bisecting fixing commit since 58b454ebf81e5ae9391957d99cf89566d9eec1b1 building syzkaller on b0e8efcb4b0aac61f4647a76bbe54a5d38a370ba testing commit 58b454ebf81e5ae9391957d99cf89566d9eec1b1 with gcc (GCC) 8.1.0 kernel signature: 98087c49a3234368dafbac1ad4d6ed7ddb2fbbe98209c24c0939da06af0e53a7 all runs: crashed: WARNING in dma_buf_vunmap testing current HEAD e0f8b8a65a473a8baa439cf865a694bbeb83fe90 testing commit e0f8b8a65a473a8baa439cf865a694bbeb83fe90 with gcc (GCC) 8.1.0 kernel signature: f5a81babf0478f87d538ef3fc3c6e26fa5e40f4e265dbe3950e3ff23c3f67679 all runs: crashed: WARNING in dma_buf_vunmap revisions tested: 2, total time: 23m9.853792847s (build: 16m7.563686206s, test: 6m30.869864402s) the crash still happens on HEAD commit msg: Linux 4.14.170 crash: WARNING in dma_buf_vunmap bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered disabled state device bridge_slave_0 entered promiscuous mode IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready ------------[ cut here ]------------ WARNING: CPU: 1 PID: 6993 at drivers/dma-buf/dma-buf.c:1039 dma_buf_vunmap+0x154/0x1b0 drivers/dma-buf/dma-buf.c:1053 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 6993 Comm: syz-executor.3 Not tainted 4.14.170-syzkaller #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+0xf7/0x13b lib/dump_stack.c:58 panic+0x1b0/0x36a kernel/panic.c:183 __warn.cold.8+0x25/0x2a kernel/panic.c:547 report_bug+0x1a4/0x1f3 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:177 [inline] do_error_trap+0x1bd/0x310 arch/x86/kernel/traps.c:295 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:963 RIP: 0010:dma_buf_vunmap+0x154/0x1b0 drivers/dma-buf/dma-buf.c:1039 RSP: 0018:ffff88808b0e7bd0 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff88809c0eef00 RCX: 1ffff11013c8eca7 RDX: 1ffff1101381dde8 RSI: ffffc90005ebc000 RDI: 0000000000000000 RBP: ffff88808b0e7bf8 R08: ffff888082dd6b48 R09: 000000000000657b R10: ffff88808b0e7ce8 R11: ffff888082dd6280 R12: ffffffff8425a420 R13: ffff88809cc7e840 R14: ffff88809cc7e868 R15: ffff88809c0eef00 vb2_vmalloc_detach_dmabuf+0x4f/0x80 drivers/media/v4l2-core/videobuf2-vmalloc.c:407 __vb2_plane_dmabuf_put.isra.6+0xff/0x2d0 drivers/media/v4l2-core/videobuf2-core.c:273 __vb2_buf_dmabuf_put drivers/media/v4l2-core/videobuf2-core.c:289 [inline] __vb2_free_mem drivers/media/v4l2-core/videobuf2-core.c:411 [inline] __vb2_queue_free+0x55c/0x770 drivers/media/v4l2-core/videobuf2-core.c:454 vb2_core_queue_release+0x57/0x70 drivers/media/v4l2-core/videobuf2-core.c:2043 vb2_queue_release drivers/media/v4l2-core/videobuf2-v4l2.c:669 [inline] _vb2_fop_release+0x1ac/0x280 drivers/media/v4l2-core/videobuf2-v4l2.c:840 vb2_fop_release+0x66/0xd0 drivers/media/v4l2-core/videobuf2-v4l2.c:854 vivid_fop_release+0x15f/0x3a0 drivers/media/platform/vivid/vivid-core.c:486 v4l2_release+0xee/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:446 __fput+0x235/0x750 fs/file_table.c:210 ____fput+0x9/0x10 fs/file_table.c:244 task_work_run+0xeb/0x180 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x16a/0x1b0 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+0x418/0x5b0 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4129e1 RSP: 002b:00007ffe50d92450 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00000000004129e1 RDX: 0000001b2ed20000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000740518 R08: 000000000000df4e R09: 000000000000df4e R10: 00007ffe50d92520 R11: 0000000000000293 R12: 0000000000000001 R13: 000000000000df53 R14: 000000000000df80 R15: 000000000073bf0c Kernel Offset: disabled Rebooting in 86400 seconds..