====================================================== WARNING: possible circular locking dependency detected 4.14.286-syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:4/3105 is trying to acquire lock: (sk_lock-AF_INET6){+.+.}, at: [] do_strp_work net/strparser/strparser.c:415 [inline] (sk_lock-AF_INET6){+.+.}, at: [] strp_work+0x3e/0x100 net/strparser/strparser.c:434 but task is already holding lock: ((&strp->work)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2092 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 ((&strp->work)){+.+.}: 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 -> #0 (sk_lock-AF_INET6){+.+.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 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 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((&strp->work)); lock(sk_lock-AF_INET6); lock((&strp->work)); lock(sk_lock-AF_INET6); *** DEADLOCK *** 2 locks held by kworker/u4:4/3105: #0: ("%s""kstrp"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2088 #1: ((&strp->work)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2092 stack backtrace: CPU: 1 PID: 3105 Comm: kworker/u4:4 Not tainted 4.14.286-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Workqueue: kstrp strp_work 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 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 unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 netlink: 32 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 32 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 32 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 32 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 76 bytes leftover after parsing attributes in process `syz-executor.3'. IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready chnl_net:chnl_net_open(): err: Unable to register and open device, Err:-19 EXT4-fs (loop1): mounted filesystem without journal. Opts: ,errors=continue caif:caif_disconnect_client(): nothing to disconnect chnl_net:chnl_flowctrl_cb(): NET flowctrl func called flow: CLOSE/DEINIT chnl_net:chnl_net_open(): state disconnected A link change request failed with some changes committed already. Interface caif0 may have been left with an inconsistent configuration, please check. EXT4-fs (loop1): mounted filesystem without journal. Opts: ,errors=continue IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready chnl_net:chnl_net_open(): err: Unable to register and open device, Err:-19 FAT-fs (loop3): Directory bread(block 6) failed caif:caif_disconnect_client(): nothing to disconnect chnl_net:chnl_flowctrl_cb(): NET flowctrl func called flow: CLOSE/DEINIT chnl_net:chnl_net_open(): state disconnected A link change request failed with some changes committed already. Interface caif0 may have been left with an inconsistent configuration, please check. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.5'. IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready EXT4-fs (loop1): mounted filesystem without journal. Opts: ,errors=continue chnl_net:chnl_net_open(): err: Unable to register and open device, Err:-19 caif:caif_disconnect_client(): nothing to disconnect FAT-fs (loop5): Directory bread(block 6) failed chnl_net:chnl_flowctrl_cb(): NET flowctrl func called flow: CLOSE/DEINIT chnl_net:chnl_net_open(): state disconnected A link change request failed with some changes committed already. Interface caif0 may have been left with an inconsistent configuration, please check. netlink: 16 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 16 bytes leftover after parsing attributes in process `syz-executor.3'. EXT4-fs (loop1): mounted filesystem without journal. Opts: ,errors=continue IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready chnl_net:chnl_net_open(): err: Unable to register and open device, Err:-19 caif:caif_disconnect_client(): nothing to disconnect chnl_net:chnl_flowctrl_cb(): NET flowctrl func called flow: CLOSE/DEINIT chnl_net:chnl_net_open(): state disconnected A link change request failed with some changes committed already. Interface caif0 may have been left with an inconsistent configuration, please check. netlink: 16 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 16 bytes leftover after parsing attributes in process `syz-executor.3'. print_req_error: I/O error, dev loop4, sector 56 F2FS-fs (loop0): Magic Mismatch, valid(0xf2f52010) - read(0x0) F2FS-fs (loop0): Can't find valid F2FS filesystem in 1th superblock F2FS-fs (loop0): Magic Mismatch, valid(0xf2f52010) - read(0x0) F2FS-fs (loop0): Can't find valid F2FS filesystem in 2th superblock F2FS-fs (loop0): Magic Mismatch, valid(0xf2f52010) - read(0x0) F2FS-fs (loop0): Can't find valid F2FS filesystem in 1th superblock F2FS-fs (loop0): Magic Mismatch, valid(0xf2f52010) - read(0x0) F2FS-fs (loop0): Can't find valid F2FS filesystem in 2th superblock FAT-fs (loop4): Unrecognized mount option "smackfsdef=+:{*" or missing value netlink: 28 bytes leftover after parsing attributes in process `syz-executor.5'. audit: type=1800 audit(1657120155.654:2): pid=11934 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.1" name="file0" dev="sda1" ino=14134 res=0 print_req_error: I/O error, dev loop0, sector 0