syzbot


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

Status: upstream: reported C repro on 2022/09/24 21:36
Reported-by: syzbot+d3389b9e781bbbea58a4@syzkaller.appspotmail.com
First crash: 125d, last: 125d

Fix bisection: failed (bisect log)
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-out-of-bounds Read in dtSearch jfs C error 19 27d 125d 0/24 upstream: reported C repro on 2022/09/25 15:20
linux-4.14 KASAN: slab-out-of-bounds Read in dtSearch C 1 8d01h 125d 0/1 upstream: reported C repro on 2022/09/24 21:35

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in ciCompare fs/jfs/jfs_dtree.c:3706 [inline]
BUG: KASAN: slab-out-of-bounds in dtSearch+0x1c7d/0x1ef0 fs/jfs/jfs_dtree.c:652
Read of size 1 at addr ffff88808db2610d by task syz-executor235/8103

CPU: 0 PID: 8103 Comm: syz-executor235 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_load1_noabort+0x88/0x90 mm/kasan/report.c:430
 ciCompare fs/jfs/jfs_dtree.c:3706 [inline]
 dtSearch+0x1c7d/0x1ef0 fs/jfs/jfs_dtree.c:652
 jfs_lookup+0x12a/0x1c0 fs/jfs/namei.c:1466
 lookup_open+0x698/0x1a20 fs/namei.c:3214
 do_last fs/namei.c:3327 [inline]
 path_openat+0x1804/0x2df0 fs/namei.c:3537
 do_filp_open+0x18c/0x3f0 fs/namei.c:3567
 do_sys_open+0x3b3/0x520 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f325b1f20c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffea7c1ff78 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f325b1f20c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200001c0
RBP: 00007f325b1b1930 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffea7c1fe40 R11: 0000000000000246 R12: 00000000f8008000
R13: 0000000000000000 R14: 00083878000000f4 R15: 0000000000000000

Allocated by task 8103:
 kmem_cache_alloc+0x122/0x370 mm/slab.c:3559
 jfs_alloc_inode+0x18/0x50 fs/jfs/super.c:118
 alloc_inode+0x5d/0x180 fs/inode.c:211
 iget_locked+0x193/0x480 fs/inode.c:1176
 jfs_iget+0x1a/0x4d0 fs/jfs/inode.c:41
 jfs_lookup+0x19e/0x1c0 fs/jfs/namei.c:1474
 __lookup_slow+0x246/0x4a0 fs/namei.c:1672
 lookup_slow fs/namei.c:1689 [inline]
 walk_component+0x7ac/0xda0 fs/namei.c:1811
 link_path_walk.part.0+0x901/0x1230 fs/namei.c:2142
 link_path_walk fs/namei.c:2073 [inline]
 path_openat+0x1db/0x2df0 fs/namei.c:3536
 do_filp_open+0x18c/0x3f0 fs/namei.c:3567
 do_sys_open+0x3b3/0x520 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff88808db261c0
 which belongs to the cache jfs_ip of size 1944
The buggy address is located 179 bytes to the left of
 1944-byte region [ffff88808db261c0, ffff88808db26958)
The buggy address belongs to the page:
page:ffffea000236c980 count:1 mapcount:0 mapping:ffff8880b0f15600 index:0xffff88808db26fff
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffffea000236c908 ffff8880b0f20a48 ffff8880b0f15600
raw: ffff88808db26fff ffff88808db261c0 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808db26000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88808db26080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88808db26100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                      ^
 ffff88808db26180: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff88808db26200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-linux-4-19 2022/09/24 21:36 linux-4.19.y 3f8a27f9e27b 0042f2b4 .config console log report syz C KASAN: slab-out-of-bounds Read in dtSearch
* Struck through repros no longer work on HEAD.