===================================== WARNING: bad unlock balance detected! 4.14.171-syzkaller #0 Not tainted ------------------------------------- syz-executor.2/9892 is trying to release lock (&file->mut) at: [] ucma_destroy_id+0x20d/0x420 drivers/infiniband/core/ucma.c:606 but there are no more locks to release! other info that might help us debug this: 1 lock held by syz-executor.2/9892: #0: (&file->mut){+.+.}, at: [] ucma_destroy_id+0x1aa/0x420 drivers/infiniband/core/ucma.c:604 stack backtrace: CPU: 0 PID: 9892 Comm: syz-executor.2 Not tainted 4.14.171-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x142/0x197 lib/dump_stack.c:58 print_unlock_imbalance_bug kernel/locking/lockdep.c:3548 [inline] print_unlock_imbalance_bug.cold+0x114/0x123 kernel/locking/lockdep.c:3525 __lock_release kernel/locking/lockdep.c:3765 [inline] lock_release+0x616/0x940 kernel/locking/lockdep.c:4013 __mutex_unlock_slowpath+0x71/0x800 kernel/locking/mutex.c:1018 mutex_unlock+0xd/0x10 kernel/locking/mutex.c:614 ucma_destroy_id+0x20d/0x420 drivers/infiniband/core/ucma.c:606 ucma_write+0x231/0x310 drivers/infiniband/core/ucma.c:1672 __vfs_write+0x105/0x6b0 fs/read_write.c:480 vfs_write+0x198/0x500 fs/read_write.c:544 SYSC_write fs/read_write.c:590 [inline] SyS_write+0xfd/0x230 fs/read_write.c:582 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c6c9 RSP: 002b:00007fd114bb8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fd114bb96d4 RCX: 000000000045c6c9 RDX: 0000000000000018 RSI: 0000000020001380 RDI: 0000000000000003 RBP: 000000000076bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000c8a R14: 00000000004d7910 R15: 000000000076bfd4 ================================================================== BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:183 [inline] BUG: KASAN: use-after-free in atomic64_read arch/x86/include/asm/atomic64_64.h:22 [inline] BUG: KASAN: use-after-free in atomic_long_read include/asm-generic/atomic-long.h:45 [inline] BUG: KASAN: use-after-free in __mutex_unlock_slowpath+0x656/0x800 kernel/locking/mutex.c:1027 Read of size 8 at addr ffff8880a1686e00 by task syz-executor.2/9892 CPU: 0 PID: 9892 Comm: syz-executor.2 Not tainted 4.14.171-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x142/0x197 lib/dump_stack.c:58 print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report mm/kasan/report.c:409 [inline] kasan_report.cold+0xa9/0x2af mm/kasan/report.c:393 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430 __read_once_size include/linux/compiler.h:183 [inline] atomic64_read arch/x86/include/asm/atomic64_64.h:22 [inline] atomic_long_read include/asm-generic/atomic-long.h:45 [inline] __mutex_unlock_slowpath+0x656/0x800 kernel/locking/mutex.c:1027 mutex_unlock+0xd/0x10 kernel/locking/mutex.c:614 ucma_destroy_id+0x20d/0x420 drivers/infiniband/core/ucma.c:606 ucma_write+0x231/0x310 drivers/infiniband/core/ucma.c:1672 __vfs_write+0x105/0x6b0 fs/read_write.c:480 vfs_write+0x198/0x500 fs/read_write.c:544 SYSC_write fs/read_write.c:590 [inline] SyS_write+0xfd/0x230 fs/read_write.c:582 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c6c9 RSP: 002b:00007fd114bb8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fd114bb96d4 RCX: 000000000045c6c9 RDX: 0000000000000018 RSI: 0000000020001380 RDI: 0000000000000003 RBP: 000000000076bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000c8a R14: 00000000004d7910 R15: 000000000076bfd4 Allocated by task 9892: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x45/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc mm/kasan/kasan.c:551 [inline] kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529 kmem_cache_alloc_trace+0x152/0x790 mm/slab.c:3618 kmalloc include/linux/slab.h:488 [inline] ucma_open+0x4f/0x290 drivers/infiniband/core/ucma.c:1704 misc_open+0x34f/0x480 drivers/char/misc.c:154 chrdev_open+0x207/0x590 fs/char_dev.c:423 do_dentry_open+0x73b/0xeb0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:891 do_last fs/namei.c:3428 [inline] path_openat+0x917/0x3e50 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_sys_open+0x2c5/0x430 fs/open.c:1084 SYSC_openat fs/open.c:1111 [inline] SyS_openat+0x30/0x40 fs/open.c:1105 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Freed by task 9882: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x45/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xcc/0x270 mm/slab.c:3815 ucma_close+0x280/0x310 drivers/infiniband/core/ucma.c:1763 __fput+0x275/0x7a0 fs/file_table.c:210 ____fput+0x16/0x20 fs/file_table.c:244 task_work_run+0x114/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1da/0x220 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4bc/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 The buggy address belongs to the object at ffff8880a1686e00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 0 bytes inside of 256-byte region [ffff8880a1686e00, ffff8880a1686f00) The buggy address belongs to the page: page:ffffea000285a180 count:1 mapcount:0 mapping:ffff8880a1686040 index:0xffff8880a1686900 flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffff8880a1686040 ffff8880a1686900 0000000100000006 raw: ffffea000249d1a0 ffffea000231bfe0 ffff8880aa8007c0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a1686d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a1686d80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8880a1686e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a1686e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a1686f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================