================================================================== BUG: KASAN: use-after-free in test_bit include/asm-generic/bitops/instrumented-non-atomic.h:110 [inline] BUG: KASAN: use-after-free in tty_port_kopened include/linux/tty.h:673 [inline] BUG: KASAN: use-after-free in tty_open_by_driver drivers/tty/tty_io.c:1966 [inline] BUG: KASAN: use-after-free in tty_open+0x6f8/0xbb0 drivers/tty/tty_io.c:2035 Read of size 8 at addr ffff888098309200 by task syz-executor827/14529 CPU: 1 PID: 14529 Comm: syz-executor827 Not tainted 5.5.0-rc2-next-20191220-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_read+0x11/0x20 mm/kasan/common.c:95 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:110 [inline] tty_port_kopened include/linux/tty.h:673 [inline] tty_open_by_driver drivers/tty/tty_io.c:1966 [inline] tty_open+0x6f8/0xbb0 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:3553 [inline] path_openat+0x12fd/0x34d0 fs/namei.c:3670 do_filp_open+0x192/0x260 fs/namei.c:3700 do_sys_openat2+0x633/0x840 fs/open.c:1152 do_sys_open+0xfc/0x190 fs/open.c:1168 ksys_open include/linux/syscalls.h:1385 [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 RIP: 0033:0x401900 Code: 48 83 c4 08 48 3d 01 f0 ff ff 0f 83 ba 0b 00 00 c3 66 0f 1f 84 00 00 00 00 00 83 3d 8d 86 2d 00 00 75 14 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 94 0b 00 00 c3 48 83 ec 08 e8 fa 00 00 00 RSP: 002b:00007ffd4560ed08 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000401900 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007ffd4560ed30 RBP: 00007ffd4560edf0 R08: 0000000000000000 R09: 000000000000000d R10: 0000000000000064 R11: 0000000000000246 R12: 0000000000015d0e R13: 0000000000000004 R14: 00007ffd4560ee20 R15: 0000000000000000 Allocated by task 14526: 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:555 [inline] kzalloc include/linux/slab.h:669 [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:3553 [inline] path_openat+0x12fd/0x34d0 fs/namei.c:3670 do_filp_open+0x192/0x260 fs/namei.c:3700 do_sys_openat2+0x633/0x840 fs/open.c:1152 do_sys_open+0xfc/0x190 fs/open.c:1168 ksys_open include/linux/syscalls.h:1385 [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 14529: 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] ksys_ioctl+0x123/0x180 fs/ioctl.c:747 __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 ffff888098309000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 512 bytes inside of 2048-byte region [ffff888098309000, ffff888098309800) The buggy address belongs to the page: page:ffffea000260c240 refcount:1 mapcount:0 mapping:ffff8880aa400e00 index:0x0 raw: 00fffe0000000200 ffffea0002569f48 ffffea00023d4ac8 ffff8880aa400e00 raw: 0000000000000000 ffff888098309000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888098309100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888098309180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888098309200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888098309280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888098309300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================