Warning: Permanently added '10.128.1.52' (ECDSA) to the list of known hosts. executing program [ 29.835835] [ 29.837472] ====================================================== [ 29.843763] WARNING: possible circular locking dependency detected [ 29.850052] 4.14.288-syzkaller #0 Not tainted [ 29.854529] ------------------------------------------------------ [ 29.860829] kworker/u4:0/5 is trying to acquire lock: [ 29.865987] (sk_lock-AF_INET6){+.+.}, at: [] strp_work+0x3e/0x100 [ 29.873851] [ 29.873851] but task is already holding lock: [ 29.879886] ((&strp->work)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 [ 29.888269] [ 29.888269] which lock already depends on the new lock. [ 29.888269] [ 29.896557] [ 29.896557] the existing dependency chain (in reverse order) is: [ 29.904149] [ 29.904149] -> #1 ((&strp->work)){+.+.}: [ 29.909669] flush_work+0xad/0x770 [ 29.913760] __cancel_work_timer+0x321/0x460 [ 29.918663] strp_done+0x53/0xd0 [ 29.922520] kcm_ioctl+0x828/0xfb0 [ 29.926555] sock_ioctl+0x2cc/0x4c0 [ 29.930675] do_vfs_ioctl+0x75a/0xff0 [ 29.934974] SyS_ioctl+0x7f/0xb0 [ 29.938831] do_syscall_64+0x1d5/0x640 [ 29.943216] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.948897] [ 29.948897] -> #0 (sk_lock-AF_INET6){+.+.}: [ 29.954675] lock_acquire+0x170/0x3f0 [ 29.958975] lock_sock_nested+0xb7/0x100 [ 29.963547] strp_work+0x3e/0x100 [ 29.967495] process_one_work+0x793/0x14a0 [ 29.974307] worker_thread+0x5cc/0xff0 [ 29.978699] kthread+0x30d/0x420 [ 29.982560] ret_from_fork+0x24/0x30 [ 29.986762] [ 29.986762] other info that might help us debug this: [ 29.986762] [ 29.994877] Possible unsafe locking scenario: [ 29.994877] [ 30.000906] CPU0 CPU1 [ 30.005571] ---- ---- [ 30.010211] lock((&strp->work)); [ 30.013725] lock(sk_lock-AF_INET6); [ 30.020017] lock((&strp->work)); [ 30.026055] lock(sk_lock-AF_INET6); [ 30.029828] [ 30.029828] *** DEADLOCK *** [ 30.029828] [ 30.035858] 2 locks held by kworker/u4:0/5: [ 30.040159] #0: ("%s""kstrp"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 [ 30.048802] #1: ((&strp->work)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 [ 30.057622] [ 30.057622] stack backtrace: [ 30.062096] CPU: 1 PID: 5 Comm: kworker/u4:0 Not tainted 4.14.288-syzkaller #0 [ 30.069428] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 [ 30.078762] Workqueue: kstrp strp_work [ 30.082621] Call Trace: [ 30.085183] dump_stack+0x1b2/0x281 [ 30.088788] print_circular_bug.constprop.0.cold+0x2d7/0x41e [ 30.094564] __lock_acquire+0x2e0e/0x3f20 [ 30.098690] ? __schedule+0x893/0x1de0 [ 30.102552] ? trace_hardirqs_on+0x10/0x10 [ 30.106774] ? lock_acquire+0x170/0x3f0 [ 30.110722] ? lock_sock_nested+0x98/0x100 [ 30.114933] lock_acquire+0x170/0x3f0 [ 30.118707] ? strp_work+0x3e/0x100 [ 30.122308] lock_sock_nested+0xb7/0x100 [ 30.126346] ? strp_work+0x3e/0x100 [ 30.129950] strp_work+0x3e/0x100 [ 30.133382] process_one_work+0x793/0x14