Hello, syzbot found the following issue on: HEAD commit: 8755ae45a9e8 Add linux-next specific files for 20220819 git tree: linux-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=107cf485080000 kernel config: https://syzkaller.appspot.com/x/.config?x=ead6107a3bbe3c62 dashboard link: https://syzkaller.appspot.com/bug?extid=78c55c7bc6f66e53dce2 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12e678cb080000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13f68e5b080000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+78c55c7bc6f66e53dce2@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 6.0.0-rc1-next-20220819-syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:3/46 is trying to acquire lock: ffff888027dc40e8 ((work_completion)(&(&cp->cp_send_w)->work)){+.+.}-{0:0}, at: __flush_work+0xdd/0xae0 kernel/workqueue.c:3066 but task is already holding lock: ffff88807e18da70 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1712 [inline] ffff88807e18da70 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: rds_tcp_reset_callbacks+0x1bf/0x4d0 net/rds/tcp.c:169 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (k-sk_lock-AF_INET6){+.+.}-{0:0}: lock_sock_nested+0x36/0xf0 net/core/sock.c:3391 lock_sock include/net/sock.h:1712 [inline] tcp_sock_set_cork+0x16/0x90 net/ipv4/tcp.c:3328 rds_send_xmit+0x386/0x2540 net/rds/send.c:194 rds_send_worker+0x92/0x2e0 net/rds/threads.c:200 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 -> #0 ((work_completion)(&(&cp->cp_send_w)->work)){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5666 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631 __flush_work+0x105/0xae0 kernel/workqueue.c:3069 __cancel_work_timer+0x3f9/0x570 kernel/workqueue.c:3160 rds_tcp_reset_callbacks+0x1cb/0x4d0 net/rds/tcp.c:171 rds_tcp_accept_one+0x9d5/0xd10 net/rds/tcp_listen.c:203 rds_tcp_accept_worker+0x55/0x80 net/rds/tcp.c:529 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(k-sk_lock-AF_INET6); lock((work_completion)(&(&cp->cp_send_w)->work)); lock(k-sk_lock-AF_INET6); lock((work_completion)(&(&cp->cp_send_w)->work)); *** DEADLOCK *** 4 locks held by kworker/u4:3/46: #0: ffff8880275f7938 ((wq_completion)krdsd){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880275f7938 ((wq_completion)krdsd){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff8880275f7938 ((wq_completion)krdsd){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff8880275f7938 ((wq_completion)krdsd){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline] #0: ffff8880275f7938 ((wq_completion)krdsd){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline] #0: ffff8880275f7938 ((wq_completion)krdsd){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260 #1: ffffc90000b77da8 ((work_completion)(&rtn->rds_tcp_accept_w)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264 #2: ffff8880733c4088 (&tc->t_conn_path_lock){+.+.}-{3:3}, at: rds_tcp_accept_one+0x892/0xd10 net/rds/tcp_listen.c:195 #3: ffff88807e18da70 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1712 [inline] #3: ffff88807e18da70 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: rds_tcp_reset_callbacks+0x1bf/0x4d0 net/rds/tcp.c:169 stack backtrace: CPU: 1 PID: 46 Comm: kworker/u4:3 Not tainted 6.0.0-rc1-next-20220819-syzkaller #0 kworker/u4:3[46] cmdline: ��a����� Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Workqueue: krdsd rds_tcp_accept_worker Call Trace: <TASK> __dump_stack lib/dump_stack.c:122 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:140 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5666 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631 __flush_work+0x105/0xae0 kernel/workqueue.c:3069 __cancel_work_timer+0x3f9/0x570 kernel/workqueue.c:3160 rds_tcp_reset_callbacks+0x1cb/0x4d0 net/rds/tcp.c:171 rds_tcp_accept_one+0x9d5/0xd10 net/rds/tcp_listen.c:203 rds_tcp_accept_worker+0x55/0x80 net/rds/tcp.c:529 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 </TASK> --- This report is generated by a bot. 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