kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN kobject: 'loop1' (ffff8880a4a349a0): kobject_uevent_env Modules linked in: CPU: 1 PID: 29256 Comm: syz-executor.4 Not tainted 4.14.139 #35 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880524126c0 task.stack: ffff8880598b0000 RIP: 0010:__read_once_size include/linux/compiler.h:183 [inline] RIP: 0010:atomic_read arch/x86/include/asm/atomic.h:27 [inline] RIP: 0010:refcount_sub_and_test+0x2b/0xf0 lib/refcount.c:179 kobject: 'loop1' (ffff8880a4a349a0): fill_kobj_path: path = '/devices/virtual/block/loop1' RSP: 0018:ffff8880598b7b98 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff888090aaf080 RCX: ffffffff842619c0 RDX: 0000000000000004 RSI: 0000000000000020 RDI: 0000000000000001 RBP: ffff8880598b7bc0 R08: 0000000002ee9e37 R09: ffff888052412f88 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000020 R13: 0000000000000001 R14: ffff888090aaf094 R15: 0000000000000000 FS: 0000000001bfe940(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 kobject: 'loop3' (ffff8880a4aaaaa0): kobject_uevent_env CR2: 0000000000000000 CR3: 00000000933cf000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: refcount_dec_and_test+0x1b/0x20 lib/refcount.c:212 vb2_vmalloc_put+0x18/0x70 drivers/media/v4l2-core/videobuf2-vmalloc.c:68 __vb2_buf_mem_free+0x103/0x1e0 drivers/media/v4l2-core/videobuf2-core.c:240 kobject: 'loop3' (ffff8880a4aaaaa0): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop1' (ffff8880a4a349a0): kobject_uevent_env __vb2_free_mem drivers/media/v4l2-core/videobuf2-core.c:409 [inline] __vb2_queue_free+0x634/0x7d0 drivers/media/v4l2-core/videobuf2-core.c:454 kobject: 'loop1' (ffff8880a4a349a0): fill_kobj_path: path = '/devices/virtual/block/loop1' vb2_core_queue_release+0x64/0x80 drivers/media/v4l2-core/videobuf2-core.c:2043 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 kobject: 'loop1' (ffff8880a4a349a0): kobject_uevent_env __fput+0x275/0x7a0 fs/file_table.c:210 kobject: 'loop1' (ffff8880a4a349a0): fill_kobj_path: path = '/devices/virtual/block/loop1' ____fput+0x16/0x20 fs/file_table.c:244 task_work_run+0x114/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1da/0x220 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+0x4bc/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x413561 RSP: 002b:00007ffc19053610 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000413561 RDX: 0000001b33620000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000001 R08: 0000000010745ce5 R09: 0000000010745ce9 R10: 00007ffc190536f0 R11: 0000000000000293 R12: 000000000075bf20 R13: 00000000000ae660 R14: 0000000000760a40 R15: ffffffffffffffff Code: 55 48 89 e5 41 56 41 55 41 89 fd 41 54 49 89 f4 53 48 83 ec 08 e8 96 66 85 fe 4c 89 e2 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <0f> b6 14 02 4c 89 e0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 RIP: __read_once_size include/linux/compiler.h:183 [inline] RSP: ffff8880598b7b98 RIP: atomic_read arch/x86/include/asm/atomic.h:27 [inline] RSP: ffff8880598b7b98 RIP: refcount_sub_and_test+0x2b/0xf0 lib/refcount.c:179 RSP: ffff8880598b7b98 kobject: 'loop3' (ffff8880a4aaaaa0): kobject_uevent_env ---[ end trace 2f9a27ddd5d33787 ]--- kobject: 'loop2' (ffff8880a4a3ca20): kobject_uevent_env kobject: 'loop2' (ffff8880a4a3ca20): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop3' (ffff8880a4aaaaa0): fill_kobj_path: path = '/devices/virtual/block/loop3'