EEVDF scheduling fail, picking leftmost ====================================================== WARNING: possible circular locking dependency detected 6.6.0-rc6-syzkaller-00207-gc8045b4a33a5 #0 Not tainted ------------------------------------------------------ udevd/4482 is trying to acquire lock: ffffffff8d208018 ((console_sem).lock){-.-.}-{2:2}, at: down_trylock+0x20/0xa0 kernel/locking/semaphore.c:139 but task is already holding lock: ffff8880b983c318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 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+0x2a/0x140 kernel/sched/core.c:558 raw_spin_rq_lock kernel/sched/sched.h:1372 [inline] rq_lock kernel/sched/sched.h:1681 [inline] task_fork_fair+0x61/0x1e0 kernel/sched/fair.c:12416 sched_cgroup_fork+0x37b/0x410 kernel/sched/core.c:4816 copy_process+0x2841/0x41a0 kernel/fork.c:2609 kernel_clone+0x222/0x840 kernel/fork.c:2909 user_mode_thread+0x132/0x190 kernel/fork.c:2987 rest_init+0x27/0x300 init/main.c:691 arch_call_rest_init+0xe/0x10 init/main.c:823 start_kernel+0x46e/0x4f0 init/main.c:1068 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:556 x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:537 secondary_startup_64_no_verify+0x167/0x16b -> #1 (&p->pi_lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:518 [inline] try_to_wake_up+0xb1/0x1300 kernel/sched/core.c:4230 up+0x72/0x90 kernel/locking/semaphore.c:191 __up_console_sem kernel/printk/printk.c:346 [inline] __console_unlock kernel/printk/printk.c:2718 [inline] console_unlock+0x22f/0x4d0 kernel/printk/printk.c:3037 vprintk_emit+0x508/0x720 kernel/printk/printk.c:2307 dev_vprintk_emit+0x2ae/0x330 drivers/base/core.c:4849 dev_printk_emit+0xdd/0x120 drivers/base/core.c:4860 _dev_warn+0x122/0x170 drivers/base/core.c:4916 firmware_fallback_sysfs+0x678/0x950 drivers/base/firmware_loader/fallback.c:229 _request_firmware+0xc97/0x1280 drivers/base/firmware_loader/main.c:909 request_firmware_work_func+0x12a/0x270 drivers/base/firmware_loader/main.c:1160 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0x90f/0x1400 kernel/workqueue.c:2703 worker_thread+0xa5f/0xff0 kernel/workqueue.c:2784 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 -> #0 ((console_sem).lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5136 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5753 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 down_trylock+0x20/0xa0 kernel/locking/semaphore.c:139 __down_trylock_console_sem+0x109/0x250 kernel/printk/printk.c:329 console_trylock kernel/printk/printk.c:2671 [inline] console_trylock_spinning kernel/printk/printk.c:1927 [inline] vprintk_emit+0x1ef/0x720 kernel/printk/printk.c:2306 _printk+0xd5/0x120 kernel/printk/printk.c:2332 pick_eevdf+0x660/0x690 kernel/sched/fair.c:976 pick_next_entity kernel/sched/fair.c:5278 [inline] pick_next_task_fair+0x122/0xdc0 kernel/sched/fair.c:8222 __pick_next_task kernel/sched/core.c:6004 [inline] pick_next_task kernel/sched/core.c:6079 [inline] __schedule+0x7c7/0x4af0 kernel/sched/core.c:6659 preempt_schedule_irq+0xfb/0x1b0 kernel/sched/core.c:7007 irqentry_exit+0x57/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 __sanitizer_cov_trace_const_cmp4+0x8/0x90 kernel/kcov.c:305 smack_str_from_perm security/smack/smack_access.c:296 [inline] smack_log+0x28d/0x540 security/smack/smack_access.c:362 smk_tskacc+0x2ff/0x360 security/smack/smack_access.c:253 smack_inode_permission+0x2dc/0x380 security/smack/smack_lsm.c:1227 security_inode_permission+0xa1/0xf0 security/security.c:2111 may_lookup fs/namei.c:1724 [inline] link_path_walk+0x2da/0xe70 fs/namei.c:2271 path_lookupat+0xa9/0x450 fs/namei.c:2482 filename_lookup+0x255/0x610 fs/namei.c:2512 vfs_statx+0x10b/0x4c0 fs/stat.c:240 vfs_fstatat+0x135/0x190 fs/stat.c:295 __do_sys_newfstatat fs/stat.c:459 [inline] __se_sys_newfstatat fs/stat.c:453 [inline] __x64_sys_newfstatat+0x117/0x190 fs/stat.c:453 