====================================================== WARNING: possible circular locking dependency detected 4.14.230-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/25391 is trying to acquire lock: (&sig->cred_guard_mutex){+.+.}, at: [] lock_trace fs/proc/base.c:407 [inline] (&sig->cred_guard_mutex){+.+.}, at: [] proc_pid_stack+0x13f/0x2f0 fs/proc/base.c:457 but task is already holding lock: (&p->lock){+.+.}, at: [] seq_read+0xba/0x1120 fs/seq_file.c:165 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&p->lock){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 seq_read+0xba/0x1120 fs/seq_file.c:165 proc_reg_read+0xee/0x1a0 fs/proc/inode.c:217 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3eb/0x5b0 fs/read_write.c:919 vfs_readv+0xc8/0x120 fs/read_write.c:981 kernel_readv fs/splice.c:361 [inline] default_file_splice_read+0x418/0x910 fs/splice.c:416 do_splice_to+0xfb/0x140 fs/splice.c:880 splice_direct_to_actor+0x207/0x730 fs/splice.c:952 do_splice_direct+0x164/0x210 fs/splice.c:1061 do_sendfile+0x47f/0xb30 fs/read_write.c:1441 SYSC_sendfile64 fs/read_write.c:1502 [inline] SyS_sendfile64+0xff/0x110 fs/read_write.c:1488 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #2 (sb_writers#3){.+.+}: percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x64/0x260 fs/super.c:1342 sb_start_write include/linux/fs.h:1549 [inline] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 ovl_create_object+0x75/0x1d0 fs/overlayfs/dir.c:538 lookup_open+0x77a/0x1750 fs/namei.c:3241 do_last fs/namei.c:3334 [inline] path_openat+0xe08/0x2970 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #1 (&ovl_i_mutex_dir_key[depth]){++++}: down_read+0x36/0x80 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:729 [inline] do_last fs/namei.c:3333 [inline] path_openat+0x149b/0x2970 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_open_execat+0xd3/0x450 fs/exec.c:849 do_execveat_common+0x711/0x1f30 fs/exec.c:1755 do_execve fs/exec.c:1860 [inline] SYSC_execve fs/exec.c:1941 [inline] SyS_execve+0x3b/0x50 fs/exec.c:1936 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #0 (&sig->cred_guard_mutex){+.+.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 lock_trace fs/proc/base.c:407 [inline] proc_pid_stack+0x13f/0x2f0 fs/proc/base.c:457 proc_single_show+0xe7/0x150 fs/proc/base.c:761 seq_read+0x4cf/0x1120 fs/seq_file.c:237 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3eb/0x5b0 fs/read_write.c:919 vfs_readv+0xc8/0x120 fs/read_write.c:981 do_preadv fs/read_write.c:1065 [inline] SYSC_preadv fs/read_write.c:1115 [inline] SyS_preadv+0x15a/0x200 fs/read_write.c:1110 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb other info that might help us debug this: Chain exists of: &sig->cred_guard_mutex --> sb_writers#3 --> &p->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&p->lock); lock(sb_writers#3); lock(&p->lock); lock(&sig->cred_guard_mutex); *** DEADLOCK *** 1 lock held by syz-executor.1/25391: #0: (&p->lock){+.+.}, at: [] seq_read+0xba/0x1120 fs/seq_file.c:165 stack backtrace: CPU: 1 PID: 25391 Comm: syz-executor.1 Not tainted 4.14.230-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 lock_trace fs/proc/base.c:407 [inline] proc_pid_stack+0x13f/0x2f0 fs/proc/base.c:457 proc_single_show+0xe7/0x150 fs/proc/base.c:761 seq_read+0x4cf/0x1120 fs/seq_file.c:237 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3eb/0x5b0 fs/read_write.c:919 vfs_readv+0xc8/0x120 fs/read_write.c:981 do_preadv fs/read_write.c:1065 [inline] SYSC_preadv fs/read_write.c:1115 [inline] SyS_preadv+0x15a/0x200 fs/read_write.c:1110 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x466459 RSP: 002b:00007f9303d13188 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 000000000056c2a8 RCX: 0000000000466459 RDX: 0000000000000375 RSI: 00000000200017c0 RDI: 0000000000000006 RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c2a8 R13: 00007ffff52c2e4f R14: 00007f9303d13300 R15: 0000000000022000 EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) squashfs: SQUASHFS error: Can't find a SQUASHFS superblock on loop5 base_sock_release(ffff88808dfd2580) sk=ffff8880a8530980 base_sock_release(ffff888094e07600) sk=ffff888095508540 EXT4-fs warning: 21 callbacks suppressed EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) vhci_hcd vhci_hcd.0: pdev(0) rhport(0) sockfd(9) vhci_hcd vhci_hcd.0: devid(0) speed(4) speed_str(wireless) vhci_hcd: connection closed vhci_hcd: stop threads vhci_hcd: release socket vhci_hcd: disconnect device EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 26490 Comm: syz-executor.4 Not tainted 4.14.230-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0x10a/0x149 lib/fault-inject.c:149 should_failslab+0xd6/0x130 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:421 [inline] slab_alloc mm/slab.c:3376 [inline] kmem_cache_alloc_trace+0x29a/0x3d0 mm/slab.c:3616 kmalloc include/linux/slab.h:488 [inline] ax25_uid_ioctl+0x4c4/0x7b0 net/ax25/ax25_uid.c:107 ax25_ioctl+0x903/0x990 net/ax25/af_ax25.c:1744 sock_do_ioctl net/socket.c:974 [inline] sock_ioctl+0x2cc/0x4c0 net/socket.c:1071 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x466459 RSP: 002b:00007f0f6cec2188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 00000000200000c0 RSI: 00000000000089e1 RDI: 0000000000000004 RBP: 00007f0f6cec21d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffd332e23bf R14: 00007f0f6cec2300 R15: 0000000000022000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 ax25_connect(): syz-executor.4 uses autobind, please contact jreuter@yaina.de CPU: 1 PID: 26619 Comm: syz-executor.0 Not tainted 4.14.230-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0x10a/0x149 lib/fault-inject.c:149 should_failslab+0xd6/0x130 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:421 [inline] slab_alloc mm/slab.c:3376 [inline] __do_kmalloc mm/slab.c:3718 [inline] __kmalloc+0x2c1/0x400 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] sctp_getsockopt_assoc_ids net/sctp/socket.c:6414 [inline] sctp_getsockopt+0x2dee/0x4c70 net/sctp/socket.c:7003 SYSC_getsockopt net/socket.c:1896 [inline] SyS_getsockopt+0x102/0x1c0 net/socket.c:1878 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x466459 RSP: 002b:00007f00de16e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 000000000000001d RSI: 0000000000000084 RDI: 0000000000000003 RBP: 00007f00de16e1d0 R08: 0000000020a8a000 R09: 0000000000000000 R10: 000000002025e000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007fff696faf2f R14: 00007f00de16e300 R15: 0000000000022000 ax25_connect(): syz-executor.4 uses autobind, please contact jreuter@yaina.de FAULT_INJECTION: forcing a failure. name fail_page_alloc, interval 1, probability 0, space 0, times 1 CPU: 1 PID: 26646 Comm: syz-executor.0 Not tainted 4.14.230-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0x10a/0x149 lib/fault-inject.c:149 should_fail_alloc_page mm/page_alloc.c:2898 [inline] prepare_alloc_pages mm/page_alloc.c:4131 [inline] __alloc_pages_nodemask+0x22c/0x2720 mm/page_alloc.c:4179 __alloc_pages include/linux/gfp.h:484 [inline] __alloc_pages_node include/linux/gfp.h:497 [inline] alloc_pages_vma+0x4b3/0x6d0 mm/mempolicy.c:2070 do_huge_pmd_anonymous_page+0x2d6/0x1700 mm/huge_memory.c:725 create_huge_pmd mm/memory.c:3974 [inline] __handle_mm_fault+0x2ac4/0x4620 mm/memory.c:4177 handle_mm_fault+0x455/0x9c0 mm/memory.c:4243 __do_page_fault+0x549/0xad0 arch/x86/mm/fault.c:1442 page_fault+0x25/0x50 arch/x86/entry/entry_64.S:1123 RIP: 0010:copy_user_generic_unrolled+0xa0/0xc0 arch/x86/lib/copy_user_64.S:76 RSP: 0018:ffff8881eccdfb98 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000000004 RDX: 0000000000000004 RSI: ffff8880b2e1aa80 RDI: 000000002025e000 RBP: ffff8880b2e1aa80 R08: 0000000000000000 R09: ffffed10165c3550 R10: 0000000000000003 R11: ffff88803ee985c0 R12: 000000002025e000 R13: 00007ffffffff000 R14: 000000002025e004 R15: 0000000000000000 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:112 [inline] _copy_to_user+0xaa/0xd0 lib/usercopy.c:28 copy_to_user include/linux/uaccess.h:155 [inline] sctp_getsockopt_assoc_ids net/sctp/socket.c:6424 [inline] sctp_getsockopt+0x2fa2/0x4c70 net/sctp/socket.c:7003 SYSC_getsockopt net/socket.c:1896 [inline] SyS_getsockopt+0x102/0x1c0 net/socket.c:1878 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x466459 RSP: 002b:00007f00de16e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 000000000000001d RSI: 0000000000000084 RDI: 0000000000000003 RBP: 00007f00de16e1d0 R08: 0000000020a8a000 R09: 0000000000000000 R10: 000000002025e000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007fff696faf2f R14: 00007f00de16e300 R15: 0000000000022000 EXT4-fs warning: 15 callbacks suppressed EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) FAULT_INJECTION: forcing a failure. name fail_page_alloc, interval 1, probability 0, space 0, times 0 EXT4-fs warning (device sda1): verify_group_input:131: Cannot add at group 255 (only 16 groups) CPU: 0 PID: 26687 Comm: syz-executor.0 Not tainted 4.14.230-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0x10a/0x149 lib/fault-inject.c:149 should_fail_alloc_page mm/page_alloc.c:2898 [inline] prepare_alloc_pages mm/page_alloc.c:4131 [inline] __alloc_pages_nodemask+0x22c/0x2720 mm/page_alloc.c:4179 alloc_pages_current+0x155/0x260 mm/mempolicy.c:2113 alloc_pages include/linux/gfp.h:520 [inline] pte_alloc_one+0x15/0x100 arch/x86/mm/pgtable.c:30 __pte_alloc+0x25/0x2c0 mm/memory.c:668 do_anonymous_page mm/memory.c:3196 [inline] handle_pte_fault mm/memory.c:4080 [inline] __handle_mm_fault+0x3259/0x4620 mm/memory.c:4206 handle_mm_fault+0x455/0x9c0 mm/memory.c:4243 __do_page_fault+0x549/0xad0 arch/x86/mm/fault.c:1442 page_fault+0x25/0x50 arch/x86/entry/entry_64.S:1123 RIP: 0010:copy_user_generic_unrolled+0xa0/0xc0 arch/x86/lib/copy_user_64.S:76 RSP: 0018:ffff88822213fb98 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000000004 RDX: 0000000000000004 RSI: ffff8880a61cda40 RDI: 000000002025e000 RBP: ffff8880a61cda40 R08: 0000000000000000 R09: ffffed1014c39b48 R10: 0000000000000003 R11: ffff88803ef2a340 R12: 000000002025e000 R13: 00007ffffffff000 R14: 000000002025e004 R15: 0000000000000000 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:112 [inline] _copy_to_user+0xaa/0xd0 lib/usercopy.c:28 copy_to_user include/linux/uaccess.h:155 [inline] sctp_getsockopt_assoc_ids net/sctp/socket.c:6424 [inline] sctp_getsockopt+0x2fa2/0x4c70 net/sctp/socket.c:7003 SYSC_getsockopt net/socket.c:1896 [inline] SyS_getsockopt+0x102/0x1c0 net/socket.c:1878 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x466459