================================================================== BUG: KASAN: use-after-free in __vb2_perform_fileio+0xce9/0xda0 drivers/media/v4l2-core/videobuf2-core.c:2390 Read of size 4 at addr ffff8880989a67dc by task syz-executor.5/9763 CPU: 1 PID: 9763 Comm: syz-executor.5 Not tainted 4.14.295-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351 kasan_report mm/kasan/report.c:409 [inline] __asan_report_load4_noabort+0x68/0x70 mm/kasan/report.c:429 __vb2_perform_fileio+0xce9/0xda0 drivers/media/v4l2-core/videobuf2-core.c:2390 vb2_fop_read+0x1ef/0x3d0 drivers/media/v4l2-core/videobuf2-v4l2.c:895 v4l2_read+0x19a/0x200 drivers/media/v4l2-core/v4l2-dev.c:309 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3eb/0x5b0 fs/read_write.c:919 vfs_readv+0xc8/0x120 fs/read_write.c:981 do_preadv fs/read_write.c:1065 [inline] SYSC_preadv fs/read_write.c:1115 [inline] SyS_preadv+0x15a/0x200 fs/read_write.c:1110 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f47f56d15a9 RSP: 002b:00007f47f4044168 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00007f47f57f1f80 RCX: 00007f47f56d15a9 RDX: 0000000000000004 RSI: 0000000020000200 RDI: 0000000000000006 RBP: 00007f47f572c580 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffee1dc262f R14: 00007f47f4044300 R15: 0000000000022000 Allocated by task 9760: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x131/0x3d0 mm/slab.c:3618 kmalloc include/linux/slab.h:488 [inline] kzalloc include/linux/slab.h:661 [inline] __vb2_init_fileio+0x17f/0xa90 drivers/media/v4l2-core/videobuf2-core.c:2235 __vb2_perform_fileio+0x993/0xda0 drivers/media/v4l2-core/videobuf2-core.c:2369 vb2_fop_read+0x1ef/0x3d0 drivers/media/v4l2-core/videobuf2-v4l2.c:895 v4l2_read+0x19a/0x200 drivers/media/v4l2-core/v4l2-dev.c:309 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3eb/0x5b0 fs/read_write.c:919 vfs_readv+0xc8/0x120 fs/read_write.c:981 do_preadv fs/read_write.c:1065 [inline] SYSC_preadv fs/read_write.c:1115 [inline] SyS_preadv+0x15a/0x200 fs/read_write.c:1110 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 9764: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xc9/0x250 mm/slab.c:3815 __vb2_cleanup_fileio+0xf5/0x150 drivers/media/v4l2-core/videobuf2-core.c:2328 vb2_core_queue_release+0x17/0x70 drivers/media/v4l2-core/videobuf2-core.c:2051 vb2_queue_release drivers/media/v4l2-core/videobuf2-v4l2.c:669 [inline] _vb2_fop_release+0x1c1/0x280 drivers/media/v4l2-core/videobuf2-v4l2.c:840 vivid_fop_release+0x17d/0x6c0 drivers/media/platform/vivid/vivid-core.c:486 v4l2_release+0xf4/0x190 drivers/media/v4l2-core/v4l2-dev.c:446 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1ad/0x200 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+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb The buggy address belongs to the object at ffff8880989a64c0 which belongs to the cache kmalloc-1024 of size 1024 The buggy address is located 796 bytes inside of 1024-byte region [ffff8880989a64c0, ffff8880989a68c0) The buggy address belongs to the page: page:ffffea0002626980 count:1 mapcount:0 mapping:ffff8880989a6040 index:0x0 compound_mapcount: 0 flags: 0xfff00000008100(slab|head) raw: 00fff00000008100 ffff8880989a6040 0000000000000000 0000000100000007 raw: ffffea0002ca62a0 ffffea0002c6b1a0 ffff88813fe74ac0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880989a6680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880989a6700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880989a6780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880989a6800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880989a6880: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================