# CVE-2023-52599: jfs: fix array-index-out-of-bounds in diNewExt

> An integer overflow in the JFS filesystem allows a local attacker to trigger an out-of-bounds array access, causing a system crash.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 Mar 2024
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2023-52599, DEBIAN-CVE-2023-52599, GHSA-2xhh-m3cf-854c, UBUNTU-CVE-2023-52599

## What is CVE-2023-52599?

CVE-2023-52599 is a high-severity vulnerability in Linux kernel, published on 6 Mar 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

jfs: fix array-index-out-of-bounds in diNewExt

[Syz report]
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_imap.c:2360:2
index -878706688 is out of range for type 'struct iagctl[128]'
CPU: 1 PID: 5065 Comm: syz-executor282 Not tainted 6.7.0-rc4-syzkaller-00009-gbee0e7762ad2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 ubsan_epilogue lib/ubsan.c:217 [inline]
 __ubsan_handle_out_of_bounds+0x11c/0x150 lib/ubsan.c:348
 diNewExt+0x3cf3/0x4000 fs/jfs/jfs_imap.c:2360
 diAllocExt fs/jfs/jfs_imap.c:1949 [inline]
 diAllocAG+0xbe8/0x1e50 fs/jfs/jfs_imap.c:1666
 diAlloc+0x1d3/0x1760 fs/jfs/jfs_imap.c:1587
 ialloc+0x8f/0x900 fs/jfs/jfs_inode.c:56
 jfs_mkdir+0x1c5/0xb90 fs/jfs/namei.c:225
 vfs_mkdir+0x2f1/0x4b0 fs/namei.c:4106
 do_mkdirat+0x264/0x3a0 fs/namei.c:4129
 __do_sys_mkdir fs/namei.c:4149 [inline]
 __se_sys_mkdir fs/namei.c:4147 [inline]
 __x64_sys_mkdir+0x6e/0x80 fs/namei.c:4147
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7fcb7e6a0b57
Code: ff ff 77 07 31 c0 c3 0f 1f 40 00 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 b8 53 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd83023038 EFLAGS: 00000286 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007fcb7e6a0b57
RDX: 00000000000a1020 RSI: 00000000000001ff RDI: 0000000020000140
RBP: 0000000020000140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000286 R12: 00007ffd830230d0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

[Analysis]
When the agstart is too large, it can cause agno overflow.

[Fix]
After obtaining agno, if the value is invalid, exit the subsequent process.

Modified the test from agno > MAXAG to agno >= MAXAG based on linux-next
report by kernel test robot (Dan Carpenter).

Weakness: CWE-129 (Improper Validation of Array Index)

## Which versions are affected by CVE-2023-52599?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-52599?

Apply the vendor's patch.

## Is CVE-2023-52599 being exploited?

There is no known exploitation of CVE-2023-52599 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-52599 and fix it if it is affected.

What it is: CVE-2023-52599 is a high-severity vulnerability in Linux kernel, published on 6 Mar 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-52599 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-52599/ (Markdown: https://insights.sbomify.com/CVE-2023-52599/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-52599
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-52599
- OSV: https://osv.dev/vulnerability/CVE-2023-52599

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-52599/
Summaries are generated and may contain mistakes; the official description above is the record.