netlink: 8 bytes leftover after parsing attributes in process `syz.1.971'. FAULT_INJECTION: forcing a failure. name fail_usercopy, interval 1, probability 0, space 0, times 0 ====================================================== WARNING: possible circular locking dependency detected 6.11.0-rc6-syzkaller-00070-gc763c4339688 #0 Not tainted ------------------------------------------------------ syz.1.971/8893 is trying to acquire lock: ffffffff8dda75d8 ((console_sem).lock){-...}-{2:2}, at: down_trylock+0x12/0x70 kernel/locking/semaphore.c:139 but task is already holding lock: ffff88802b63edd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:568 [inline] ffff88802b63edd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:553 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #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:560 raw_spin_rq_lock kernel/sched/sched.h:1415 [inline] rq_lock kernel/sched/sched.h:1714 [inline] task_fork_fair+0x73/0x250 kernel/sched/fair.c:12710 sched_cgroup_fork+0x3cf/0x510 kernel/sched/core.c:4633 copy_process+0x4710/0x6f50 kernel/fork.c:2483 kernel_clone+0xfd/0x960 kernel/fork.c:2781 user_mode_thread+0xb4/0xf0 kernel/fork.c:2859 rest_init+0x23/0x2b0 init/main.c:712 start_kernel+0x3df/0x4c0 init/main.c:1103 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/0x13e0 kernel/sched/core.c:4051 up+0x79/0xb0 kernel/locking/semaphore.c:191 __up_console_sem kernel/printk/printk.c:340 [inline] __console_unlock kernel/printk/printk.c:2801 [inline] console_unlock+0x23e/0x290 kernel/printk/printk.c:3120 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+0x29d/0x7b0 drivers/pci/pci-driver.c:451 call_driver_probe drivers/base/dd.c:578 [inline] really_probe+0x23e/0xa90 drivers/base/dd.c:657 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:799 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:829 __driver_attach+0x283/0x580 drivers/base/dd.c:1215 bus_for_each_dev+0x13c/0x1d0 drivers/base/bus.c:368 bus_add_driver+0x2e9/0x690 drivers/base/bus.c:673 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:1267 do_initcall_level init/main.c:1329 [inline] do_initcalls init/main.c:1345 [inline] do_basic_setup init/main.c:1364 [inline] kernel_init_freeable+0x660/0xc50 init/main.c:1578 kernel_init+0x1c/0x2b0 init/main.c:1467 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:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x24ed/0x3cb0 kernel/locking/lockdep.c:5142 lock_acquire kernel/locking/lockdep.c:5759 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724 __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:323 console_trylock kernel/printk/printk.c:2754 [inline] console_trylock_spinning kernel/printk/printk.c:1958 [inline] vprintk_emit+0x3d3/0x600 kernel/printk/printk.c:2347 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:45 _printk+0xc8/0x100 kernel/printk/printk.c:2373 fail_dump lib/fault-inject.c:45 [inline] should_fail_ex+0x46c/0x5b0 lib/fault-inject.c:153 strncpy_from_user+0x38/0x320 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:216 [inline] ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:225 [inline] bpf_probe_read_user_str+0x26/0x70 kernel/trace/bpf_trace.c:222 bpf_prog_bc7c5c6b9645592f+0x3d/0x3f bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2406 [inline] bpf_trace_run4+0x245/0x5a0 kernel/trace/bpf_trace.c:2449 __traceiter_sched_switch+0x6c/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x17cf/0x5490 kernel/sched/core.c:6526 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6708 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] pcpu_alloc_noprof+0x7b1/0x14e0 mm/percpu.c:1867 fib_trie_table+0x1fd/0x2a0 net/ipv4/fib_trie.c:2436 fib_trie_unmerge+0xb9/0xc20 net/ipv4/fib_trie.c:1913 fib_unmerge+0xf8/0x520 net/ipv4/fib_frontend.c:161 fib4_rule_configure+0x129/0xc00 net/ipv4/fib_rules.c:242 fib_nl_newrule+0x3bd/0x1f30 net/core/fib_rules.c:812 rtnetlink_rcv_msg+0x3c7/0xea0 net/core/rtnetlink.c:6647 netlink_rcv_skb+0x165/0x410 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline] netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1357 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x9b4/0xb50 net/socket.c:2597 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2651 __sys_sendmsg+0x117/0x1f0 net/socket.c:2680 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 --> &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 *** 4 locks held by syz.1.971/8893: #0: ffffffff8fa179e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fa179e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x372/0xea0 net/core/rtnetlink.c:6644 #1: ffffffff8df0df68 (pcpu_alloc_mutex){+.+.