================================================================== BUG: KASAN: use-after-free in __vb2_perform_fileio+0xddf/0xeb0 drivers/media/v4l2-core/videobuf2-core.c:2379 Read of size 4 at addr ffff8880a121ac5c by task syz-executor279/6996 CPU: 0 PID: 6996 Comm: syz-executor279 Not tainted 4.14.147 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x138/0x197 lib/dump_stack.c:53 print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report mm/kasan/report.c:409 [inline] kasan_report.cold+0xa9/0x2af mm/kasan/report.c:393 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429 __vb2_perform_fileio+0xddf/0xeb0 drivers/media/v4l2-core/videobuf2-core.c:2379 vb2_read+0x3b/0x50 drivers/media/v4l2-core/videobuf2-core.c:2490 vb2_fop_read+0x1f5/0x3e0 drivers/media/v4l2-core/videobuf2-v4l2.c:895 v4l2_read+0x1a9/0x200 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+0x3e2/0x5b0 fs/read_write.c:919 vfs_readv+0xd3/0x130 fs/read_write.c:981 do_readv+0x10a/0x2d0 fs/read_write.c:1014 SYSC_readv fs/read_write.c:1101 [inline] SyS_readv+0x28/0x30 fs/read_write.c:1098 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x44a439 RSP: 002b:00007f274b9eadb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000013 RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 000000000044a439 RDX: 0000000000000001 RSI: 0000000020000240 RDI: 0000000000000006 RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c R13: 00007ffecee4f4bf R14: 00007f274b9eb9c0 R15: 0000000000000000 Allocated by task 6996: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x45/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc mm/kasan/kasan.c:551 [inline] kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529 kmem_cache_alloc_trace+0x152/0x790 mm/slab.c:3618 kmalloc include/linux/slab.h:488 [inline] kzalloc include/linux/slab.h:661 [inline] __vb2_init_fileio+0x182/0xa90 drivers/media/v4l2-core/videobuf2-core.c:2224 __vb2_perform_fileio+0x9f0/0xeb0 drivers/media/v4l2-core/videobuf2-core.c:2358 vb2_read+0x3b/0x50 drivers/media/v4l2-core/videobuf2-core.c:2490 vb2_fop_read+0x1f5/0x3e0 drivers/media/v4l2-core/videobuf2-v4l2.c:895 v4l2_read+0x1a9/0x200 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+0x3e2/0x5b0 fs/read_write.c:919 vfs_readv+0xd3/0x130 fs/read_write.c:981 do_readv+0x10a/0x2d0 fs/read_write.c:1014 SYSC_readv fs/read_write.c:1101 [inline] SyS_readv+0x28/0x30 fs/read_write.c:1098 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Freed by task 6989: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x45/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xcc/0x270 mm/slab.c:3815 __vb2_cleanup_fileio+0xfc/0x150 drivers/media/v4l2-core/videobuf2-core.c:2317 vb2_core_queue_release+0x1d/0x80 drivers/media/v4l2-core/videobuf2-core.c:2040 vb2_queue_release drivers/media/v4l2-core/videobuf2-v4l2.c:669 [inline] _vb2_fop_release+0x1cf/0x2a0 drivers/media/v4l2-core/videobuf2-v4l2.c:840 vb2_fop_release+0x75/0xc0 drivers/media/v4l2-core/videobuf2-v4l2.c:854 vivid_fop_release+0x180/0x3f0 drivers/media/platform/vivid/vivid-core.c:486 v4l2_release+0xf9/0x190 drivers/media/v4l2-core/v4l2-dev.c:446 __fput+0x275/0x7a0 fs/file_table.c:210 ____fput+0x16/0x20 fs/file_table.c:244 task_work_run+0x114/0x190 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x7df/0x2c10 kernel/exit.c:874 do_group_exit+0x111/0x330 kernel/exit.c:977 get_signal+0x381/0x1cd0 kernel/signal.c:2409 do_signal+0x86/0x19a0 arch/x86/kernel/signal.c:814 exit_to_usermode_loop+0x15c/0x220 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4bc/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 The buggy address belongs to the object at ffff8880a121a940 which belongs to the cache kmalloc-1024 of size 1024 The buggy address is located 796 bytes inside of 1024-byte region [ffff8880a121a940, ffff8880a121ad40) The buggy address belongs to the page: page:ffffea0002848680 count:1 mapcount:0 mapping:ffff8880a121a040 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000008100(slab|head) raw: 01fffc0000008100 ffff8880a121a040 0000000000000000 0000000100000007 raw: ffffea00021d2a20 ffffea0002234920 ffff8880aa800ac0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a121ab00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a121ab80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880a121ac00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a121ac80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a121ad00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================