FAULT_INJECTION: forcing a failure. name fail_usercopy, interval 1, probability 0, space 0, times 0 ====================================================== WARNING: possible circular locking dependency detected 6.12.0-rc1-syzkaller-00031-ge32cde8d2bd7 #0 Not tainted ------------------------------------------------------ syz.3.3299/17324 is trying to acquire lock: ffffffff8dda5478 ((console_sem).lock){-.-.}-{2:2}, at: down_trylock+0x12/0x70 kernel/locking/semaphore.c:139 but task is already holding lock: ffff88802b52a858 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x5d/0x220 kernel/time/timer.c:1051 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&base->lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 lock_timer_base+0x5d/0x220 kernel/time/timer.c:1051 __mod_timer+0x426/0xdc0 kernel/time/timer.c:1132 add_timer_global+0x8a/0xc0 kernel/time/timer.c:1330 __queue_delayed_work+0x1ba/0x2e0 kernel/workqueue.c:2523 queue_delayed_work_on+0x12a/0x150 kernel/workqueue.c:2552 psi_task_change+0x1b4/0x2e0 kernel/sched/psi.c:913 psi_enqueue kernel/sched/stats.h:143 [inline] enqueue_task+0x1a5/0x350 kernel/sched/core.c:2017 activate_task kernel/sched/core.c:2062 [inline] wake_up_new_task+0x662/0xd30 kernel/sched/core.c:4816 kernel_clone+0x236/0x960 kernel/fork.c:2818 user_mode_thread+0xb4/0xf0 kernel/fork.c:2865 rest_init+0x23/0x2b0 init/main.c:712 start_kernel+0x3e4/0x4d0 init/main.c:1105 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:488 common_startup_64+0x13e/0x148 -> #2 (&rq->__lock){-.-.}-{2:2}: _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:593 raw_spin_rq_lock kernel/sched/sched.h:1505 [inline] task_rq_lock+0xcf/0x3b0 kernel/sched/core.c:695 cgroup_move_task+0x82/0x250 kernel/sched/psi.c:1161 css_set_move_task+0x288/0x5f0 kernel/cgroup/cgroup.c:898 cgroup_post_fork+0x1c6/0x910 kernel/cgroup/cgroup.c:6692 copy_process+0x54dd/0x6f00 kernel/fork.c:2601 kernel_clone+0xfd/0x960 kernel/fork.c:2787 user_mode_thread+0xb4/0xf0 kernel/fork.c:2865 rest_init+0x23/0x2b0 init/main.c:712 start_kernel+0x3e4/0x4d0 init/main.c:1105 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:488 common_startup_64+0x13e/0x148 -> #1 (&p->pi_lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline] try_to_wake_up+0x9a/0x1440 kernel/sched/core.c:4154 up+0x79/0xb0 kernel/locking/semaphore.c:191 __up_console_sem+0x85/0xe0 kernel/printk/printk.c:343 __console_unlock kernel/printk/printk.c:2844 [inline] __console_flush_and_unlock kernel/printk/printk.c:3241 [inline] console_unlock+0x1dc/0x210 kernel/printk/printk.c:3279 vga_remove_vgacon drivers/pci/vgaarb.c:186 [inline] vga_remove_vgacon+0x90/0xd0 drivers/pci/vgaarb.c:167 __aperture_remove_legacy_vga_devices drivers/video/aperture.c:331 [inline] aperture_remove_conflicting_pci_devices+0x16a/0x1e0 drivers/video/aperture.c:369 bochs_pci_probe+0x101/0x1150 drivers/gpu/drm/tiny/bochs.c:648 local_pci_probe+0xde/0x1b0 drivers/pci/pci-driver.c:324 pci_call_probe drivers/pci/pci-driver.c:392 [inline] __pci_device_probe drivers/pci/pci-driver.c:417 [inline] pci_device_probe+0x5ad/0x7b0 drivers/pci/pci-driver.c:451 call_driver_probe drivers/base/dd.c:579 [inline] really_probe+0x23e/0xa90 drivers/base/dd.c:658 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830 __driver_attach+0x283/0x580 drivers/base/dd.c:1216 bus_for_each_dev+0x13c/0x1d0 drivers/base/bus.c:370 bus_add_driver+0x2e9/0x690 drivers/base/bus.c:675 driver_register+0x15c/0x4b0 drivers/base/driver.c:246 drm_pci_register_driver_if_modeset include/drm/drm_module.h:69 [inline] bochs_pci_driver_init+0x67/0x80 drivers/gpu/drm/tiny/bochs.c:732 do_one_initcall+0x128/0x630 init/main.c:1269 do_initcall_level init/main.c:1331 [inline] do_initcalls init/main.c:1347 [inline] do_basic_setup init/main.c:1366 [inline] kernel_init_freeable+0x58f/0x8b0 init/main.c:1580 kernel_init+0x1c/0x2b0 init/main.c:1469 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #0 ((console_sem).lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain kernel/locking/lockdep.c:3904 [inline] __lock_acquire+0x250b/0x3ce0 kernel/locking/lockdep.c:5202 