014 loop_init+0x173/0x230 drivers/block/loop.c:2249 do_one_initcall+0x233/0x820 init/main.c:1273 do_initcall_level+0x137/0x1f0 init/main.c:1335 do_initcalls+0x69/0xd0 init/main.c:1351 kernel_init_freeable+0x3d9/0x570 init/main.c:1583 kernel_init+0x1d/0x1d0 init/main.c:1473 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #1 (fs_reclaim){+.+.}-{0:0}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __fs_reclaim_acquire mm/page_alloc.c:4045 [inline] fs_reclaim_acquire+0x72/0x100 mm/page_alloc.c:4059 might_alloc include/linux/sched/mm.h:318 [inline] slab_pre_alloc_hook mm/slub.c:4099 [inline] slab_alloc_node mm/slub.c:4177 [inline] kmem_cache_alloc_node_noprof+0x47/0x3c0 mm/slub.c:4249 __alloc_skb+0x112/0x2d0 net/core/skbuff.c:660 alloc_skb include/linux/skbuff.h:1336 [inline] alloc_uevent_skb+0x7d/0x230 lib/kobject_uevent.c:289 uevent_net_broadcast_untagged lib/kobject_uevent.c:326 [inline] kobject_uevent_net_broadcast+0x2fa/0x560 lib/kobject_uevent.c:410 kobject_uevent_env+0x55b/0x8c0 lib/kobject_uevent.c:608 kobject_synth_uevent+0x527/0xb00 lib/kobject_uevent.c:207 bus_uevent_store+0x115/0x170 drivers/base/bus.c:832 kernfs_fop_write_iter+0x378/0x4f0 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x548/0xa90 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 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:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3911 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747 uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline] kobject_uevent_net_broadcast+0x27e/0x560 lib/kobject_uevent.c:410 kobject_uevent_env+0x55b/0x8c0 lib/kobject_uevent.c:608 set_capacity_and_notify+0x26d/0x2d0 block/genhd.c:102 loop_set_size drivers/block/loop.c:210 [inline] loop_set_status+0x45b/0xaf0 drivers/block/loop.c:1254 lo_ioctl+0xa5e/0x2410 drivers/block/loop.c:-1 blkdev_ioctl+0x5a8/0x6d0 block/ioctl.c:704 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 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)#17 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&q->q_usage_counter(io)#17); lock(fs_reclaim); lock(&q->q_usage_counter(io)#17); lock(uevent_sock_mutex); *** DEADLOCK *** 3 locks held by syz.0.16/5894: #0: ffff888031365400 (&lo->lo_mutex){+.+.}-{4:4}, at: loop_set_status+0x2c/0xaf0 drivers/block/loop.c:1223 #1: ffff888000ea9e00 (&q->q_usage_counter(io)#17){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline] #1: ffff888000ea9e00 (&q->q_usage_counter(io)#17){++++}-{0:0}, at: loop_set_status+0x227/0xaf0 drivers/block/loop.c:1239 #2: ffff888000ea9e38 (&q->q_usage_counter(queue)#20){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline] #2: ffff888000ea9e38 (&q->q_usage_counter(queue)#20){+.+.}-{0:0}, at: loop_set_status+0x227/0xaf0 drivers/block/loop.c:1239 stack backtrace: CPU: 0 UID: 0 PID: 5894 Comm: syz.0.16 Not tainted 6.16.0-rc1-syzkaller-g4774cfe3543a #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2046 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3911 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747 uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline] kobject_uevent_net_broadcast+0x27e/0x560 lib/kobject_uevent.c:410 kobject_uevent_env+0x55b/0x8c0 lib/kobject_uevent.c:608 set_capacity_and_notify+0x26d/0x2d0 block/genhd.c:102 loop_set_size drivers/block/loop.c:210 [inline] loop_set_status+0x45b/0xaf0 drivers/block/loop.c:1254 lo_ioctl+0xa5e/0x2410 drivers/block/loop.c:-1 blkdev_ioctl+0x5a8/0x6d0 block/ioctl.c:704 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6405b8d169 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:00007f640690a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f6405da5fa0 RCX: 00007f6405b8d169 RDX: 0000400000000300 RSI: 0000000000004c02 RDI: 0000000000000004 