================================================================== BUG: KASAN: use-after-free in __vb2_perform_fileio+0x1065/0x1140 drivers/media/common/videobuf2/videobuf2-core.c:2620 Read of size 4 at addr ffff88808f0be31c by task syz-executor341/7813 CPU: 0 PID: 7813 Comm: syz-executor341 Not tainted 5.1.0-rc5-next-20190418 #28 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 __kasan_report.cold+0x1b/0x40 mm/kasan/report.c:316 kasan_report+0x12/0x20 mm/kasan/common.c:620 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:131 __vb2_perform_fileio+0x1065/0x1140 drivers/media/common/videobuf2/videobuf2-core.c:2620 vb2_read+0x3b/0x50 drivers/media/common/videobuf2/videobuf2-core.c:2731 vb2_fop_read+0x212/0x410 drivers/media/common/videobuf2/videobuf2-v4l2.c:1093 v4l2_read+0x1ce/0x230 drivers/media/v4l2-core/v4l2-dev.c:317 __vfs_read+0x8d/0x110 fs/read_write.c:416 vfs_read+0x194/0x3e0 fs/read_write.c:452 ksys_read+0x14f/0x2d0 fs/read_write.c:579 __do_sys_read fs/read_write.c:589 [inline] __se_sys_read fs/read_write.c:587 [inline] __x64_sys_read+0x73/0xb0 fs/read_write.c:587 do_syscall_64+0x103/0x670 arch/x86/entry/common.c:298 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x44a5d9 Code: e8 0c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 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 0f 83 7b cb fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f30864d9ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00000000006dbc38 RCX: 000000000044a5d9 RDX: 000000000000004b RSI: 0000000020000280 RDI: 0000000000000004 RBP: 00000000006dbc30 R08: 00007f30864da700 R09: 0000000000000000 R10: 00007f30864da700 R11: 0000000000000246 R12: 00000000006dbc3c R13: 00007ffd7767546f R14: 00007f30864da9c0 R15: 0000000000000001 Allocated by task 7814: save_stack+0x45/0xb0 mm/kasan/common.c:76 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:495 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:468 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:509 kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3585 kmalloc include/linux/slab.h:547 [inline] kzalloc include/linux/slab.h:742 [inline] __vb2_init_fileio+0x1cb/0xbe0 drivers/media/common/videobuf2/videobuf2-core.c:2465 __vb2_perform_fileio+0xc01/0x1140 drivers/media/common/videobuf2/videobuf2-core.c:2599 vb2_read+0x3b/0x50 drivers/media/common/videobuf2/videobuf2-core.c:2731 vb2_fop_read+0x212/0x410 drivers/media/common/videobuf2/videobuf2-v4l2.c:1093 v4l2_read+0x1ce/0x230 drivers/media/v4l2-core/v4l2-dev.c:317 __vfs_read+0x8d/0x110 fs/read_write.c:416 vfs_read+0x194/0x3e0 fs/read_write.c:452 ksys_read+0x14f/0x2d0 fs/read_write.c:579 __do_sys_read fs/read_write.c:589 [inline] __se_sys_read fs/read_write.c:587 [inline] __x64_sys_read+0x73/0xb0 fs/read_write.c:587 do_syscall_64+0x103/0x670 arch/x86/entry/common.c:298 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 7812: save_stack+0x45/0xb0 mm/kasan/common.c:76 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:457 kasan_slab_free+0xe/0x10 mm/kasan/common.c:465 __cache_free mm/slab.c:3462 [inline] kfree+0xcf/0x230 mm/slab.c:3785 __vb2_cleanup_fileio+0x100/0x170 drivers/media/common/videobuf2/videobuf2-core.c:2558 vb2_core_queue_release+0x20/0x80 drivers/media/common/videobuf2/videobuf2-core.c:2281 vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:867 [inline] _vb2_fop_release+0x1cf/0x2a0 drivers/media/common/videobuf2/videobuf2-v4l2.c:1038 vb2_fop_release+0x75/0xc0 drivers/media/common/videobuf2/videobuf2-v4l2.c:1052 vivid_fop_release+0x18e/0x430 drivers/media/platform/vivid/vivid-core.c:475 v4l2_release+0x224/0x3a0 drivers/media/v4l2-core/v4l2-dev.c:456 __fput+0x2e5/0x8d0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x14a/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x90a/0x2fa0 kernel/exit.c:876 do_group_exit+0x135/0x370 kernel/exit.c:980 get_signal+0x399/0x1d50 kernel/signal.c:2578 do_signal+0x87/0x1900 arch/x86/kernel/signal.c:818 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:276 [inline] do_syscall_64+0x57e/0x670 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88808f0be000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 796 bytes inside of 1024-byte region [ffff88808f0be000, ffff88808f0be400) The buggy address belongs to the page: page:ffffea00023c2f80 count:1 mapcount:0 mapping:ffff88812c3deac0 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0002a28e88 ffffea0002a6b488 ffff88812c3deac0 raw: 0000000000000000 ffff88808f0be000 0000000100000007 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808f0be200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808f0be280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88808f0be300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88808f0be380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808f0be400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================