====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc5-syzkaller-01502-gfcd1ed89a043 #0 Not tainted ------------------------------------------------------ syz-executor.1/5103 is trying to acquire lock: ffff888041a24a18 (&sighand->siglock){....}-{2:2}, at: __lock_task_sighand+0x149/0x2e0 kernel/signal.c:1414 but task is already holding lock: ffff8880b95387e8 (lock#10){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b95387e8 (lock#10){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x8f/0x630 mm/mmap_lock.c:237 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (lock#10){+.+.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_acquire_returned+0xa8/0x630 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:166 [inline] stack_map_get_build_id_offset+0x9b2/0x9d0 kernel/bpf/stackmap.c:141 __bpf_get_stack+0x4ad/0x5a0 kernel/bpf/stackmap.c:449 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1994 [inline] bpf_get_stack_raw_tp+0x1a3/0x240 kernel/trace/bpf_trace.c:1984 bpf_prog_ec3b2eefa702d8d3+0x42/0x46 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:2403 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2444 trace_tlb_flush+0x118/0x140 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x7cb/0xae0 context_switch kernel/sched/core.c:5393 [inline] __schedule+0x1066/0x4a50 kernel/sched/core.c:6746 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7068 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 __find_get_block+0xa4/0x10d0 fs/buffer.c:1396 bdev_getblk+0x38/0x610 fs/buffer.c:1423 __getblk include/linux/buffer_head.h:355 [inline] sb_getblk include/linux/buffer_head.h:361 [inline] __ext4_get_inode_loc+0x533/0xe10 fs/ext4/inode.c:4369 ext4_get_inode_loc fs/ext4/inode.c:4497 [inline] ext4_reserve_inode_write+0x182/0x360 fs/ext4/inode.c:5728 __ext4_mark_inode_dirty+0x1ec/0x880 fs/ext4/inode.c:5905 add_dirent_to_buf+0x5f4/0x730 fs/ext4/namei.c:2212 ext4_add_entry+0x7c6/0x25d0 fs/ext4/namei.c:2444 ext4_mkdir+0x554/0xcf0 fs/ext4/namei.c:3028 vfs_mkdir+0x2f9/0x4b0 fs/namei.c:4123 do_mkdirat+0x264/0x3a0 fs/namei.c:4146 __do_sys_mkdirat fs/namei.c:4161 [inline] __se_sys_mkdirat fs/namei.c:4159 [inline] __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4159 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 raw_spin_rq_lock kernel/sched/sched.h:1387 [inline] _raw_spin_rq_lock_irqsave kernel/sched/sched.h:1406 [inline] rq_lock_irqsave kernel/sched/sched.h:1685 [inline] class_rq_lock_irqsave_constructor kernel/sched/sched.h:1739 [inline] sched_mm_cid_exit_signals+0x17b/0x4b0 kernel/sched/core.c:12005 exit_signals+0x2a1/0x5c0 kernel/signal.c:3016 do_exit+0x6a8/0x27e0 kernel/exit.c:837 __do_sys_exit kernel/exit.c:994 [inline] __se_sys_exit kernel/exit.c:992 [inline] __pfx___ia32_sys_exit+0x0/0x10 kernel/exit.c:992 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&sighand->siglock){....}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x149/0x2e0 kernel/signal.c:1414 lock_task_sighand include/linux/sched/signal.h:746 [inline] do_send_sig_info kernel/signal.c:1300 [inline] group_send_sig_info+0x274/0x310 kernel/signal.c:1453 bpf_send_signal_common+0x2dd/0x430 kernel/trace/bpf_trace.c:881 ____bpf_send_signal_thread kernel/trace/bpf_trace.c:898 [inline] bpf_send_signal_thread+0x16/0x20 kernel/trace/bpf_trace.c:896 bpf_prog_7bb747c56a8bcba8+0x1d/0x25 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:2403 [inline] bpf_trace_run4+0x334/0x590 kernel/trace/bpf_trace.c:2446 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:52 [inline] __mmap_lock_do_trace_acquire_returned+0x5c8/0x630 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:166 [inline] get_mmap_lock_carefully mm/memory.c:5633 [inline] lock_mm_and_find_vma+0x213/0x2f0 mm/memory.c:5693 do_user_addr_fault arch/x86/mm/fault.c:1385 [inline] handle_page_fault arch/x86/mm/fault.c:1505 [inline] exc_page_fault+0x1a9/0x8e0 arch/x86/mm/fault.c:1563 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 rep_movs_alternative+0x4a/0x70 arch/x86/lib/copy_user_64.S:65 copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:131 [inline] copy_to_user_iter lib/iov_iter.c:25 [inline] iterate_ubuf include/linux/iov_iter.h:29 [inline] iterate_and_advance2 include/linux/iov_iter.h:245 [inline] iterate_and_advance include/linux/iov_iter.h:271 [inline] _copy_to_iter+0x257/0x1cf0 lib/iov_iter.c:185 copy_page_to_iter+0xb1/0x160 lib/iov_iter.c:362 pipe_read+0x59c/0x13e0 fs/pipe.c:327 call_read_iter include/linux/fs.h:2104 [inline] new_sync_read fs/read_write.c:395 [inline] vfs_read+0x97b/0xb70 fs/read_write.c:476 ksys_read+0x1a0/0x2c0 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &sighand->siglock --> &rq->__lock --> lock#10 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lock#10); lock(&rq->__lock); lock(lock#10); lock(&sighand->siglock); *** DEADLOCK *** 6 locks held by syz-executor.1/5103: #0: ffff8880226f9068 (&pipe->mutex){+.+.}-{3:3}, at: pipe_read+0x12a/0x13e0 fs/pipe.c:264 #1: ffff8880412b4420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline] #1: ffff8880412b4420 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5633 [inline] #1: ffff8880412b4420 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5693 #2: ffff8880b95387e8 (lock#10){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #2: ffff8880b95387e8 (lock#10){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x8f/0x630 mm/mmap_lock.c:237 #3: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #3: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #3: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: get_memcg_path_buf mm/mmap_lock.c:139 [inline] #3: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: get_mm_memcg_path+0xb1/0x600 mm/mmap_lock.c:209 #4: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #4: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #4: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #4: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x244/0x590 kernel/trace/bpf_trace.c:2446 #5: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #5: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #5: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: __lock_task_sighand+0x29/0x2e0 kernel/signal.c:1397 stack backtrace: CPU: 1 PID: 5103 Comm: syz-executor.1 Not tainted 6.9.0-rc5-syzkaller-01502-gfcd1ed89a043 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_noncircular+0x36a/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+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x149/0x2e0 kernel/signal.c:1414 lock_task_sighand include/linux/sched/signal.h:746 [inline] do_send_sig_info kernel/signal.c:1300 [inline] group_send_sig_info+0x274/0x310 kernel/signal.c:1453 bpf_send_signal_common+0x2dd/0x430 kernel/trace/bpf_trace.c:881 ____bpf_send_signal_thread kernel/trace/bpf_trace.c:898 [inline] bpf_send_signal_thread+0x16/0x20 kernel/trace/bpf_trace.c:896 bpf_prog_7bb747c56a8bcba8+0x1d/0x25 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:2403 [inline] bpf_trace_run4+0x334/0x590 kernel/trace/bpf_trace.c:2446 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:52 [inline] __mmap_lock_do_trace_acquire_returned+0x5c8/0x630 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:166 [inline] get_mmap_lock_carefully mm/memory.c:5633 [inline] lock_mm_and_find_vma+0x213/0x2f0 mm/memory.c:5693 do_user_addr_fault arch/x86/mm/fault.c:1385 [inline] handle_page_fault arch/x86/mm/fault.c:1505 [inline] exc_page_fault+0x1a9/0x8e0 arch/x86/mm/fault.c:1563 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:rep_movs_alternative+0x4a/0x70 arch/x86/lib/copy_user_64.S:71 Code: 75 f1 c3 cc cc cc cc 66 0f 1f 84 00 00 00 00 00 48 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 df 83 f9 08 73 e8 eb c9 a4 c3 cc cc cc cc 48 89 c8 48 c1 e9 03 83 e0 07 f3 48 a5 89 c1 RSP: 0018:ffffc90003a678b8 EFLAGS: 00050246 RAX: ffffffff84ad0501 RBX: 00007f6882ba8020 RCX: 0000000000000040 RDX: 0000000000000000 RSI: ffff88802a027000 RDI: 00007f6882ba8020 RBP: ffffc90003a67a38 R08: ffff88802a02703f R09: 1ffff11005404e07 R10: dffffc0000000000 R11: ffffed1005404e08 R12: 0000000000000040 R13: ffff88802a027000 R14: ffffc90003a67d78 R15: 1ffff9200074cfaf copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:131 [inline] copy_to_user_iter lib/iov_iter.c:25 [inline] iterate_ubuf include/linux/iov_iter.h:29 [inline] iterate_and_advance2 include/linux/iov_iter.h:245 [inline] iterate_and_advance include/linux/iov_iter.h:271 [inline] _copy_to_iter+0x257/0x1cf0 lib/iov_iter.c:185 copy_page_to_iter+0xb1/0x160 lib/iov_iter.c:362 pipe_read+0x59c/0x13e0 fs/pipe.c:327 call_read_iter include/linux/fs.h:2104 [inline] new_sync_read fs/read_write.c:395 [inline] vfs_read+0x97b/0xb70 fs/read_write.c:476 ksys_read+0x1a0/0x2c0 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6882a7ca0c Code: ec 28 48 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 59 81 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 34 44 89 c7 48 89 44 24 08 e8 af 81 02 00 48 RSP: 002b:00007ffdd82c49b0 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f6882a7ca0c RDX: 0000000000000040 RSI: 00007f6882ba8020 RDI: 00000000000000f9 RBP: 00007ffdd82c4a3c R08: 0000000000000000 R09: 0079746972756365 R10: 00007f6882b7c6a0 R11: 0000000000000246 R12: 0000000000000032 R13: 0000000000017b1c R14: 000000000001791a R15: 000000000000001c ---------------- Code disassembly (best guess): 0: 75 f1 jne 0xfffffff3 2: c3 ret 3: cc int3 4: cc int3 5: cc int3 6: cc int3 7: 66 0f 1f 84 00 00 00 nopw 0x0(%rax,%rax,1) e: 00 00 10: 48 8b 06 mov (%rsi),%rax 13: 48 89 07 mov %rax,(%rdi) 16: 48 83 c6 08 add $0x8,%rsi 1a: 48 83 c7 08 add $0x8,%rdi 1e: 83 e9 08 sub $0x8,%ecx 21: 74 df je 0x2 23: 83 f9 08 cmp $0x8,%ecx 26: 73 e8 jae 0x10 28: eb c9 jmp 0xfffffff3 * 2a: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction 2c: c3 ret 2d: cc int3 2e: cc int3 2f: cc int3 30: cc int3 31: 48 89 c8 mov %rcx,%rax 34: 48 c1 e9 03 shr $0x3,%rcx 38: 83 e0 07 and $0x7,%eax 3b: f3 48 a5 rep movsq %ds:(%rsi),%es:(%rdi) 3e: 89 c1 mov %eax,%ecx