syzbot


KASAN: use-after-free Write in process_preds
Status: closed as dup on 2018/05/04 05:37
Reported-by: syzbot+873ae613c636f037d5f8@syzkaller.appspotmail.com
First crash: 1478d, last: 1429d
Duplicate of (1):
Title Repro Cause bisect Fix bisect Count Last Reported
KASAN: slab-out-of-bounds Write in process_preds C 6020 1425d 1501d

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in predicate_parse kernel/trace/trace_events_filter.c:557 [inline]
BUG: KASAN: use-after-free in process_preds+0x191f/0x19d0 kernel/trace/trace_events_filter.c:1509
Write of size 4 at addr ffff880195a4fff0 by task syz-executor2/11987

CPU: 1 PID: 11987 Comm: syz-executor2 Not tainted 4.17.0+ #39
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
 __asan_report_store4_noabort+0x17/0x20 mm/kasan/report.c:437
 predicate_parse kernel/trace/trace_events_filter.c:557 [inline]
 process_preds+0x191f/0x19d0 kernel/trace/trace_events_filter.c:1509
 create_filter+0x155/0x270 kernel/trace/trace_events_filter.c:1717
 ftrace_profile_set_filter+0x130/0x2e0 kernel/trace/trace_events_filter.c:2042
 perf_event_set_filter+0x22e/0x1230 kernel/events/core.c:9078
 _perf_ioctl+0x84c/0x15e0 kernel/events/core.c:5059
 perf_ioctl+0x59/0x80 kernel/events/core.c:5110
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x1cf/0x16f0 fs/ioctl.c:684
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701
 __do_sys_ioctl fs/ioctl.c:708 [inline]
 __se_sys_ioctl fs/ioctl.c:706 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x455b29
Code: 1d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007ff6cd6e7c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ff6cd6e86d4 RCX: 0000000000455b29
RDX: 00000000200002c0 RSI: 0000000040082406 RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004c4f20 R14: 00000000004cc670 R15: 0000000000000000

The buggy address belongs to the page:
page:ffffea00065693c0 count:0 mapcount:-128 mapping:0000000000000000 index:0x0
flags: 0x2fffc0000000000()
raw: 02fffc0000000000 ffffea0006525448 ffffea0006a21388 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffff7f 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff880195a4fe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff880195a4ff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff880195a4ff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                             ^
 ffff880195a50000: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
 ffff880195a50080: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================

Crashes (7):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-bpf-next-kasan-gce 2018/06/22 14:09 bpf-next f0dc7f9c6dd9 095ef806 .config log report
ci-upstream-bpf-next-kasan-gce 2018/06/22 10:32 bpf-next f0dc7f9c6dd9 095ef806 .config log report
ci-upstream-bpf-next-kasan-gce 2018/06/20 12:12 bpf-next f0dc7f9c6dd9 095ef806 .config log report
ci-upstream-bpf-next-kasan-gce 2018/06/18 03:15 bpf-next f0dc7f9c6dd9 27c5f59f .config log report
ci-upstream-bpf-next-kasan-gce 2018/06/05 06:23 bpf-next 34ea38ca2799 a50d873b .config log report
ci-upstream-bpf-next-kasan-gce 2018/05/31 22:52 bpf-next bcece5dc40b9 2f93b54f .config log report
ci-upstream-bpf-next-kasan-gce 2018/05/04 03:57 bpf-next 03f5781be2c7 9ce14f4b .config log report