===================================== WARNING: bad unlock balance detected! 5.6.0-rc3-next-20200225-syzkaller #0 Not tainted ------------------------------------- syz-executor.0/10271 is trying to release lock (&file->mut) at: [] ucma_destroy_id+0x24a/0x490 drivers/infiniband/core/ucma.c:621 but there are no more locks to release! other info that might help us debug this: 1 lock held by syz-executor.0/10271: #0: ffff8880a8995260 (&file->mut){+.+.}, at: ucma_destroy_id+0x1e7/0x490 drivers/infiniband/core/ucma.c:619 stack backtrace: CPU: 1 PID: 10271 Comm: syz-executor.0 Not tainted 5.6.0-rc3-next-20200225-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 print_unlock_imbalance_bug kernel/locking/lockdep.c:4243 [inline] print_unlock_imbalance_bug.cold+0x114/0x123 kernel/locking/lockdep.c:4219 __lock_release kernel/locking/lockdep.c:4477 [inline] lock_release+0x5f2/0x960 kernel/locking/lockdep.c:4738 __mutex_unlock_slowpath+0x86/0x6a0 kernel/locking/mutex.c:1228 mutex_unlock+0xd/0x10 kernel/locking/mutex.c:740 ucma_destroy_id+0x24a/0x490 drivers/infiniband/core/ucma.c:621 ucma_write+0x2d7/0x3c0 drivers/infiniband/core/ucma.c:1684 __vfs_write+0x8a/0x110 fs/read_write.c:494 vfs_write+0x268/0x5d0 fs/read_write.c:558 ksys_write+0x220/0x290 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:620 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c479 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fa3b8ff8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fa3b8ff96d4 RCX: 000000000045c479 RDX: 0000000000000018 RSI: 0000000020001380 RDI: 0000000000000003 RBP: 000000000076bfc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000cb7 R14: 00000000004d7b50 R15: 000000000076bfcc ================================================================== BUG: KASAN: use-after-free in ucma_destroy_id+0x448/0x490 drivers/infiniband/core/ucma.c:623 Read of size 8 at addr ffff8880a8995068 by task syz-executor.0/10271 CPU: 1 PID: 10271 Comm: syz-executor.0 Not tainted 5.6.0-rc3-next-20200225-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 __kasan_report.cold+0x1b/0x32 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:641 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 ucma_destroy_id+0x448/0x490 drivers/infiniband/core/ucma.c:623 ucma_write+0x2d7/0x3c0 drivers/infiniband/core/ucma.c:1684 __vfs_write+0x8a/0x110 fs/read_write.c:494 vfs_write+0x268/0x5d0 fs/read_write.c:558 ksys_write+0x220/0x290 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:620 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c479 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fa3b8ff8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fa3b8ff96d4 RCX: 000000000045c479 RDX: 0000000000000018 RSI: 0000000020001380 RDI: 0000000000000003 RBP: 000000000076bfc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000cb7 R14: 00000000004d7b50 R15: 000000000076bfcc Allocated by task 10266: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:515 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:488 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:529 kmem_cache_alloc_trace+0x158/0x790 mm/slab.c:3551 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:669 [inline] ucma_alloc_ctx+0x4e/0x470 drivers/infiniband/core/ucma.c:210 ucma_create_id+0x12d/0x620 drivers/infiniband/core/ucma.c:495 ucma_write+0x2d7/0x3c0 drivers/infiniband/core/ucma.c:1684 __vfs_write+0x8a/0x110 fs/read_write.c:494 vfs_write+0x268/0x5d0 fs/read_write.c:558 ksys_write+0x220/0x290 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:620 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 10265: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:337 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:476 kasan_slab_free+0xe/0x10 mm/kasan/common.c:485 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x2c0 mm/slab.c:3757 ucma_free_ctx+0x839/0xbc0 drivers/infiniband/core/ucma.c:592 ucma_close+0x122/0x310 drivers/infiniband/core/ucma.c:1767 __fput+0x2ff/0x890 fs/file_table.c:280 ____fput+0x16/0x20 fs/file_table.c:313 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x316/0x380 arch/x86/entry/common.c:165 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x676/0x790 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a8995000 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 104 bytes inside of 256-byte region [ffff8880a8995000, ffff8880a8995100) The buggy address belongs to the page: page:ffffea0002a26540 refcount:1 mapcount:0 mapping:0000000081b320c6 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002a2fc48 ffffea00024e2908 ffff8880aa4008c0 raw: 0000000000000000 ffff8880a8995000 0000000100000008 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a8994f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880a8994f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880a8995000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a8995080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a8995100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================