bisecting fixing commit since 1ec8f1f0bffe34ebdf95dbe0fd4a6635a84612a8 building syzkaller on 505ab413c77ce8c6bd4658ea5e68ea2534d47b39 testing commit 1ec8f1f0bffe34ebdf95dbe0fd4a6635a84612a8 with gcc (GCC) 8.1.0 kernel signature: 2c502aa672f9b2c06e248ba41f564a4f83eb91329c1e92970cee5e272c6c7107 all runs: crashed: general protection fault in vb2_vmalloc_put testing current HEAD 01364dad1d4577e27a57729d41053f661bb8a5b9 testing commit 01364dad1d4577e27a57729d41053f661bb8a5b9 with gcc (GCC) 8.1.0 kernel signature: c8d3247fd7bc1c1f13cf1d42997476f02b3f749fb9c342cffc10161454d96c81 all runs: crashed: general protection fault in vb2_vmalloc_put revisions tested: 2, total time: 23m7.031272914s (build: 16m24.467931379s, test: 6m10.239479807s) the crash still happens on HEAD commit msg: Linux 4.14.174 crash: general protection fault in vb2_vmalloc_put IPv6: ADDRCONF(NETDEV_UP): team0: link is not ready 8021q: adding VLAN 0 to HW filter on device team0 kasan: CONFIG_KASAN_INLINE enabled 8021q: adding VLAN 0 to HW filter on device bond0 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: 7002 Comm: syz-executor.5 Not tainted 4.14.174-syzkaller #0 IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 IPv6: ADDRCONF(NETDEV_UP): vxcan1: link is not ready task: ffff8880964366c0 task.stack: ffff888098788000 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:ffff88809878fbd0 EFLAGS: 00010282 RAX: dffffc0000000000 RBX: 0000000000000001 RCX: 1ffff11012c86df1 RDX: 0000000000000004 RSI: 0000000000000020 RDI: 0000000000000001 RBP: ffff88809878fbe0 R08: ffff888096436f88 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff888096fce7c0 R13: dffffc0000000000 R14: ffff888096fce7d4 R15: 0000000000000000 FS: 0000000001354940(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000073c061 CR3: 0000000097205000 CR4: 00000000001406e0 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+0xf3/0x1c0 drivers/media/v4l2-core/videobuf2-core.c:240 __vb2_free_mem drivers/media/v4l2-core/videobuf2-core.c:409 [inline] __vb2_queue_free+0x580/0x770 drivers/media/v4l2-core/videobuf2-core.c:454 IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready 8021q: adding VLAN 0 to HW filter on device batadv0 vb2_core_queue_release+0x57/0x70 drivers/media/v4l2-core/videobuf2-core.c:2043 IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready 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 IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready ____fput+0x9/0x10 fs/file_table.c:244 IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bond: link becomes ready 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 IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready RIP: 0033:0x4129e1 IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready RSP: 002b:00007ffe9e239e70 EFLAGS: 00000293 bridge0: port 1(bridge_slave_0) entered blocking state ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00000000004129e1 RDX: 0000001b32120000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000740868 R08: 000000000000ad46 R09: 000000000000ad46 R10: 00007ffe9e239f40 R11: 0000000000000293 R12: 0000000000000001 R13: 000000000000ad4a R14: 000000000000ad77 R15: 000000000073bf0c Code: 09 6a 6d 05 00 0f 84 42 02 00 00 5d c3 66 90 bridge0: port 1(bridge_slave_0) entered forwarding state 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 IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready 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: ffff88809878fbd0 RIP: atomic_read arch/x86/include/asm/atomic.h:27 [inline] RSP: ffff88809878fbd0 RIP: refcount_sub_and_test+0x1c/0x90 lib/refcount.c:179 RSP: ffff88809878fbd0 ---[ end trace 9686cd1097f9b4da ]--- IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready