============================================ WARNING: possible recursive locking detected 6.1.71-syzkaller #0 Not tainted -------------------------------------------- syz-executor316/3549 is trying to acquire lock: ffffffff8d188238 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] ffffffff8d188238 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:376 but task is already holding lock: ffffffff8d188238 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] ffffffff8d188238 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:376 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(trace_printk_lock); lock(trace_printk_lock); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by syz-executor316/3549: #0: ffffffff8d1c4b10 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:592 [inline] #0: ffffffff8d1c4b10 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1540 [inline] #0: ffffffff8d1c4b10 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x3cb/0x1990 kernel/fork.c:1589 #1: ffff888012469f58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #1: ffff888012469f58 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:593 [inline] #1: ffff888012469f58 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1540 [inline] #1: ffff888012469f58 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x3e5/0x1990 kernel/fork.c:1589 #2: ffff88807bc535d8 (&mm->mmap_lock/1){+.+.}-{3:3}, at: mmap_write_lock_nested include/linux/mmap_lock.h:78 [inline] #2: ffff88807bc535d8 (&mm->mmap_lock/1){+.+.}-{3:3}, at: dup_mmap kernel/fork.c:602 [inline] #2: ffff88807bc535d8 (&mm->mmap_lock/1){+.+.}-{3:3}, at: dup_mm kernel/fork.c:1540 [inline] #2: ffff88807bc535d8 (&mm->mmap_lock/1){+.+.}-{3:3}, at: copy_mm+0x4ca/0x1990 kernel/fork.c:1589 #3: ffff88801246a368 (&mm->context.lock){+.+.}-{3:3}, at: ldt_dup_context+0x3b/0x2e0 arch/x86/kernel/ldt.c:457 #4: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline] #4: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #4: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2274 [inline] #4: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x110/0x410 kernel/trace/bpf_trace.c:2314 #5: ffffffff8d188238 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] #5: ffffffff8d188238 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:376 #6: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline] #6: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #6: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2274 [inline] #6: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x110/0x410 kernel/trace/bpf_trace.c:2314 stack backtrace: CPU: 1 PID: 3549 Comm: syz-executor316 Not tainted 6.1.71-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2983 [inline] check_deadlock kernel/locking/lockdep.c:3026 [inline] validate_chain+0x4711/0x5950 kernel/locking/lockdep.c:3812 __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 ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:376 bpf_prog_0605f9f479290f07+0x2f/0x33 bpf_dispatcher_nop_func include/linux/bpf.h:970 [inline] __bpf_prog_run include/linux/filter.h:600 [inline] bpf_prog_run include/linux/filter.h:607 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2275 [inline] bpf_trace_run2+0x1fd/0x410 kernel/trace/bpf_trace.c:2314 __traceiter_contention_begin+0x74/0xa0 include/trace/events/lock.h:95 trace_contention_begin+0x14f/0x1a0 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0x111/0xc50 kernel/locking/qspinlock.c:405 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath+0x42/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x269/0x370 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xdd/0x120 kernel/locking/spinlock.c:162 ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:376 bpf_prog_0605f9f479290f07+0x2f/0x33 bpf_dispatcher_nop_func include/linux/bpf.h:970 [inline] __bpf_prog_run include/linux/filter.h:600 [inline] bpf_prog_run include/linux/filter.h:607 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2275 [inline] bpf_trace_run2+0x1fd/0x410 kernel/trace/bpf_trace.c:2314 __traceiter_contention_begin+0x74/0xa0 include/trace/events/lock.h:95 trace_contention_begin+0x12f/0x170 include/trace/events/lock.h:95 __mutex_lock_common kernel/locking/mutex.c:605 [inline] __mutex_lock+0x143/0xd80 kernel/locking/mutex.c:747 ldt_dup_context+0x3b/0x2e0 arch/x86/kernel/ldt.c:457 arch_dup_mmap arch/x86/include/asm/mmu_context.h:171 [inline] dup_mmap kernel/fork.c:705 [inline] dup_mm kernel/fork.c:1540 [inline] copy_mm+0x10ba/0x1990 kernel/fork.c:1589 copy_process+0x19d5/0x4060 kernel/fork.c:2267 kernel_clone+0x222/0x920 kernel/fork.c:2682 __do_sys_clone kernel/fork.c:2823 [inline] __se_sys_clone kernel/fork.c:2807 [inline] __x64_sys_clone+0x231/0x280 kernel/fork.c:2807 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f4ade0f9d33 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffd70640498 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4ade0f9d33 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000010 R10: 0000555556553650 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffd706405ac R14: 00007ffd706405c0 R15: 00007ffd706405b0