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd 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 *** 1 lock held by udevd/4482: #0: ffff8880b983c318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 stack backtrace: CPU: 0 PID: 4482 Comm: udevd Not tainted 6.6.0-rc6-syzkaller-00207-gc8045b4a33a5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 check_noncircular+0x375/0x4a0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5136 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5753 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 down_trylock+0x20/0xa0 kernel/locking/semaphore.c:139 __down_trylock_console_sem+0x109/0x250 kernel/printk/printk.c:329 console_trylock kernel/printk/printk.c:2671 [inline] console_trylock_spinning kernel/printk/printk.c:1927 [inline] vprintk_emit+0x1ef/0x720 kernel/printk/printk.c:2306 _printk+0xd5/0x120 kernel/printk/printk.c:2332 pick_eevdf+0x660/0x690 kernel/sched/fair.c:976 pick_next_entity kernel/sched/fair.c:5278 [inline] pick_next_task_fair+0x122/0xdc0 kernel/sched/fair.c:8222 __pick_next_task kernel/sched/core.c:6004 [inline] pick_next_task kernel/sched/core.c:6079 [inline] __schedule+0x7c7/0x4af0 kernel/sched/core.c:6659 preempt_schedule_irq+0xfb/0x1b0 kernel/sched/core.c:7007 irqentry_exit+0x57/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline] RIP: 0010:write_comp_data kernel/kcov.c:235 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x8/0x90 kernel/kcov.c:304 Code: 00 00 00 48 89 44 0a 10 48 89 74 0a 18 4c 89 44 0a 20 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 f3 0f 1e fa 4c 8b 04 24 <65> 48 8b 15 d0 a7 75 7e 65 8b 05 d1 a7 75 7e a9 00 01 ff 00 74 10 RSP: 0018:ffffc9000319f5f8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000319f6d8 R08: ffffffff83fbb0ad R09: 0000000000000000 R10: ffffc9000319f7a8 R11: fffff52000633ef9 R12: ffffc9000319f7a0 R13: ffffc9000319f660 R14: 1ffff92000633ecc R15: 0000000000000001 smack_str_from_perm security/smack/smack_access.c:296 [inline] smack_log+0x28d/0x540 security/smack/smack_access.c:362 smk_tskacc+0x2ff/0x360 security/smack/smack_access.c:253 smack_inode_permission+0x2dc/0x380 security/smack/smack_lsm.c:1227 security_inode_permission+0xa1/0xf0 security/security.c:2111 may_lookup fs/namei.c:1724 [inline] link_path_walk+0x2da/0xe70 fs/namei.c:2271 path_lookupat+0xa9/0x450 fs/namei.c:2482 filename_lookup+0x255/0x610 fs/namei.c:2512 vfs_statx+0x10b/0x4c0 fs/stat.c:240 vfs_fstatat+0x135/0x190 fs/stat.c:295 __do_sys_newfstatat fs/stat.c:459 [inline] __se_sys_newfstatat fs/stat.c:453 [inline] __x64_sys_newfstatat+0x117/0x190 fs/stat.c:453 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f3fcb3165f4 Code: 64 c7 00 09 00 00 00 83 c8 ff c3 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 00 00 00 00 41 89 ca b8 06 01 00 00 0f 05 <45> 31 c0 3d 00 f0 ff ff 76 10 48 8b 15 03 a8 0d 00 f7 d8 41 83 c8 RSP: 002b:00007ffd59284868 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 000055bc52918e10 RCX: 00007f3fcb3165f4 RDX: 00007ffd59284878 RSI: 00007ffd59284d08 RDI: 00000000ffffff9c RBP: 00007ffd59284908 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd59284d08 R13: 00007ffd59284878 R14: 000055bc528f7910 R15: 0000000000000000 audit: audit_backlog=65 > audit_backlog_limit=64 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 00 48 89 add %cl,-0x77(%rax) 5: 44 0a 10 or (%rax),%r10b 8: 48 89 74 0a 18 mov %rsi,0x18(%rdx,%rcx,1) d: 4c 89 44 0a 20 mov %r8,0x20(%rdx,%rcx,1) 12: c3 ret 13: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 1a: 00 00 00 1d: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 22: f3 0f 1e fa endbr64 26: 4c 8b 04 24 mov (%rsp),%r8 * 2a: 65 48 8b 15 d0 a7 75 mov %gs:0x7e75a7d0(%rip),%rdx # 0x7e75a802 <-- trapping instruction 31: 7e 32: 65 8b 05 d1 a7 75 7e mov %gs:0x7e75a7d1(%rip),%eax # 0x7e75a80a 39: a9 00 01 ff 00 test $0xff0100,%eax 3e: 74 10 je 0x50