}-{3:3}, at: pcpu_alloc_noprof+0xbc3/0x14e0 mm/percpu.c:1795 #2: ffff88802b63edd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:568 [inline] #2: ffff88802b63edd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:553 #3: ffffffff8ddb94a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #3: ffffffff8ddb94a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8ddb94a0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2405 [inline] #3: ffffffff8ddb94a0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x1d6/0x5a0 kernel/trace/bpf_trace.c:2449 stack backtrace: CPU: 1 UID: 0 PID: 8893 Comm: syz.1.971 Not tainted 6.11.0-rc6-syzkaller-00070-gc763c4339688 #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:93 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2186 check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x24ed/0x3cb0 kernel/locking/lockdep.c:5142 lock_acquire kernel/locking/lockdep.c:5759 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724 __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:323 console_trylock kernel/printk/printk.c:2754 [inline] console_trylock_spinning kernel/printk/printk.c:1958 [inline] vprintk_emit+0x3d3/0x600 kernel/printk/printk.c:2347 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:45 _printk+0xc8/0x100 kernel/printk/printk.c:2373 fail_dump lib/fault-inject.c:45 [inline] should_fail_ex+0x46c/0x5b0 lib/fault-inject.c:153 strncpy_from_user+0x38/0x320 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:216 [inline] ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:225 [inline] bpf_probe_read_user_str+0x26/0x70 kernel/trace/bpf_trace.c:222 bpf_prog_bc7c5c6b9645592f+0x3d/0x3f bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2406 [inline] bpf_trace_run4+0x245/0x5a0 kernel/trace/bpf_trace.c:2449 __traceiter_sched_switch+0x6c/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x17cf/0x5490 kernel/sched/core.c:6526 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6708 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] pcpu_alloc_noprof+0x7b1/0x14e0 mm/percpu.c:1867 fib_trie_table+0x1fd/0x2a0 net/ipv4/fib_trie.c:2436 fib_trie_unmerge+0xb9/0xc20 net/ipv4/fib_trie.c:1913 fib_unmerge+0xf8/0x520 net/ipv4/fib_frontend.c:161 fib4_rule_configure+0x129/0xc00 net/ipv4/fib_rules.c:242 fib_nl_newrule+0x3bd/0x1f30 net/core/fib_rules.c:812 rtnetlink_rcv_msg+0x3c7/0xea0 net/core/rtnetlink.c:6647 netlink_rcv_skb+0x165/0x410 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline] netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1357 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x9b4/0xb50 net/socket.c:2597 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2651 __sys_sendmsg+0x117/0x1f0 net/socket.c:2680 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: 0023:0xf7fa6579 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:00000000f573656c EFLAGS: 00000296 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000200002c0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 CPU: 1 UID: 0 PID: 8893 Comm: syz.1.971 Not tainted 6.11.0-rc6-syzkaller-00070-gc763c4339688 #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:93 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119 fail_dump lib/fault-inject.c:52 [inline] should_fail_ex+0x497/0x5b0 lib/fault-inject.c:153 strncpy_from_user+0x38/0x320 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:216 [inline] ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:225 [inline] bpf_probe_read_user_str+0x26/0x70 kernel/trace/bpf_trace.c:222 bpf_prog_bc7c5c6b9645592f+0x3d/0x3f bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2406 [inline] bpf_trace_run4+0x245/0x5a0 kernel/trace/bpf_trace.c:2449 __traceiter_sched_switch+0x6c/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x17cf/0x5490 kernel/sched/core.c:6526 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6708 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] pcpu_alloc_noprof+0x7b1/0x14e0 mm/percpu.c:1867 fib_trie_table+0x1fd/0x2a0 net/ipv4/fib_trie.c:2436 fib_trie_unmerge+0xb9/0xc20 net/ipv4/fib_trie.c:1913 fib_unmerge+0xf8/0x520 net/ipv4/fib_frontend.c:161 fib4_rule_configure+0x129/0xc00 net/ipv4/fib_rules.c:242 fib_nl_newrule+0x3bd/0x1f30 net/core/fib_rules.c:812 rtnetlink_rcv_msg+0x3c7/0xea0 net/core/rtnetlink.c:6647 netlink_rcv_skb+0x165/0x410 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline] netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1357 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x9b4/0xb50 net/socket.c:2597 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2651 __sys_sendmsg+0x117/0x1f0 net/socket.c:2680 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: 0023:0xf7fa6579 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:00000000f573656c EFLAGS: 00000296 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000200002c0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 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