Hello, syzbot found the following issue on: HEAD commit: 2ae2aaafb214 Add linux-next specific files for 20250624 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=10deb70c580000 kernel config: https://syzkaller.appspot.com/x/.config?x=d85d3c440a754f86 dashboard link: https://syzkaller.appspot.com/bug?extid=bd936ccd4339cea66e6b compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/689f558e5251/disk-2ae2aaaf.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/355aae0f4972/vmlinux-2ae2aaaf.xz kernel image: https://storage.googleapis.com/syzbot-assets/94e736ebe604/bzImage-2ae2aaaf.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+bd936ccd4339cea66e6b@xxxxxxxxxxxxxxxxxxxxxxxxx ============================================ WARNING: possible recursive locking detected 6.16.0-rc3-next-20250624-syzkaller #0 Not tainted -------------------------------------------- kworker/u8:11/20346 is trying to acquire lock: ffffe8ffffd55fd8 (&pd_list->lock){+...}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] ffffe8ffffd55fd8 (&pd_list->lock){+...}-{3:3}, at: padata_find_next kernel/padata.c:256 [inline] ffffe8ffffd55fd8 (&pd_list->lock){+...}-{3:3}, at: padata_reorder kernel/padata.c:309 [inline] ffffe8ffffd55fd8 (&pd_list->lock){+...}-{3:3}, at: padata_do_serial+0x73e/0xb80 kernel/padata.c:379 but task is already holding lock: ffffe8ffffd5f4d8 (&pd_list->lock){+...}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] ffffe8ffffd5f4d8 (&pd_list->lock){+...}-{3:3}, at: padata_reorder kernel/padata.c:300 [inline] ffffe8ffffd5f4d8 (&pd_list->lock){+...}-{3:3}, at: padata_do_serial+0x5b5/0xb80 kernel/padata.c:379 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&pd_list->lock); lock(&pd_list->lock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by kworker/u8:11/20346: #0: ffff888146e84948 ((wq_completion)pencrypt_parallel){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #0: ffff888146e84948 ((wq_completion)pencrypt_parallel){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322 #1: ffffc9000bf7fbc0 ((work_completion)(&pw->pw_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline] #1: ffffc9000bf7fbc0 ((work_completion)(&pw->pw_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322 #2: ffffe8ffffd5f4d8 (&pd_list->lock){+...}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffffe8ffffd5f4d8 (&pd_list->lock){+...}-{3:3}, at: padata_reorder kernel/padata.c:300 [inline] #2: ffffe8ffffd5f4d8 (&pd_list->lock){+...}-{3:3}, at: padata_do_serial+0x5b5/0xb80 kernel/padata.c:379 stack backtrace: CPU: 1 UID: 0 PID: 20346 Comm: kworker/u8:11 Not tainted 6.16.0-rc3-next-20250624-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: pencrypt_parallel padata_parallel_worker Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_deadlock_bug+0x28b/0x2a0 kernel/locking/lockdep.c:3044 check_deadlock kernel/locking/lockdep.c:3096 [inline] validate_chain+0x1a3f/0x2140 kernel/locking/lockdep.c:3898 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] padata_find_next kernel/padata.c:256 [inline] padata_reorder kernel/padata.c:309 [inline] padata_do_serial+0x73e/0xb80 kernel/padata.c:379 padata_parallel_worker+0x75/0x1d0 kernel/padata.c:157 process_one_work kernel/workqueue.c:3239 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3322 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3403 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK> --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
