bisecting fixing commit since 1ec8f1f0bffe34ebdf95dbe0fd4a6635a84612a8
building syzkaller on 505ab413c77ce8c6bd4658ea5e68ea2534d47b39
testing commit 1ec8f1f0bffe34ebdf95dbe0fd4a6635a84612a8 with gcc (GCC) 8.1.0
kernel signature: 8c493a3c319f97f507fe29a22230569e4fe4b533b6665f83a5759f9c1a364ba7
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: 34d839a40f952dddf2f729182f6d5a768af6a58aa74c89438a340c86c649a841
all runs: crashed: general protection fault in vb2_vmalloc_put
revisions tested: 2, total time: 24m21.360542771s (build: 17m14.581849975s, test: 6m20.055030983s)
the crash still happens on HEAD
commit msg: Linux 4.14.171
crash: general protection fault in vb2_vmalloc_put
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bond: link becomes ready
device hsr_slave_0 entered promiscuous mode
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
device hsr_slave_1 entered promiscuous mode
Modules linked in:
CPU: 1 PID: 6889 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: ffff88808bb3c5c0 task.stack: ffff8880a9ab0000
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:ffff8880a9ab7bd0 EFLAGS: 00010282
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: 1ffff110117679d1
RDX: 0000000000000004 RSI: 0000000000000020 RDI: 0000000000000001
RBP: ffff8880a9ab7be0 R08: ffff88808bb3ce88 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88808d2bc300
R13: dffffc0000000000 R14: ffff88808d2bc314 R15: 0000000000000000
FS:  00000000021a4940(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f905dbbb000 CR3: 000000008b926000 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
 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:00007ffc7833ace0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00000000004129e1
RDX: 0000001b2ff20000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000740868 R08: 000000000000d53f R09: 000000000000d53f
R10: 00007ffc7833adb0 R11: 0000000000000293 R12: 0000000000000001
R13: 000000000000d545 R14: 000000000000d572 R15: 000000000073bf0c
Code: 83 87 6d 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: ffff8880a9ab7bd0
RIP: atomic_read arch/x86/include/asm/atomic.h:27 [inline] RSP: ffff8880a9ab7bd0
RIP: refcount_sub_and_test+0x1c/0x90 lib/refcount.c:179 RSP: ffff8880a9ab7bd0
---[ end trace 3223188b0e3695f0 ]---