Messages in this thread | | | Date | Fri, 26 Mar 2021 03:29:19 -0700 | Subject | [syzbot] possible deadlock in register_for_each_vma | From | syzbot <> |
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Hello,
syzbot found the following issue on:
HEAD commit: 0d02ec6b Linux 5.12-rc4 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1719e4aad00000 kernel config: https://syzkaller.appspot.com/x/.config?x=5adab0bdee099d7a dashboard link: https://syzkaller.appspot.com/bug?extid=b804f902bbb6bcf290cb
Unfortunately, I don't have any reproducer for this issue yet.
IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+b804f902bbb6bcf290cb@syzkaller.appspotmail.com
====================================================== WARNING: possible circular locking dependency detected 5.12.0-rc4-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/23522 is trying to acquire lock: ffffffff8c03e530 (dup_mmap_sem){++++}-{0:0}, at: register_for_each_vma+0x2c/0xc10 kernel/events/uprobes.c:1040
but task is already holding lock: ffff8880624a8c90 (&uprobe->register_rwsem){+.+.}-{3:3}, at: __uprobe_register+0x531/0x850 kernel/events/uprobes.c:1177
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&uprobe->register_rwsem){+.+.}-{3:3}: down_write+0x92/0x150 kernel/locking/rwsem.c:1406 __uprobe_register+0x531/0x850 kernel/events/uprobes.c:1177 trace_uprobe_enable kernel/trace/trace_uprobe.c:1065 [inline] probe_event_enable+0x357/0xa00 kernel/trace/trace_uprobe.c:1134 trace_uprobe_register+0x443/0x880 kernel/trace/trace_uprobe.c:1461 perf_trace_event_reg kernel/trace/trace_event_perf.c:129 [inline] perf_trace_event_init+0x549/0xa20 kernel/trace/trace_event_perf.c:204 perf_uprobe_init+0x16f/0x210 kernel/trace/trace_event_perf.c:336 perf_uprobe_event_init+0xff/0x1c0 kernel/events/core.c:9754 perf_try_init_event+0x12a/0x560 kernel/events/core.c:11071 perf_init_event kernel/events/core.c:11123 [inline] perf_event_alloc.part.0+0xe3b/0x3960 kernel/events/core.c:11403 perf_event_alloc kernel/events/core.c:11785 [inline] __do_sys_perf_event_open+0x647/0x2e60 kernel/events/core.c:11883 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #2 (event_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:949 [inline] __mutex_lock+0x139/0x1120 kernel/locking/mutex.c:1096 perf_trace_destroy+0x23/0xf0 kernel/trace/trace_event_perf.c:241 _free_event+0x2ee/0x1380 kernel/events/core.c:4863 put_event kernel/events/core.c:4957 [inline] perf_mmap_close+0x572/0xe10 kernel/events/core.c:6002 remove_vma+0xae/0x170 mm/mmap.c:180 remove_vma_list mm/mmap.c:2653 [inline] __do_munmap+0x74f/0x11a0 mm/mmap.c:2909 do_munmap mm/mmap.c:2917 [inline] munmap_vma_range mm/mmap.c:598 [inline] mmap_region+0x85a/0x1730 mm/mmap.c:1750 do_mmap+0xcff/0x11d0 mm/mmap.c:1581 vm_mmap_pgoff+0x1b7/0x290 mm/util.c:519 ksys_mmap_pgoff+0x49c/0x620 mm/mmap.c:1632 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #1 (&mm->mmap_lock#2){++++}-{3:3}: down_write_killable+0x95/0x170 kernel/locking/rwsem.c:1417 mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] dup_mmap kernel/fork.c:480 [inline] dup_mm+0x12e/0x1380 kernel/fork.c:1368 copy_mm kernel/fork.c:1424 [inline] copy_process+0x2b99/0x7150 kernel/fork.c:2107 kernel_clone+0xe7/0xab0 kernel/fork.c:2500 __do_sys_clone+0xc8/0x110 kernel/fork.c:2617 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #0 (dup_mmap_sem){++++}-{0:0}: check_prev_add kernel/locking/lockdep.c:2936 [inline] check_prevs_add kernel/locking/lockdep.c:3059 [inline] validate_chain kernel/locking/lockdep.c:3674 [inline] __lock_acquire+0x2b14/0x54c0 kernel/locking/lockdep.c:4900 lock_acquire kernel/locking/lockdep.c:5510 [inline] lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475 percpu_down_write+0x95/0x440 kernel/locking/percpu-rwsem.c:217 register_for_each_vma+0x2c/0xc10 kernel/events/uprobes.c:1040 __uprobe_register+0x5c2/0x850 kernel/events/uprobes.c:1181 trace_uprobe_enable kernel/trace/trace_uprobe.c:1065 [inline] probe_event_enable+0x357/0xa00 kernel/trace/trace_uprobe.c:1134 trace_uprobe_register+0x443/0x880 kernel/trace/trace_uprobe.c:1461 perf_trace_event_reg kernel/trace/trace_event_perf.c:129 [inline] perf_trace_event_init+0x549/0xa20 kernel/trace/trace_event_perf.c:204 perf_uprobe_init+0x16f/0x210 kernel/trace/trace_event_perf.c:336 perf_uprobe_event_init+0xff/0x1c0 kernel/events/core.c:9754 perf_try_init_event+0x12a/0x560 kernel/events/core.c:11071 perf_init_event kernel/events/core.c:11123 [inline] perf_event_alloc.part.0+0xe3b/0x3960 kernel/events/core.c:11403 perf_event_alloc kernel/events/core.c:11785 [inline] __do_sys_perf_event_open+0x647/0x2e60 kernel/events/core.c:11883 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Chain exists of: dup_mmap_sem --> event_mutex --> &uprobe->register_rwsem
Possible unsafe locking scenario:
CPU0 CPU1 ---- ---- lock(&uprobe->register_rwsem); lock(event_mutex); lock(&uprobe->register_rwsem); lock(dup_mmap_sem);
*** DEADLOCK ***
3 locks held by syz-executor.3/23522: #0: ffffffff8fe4fcd8 (&pmus_srcu){....}-{0:0}, at: perf_event_alloc.part.0+0xc8e/0x3960 kernel/events/core.c:11401 #1: ffffffff8bfe5688 (event_mutex){+.+.}-{3:3}, at: perf_uprobe_init+0x164/0x210 kernel/trace/trace_event_perf.c:335 #2: ffff8880624a8c90 (&uprobe->register_rwsem){+.+.}-{3:3}, at: __uprobe_register+0x531/0x850 kernel/events/uprobes.c:1177
stack backtrace: CPU: 0 PID: 23522 Comm: syz-executor.3 Not tainted 5.12.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2127 check_prev_add kernel/locking/lockdep.c:2936 [inline] check_prevs_add kernel/locking/lockdep.c:3059 [inline] validate_chain kernel/locking/lockdep.c:3674 [inline] __lock_acquire+0x2b14/0x54c0 kernel/locking/lockdep.c:4900 lock_acquire kernel/locking/lockdep.c:5510 [inline] lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475 percpu_down_write+0x95/0x440 kernel/locking/percpu-rwsem.c:217 register_for_each_vma+0x2c/0xc10 kernel/events/uprobes.c:1040 __uprobe_register+0x5c2/0x850 kernel/events/uprobes.c:1181 trace_uprobe_enable kernel/trace/trace_uprobe.c:1065 [inline] probe_event_enable+0x357/0xa00 kernel/trace/trace_uprobe.c:1134 trace_uprobe_register+0x443/0x880 kernel/trace/trace_uprobe.c:1461 perf_trace_event_reg kernel/trace/trace_event_perf.c:129 [inline] perf_trace_event_init+0x549/0xa20 kernel/trace/trace_event_perf.c:204 perf_uprobe_init+0x16f/0x210 kernel/trace/trace_event_perf.c:336 perf_uprobe_event_init+0xff/0x1c0 kernel/events/core.c:9754 perf_try_init_event+0x12a/0x560 kernel/events/core.c:11071 perf_init_event kernel/events/core.c:11123 [inline] perf_event_alloc.part.0+0xe3b/0x3960 kernel/events/core.c:11403 perf_event_alloc kernel/events/core.c:11785 [inline] __do_sys_perf_event_open+0x647/0x2e60 kernel/events/core.c:11883 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x466459 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f30c08b8188 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000180 RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffedcea592f R14: 00007f30c08b8300 R15: 0000000000022000
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