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KASAN: slab-out-of-bounds Read in process_preds

Status: closed as dup on 2018/04/27 15:18
Subsystems: trace
[Documentation on labels]
Reported-by: syzbot+e47d942a98e75b4bd03e@syzkaller.appspotmail.com
First crash: 2436d, last: 2376d
▶ ▼ Duplicate of
Title Repro Cause bisect Fix bisect Count Last Reported
KASAN: use-after-free Read in process_preds trace 2 2409d 2436d
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
KASAN: slab-out-of-bounds Read in process_preds 1 (2) 2018/04/27 15:18

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in predicate_parse kernel/trace/trace_events_filter.c:563 [inline]
BUG: KASAN: slab-out-of-bounds in process_preds+0x18f2/0x19d0 kernel/trace/trace_events_filter.c:1509
Read of size 4 at addr ffff8801bd0c0004 by task syz-executor3/9897

CPU: 1 PID: 9897 Comm: syz-executor3 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_load4_noabort+0x14/0x20 mm/kasan/report.c:432
 predicate_parse kernel/trace/trace_events_filter.c:563 [inline]
 process_preds+0x18f2/0x19d0 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: 0033:0x455a99
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:00007fc9d36d8c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fc9d36d96d4 RCX: 0000000000455a99
RDX: 0000000020000000 RSI: 0000000040082406 RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004c4e70 R14: 00000000004cc5d0 R15: 0000000000000000

Allocated by task 2415:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554
 getname_flags+0xd0/0x5a0 fs/namei.c:140
 user_path_at_empty+0x2d/0x50 fs/namei.c:2555
 do_readlinkat+0x143/0x3e0 fs/stat.c:394
 __do_sys_readlink fs/stat.c:427 [inline]
 __se_sys_readlink fs/stat.c:424 [inline]
 __x64_sys_readlink+0x78/0xb0 fs/stat.c:424
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 2415:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kmem_cache_free+0x86/0x2d0 mm/slab.c:3756
 putname+0xf2/0x130 fs/namei.c:261
 filename_lookup+0x38b/0x4f0 fs/namei.c:2330
 user_path_at_empty+0x40/0x50 fs/namei.c:2555
 do_readlinkat+0x143/0x3e0 fs/stat.c:394
 __do_sys_readlink fs/stat.c:427 [inline]
 __se_sys_readlink fs/stat.c:424 [inline]
 __x64_sys_readlink+0x78/0xb0 fs/stat.c:424
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801bd0c0d80
 which belongs to the cache names_cache of size 4096
The buggy address is located 3452 bytes to the left of
 4096-byte region [ffff8801bd0c0d80, ffff8801bd0c1d80)
The buggy address belongs to the page:
page:ffffea0006f43000 count:1 mapcount:0 mapping:ffff8801da986dc0 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffffea000654e288 ffffea0006f43088 ffff8801da986dc0
raw: 0000000000000000 ffff8801bd0c0d80 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801bd0bff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801bd0bff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8801bd0c0000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff8801bd0c0080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801bd0c0100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (20):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/06/26 06:38 bpf-next f0dc7f9c6dd9 2064fc5c .config console log report ci-upstream-bpf-next-kasan-gce
2018/06/25 19:49 bpf-next f0dc7f9c6dd9 2064fc5c .config console log report ci-upstream-bpf-next-kasan-gce
2018/06/23 02:02 bpf-next f0dc7f9c6dd9 c97f0d7a .config console log report ci-upstream-bpf-next-kasan-gce
2018/06/17 14:08 bpf-next f0dc7f9c6dd9 27c5f59f .config console log report ci-upstream-bpf-next-kasan-gce
2018/06/15 09:53 bpf-next f0dc7f9c6dd9 27c5f59f .config console log report ci-upstream-bpf-next-kasan-gce
2018/06/08 06:29 bpf-next 75d4e704fa8d f7b27b7a .config console log report ci-upstream-bpf-next-kasan-gce
2018/06/05 23:47 bpf-next 9fa06104a235 863a24bb .config console log report ci-upstream-bpf-next-kasan-gce
2018/05/27 20:00 bpf-next 9c5904904b88 f48c20b8 .config console log report ci-upstream-bpf-next-kasan-gce
2018/05/27 08:08 bpf-next 9c5904904b88 f48c20b8 .config console log report ci-upstream-bpf-next-kasan-gce
2018/05/25 15:57 bpf-next 10f678683e40 f48c20b8 .config console log report ci-upstream-bpf-next-kasan-gce
2018/05/22 13:44 bpf-next fd0bfa8d6e04 f48c20b8 .config console log report ci-upstream-bpf-next-kasan-gce
2018/05/21 20:45 bpf-next d849f9f9768c f48c20b8 .config console log report ci-upstream-bpf-next-kasan-gce
2018/05/13 09:41 bpf-next a84880ef4352 e726f42b .config console log report ci-upstream-bpf-next-kasan-gce
2018/05/12 17:06 bpf-next a84880ef4352 e726f42b .config console log report ci-upstream-bpf-next-kasan-gce
2018/05/11 18:16 bpf-next 96112e936350 12c7428a .config console log report ci-upstream-bpf-next-kasan-gce
2018/05/09 18:16 bpf-next 53a7bdfb2a27 12c7428a .config console log report ci-upstream-bpf-next-kasan-gce
2018/05/08 18:14 bpf-next 724e47a149f5 b88872ba .config console log report ci-upstream-bpf-next-kasan-gce
2018/05/08 14:06 bpf-next 724e47a149f5 045bbd4a .config console log report ci-upstream-bpf-next-kasan-gce
2018/05/08 10:06 bpf-next 724e47a149f5 045bbd4a .config console log report ci-upstream-bpf-next-kasan-gce
2018/04/26 18:56 bpf-next af487c577770 73417389 .config console log report ci-upstream-bpf-next-kasan-gce
* Struck through repros no longer work on HEAD.