syzbot


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

Status: upstream: reported C repro on 2022/09/24 21:35
Reported-by: syzbot+82ae746b8586a568571a@syzkaller.appspotmail.com
First crash: 130d, last: 3d16h
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 22 3d16h 129d 0/24 upstream: reported C repro on 2022/09/25 15:20
linux-4.19 KASAN: slab-out-of-bounds Read in dtSearch C error 1 130d 130d 0/1 upstream: reported C repro on 2022/09/24 21:36

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in ciCompare fs/jfs/jfs_dtree.c:3705 [inline]
BUG: KASAN: slab-out-of-bounds in dtSearch+0x192d/0x1ba0 fs/jfs/jfs_dtree.c:651
Read of size 1 at addr ffff88808e2d310d by task syz-executor194/7989

CPU: 1 PID: 7989 Comm: syz-executor194 Not tainted 4.14.294-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351
 kasan_report mm/kasan/report.c:409 [inline]
 __asan_report_load1_noabort+0x68/0x70 mm/kasan/report.c:427
 ciCompare fs/jfs/jfs_dtree.c:3705 [inline]
 dtSearch+0x192d/0x1ba0 fs/jfs/jfs_dtree.c:651
 jfs_lookup+0xf7/0x170 fs/jfs/namei.c:1470
 lookup_open+0x5c4/0x1750 fs/namei.c:3220
 do_last fs/namei.c:3334 [inline]
 path_openat+0x14bb/0x2970 fs/namei.c:3571
 do_filp_open+0x179/0x3c0 fs/namei.c:3605
 do_sys_open+0x296/0x410 fs/open.c:1081
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7f2dd34c40c9
RSP: 002b:00007ffffdafe728 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f2dd34c40c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200001c0
RBP: 00007f2dd3483930 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffffdafe5f0 R11: 0000000000000246 R12: 00000000f8008000
R13: 0000000000000000 R14: 00083878000000f4 R15: 0000000000000000

Allocated by task 7989:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
 kmem_cache_alloc+0x124/0x3c0 mm/slab.c:3552
 jfs_alloc_inode+0x18/0x50 fs/jfs/super.c:118
 alloc_inode+0x5d/0x170 fs/inode.c:210
 iget_locked+0x151/0x400 fs/inode.c:1127
 jfs_iget+0x1e/0x480 fs/jfs/inode.c:41
 jfs_lookup+0x156/0x170 fs/jfs/namei.c:1478
 lookup_slow+0x20a/0x400 fs/namei.c:1696
 walk_component+0x6a1/0xbc0 fs/namei.c:1825
 link_path_walk+0x823/0x10a0 fs/namei.c:2154
 path_openat+0x15e/0x2970 fs/namei.c:3570
 do_filp_open+0x179/0x3c0 fs/namei.c:3605
 do_sys_open+0x296/0x410 fs/open.c:1081
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff88808e2d31c0
 which belongs to the cache jfs_ip of size 1952
The buggy address is located 179 bytes to the left of
 1952-byte region [ffff88808e2d31c0, ffff88808e2d3960)
The buggy address belongs to the page:
page:ffffea000238b4c0 count:1 mapcount:0 mapping:ffff88808e2d31c0 index:0xffff88808e2d3fff
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffff88808e2d31c0 ffff88808e2d3fff 0000000100000001
raw: ffffea000238b4a0 ffff8880b0c1f348 ffff8880b0c1d680 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808e2d3000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88808e2d3080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88808e2d3100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                      ^
 ffff88808e2d3180: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff88808e2d3200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Fix bisection attempts:
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-linux-4-14 2023/01/20 16:48 linux-4.14.y 97205fccccdc 0042f2b4 .config console log report syz C
ci2-linux-4-14 2022/10/28 15:58 linux-4.14.y 41f36d7859a7 0042f2b4 .config console log report syz C
* Struck through repros no longer work on HEAD.
Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-linux-4-14 2022/09/24 21:35 linux-4.14.y 4edbf74132a4 0042f2b4 .config console log report syz C [disk image] [vmlinux] KASAN: slab-out-of-bounds Read in dtSearch
ci2-linux-4-14 2023/01/29 16:29 linux-4.14.y 3949d1610004 9dfcf09c .config console log report info [disk image] [vmlinux] [kernel image] KASAN: slab-out-of-bounds Read in dtSearch
* Struck through repros no longer work on HEAD.