====================================================== WARNING: possible circular locking dependency detected 4.14.68+ #4 Not tainted ------------------------------------------------------ syz-executor1/24168 is trying to acquire lock: (event_mutex){+.+.}, at: [] perf_trace_destroy+0x23/0x100 kernel/trace/trace_event_perf.c:234 but task is already holding lock: (&mm->mmap_sem){++++}, at: [] vm_mmap_pgoff+0x14f/0x1d0 mm/util.c:331 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&mm->mmap_sem){++++}: __might_fault+0x137/0x1b0 mm/memory.c:4538 _copy_to_user+0x27/0xc0 lib/usercopy.c:25 copy_to_user include/linux/uaccess.h:155 [inline] filldir+0x192/0x340 fs/readdir.c:197 dir_emit_dot include/linux/fs.h:3380 [inline] dir_emit_dots include/linux/fs.h:3391 [inline] dcache_readdir+0x12f/0x5d0 fs/libfs.c:192 iterate_dir+0x19f/0x5e0 fs/readdir.c:52 SYSC_getdents fs/readdir.c:232 [inline] SyS_getdents+0x146/0x270 fs/readdir.c:213 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #1 (&sb->s_type->i_mutex_key#6){++++}: down_write+0x34/0x90 kernel/locking/rwsem.c:54 inode_lock include/linux/fs.h:713 [inline] start_creating.part.2+0x4c/0x160 fs/tracefs/inode.c:335 start_creating fs/tracefs/inode.c:324 [inline] tracefs_create_file+0x75/0x450 fs/tracefs/inode.c:400 create_event_toplevel_files+0x2d/0x150 kernel/trace/trace_events.c:2912 early_event_add_tracer kernel/trace/trace_events.c:2999 [inline] event_trace_init+0x30a/0x4e3 kernel/trace/trace_events.c:3164 do_one_initcall+0x99/0x1aa init/main.c:826 do_initcall_level init/main.c:892 [inline] do_initcalls init/main.c:900 [inline] do_basic_setup init/main.c:918 [inline] kernel_init_freeable+0x2df/0x39f init/main.c:1073 kernel_init+0xc/0x157 init/main.c:1000 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 -> #0 (event_mutex){+.+.}: lock_acquire+0x10f/0x380 kernel/locking/lockdep.c:3991 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xf5/0x1480 kernel/locking/mutex.c:893 perf_trace_destroy+0x23/0x100 kernel/trace/trace_event_perf.c:234 _free_event+0x293/0xb00 kernel/events/core.c:4237 put_event+0x20/0x30 kernel/events/core.c:4323 perf_mmap_close+0x3f2/0xc40 kernel/events/core.c:5271 remove_vma+0xaa/0x150 mm/mmap.c:172 remove_vma_list mm/mmap.c:2516 [inline] do_munmap+0x8f0/0xd60 mm/mmap.c:2757 mmap_region+0x164/0xfb0 mm/mmap.c:1672 do_mmap+0x551/0xb80 mm/mmap.c:1509 do_mmap_pgoff include/linux/mm.h:2167 [inline] vm_mmap_pgoff+0x180/0x1d0 mm/util.c:333 SYSC_mmap_pgoff mm/mmap.c:1559 [inline] SyS_mmap_pgoff+0xf8/0x1a0 mm/mmap.c:1517 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 other info that might help us debug this: Chain exists of: event_mutex --> &sb->s_type->i_mutex_key#6 --> &mm->mmap_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&mm->mmap_sem); lock(&sb->s_type->i_mutex_key#6); lock(&mm->mmap_sem); lock(event_mutex); *** DEADLOCK *** 1 lock held by syz-executor1/24168: #0: (&mm->mmap_sem){++++}, at: [] vm_mmap_pgoff+0x14f/0x1d0 mm/util.c:331 stack backtrace: CPU: 1 PID: 24168 Comm: syz-executor1 Not tainted 4.14.68+ #4 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x11b lib/dump_stack.c:53 print_circular_bug.isra.18.cold.43+0x2d3/0x40c kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1901 [inline] check_prevs_add kernel/locking/lockdep.c:2018 [inline] validate_chain kernel/locking/lockdep.c:2460 [inline] __lock_acquire+0x2ff9/0x4320 kernel/locking/lockdep.c:3487 lock_acquire+0x10f/0x380 kernel/locking/lockdep.c:3991 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xf5/0x1480 kernel/locking/mutex.c:893 perf_trace_destroy+0x23/0x100 kernel/trace/trace_event_perf.c:234 _free_event+0x293/0xb00 kernel/events/core.c:4237 put_event+0x20/0x30 kernel/events/core.c:4323 perf_mmap_close+0x3f2/0xc40 kernel/events/core.c:5271 remove_vma+0xaa/0x150 mm/mmap.c:172 remove_vma_list mm/mmap.c:2516 [inline] do_munmap+0x8f0/0xd60 mm/mmap.c:2757 mmap_region+0x164/0xfb0 mm/mmap.c:1672 do_mmap+0x551/0xb80 mm/mmap.c:1509 do_mmap_pgoff include/linux/mm.h:2167 [inline] vm_mmap_pgoff+0x180/0x1d0 mm/util.c:333 SYSC_mmap_pgoff mm/mmap.c:1559 [inline] SyS_mmap_pgoff+0xf8/0x1a0 mm/mmap.c:1517 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x457099 RSP: 002b:00007f1117048c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f11170496d4 RCX: 0000000000457099 RDX: 0000000000000000 RSI: 0000000000002000 RDI: 00000000201c0000 RBP: 00000000009300a0 R08: 000000000000000c R09: 0000000000000000 R10: 0000000000004011 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d3168 R14: 00000000004c8161 R15: 0000000000000000 netlink: 4 bytes leftover after parsing attributes in process `syz-executor0'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor0'. input: syz1 as /devices/virtual/input/input47 uinput: write device info first EXT4-fs (loop2): feature flags set on rev 0 fs, running e2fsck is recommended EXT4-fs (loop2): bad geometry: block count 65280 exceeds size of device (2 blocks) EXT4-fs warning (device sda1): ext4_group_add:1607: No reserved GDT blocks, can't resize sock: sock_set_timeout: `syz-executor3' (pid 24817) tries to set negative timeout sock: sock_set_timeout: `syz-executor3' (pid 24829) tries to set negative timeout SELinux: unrecognized netlink message: protocol=0 nlmsg_type=1548 sclass=netlink_route_socket pig=24851 comm=syz-executor1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=1548 sclass=netlink_route_socket pig=24861 comm=syz-executor1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=25955 sclass=netlink_route_socket pig=25031 comm=syz-executor2 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=25955 sclass=netlink_route_socket pig=25039 comm=syz-executor2 SELinux: policydb magic number 0x30343030 does not match expected magic number 0xf97cff8c SELinux: failed to load policy SELinux: policydb magic number 0x30343030 does not match expected magic number 0xf97cff8c SELinux: failed to load policy netlink: 8 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor3'.