FAULT_INJECTION: forcing a failure. name fail_usercopy, interval 1, probability 0, space 0, times 0 ====================================================== WARNING: possible circular locking dependency detected 6.1.123-syzkaller #0 Not tainted ------------------------------------------------------ syz.9.122/5132 is trying to acquire lock: ffffffff8d207278 ((console_sem).lock){-...}-{2:2}, at: down_trylock+0x1c/0xa0 kernel/locking/semaphore.c:139 but task is already holding lock: ffff8880b8e3a9d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 _raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 raw_spin_rq_lock kernel/sched/sched.h:1355 [inline] rq_lock kernel/sched/sched.h:1645 [inline] task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11877 sched_cgroup_fork+0x374/0x400 kernel/sched/core.c:4682 copy_process+0x2442/0x4060 kernel/fork.c:2383 kernel_clone+0x222/0x920 kernel/fork.c:2681 user_mode_thread+0x12e/0x190 kernel/fork.c:2757 rest_init+0x23/0x300 init/main.c:698 start_kernel+0x0/0x53f init/main.c:893 start_kernel+0x496/0x53f init/main.c:1140 secondary_startup_64_no_verify+0xcf/0xdb -> #1 (&p->pi_lock){-.-.}-{2:2}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 try_to_wake_up+0xad/0x12e0 kernel/sched/core.c:4108 up+0x6e/0x90 kernel/locking/semaphore.c:191 __up_console_sem+0x11a/0x1e0 kernel/printk/printk.c:260 __console_unlock kernel/printk/printk.c:2697 [inline] console_unlock+0x591/0x7c0 kernel/printk/printk.c:2908 vprintk_emit+0x523/0x740 kernel/printk/printk.c:2303 _printk+0xd1/0x111 kernel/printk/printk.c:2328 blk_print_req_error+0x176/0x210 block/blk-mq.c:796 blk_update_request+0xcc5/0x1010 block/blk-mq.c:909 blk_mq_end_request block/blk-mq.c:1050 [inline] blk_mq_try_issue_directly+0x1a7/0x1f0 block/blk-mq.c:2713 blk_mq_submit_bio+0x130e/0x2190 block/blk-mq.c:3045 __submit_bio+0x261/0x2f0 block/blk-core.c:591 __submit_bio_noacct_mq block/blk-core.c:668 [inline] submit_bio_noacct_nocheck+0x976/0xd10 block/blk-core.c:697 submit_bio_wait+0x102/0x200 block/bio.c:1319 squashfs_bio_read+0x2c4/0x560 fs/squashfs/block.c:116 squashfs_read_data+0x2d9/0xaf0 fs/squashfs/block.c:210 squashfs_read_table+0x31a/0x370 fs/squashfs/cache.c:432 squashfs_fill_super+0x1b6/0x1d80 fs/squashfs/super.c:151 get_tree_bdev+0x3fe/0x620 fs/super.c:1366 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x2ba/0xb40 fs/namespace.c:3056 do_mount fs/namespace.c:3399 [inline] __do_sys_mount fs/namespace.c:3607 [inline] __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3584 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 ((console_sem).lock){-...}-{2:2}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 down_trylock+0x1c/0xa0 kernel/locking/semaphore.c:139 __down_trylock_console_sem+0x105/0x250 kernel/printk/printk.c:243 console_trylock kernel/printk/printk.c:2650 [inline] console_trylock_spinning kernel/printk/printk.c:1896 [inline] vprintk_emit+0x1ee/0x740 kernel/printk/printk.c:2302 _printk+0xd1/0x111 kernel/printk/printk.c:2328 fail_dump lib/fault-inject.c:45 [inline] should_fail_ex+0x387/0x4d0 lib/fault-inject.c:147 strncpy_from_user+0x32/0x360 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x6c/0x130 mm/maccess.c:186 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:204 [inline] ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:213 [inline] bpf_probe_read_user_str+0x26/0x70 kernel/trace/bpf_trace.c:210 bpf_prog_bc7c5c6b9645592f+0x35/0x37 bpf_dispatcher_nop_func include/linux/bpf.h:992 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline] bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2325 __traceiter_sched_switch+0x91/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x2128/0x4570 kernel/sched/core.c:6555 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696 __might_fault+0x3/0x110 mm/memory.c:5845 _copy_from_user+0x26/0x170 lib/usercopy.c:14 copy_from_user include/linux/uaccess.h:161 [inline] copy_msghdr_from_user+0xaa/0x670 net/socket.c:2449 sendmsg_copy_msghdr net/socket.c:2550 [inline] ___sys_sendmsg net/socket.c:2569 [inline] __sys_sendmmsg+0x36d/0x730 net/socket.c:2659 __do_sys_sendmmsg net/socket.c:2688 [inline] __se_sys_sendmmsg net/socket.c:2685 [inline] __x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2685 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Chain exists of: (console_sem).lock --> &p->pi_lock --> &rq->__lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->__lock); lock(&p->pi_lock); lock(&rq->__lock); lock((console_sem).lock); *** DEADLOCK *** 2 locks held by syz.9.122/5132: #0: ffff8880b8e3a9d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 #1: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #1: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #1: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2283 [inline] #1: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x16a/0x470 kernel/trace/bpf_trace.c:2325 stack backtrace: CPU: 0 PID: 5132 Comm: syz.9.122 Not tainted 6.1.123-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 down_trylock+0x1c/0xa0 kernel/locking/semaphore.c:139 __down_trylock_console_sem+0x105/0x250 kernel/printk/printk.c:243 console_trylock kernel/printk/printk.c:2650 [inline] console_trylock_spinning kernel/printk/printk.c:1896 [inline] vprintk_emit+0x1ee/0x740 kernel/printk/printk.c:2302 _printk+0xd1/0x111 kernel/printk/printk.c:2328 fail_dump lib/fault-inject.c:45 [inline] should_fail_ex+0x387/0x4d0 lib/fault-inject.c:147 strncpy_from_user+0x32/0x360 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x6c/0x130 mm/maccess.c:186 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:204 [inline] ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:213 [inline] bpf_probe_read_user_str+0x26/0x70 kernel/trace/bpf_trace.c:210 bpf_prog_bc7c5c6b9645592f+0x35/0x37 bpf_dispatcher_nop_func include/linux/bpf.h:992 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline] bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2325 __traceiter_sched_switch+0x91/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x2128/0x4570 kernel/sched/core.c:6555 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696 RIP: 0010:__might_fault+0x3/0x110 mm/memory.c:5845 Code: c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 85 c5 bc ff 4c 89 f7 31 f6 e8 5b ce fd ff e9 dd fe ff ff 66 0f 1f 44 00 00 55 41 57 <41> 56 41 54 53 41 89 f6 49 89 ff 49 bc 00 00 00 00 00 fc ff df e8 RSP: 0018:ffffc90003dc78a0 EFLAGS: 00000293 RAX: ffffffff84447375 RBX: 0000000020007fc0 RCX: ffff88802c99bb80 RDX: 0000000000000000 RSI: 000000000000000e RDI: ffffffff8b5e2d40 RBP: ffffc90003dc79f0 R08: dffffc0000000000 R09: ffffc90003dc7940 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000038 R13: dffffc0000000000 R14: ffffc90003dc7940 R15: 0000000020007fc0 _copy_from_user+0x26/0x170 lib/usercopy.c:14 copy_from_user include/linux/uaccess.h:161 [inline] copy_msghdr_from_user+0xaa/0x670 net/socket.c:2449 sendmsg_copy_msghdr net/socket.c:2550 [inline] ___sys_sendmsg net/socket.c:2569 [inline] __sys_sendmmsg+0x36d/0x730 net/socket.c:2659 __do_sys_sendmmsg net/socket.c:2688 [inline] __se_sys_sendmmsg net/socket.c:2685 [inline] __x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2685 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f79d2785d29 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f79d34f2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f79d2976160 RCX: 00007f79d2785d29 RDX: 000000000800001d RSI: 0000000020007fc0 RDI: 0000000000000007 RBP: 00007f79d34f2090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000a1a R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 00007f79d2976160 R15: 00007ffdbdf18c68 CPU: 0 PID: 5132 Comm: syz.9.122 Not tainted 6.1.123-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 fail_dump lib/fault-inject.c:52 [inline] should_fail_ex+0x3a6/0x4d0 lib/fault-inject.c:147 strncpy_from_user+0x32/0x360 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x6c/0x130 mm/maccess.c:186 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:204 [inline] ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:213 [inline] bpf_probe_read_user_str+0x26/0x70 kernel/trace/bpf_trace.c:210 bpf_prog_bc7c5c6b9645592f+0x35/0x37 bpf_dispatcher_nop_func include/linux/bpf.h:992 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline] bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2325 __traceiter_sched_switch+0x91/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x2128/0x4570 kernel/sched/core.c:6555 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696 RIP: 0010:__might_fault+0x3/0x110 mm/memory.c:5845 Code: c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 85 c5 bc ff 4c 89 f7 31 f6 e8 5b ce fd ff e9 dd fe ff ff 66 0f 1f 44 00 00 55 41 57 <41> 56 41 54 53 41 89 f6 49 89 ff 49 bc 00 00 00 00 00 fc ff df e8 RSP: 0018:ffffc90003dc78a0 EFLAGS: 00000293 RAX: ffffffff84447375 RBX: 0000000020007fc0 RCX: ffff88802c99bb80 RDX: 0000000000000000 RSI: 000000000000000e RDI: ffffffff8b5e2d40 RBP: ffffc90003dc79f0 R08: dffffc0000000000 R09: ffffc90003dc7940 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000038 R13: dffffc0000000000 R14: ffffc90003dc7940 R15: 0000000020007fc0 _copy_from_user+0x26/0x170 lib/usercopy.c:14 copy_from_user include/linux/uaccess.h:161 [inline] copy_msghdr_from_user+0xaa/0x670 net/socket.c:2449 sendmsg_copy_msghdr net/socket.c:2550 [inline] ___sys_sendmsg net/socket.c:2569 [inline] __sys_sendmmsg+0x36d/0x730 net/socket.c:2659 __do_sys_sendmmsg net/socket.c:2688 [inline] __se_sys_sendmmsg net/socket.c:2685 [inline] __x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2685 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f79d2785d29 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f79d34f2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f79d2976160 RCX: 00007f79d2785d29 RDX: 000000000800001d RSI: 0000000020007fc0 RDI: 0000000000000007 RBP: 00007f79d34f2090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000a1a R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 00007f79d2976160 R15: 00007ffdbdf18c68 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 10 5b 41 adc %bl,0x41(%rbx) 3: 5c pop %rsp 4: 41 5d pop %r13 6: 41 5e pop %r14 8: 41 5f pop %r15 a: 5d pop %rbp b: c3 ret c: e8 85 c5 bc ff call 0xffbcc596 11: 4c 89 f7 mov %r14,%rdi 14: 31 f6 xor %esi,%esi 16: e8 5b ce fd ff call 0xfffdce76 1b: e9 dd fe ff ff jmp 0xfffffefd 20: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 26: 55 push %rbp 27: 41 57 push %r15 * 29: 41 56 push %r14 <-- trapping instruction 2b: 41 54 push %r12 2d: 53 push %rbx 2e: 41 89 f6 mov %esi,%r14d 31: 49 89 ff mov %rdi,%r15 34: 49 bc 00 00 00 00 00 movabs $0xdffffc0000000000,%r12 3b: fc ff df 3e: e8 .byte 0xe8