CVE-2025-38415
Last modified
CVE-2025-38415 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: Squashfs: check return result of sb_min_blocksize Syzkaller reports an "UBSAN: shift-out-of-bounds in squashfs_bio_read" bug. Syzkaller forks multiple processes which after mounting the Squashfs filesystem, issues an ioctl("/dev/loop0", LOOP_SET_BLOCK_SIZE, 0x8000). Now if this ioctl occurs at the same time another process is in the process of mounting a Squashfs filesystem on /dev/loop0, the failure occurs. EPSS estimates a 0.18% chance of exploitation in the next 30 days.
Description
In the Linux kernel, the following vulnerability has been resolved: Squashfs: check return result of sb_min_blocksize Syzkaller reports an "UBSAN: shift-out-of-bounds in squashfs_bio_read" bug. Syzkaller forks multiple processes which after mounting the Squashfs filesystem, issues an ioctl("/dev/loop0", LOOP_SET_BLOCK_SIZE, 0x8000). Now if this ioctl occurs at the same time another process is in the process of mounting a Squashfs filesystem on /dev/loop0, the failure occurs. When this happens the following code in squashfs_fill_super() fails. ---- msblk->devblksize = sb_min_blocksize(sb, SQUASHFS_DEVBLK_SIZE); msblk->devblksize_log2 = ffz(~msblk->devblksize); ---- sb_min_blocksize() returns 0, which means msblk->devblksize is set to 0. As a result, ffz(~msblk->devblksize) returns 64, and msblk->devblksize_log2 is set to 64. This subsequently causes the UBSAN: shift-out-of-bounds in fs/squashfs/block.c:195:36 shift exponent 64 is too large for 64-bit type 'u64' (aka 'unsigned long long') This commit adds a check for a 0 return by sb_min_blocksize().
Metrics
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 2.6.29, < 5.4.295 |
| Linux | Linux Kernel | >= 5.5, < 5.10.239 |
| Linux | Linux Kernel | >= 5.11, < 5.15.186 |
| Linux | Linux Kernel | >= 5.16, < 6.1.142 |
| Linux | Linux Kernel | >= 6.2, < 6.6.94 |
| Linux | Linux Kernel | >= 6.7, < 6.12.34 |
| Linux | Linux Kernel | >= 6.13, < 6.15.3 |
| Debian | Debian Linux | 11.0 |
References
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.htmlMailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.htmlMailing List, Third Party Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
What is CVE-2025-38415?
How severe is CVE-2025-38415?
How do I fix CVE-2025-38415?
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2025
- CVE-2025-3841A vulnerability, which was classified as problematic, was fo…9.8
- CVE-2025-38410In the Linux kernel, the following vulnerability has been re…5.5
- CVE-2025-38411In the Linux kernel, the following vulnerability has been re…7.8
- CVE-2025-38412In the Linux kernel, the following vulnerability has been re…5.5
- CVE-2025-38413In the Linux kernel, the following vulnerability has been re…5.5
- CVE-2025-38414In the Linux kernel, the following vulnerability has been re…5.5
- CVE-2025-38416In the Linux kernel, the following vulnerability has been re…7.8
- CVE-2025-38417In the Linux kernel, the following vulnerability has been re…5.5
- CVE-2025-38418In the Linux kernel, the following vulnerability has been re…5.5
- CVE-2025-38419In the Linux kernel, the following vulnerability has been re…5.5
- CVE-2025-3842A vulnerability was found in panhainan DS-Java 1.0 and class…9.8
- CVE-2025-38420In the Linux kernel, the following vulnerability has been re…5.5
Are you affected by CVE-2025-38415?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST