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 down_trylock+0x12/0x70 kernel/locking/semaphore.c:139 __down_trylock_console_sem+0x40/0x140 kernel/printk/printk.c:326 console_trylock kernel/printk/printk.c:2827 [inline] console_trylock_spinning kernel/printk/printk.c:1990 [inline] vprintk_emit+0x3e3/0x6f0 kernel/printk/printk.c:2406 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:68 _printk+0xc8/0x100 kernel/printk/printk.c:2432 fail_dump lib/fault-inject.c:46 [inline] should_fail_ex+0x46c/0x5b0 lib/fault-inject.c:154 strncpy_from_user+0x3b/0x2a0 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x7f/0x180 mm/maccess.c:186 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:215 [inline] ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:310 [inline] bpf_probe_read_compat_str+0x131/0x170 kernel/trace/bpf_trace.c:306 bpf_prog_5c83d719bb699f4a+0x46/0x48 bpf_dispatcher_nop_func include/linux/bpf.h:1257 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2318 [inline] bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2359 trace_timer_start include/trace/events/timer.h:52 [inline] enqueue_timer+0x2b4/0x550 kernel/time/timer.c:663 internal_add_timer kernel/time/timer.c:688 [inline] __mod_timer+0x8d7/0xdc0 kernel/time/timer.c:1183 inet_frag_create net/ipv4/inet_fragment.c:348 [inline] inet_frag_find+0x8c1/0x2260 net/ipv4/inet_fragment.c:375 ip_find net/ipv4/ip_fragment.c:218 [inline] ip_defrag+0x29a/0x2530 net/ipv4/ip_fragment.c:493 nf_ct_ipv4_gather_frags net/ipv4/netfilter/nf_defrag_ipv4.c:32 [inline] ipv4_conntrack_defrag+0x404/0x600 net/ipv4/netfilter/nf_defrag_ipv4.c:87 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] raw_send_hdrinc net/ipv4/raw.c:412 [inline] raw_sendmsg+0x27f6/0x3ad0 net/ipv4/raw.c:644 inet_sendmsg+0x119/0x140 net/ipv4/af_inet.c:853 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg net/socket.c:744 [inline] __sys_sendto+0x426/0x4d0 net/socket.c:2209 __do_sys_sendto net/socket.c:2221 [inline] __se_sys_sendto net/socket.c:2217 [inline] __ia32_sys_sendto+0xdd/0x1b0 net/socket.c:2217 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e other info that might help us debug this: Chain exists of: (console_sem).lock --> &rq->__lock --> &base->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&base->lock); lock(&rq->__lock); lock(&base->lock); lock((console_sem).lock); *** DEADLOCK *** 4 locks held by syz.3.3299/17324: #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: nf_hook include/linux/netfilter.h:238 [inline] #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: NF_HOOK include/linux/netfilter.h:312 [inline] #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: raw_send_hdrinc net/ipv4/raw.c:412 [inline] #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: raw_sendmsg+0x2714/0x3ad0 net/ipv4/raw.c:644 #1: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #1: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: inet_frag_find+0x12d/0x2260 net/ipv4/inet_fragment.c:371 #2: ffff88802b52a858 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x5d/0x220 kernel/time/timer.c:1051 #3: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #3: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2317 [inline] #3: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2359 stack backtrace: CPU: 1 UID: 0 PID: 17324 Comm: syz.3.3299 Not tainted 6.12.0-rc1-syzkaller-00031-ge32cde8d2bd7 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x419/0x5d0 kernel/locking/lockdep.c:2074 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain kernel/locking/lockdep.c:3904 [inline] __lock_acquire+0x250b/0x3ce0 kernel/locking/lockdep.c:5202 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 down_trylock+0x12/0x70 kernel/locking/semaphore.c:139 __down_trylock_console_sem+0x40/0x140 kernel/printk/printk.c:326 console_trylock kernel/printk/printk.c:2827 [inline] console_trylock_spinning kernel/printk/printk.c:1990 [inline] vprintk_emit+0x3e3/0x6f0 kernel/printk/printk.c:2406 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:68 _printk+0xc8/0x100 kernel/printk/printk.c:2432 fail_dump lib/fault-inject.c:46 [inline] should_fail_ex+0x46c/0x5b0 lib/fault-inject.c:154 strncpy_from_user+0x3b/0x2a0 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x7f/0x180 mm/maccess.c:186 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:215 [inline] ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:310 [inline] bpf_probe_read_compat_str+0x131/0x170 kernel/trace/bpf_trace.c:306 bpf_prog_5c83d719bb699f4a+0x46/0x48 bpf_dispatcher_nop_func include/linux/bpf.h:1257 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2318 [inline] bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2359 trace_timer_start include/trace/events/timer.h:52 [inline] enqueue_timer+0x2b4/0x550 kernel/time/timer.c:663 internal_add_timer kernel/time/timer.c:688 [inline] __mod_timer+0x8d7/0xdc0 kernel/time/timer.c:1183 inet_frag_create net/ipv4/inet_fragment.c:348 [inline] inet_frag_find+0x8c1/0x2260 net/ipv4/inet_fragment.c:375 ip_find net/ipv4/ip_fragment.c:218 [inline] ip_defrag+0x29a/0x2530 net/ipv4/ip_fragment.c:493 nf_ct_ipv4_gather_frags net/ipv4/netfilter/nf_defrag_ipv4.c:32 [inline] ipv4_conntrack_defrag+0x404/0x600 net/ipv4/netfilter/nf_defrag_ipv4.c:87 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] raw_send_hdrinc net/ipv4/raw.c:412 [inline] raw_sendmsg+0x27f6/0x3ad0 net/ipv4/raw.c:644 inet_sendmsg+0x119/0x140 net/ipv4/af_inet.c:853 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg net/socket.c:744 [inline] __sys_sendto+0x426/0x4d0 net/socket.c:2209 __do_sys_sendto net/socket.c:2221 [inline] __se_sys_sendto net/socket.c:2217 [inline] __ia32_sys_sendto+0xdd/0x1b0 net/socket.c:2217 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf73de579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f56c656c EFLAGS: 00000296 ORIG_RAX: 0000000000000171 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000020000100 RDX: 000000000000ffeb RSI: 0000000000000000 RDI: 0000000020001100 RBP: 0000000000000010 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 CPU: 1 UID: 0 PID: 17324 Comm: syz.3.3299 Not tainted 6.12.0-rc1-syzkaller-00031-ge32cde8d2bd7 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 fail_dump lib/fault-inject.c:53 [inline] should_fail_ex+0x497/0x5b0 lib/fault-inject.c:154 strncpy_from_user+0x3b/0x2a0 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x7f/0x180 mm/maccess.c:186 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:215 [inline] ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:310 [inline] bpf_probe_read_compat_str+0x131/0x170 kernel/trace/bpf_trace.c:306 bpf_prog_5c83d719bb699f4a+0x46/0x48 bpf_dispatcher_nop_func include/linux/bpf.h:1257 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2318 [inline] bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2359 trace_timer_start include/trace/events/timer.h:52 [inline] enqueue_timer+0x2b4/0x550 kernel/time/timer.c:663 internal_add_timer kernel/time/timer.c:688 [inline] __mod_timer+0x8d7/0xdc0 kernel/time/timer.c:1183 inet_frag_create net/ipv4/inet_fragment.c:348 [inline] inet_frag_find+0x8c1/0x2260 net/ipv4/inet_fragment.c:375 ip_find net/ipv4/ip_fragment.c:218 [inline] ip_defrag+0x29a/0x2530 net/ipv4/ip_fragment.c:493 nf_ct_ipv4_gather_frags net/ipv4/netfilter/nf_defrag_ipv4.c:32 [inline] ipv4_conntrack_defrag+0x404/0x600 net/ipv4/netfilter/nf_defrag_ipv4.c:87 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] raw_send_hdrinc net/ipv4/raw.c:412 [inline] raw_sendmsg+0x27f6/0x3ad0 net/ipv4/raw.c:644 inet_sendmsg+0x119/0x140 net/ipv4/af_inet.c:853 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg net/socket.c:744 [inline] __sys_sendto+0x426/0x4d0 net/socket.c:2209 __do_sys_sendto net/socket.c:2221 [inline] __se_sys_sendto net/socket.c:2217 [inline] __ia32_sys_sendto+0xdd/0x1b0 net/socket.c:2217 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf73de579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f56c656c EFLAGS: 00000296 ORIG_RAX: 0000000000000171 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000020000100 RDX: 000000000000ffeb RSI: 0000000000000000 RDI: 0000000020001100 RBP: 0000000000000010 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi