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[syzbot] [trace?] possible deadlock in ring_buffer_resize | 1 (2) | 2025/04/09 14:36 |
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[syzbot] [trace?] possible deadlock in ring_buffer_resize | 1 (2) | 2025/04/09 14:36 |
====================================================== WARNING: possible circular locking dependency detected 6.14.0-syzkaller-13408-g9f867ba24d36 #0 Not tainted ------------------------------------------------------ syz.2.506/8033 is trying to acquire lock: ffffffff8e2643f0 (cpu_hotplug_lock){++++}-{0:0}, at: ring_buffer_resize+0x7ea/0x1560 kernel/trace/ring_buffer.c:2894 but task is already holding lock: ffff88801b480488 (&buffer->mutex){+.+.}-{4:4}, at: ring_buffer_resize+0x113/0x1560 kernel/trace/ring_buffer.c:2851 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&buffer->mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:746 ring_buffer_map+0x144/0xa40 kernel/trace/ring_buffer.c:7157 tracing_buffers_mmap+0x120/0x1c0 kernel/trace/trace.c:8516 call_mmap include/linux/fs.h:2243 [inline] mmap_file mm/internal.h:167 [inline] __mmap_new_file_vma mm/vma.c:2310 [inline] __mmap_new_vma mm/vma.c:2374 [inline] __mmap_region+0x1485/0x27c0 mm/vma.c:2476 mmap_region+0x1ab/0x3f0 mm/vma.c:2554 do_mmap+0xd8e/0x11b0 mm/mmap.c:561 vm_mmap_pgoff+0x281/0x450 mm/util.c:579 ksys_mmap_pgoff+0x32c/0x5c0 mm/mmap.c:607 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #4 (&cpu_buffer->mapping_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:746 ring_buffer_map+0xdc/0xa40 kernel/trace/ring_buffer.c:7146 tracing_buffers_mmap+0x120/0x1c0 kernel/trace/trace.c:8516 call_mmap include/linux/fs.h:2243 [inline] mmap_file mm/internal.h:167 [inline] __mmap_new_file_vma mm/vma.c:2310 [inline] __mmap_new_vma mm/vma.c:2374 [inline] __mmap_region+0x1485/0x27c0 mm/vma.c:2476 mmap_region+0x1ab/0x3f0 mm/vma.c:2554 do_mmap+0xd8e/0x11b0 mm/mmap.c:561 vm_mmap_pgoff+0x281/0x450 mm/util.c:579 ksys_mmap_pgoff+0x32c/0x5c0 mm/mmap.c:607 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (&mm->mmap_lock){++++}-{4:4}: down_read_killable+0x9e/0x4b0 kernel/locking/rwsem.c:1547 mmap_read_lock_killable include/linux/mmap_lock.h:193 [inline] get_mmap_lock_carefully mm/memory.c:6355 [inline] lock_mm_and_find_vma+0x3e7/0x6e0 mm/memory.c:6406 do_user_addr_fault+0x2ac/0x1370 arch/x86/mm/fault.c:1360 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 filldir+0x29c/0x5f0 fs/readdir.c:290 dir_emit include/linux/fs.h:3861 [inline] kernfs_fop_readdir+0x3d5/0x930 fs/kernfs/dir.c:1907 iterate_dir+0x293/0xb40 fs/readdir.c:108 __do_sys_getdents fs/readdir.c:322 [inline] __se_sys_getdents fs/readdir.c:308 [inline] __x64_sys_getdents+0x14d/0x2c0 fs/readdir.c:308 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&root->kernfs_rwsem){++++}-{4:4}: down_write+0x92/0x200 kernel/locking/rwsem.c:1577 kernfs_add_one+0x38/0x840 fs/kernfs/dir.c:791 kernfs_create_dir_ns+0xfc/0x1a0 fs/kernfs/dir.c:1091 internal_create_group+0x34d/0xf30 fs/sysfs/group.c:170 cpuhp_invoke_callback+0x3d2/0xa10 kernel/cpu.c:194 cpuhp_issue_call+0x1c0/0x980 kernel/cpu.c:2372 __cpuhp_setup_state_cpuslocked+0x3a1/0x7b0 kernel/cpu.c:2518 __cpuhp_setup_state+0xf4/0x300 kernel/cpu.c:2547 do_one_initcall+0x120/0x6e0 init/main.c:1257 do_initcall_level init/main.c:1319 [inline] do_initcalls init/main.c:1335 [inline] do_basic_setup init/main.c:1354 [inline] kernel_init_freeable+0x5c2/0x900 init/main.c:1567 kernel_init+0x1c/0x2b0 init/main.c:1457 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #1 (cpuhp_state_mutex){+.+.}-{4:4}: -> #0 (cpu_hotplug_lock){++++}-{0:0}: check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain kernel/locking/lockdep.c:3909 [inline] __lock_acquire+0x1173/0x1ba0 kernel/locking/lockdep.c:5235 lock_acquire kernel/locking/lockdep.c:5866 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823 percpu_down_read include/linux/percpu-rwsem.h:52 [inline] cpus_read_lock+0x42/0x160 kernel/cpu.c:490 ring_buffer_resize+0x7ea/0x1560 kernel/trace/ring_buffer.c:2894 __tracing_resize_ring_buffer.part.0+0x52/0x1f0 kernel/trace/trace.c:5943 __tracing_resize_ring_buffer kernel/trace/trace.c:5937 [inline] tracing_update_buffers+0x102/0x130 kernel/trace/trace.c:6168 event_pid_write.isra.0+0xf8/0x7c0 kernel/trace/trace_events.c:2415 vfs_write+0x25c/0x1180 fs/read_write.c:682 ksys_write+0x12a/0x240 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: cpu_hotplug_lock --> &cpu_buffer->mapping_lock --> &buffer->mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&buffer->mutex); lock(&cpu_buffer->mapping_lock); lock(&buffer->mutex); rlock(cpu_hotplug_lock); *** DEADLOCK *** 4 locks held by syz.2.506/8033: #0: ffff88807cd2a0f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1213 #1: ffff888145eba420 (sb_writers#14){.+.+}-{0:0}, at: ksys_write+0x12a/0x240 fs/read_write.c:736 #2: ffffffff8e4451a8 (trace_types_lock){+.+.}-{4:4}, at: tracing_update_buffers+0x1e/0x130 kernel/trace/trace.c:6163 #3: ffff88801b480488 (&buffer->mutex){+.+.}-{4:4}, at: ring_buffer_resize+0x113/0x1560 kernel/trace/ring_buffer.c:2851 stack backtrace: CPU: 0 UID: 0 PID: 8033 Comm: syz.2.506 Not tainted 6.14.0-syzkaller-13408-g9f867ba24d36 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2079 check_noncircular+0x14c/0x170 kernel/locking/lockdep.c:2211 check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain kernel/locking/lockdep.c:3909 [inline] __lock_acquire+0x1173/0x1ba0 kernel/locking/lockdep.c:5235 lock_acquire kernel/locking/lockdep.c:5866 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823 percpu_down_read include/linux/percpu-rwsem.h:52 [inline] cpus_read_lock+0x42/0x160 kernel/cpu.c:490 ring_buffer_resize+0x7ea/0x1560 kernel/trace/ring_buffer.c:2894 __tracing_resize_ring_buffer.part.0+0x52/0x1f0 kernel/trace/trace.c:5943 __tracing_resize_ring_buffer kernel/trace/trace.c:5937 [inline] tracing_update_buffers+0x102/0x130 kernel/trace/trace.c:6168 event_pid_write.isra.0+0xf8/0x7c0 kernel/trace/trace_events.c:2415 vfs_write+0x25c/0x1180 fs/read_write.c:682 ksys_write+0x12a/0x240 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb813f8d169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb811df6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fb8141a6320 RCX: 00007fb813f8d169 RDX: 0000000000000001 RSI: 0000200000001240 RDI: 0000000000000006 RBP: 00007fb81400e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb8141a6320 R15: 00007ffde8fb74c8 </TASK>
Time | Kernel | Commit | Syzkaller | Config | Log | Report | Syz repro | C repro | VM info | Assets (help?) | Manager | Title |
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2025/04/05 13:27 | upstream | 9f867ba24d36 | c53ea9c9 | .config | console log | report | info | [disk image] [vmlinux] [kernel image] | ci-qemu-gce-upstream-auto | possible deadlock in ring_buffer_resize |