L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details. ====================================================== WARNING: possible circular locking dependency detected 4.14.288-syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:1/23 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/u4:1/23: #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: 23 Comm: kworker/u4:1 Not tainted 4.14.288-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 base_sock_release(ffff8880711fb640) sk=ffff88809f901580 base_sock_release(ffff88807121d100) sk=ffff88809d058180 base_sock_release(ffff888071235500) sk=ffff8880a39b56c0 base_sock_release(ffff888071288000) sk=ffff8880abdfd440 BTRFS: device fsid 1ec9bb8f-f528-40a0-88c7-e37435d3f692 devid 1 transid 7 /dev/loop2 BTRFS: device fsid f90cac8b-044b-4fa8-8bee-4b8d3da88dc2 devid 1 transid 7 /dev/loop5 BTRFS error (device loop2): unsupported checksum algorithm 3 BTRFS error (device loop5): superblock checksum mismatch BTRFS error (device loop2): superblock checksum mismatch BTRFS error (device loop5): open_ctree failed BTRFS error (device loop2): open_ctree failed BTRFS error (device loop5): superblock checksum mismatch BTRFS error (device loop2): unsupported checksum algorithm 3 BTRFS error (device loop2): superblock checksum mismatch BTRFS error (device loop5): open_ctree failed BTRFS error (device loop5): superblock checksum mismatch BTRFS error (device loop2): open_ctree failed BTRFS error (device loop5): open_ctree failed BTRFS error (device loop5): superblock checksum mismatch BTRFS error (device loop2): unsupported checksum algorithm 3 BTRFS error (device loop2): superblock checksum mismatch BTRFS error (device loop5): open_ctree failed BTRFS error (device loop5): superblock checksum mismatch BTRFS error (device loop2): open_ctree failed BTRFS error (device loop5): open_ctree failed BTRFS error (device loop4): superblock checksum mismatch BTRFS error (device loop4): open_ctree failed BTRFS error (device loop1): superblock checksum mismatch BTRFS error (device loop1): open_ctree failed BTRFS error (device loop2): unsupported checksum algorithm 3 BTRFS error (device loop3): superblock checksum mismatch BTRFS error (device loop2): superblock checksum mismatch BTRFS error (device loop3): open_ctree failed BTRFS error (device loop3): superblock checksum mismatch BTRFS error (device loop2): open_ctree failed BTRFS error (device loop3): open_ctree failed BTRFS error (device loop3): superblock checksum mismatch ip6_tables: ip6tables: counters copy to user failed while replacing table hrtimer: interrupt took 29712 ns BTRFS error (device loop3): open_ctree failed BTRFS error (device loop3): superblock checksum mismatch ip6_tables: ip6tables: counters copy to user failed while replacing table BTRFS error (device loop3): open_ctree failed ip6_tables: ip6tables: counters copy to user failed while replacing table ISO 9660 Extensions: Microsoft Joliet Level 3 ISOFS: changing to secondary root ip6_tables: ip6tables: counters copy to user failed while replacing table ip6_tables: ip6tables: counters copy to user failed while replacing table ISO 9660 Extensions: Microsoft Joliet Level 3 ISOFS: changing to secondary root ip6_tables: ip6tables: counters copy to user failed while replacing table ISO 9660 Extensions: Microsoft Joliet Level 3 ip6_tables: ip6tables: counters copy to user failed while replacing table ISOFS: changing to secondary root ISO 9660 Extensions: Microsoft Joliet Level 3 ISOFS: changing to secondary root