syzbot


UBSAN: array-index-out-of-bounds in dbAllocBits

Status: upstream: reported C repro on 2023/05/19 04:28
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+fc68ece19701d9c7f9d4@syzkaller.appspotmail.com
First crash: 205d, last: 6d03h
Bug presence (1)
Date Name Commit Repro Result
2023/05/21 upstream (ToT) 0dd2a6fb1e34 C [report] UBSAN: array-index-out-of-bounds in dbAllocBits
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream UBSAN: array-index-out-of-bounds in dbAllocBits jfs C inconclusive error 232 1d13h 432d 0/25 upstream: reported C repro on 2022/10/04 09:00
linux-5.15 UBSAN: array-index-out-of-bounds in dbAllocBits origin:upstream C error 2 176d 205d 0/3 upstream: reported C repro on 2023/05/19 07:30
linux-4.19 KASAN: use-after-free Read in dbAllocBits C error 2 414d 435d 0/1 upstream: reported C repro on 2022/10/01 12:57
Fix bisection attempts (5)
Created Duration User Patch Repo Result
2023/12/04 23:44 1h16m bisect fix linux-6.1.y job log (0) log
2023/11/04 11:51 1h35m bisect fix linux-6.1.y job log (0) log
2023/10/04 00:47 1h23m bisect fix linux-6.1.y job log (0) log
2023/08/09 13:36 4h05m bisect fix linux-6.1.y job log (0) log
2023/06/19 03:48 58m bisect fix linux-6.1.y job log (0) log

Sample crash report:
loop0: detected capacity change from 0 to 32768
================================================================================
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:2238:2
index 2000 is out of range for type 's64[128]' (aka 'long long[128]')
CPU: 1 PID: 4216 Comm: syz-executor247 Not tainted 6.1.29-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
Call trace:
 dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 dump_stack+0x1c/0x5c lib/dump_stack.c:113
 ubsan_epilogue lib/ubsan.c:151 [inline]
 __ubsan_handle_out_of_bounds+0xfc/0x148 lib/ubsan.c:282
 dbAllocBits+0x8a4/0x8d0 fs/jfs/jfs_dmap.c:2238
 dbAllocDmap fs/jfs/jfs_dmap.c:2015 [inline]
 dbAllocNear+0x224/0x334 fs/jfs/jfs_dmap.c:1244
 dbAlloc+0x8b4/0xb68 fs/jfs/jfs_dmap.c:829
 ea_get+0x6f8/0xef0 fs/jfs/xattr.c:514
 __jfs_setxattr+0x41c/0x1338 fs/jfs/xattr.c:718
 __jfs_set_acl+0x108/0x1a4 fs/jfs/acl.c:87
 jfs_set_acl+0x1f0/0x45c fs/jfs/acl.c:114
 set_posix_acl fs/posix_acl.c:1160 [inline]
 posix_acl_xattr_set+0x2f8/0x398 fs/posix_acl.c:1189
 __vfs_setxattr+0x388/0x3a4 fs/xattr.c:182
 __vfs_setxattr_noperm+0x110/0x528 fs/xattr.c:216
 __vfs_setxattr_locked+0x1ec/0x218 fs/xattr.c:277
 vfs_setxattr+0x1a8/0x344 fs/xattr.c:309
 do_setxattr fs/xattr.c:594 [inline]
 setxattr+0x230/0x294 fs/xattr.c:617
 path_setxattr+0x17c/0x258 fs/xattr.c:636
 __do_sys_lsetxattr fs/xattr.c:659 [inline]
 __se_sys_lsetxattr fs/xattr.c:655 [inline]
 __arm64_sys_lsetxattr+0xbc/0xd8 fs/xattr.c:655
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581
================================================================================
==================================================================
BUG: KASAN: slab-out-of-bounds in dbAllocBits+0x7a8/0x8d0 fs/jfs/jfs_dmap.c:2238
Read of size 8 at addr ffff0000d2446eb8 by task syz-executor247/4216

CPU: 1 PID: 4216 Comm: syz-executor247 Not tainted 6.1.29-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
Call trace:
 dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:284 [inline]
 print_report+0x174/0x4c0 mm/kasan/report.c:395
 kasan_report+0xd4/0x130 mm/kasan/report.c:495
 __asan_report_load8_noabort+0x2c/0x38 mm/kasan/report_generic.c:351
 dbAllocBits+0x7a8/0x8d0 fs/jfs/jfs_dmap.c:2238
 dbAllocDmap fs/jfs/jfs_dmap.c:2015 [inline]
 dbAllocNear+0x224/0x334 fs/jfs/jfs_dmap.c:1244
 dbAlloc+0x8b4/0xb68 fs/jfs/jfs_dmap.c:829
 ea_get+0x6f8/0xef0 fs/jfs/xattr.c:514
 __jfs_setxattr+0x41c/0x1338 fs/jfs/xattr.c:718
 __jfs_set_acl+0x108/0x1a4 fs/jfs/acl.c:87
 jfs_set_acl+0x1f0/0x45c fs/jfs/acl.c:114
 set_posix_acl fs/posix_acl.c:1160 [inline]
 posix_acl_xattr_set+0x2f8/0x398 fs/posix_acl.c:1189
 __vfs_setxattr+0x388/0x3a4 fs/xattr.c:182
 __vfs_setxattr_noperm+0x110/0x528 fs/xattr.c:216
 __vfs_setxattr_locked+0x1ec/0x218 fs/xattr.c:277
 vfs_setxattr+0x1a8/0x344 fs/xattr.c:309
 do_setxattr fs/xattr.c:594 [inline]
 setxattr+0x230/0x294 fs/xattr.c:617
 path_setxattr+0x17c/0x258 fs/xattr.c:636
 __do_sys_lsetxattr fs/xattr.c:659 [inline]
 __se_sys_lsetxattr fs/xattr.c:655 [inline]
 __arm64_sys_lsetxattr+0xbc/0xd8 fs/xattr.c:655
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

The buggy address belongs to the object at ffff0000d2446000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1720 bytes to the right of
 2048-byte region [ffff0000d2446000, ffff0000d2446800)

The buggy address belongs to the physical page:
page:000000005eac5069 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x112440
head:000000005eac5069 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000010200 0000000000000000 dead000000000122 ffff0000c0002900
raw: 0000000000000000 0000000080080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000d2446d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000d2446e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff0000d2446e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                        ^
 ffff0000d2446f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000d2446f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
JFS: metapage_get_blocks failed
ERROR: (device loop0): release_metapage: write_one_page() failed

ERROR: (device loop0): remounting filesystem as read-only

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/05/19 04:28 linux-6.1.y fa74641fb6b9 3bb7af1d .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 UBSAN: array-index-out-of-bounds in dbAllocBits
2023/06/19 12:10 linux-6.1.y ca87e77a2ef8 f3921d4d .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan UBSAN: array-index-out-of-bounds in dbAllocBits
* Struck through repros no longer work on HEAD.