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 Modules linked in: CPU: 1 PID: 8846 Comm: syz-executor.4 Not tainted 4.14.134 #29 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ISOFS: Unable to identify CD-ROM format. task: ffff88805939e3c0 task.stack: ffff888055b50000 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 RSP: 0018:ffff888055b57b98 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8880899712c0 RCX: ffffffff8424e670 RDX: 0000000000000004 RSI: 0000000000000020 RDI: 0000000000000001 RBP: ffff888055b57bc0 R08: 000000000124fc05 R09: ffff88805939ec88 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000020 R13: 0000000000000001 R14: ffff8880899712d4 R15: 0000000000000000 FS: 00000000019b2940(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000137a028 CR3: 000000008ab50000 CR4: 00000000001406e0 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 __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 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 __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 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: 0033:0x413511 RSP: 002b:00007ffc718756b0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000413511 RDX: 0000001b2bc20000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000001 R08: 000000006e783fbb R09: 000000006e783fbf R10: 00007ffc71875790 R11: 0000000000000293 R12: 000000000075bf20 R13: 000000000002e4d5 R14: 0000000000760c50 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 06 b0 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: ffff888055b57b98 RIP: atomic_read arch/x86/include/asm/atomic.h:27 [inline] RSP: ffff888055b57b98 RIP: refcount_sub_and_test+0x2b/0xf0 lib/refcount.c:179 RSP: ffff888055b57b98 kobject: 'loop0' (ffff88809b56c620): kobject_uevent_env kobject: 'loop0' (ffff88809b56c620): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop5' (ffff8880a4ab6160): kobject_uevent_env kobject: 'loop5' (ffff8880a4ab6160): fill_kobj_path: path = '/devices/virtual/block/loop5' ---[ end trace 7531195f24ab32ff ]--- kobject: 'loop2' (ffff8880a49d6f20): kobject_uevent_env kobject: 'loop2' (ffff8880a49d6f20): fill_kobj_path: path = '/devices/virtual/block/loop2'