RBP: 00007f6405c0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6405da5fa0 R15: 00007ffd7c1dff28 ERROR: (device loop0): txBegin: read-only filesystem ERROR: (device loop0): remounting filesystem as read-only ERROR: (device loop0): dbFindCtl: Corrupt dmapctl page jfs_create: dtInsert returned -EIO ERROR: (device (efault)): jfs_create: Oops: general protection fault, probably for non-canonical address 0xdffffc000000000a: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000050-0x0000000000000057] CPU: 0 UID: 0 PID: 5894 Comm: syz.0.16 Not tainted 6.16.0-rc1-syzkaller-g4774cfe3543a #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:sb_rdonly include/linux/fs.h:2411 [inline] RIP: 0010:jfs_handle_error fs/jfs/super.c:66 [inline] RIP: 0010:jfs_error+0x130/0x2c0 fs/jfs/super.c:98 Code: 8d 4c 24 60 48 c7 c7 60 73 c3 8b 48 89 74 24 08 e8 e5 8d fe ff 4d 8d 6f 50 4d 89 ee 49 c1 ee 03 48 b8 00 00 00 00 00 fc ff df <41> 80 3c 06 00 74 08 4c 89 ef e8 a1 d2 fa 00 4d 8b 65 00 4c 89 e6 RSP: 0018:ffffc90002b5f600 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: 1ffff9200056bec8 RCX: 30579ff254064200 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: ffffc90002b5f710 R08: ffffc90002b5f327 R09: 1ffff9200056be64 R10: dffffc0000000000 R11: fffff5200056be65 R12: ffffc90002b5f680 R13: 0000000000000050 R14: 000000000000000a R15: 0000000000000000 FS: 00007f640690a6c0(0000) GS:ffff88808d252000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000560d39412048 CR3: 0000000056f65000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: jfs_create+0x732/0xa80 fs/jfs/namei.c:140 lookup_open fs/namei.c:3708 [inline] open_last_lookups fs/namei.c:3807 [inline] path_openat+0x14f1/0x3830 fs/namei.c:4043 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_creat fs/open.c:1530 [inline] __se_sys_creat fs/open.c:1524 [inline] __x64_sys_creat+0x8f/0xc0 fs/open.c:1524 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6405b8d169 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:00007f640690a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007f6405da5fa0 RCX: 00007f6405b8d169 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000400000000e00 RBP: 00007f6405c0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6405da5fa0 R15: 00007ffd7c1dff28 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:sb_rdonly include/linux/fs.h:2411 [inline] RIP: 0010:jfs_handle_error fs/jfs/super.c:66 [inline] RIP: 0010:jfs_error+0x130/0x2c0 fs/jfs/super.c:98 Code: 8d 4c 24 60 48 c7 c7 60 73 c3 8b 48 89 74 24 08 e8 e5 8d fe ff 4d 8d 6f 50 4d 89 ee 49 c1 ee 03 48 b8 00 00 00 00 00 fc ff df <41> 80 3c 06 00 74 08 4c 89 ef e8 a1 d2 fa 00 4d 8b 65 00 4c 89 e6 RSP: 0018:ffffc90002b5f600 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: 1ffff9200056bec8 RCX: 30579ff254064200 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: ffffc90002b5f710 R08: ffffc90002b5f327 R09: 1ffff9200056be64 R10: dffffc0000000000 R11: fffff5200056be65 R12: ffffc90002b5f680 R13: 0000000000000050 R14: 000000000000000a R15: 0000000000000000 FS: 00007f640690a6c0(0000) GS:ffff88808d252000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4010075e9c CR3: 0000000056f65000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 8d 4c 24 60 lea 0x60(%rsp),%ecx 4: 48 c7 c7 60 73 c3 8b mov $0xffffffff8bc37360,%rdi b: 48 89 74 24 08 mov %rsi,0x8(%rsp) 10: e8 e5 8d fe ff call 0xfffe8dfa 15: 4d 8d 6f 50 lea 0x50(%r15),%r13 19: 4d 89 ee mov %r13,%r14 1c: 49 c1 ee 03 shr $0x3,%r14 20: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 27: fc ff df * 2a: 41 80 3c 06 00 cmpb $0x0,(%r14,%rax,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 4c 89 ef mov %r13,%rdi 34: e8 a1 d2 fa 00 call 0xfad2da 39: 4d 8b 65 00 mov 0x0(%r13),%r12 3d: 4c 89 e6 mov %r12,%rsi