====================================================== WARNING: possible circular locking dependency detected 4.14.290-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.5/15708 is trying to acquire lock: ((&strp->work)){+.+.}, at: [] flush_work+0x88/0x770 kernel/workqueue.c:2887 but task is already holding lock: (sk_lock-AF_INET6){+.+.}, at: [] lock_sock include/net/sock.h:1473 [inline] (sk_lock-AF_INET6){+.+.}, at: [] kcm_attach net/kcm/kcmsock.c:1390 [inline] (sk_lock-AF_INET6){+.+.}, at: [] kcm_attach_ioctl net/kcm/kcmsock.c:1490 [inline] (sk_lock-AF_INET6){+.+.}, at: [] kcm_ioctl+0x328/0xfb0 net/kcm/kcmsock.c:1701 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (sk_lock-AF_INET6){+.+.}: lock_sock_nested+0xb7/0x100 net/core/sock.c:2813 do_strp_work net/strparser/strparser.c:415 [inline] strp_work+0x3e/0x100 net/strparser/strparser.c:434 process_one_work+0x793/0x14a0 kernel/workqueue.c:2117 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 -> #0 ((&strp->work)){+.+.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 flush_work+0xad/0x770 kernel/workqueue.c:2890 __cancel_work_timer+0x321/0x460 kernel/workqueue.c:2965 strp_done+0x53/0xd0 net/strparser/strparser.c:519 kcm_attach net/kcm/kcmsock.c:1429 [inline] kcm_attach_ioctl net/kcm/kcmsock.c:1490 [inline] kcm_ioctl+0x828/0xfb0 net/kcm/kcmsock.c:1701 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 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sk_lock-AF_INET6); lock((&strp->work)); lock(sk_lock-AF_INET6); lock((&strp->work)); *** DEADLOCK *** 1 lock held by syz-executor.5/15708: #0: (sk_lock-AF_INET6){+.+.}, at: [] lock_sock include/net/sock.h:1473 [inline] #0: (sk_lock-AF_INET6){+.+.}, at: [] kcm_attach net/kcm/kcmsock.c:1390 [inline] #0: (sk_lock-AF_INET6){+.+.}, at: [] kcm_attach_ioctl net/kcm/kcmsock.c:1490 [inline] #0: (sk_lock-AF_INET6){+.+.}, at: [] kcm_ioctl+0x328/0xfb0 net/kcm/kcmsock.c:1701 stack backtrace: CPU: 1 PID: 15708 Comm: syz-executor.5 Not tainted 4.14.290-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 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 flush_work+0xad/0x770 kernel/workqueue.c:2890 __cancel_work_timer+0x321/0x460 kernel/workqueue.c:2965 strp_done+0x53/0xd0 net/strparser/strparser.c:519 kcm_attach net/kcm/kcmsock.c:1429 [inline] kcm_attach_ioctl net/kcm/kcmsock.c:1490 [inline] kcm_ioctl+0x828/0xfb0 net/kcm/kcmsock.c:1701 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: 0033:0x7f248ed9b279 RSP: 002b:00007f248d6ef168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f248eeae050 RCX: 00007f248ed9b279 RDX: 0000000020000180 RSI: 00000000000089e0 RDI: 0000000000000003 RBP: 00007f248edf5189 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc21b3954f R14: 00007f248d6ef300 R15: 0000000000022000 print_req_error: I/O error, dev loop4, sector 0 print_req_error: I/O error, dev loop0, sector 0 tmpfs: No value for mount option '01777777777777777777777' audit: type=1800 audit(1660952562.666:46): pid=15833 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.0" name="file0" dev="sda1" ino=14429 res=0 9pnet: Insufficient options for proto=fd audit: type=1804 audit(1660952562.686:47): pid=15833 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir1242399139/syzkaller.VLkyAE/186/file0" dev="sda1" ino=14429 res=1 tmpfs: No value for mount option '01777777777777777777777' print_req_error: I/O error, dev loop1, sector 0 Buffer I/O error on dev loop1, logical block 0, async page read tmpfs: No value for mount option '01777777777777777777777' tmpfs: No value for mount option '01777777777777777777777' device lo entered promiscuous mode Y4cRݘOC: renamed from lo EXT4-fs (loop3): ext4_check_descriptors: Inode bitmap for group 0 not in group (block 0)! EXT4-fs (loop3): group descriptors corrupted! print_req_error: I/O error, dev loop3, sector 0 Buffer I/O error on dev loop3, logical block 0, async page read print_req_error: I/O error, dev loop3, sector 6 Buffer I/O error on dev loop3, logical block 3, async page read EXT4-fs (loop4): ext4_check_descriptors: Inode bitmap for group 0 not in group (block 0)! EXT4-fs (loop4): group descriptors corrupted! EXT4-fs (loop1): ext4_check_descriptors: Inode bitmap for group 0 not in group (block 0)! EXT4-fs (loop1): group descriptors corrupted! EXT4-fs (loop2): ext4_check_descriptors: Inode bitmap for group 0 not in group (block 0)! EXT4-fs (loop2): group descriptors corrupted! print_req_error: I/O error, dev loop1, sector 0 Buffer I/O error on dev loop1, logical block 0, async page read print_req_error: I/O error, dev loop1, sector 6 Buffer I/O error on dev loop1, logical block 3, async page read print_req_error: I/O error, dev loop4, sector 0 Buffer I/O error on dev loop4, logical block 0, async page read print_req_error: I/O error, dev loop4, sector 6 Buffer I/O error on dev loop4, logical block 3, async page read unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 EXT4-fs (loop4): ext4_check_descriptors: Inode bitmap for group 0 not in group (block 0)! EXT4-fs (loop4): group descriptors corrupted! EXT4-fs (loop3): ext4_check_descriptors: Inode bitmap for group 0 not in group (block 0)! EXT4-fs (loop3): group descriptors corrupted!