================================================================== BUG: KASAN: use-after-free in test_and_set_bit include/asm-generic/bitops/instrumented-atomic.h:70 [inline] BUG: KASAN: use-after-free in try_to_grab_pending kernel/workqueue.c:1251 [inline] BUG: KASAN: use-after-free in try_to_grab_pending+0x115/0x910 kernel/workqueue.c:1229 Write of size 8 at addr ffff888091e61008 by task syz-executor045/24483 CPU: 1 PID: 24483 Comm: syz-executor045 Not tainted 5.5.0-rc2-next-20191217-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/0x41 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:639 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x134/0x1a0 mm/kasan/generic.c:192 __kasan_check_write+0x14/0x20 mm/kasan/common.c:101 test_and_set_bit include/asm-generic/bitops/instrumented-atomic.h:70 [inline] try_to_grab_pending kernel/workqueue.c:1251 [inline] try_to_grab_pending+0x115/0x910 kernel/workqueue.c:1229 __cancel_work_timer+0xc4/0x540 kernel/workqueue.c:3087 cancel_work_sync+0x18/0x20 kernel/workqueue.c:3164 tty_buffer_cancel_work+0x16/0x20 drivers/tty/tty_buffer.c:613 release_tty+0x261/0x470 drivers/tty/tty_io.c:1520 tty_release_struct+0x3c/0x50 drivers/tty/tty_io.c:1629 tty_release+0xbcb/0xe90 drivers/tty/tty_io.c:1789 __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:164 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath arch/x86/entry/common.c:278 [inline] do_syscall_64+0x676/0x790 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x406691 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 24 1a 00 00 c3 48 83 ec 08 e8 6a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 b3 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007fffa50bbc80 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000406691 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 0000000000000003 RBP: 00000000006ddc4c R08: 0000000000000000 R09: 0000000000000000 R10: 00007fffa50bbca0 R11: 0000000000000293 R12: 00000000006ddc40 R13: 0000000000000000 R14: 20c49ba5e353f7cf R15: 0000000000000008 Allocated by task 23549: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:486 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:527 kmem_cache_alloc_trace+0x158/0x790 mm/slab.c:3551 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:670 [inline] vc_allocate drivers/tty/vt/vt.c:1085 [inline] vc_allocate+0x1fc/0x760 drivers/tty/vt/vt.c:1066 con_install+0x52/0x410 drivers/tty/vt/vt.c:3229 tty_driver_install_tty drivers/tty/tty_io.c:1228 [inline] tty_init_dev drivers/tty/tty_io.c:1341 [inline] tty_init_dev+0xf9/0x470 drivers/tty/tty_io.c:1318 tty_open_by_driver drivers/tty/tty_io.c:1987 [inline] tty_open+0x4a5/0xbb0 drivers/tty/tty_io.c:2035 chrdev_open+0x245/0x6b0 fs/char_dev.c:414 do_dentry_open+0x4ca/0x1350 fs/open.c:797 vfs_open+0xa0/0xd0 fs/open.c:914 do_last fs/namei.c:3551 [inline] path_openat+0x12fd/0x34d0 fs/namei.c:3668 do_filp_open+0x192/0x260 fs/namei.c:3698 do_sys_openat2+0x633/0x840 fs/open.c:1152 do_sys_open+0xfc/0x190 fs/open.c:1168 ksys_open include/linux/syscalls.h:1386 [inline] __do_sys_open fs/open.c:1174 [inline] __se_sys_open fs/open.c:1172 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1172 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 24491: 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:335 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:474 kasan_slab_free+0xe/0x10 mm/kasan/common.c:483 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x2c0 mm/slab.c:3757 vt_disallocate_all+0x2bd/0x3e0 drivers/tty/vt/vt_ioctl.c:323 vt_ioctl+0xc38/0x26d0 drivers/tty/vt/vt_ioctl.c:816 tty_ioctl+0xa37/0x14f0 drivers/tty/tty_io.c:2660 vfs_ioctl fs/ioctl.c:47 [inline] file_ioctl fs/ioctl.c:545 [inline] do_vfs_ioctl+0x977/0x14e0 fs/ioctl.c:732 ksys_ioctl+0xab/0xd0 fs/ioctl.c:749 __do_sys_ioctl fs/ioctl.c:756 [inline] __se_sys_ioctl fs/ioctl.c:754 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888091e61000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 8 bytes inside of 2048-byte region [ffff888091e61000, ffff888091e61800) The buggy address belongs to the page: page:ffffea0002479840 refcount:1 mapcount:0 mapping:ffff8880aa400e00 index:0x0 raw: 00fffe0000000200 ffffea00028e23c8 ffffea0002449308 ffff8880aa400e00 raw: 0000000000000000 ffff888091e61000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888091e60f00: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc ffff888091e60f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888091e61000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888091e61080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888091e61100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================