bisecting fixing commit since e6a95d8851f1e993269b2172595107061f9371ae building syzkaller on 0159583c3bcfe4ece6b839712327cd955aabee66 testing commit e6a95d8851f1e993269b2172595107061f9371ae with gcc (GCC) 8.1.0 kernel signature: e29f6e0c8736bfeb4895796e7061f9783c7261fd9082756cbb44a0721763364b all runs: crashed: general protection fault in vb2_vmalloc_put testing current HEAD 98db2bf27b9ed2d5ed0b6c9c8a4bfcb127a19796 testing commit 98db2bf27b9ed2d5ed0b6c9c8a4bfcb127a19796 with gcc (GCC) 8.1.0 kernel signature: 904893cbe6884e3ec3a9d423d4ef621244db708587e89334740d39ba09122cc8 all runs: crashed: general protection fault in vb2_vmalloc_put revisions tested: 2, total time: 23m50.696045638s (build: 16m30.268876611s, test: 6m20.14074565s) the crash still happens on HEAD commit msg: Linux 4.14.171 crash: general protection fault in vb2_vmalloc_put IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready kasan: CONFIG_KASAN_INLINE enabled IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN bridge0: port 2(bridge_slave_1) entered blocking state Modules linked in: bridge0: port 2(bridge_slave_1) entered forwarding state CPU: 0 PID: 6924 Comm: syz-executor.2 Not tainted 4.14.171-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880a84385c0 task.stack: ffff88808d0c8000 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+0x1c/0x90 lib/refcount.c:179 RSP: 0018:ffff88808d0cfbd0 EFLAGS: 00010282 IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bond: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready RAX: dffffc0000000000 RBX: 0000000000000001 RCX: 1ffff110150871d1 RDX: 0000000000000004 RSI: 0000000000000020 RDI: 0000000000000001 RBP: ffff88808d0cfbe0 R08: ffff8880a8438e88 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88808b23e580 R13: dffffc0000000000 R14: ffff88808b23e594 R15: 0000000000000000 FS: 00000000012de940(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000075c081 CR3: 0000000099019000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: refcount_dec_and_test+0x11/0x20 lib/refcount.c:212 vb2_vmalloc_put+0x11/0x50 drivers/media/v4l2-core/videobuf2-vmalloc.c:68 __vb2_buf_mem_free+0xf0/0x1c0 drivers/media/v4l2-core/videobuf2-core.c:240 IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready __vb2_free_mem drivers/media/v4l2-core/videobuf2-core.c:409 [inline] __vb2_queue_free+0x57a/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+0xeb/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:446 IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready __fput+0x232/0x750 fs/file_table.c:210 IPv6: ADDRCONF(NETDEV_UP): team0: link is not ready ____fput+0x9/0x10 fs/file_table.c:244 task_work_run+0xe5/0x170 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+0x416/0x5b0 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x412f61 8021q: adding VLAN 0 to HW filter on device team0 RSP: 002b:00007ffe2dd3af10 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000412f61 RDX: 0000001b32620000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000001 R08: ffffffffffffffff R09: ffffffffffffffff R10: 00007ffe2dd3aff0 R11: 0000000000000293 R12: 0000000000760ef8 R13: 000000000000dc42 R14: 000000000000dc6f R15: 000000000075bf2c Code: 70 95 6e 05 00 0f 84 42 02 00 00 5d c3 66 90 48 b8 00 00 00 00 00 fc ff df 55 48 89 f2 48 89 e5 48 c1 ea 03 53 89 fb 48 83 ec 08 <0f> b6 14 02 48 89 f0 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 3a RIP: __read_once_size include/linux/compiler.h:183 [inline] RSP: ffff88808d0cfbd0 RIP: atomic_read arch/x86/include/asm/atomic.h:27 [inline] RSP: ffff88808d0cfbd0 RIP: refcount_sub_and_test+0x1c/0x90 lib/refcount.c:179 RSP: ffff88808d0cfbd0 ---[ end trace d151221853fc1a12 ]---