Bug 2383404 (CVE-2025-38415)
| Summary: | CVE-2025-38415 kernel: Linux kernel: Memory corruption in Squashfs due to incorrect block size calculation | ||
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| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | Keywords: | Security |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | --- | |
| Doc Text: |
A flaw was found in the Linux kernel's Squashfs filesystem. A local attacker can exploit this vulnerability by simultaneously mounting a Squashfs filesystem and issuing a specific input/output control (ioctl) command. This can lead to an incorrect block size calculation, causing a shift-out-of-bounds error. This memory corruption vulnerability can result in a denial of service or potentially lead to more severe system compromise.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
Upstream advisory: https://lore.kernel.org/linux-cve-announce/2025072513-CVE-2025-38415-c634@gregkh/T This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2026:1661 https://access.redhat.com/errata/RHSA-2026:1661 This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2026:1662 https://access.redhat.com/errata/RHSA-2026:1662 This issue has been addressed in the following products: Red Hat Enterprise Linux 9 Via RHSA-2026:2212 https://access.redhat.com/errata/RHSA-2026:2212 This issue has been addressed in the following products: Red Hat Enterprise Linux 10 Via RHSA-2026:2282 https://access.redhat.com/errata/RHSA-2026:2282 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.4 Extended Update Support Via RHSA-2026:2766 https://access.redhat.com/errata/RHSA-2026:2766 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.6 Extended Update Support Via RHSA-2026:3088 https://access.redhat.com/errata/RHSA-2026:3088 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions Red Hat Enterprise Linux 8.6 Telecommunications Update Service Via RHSA-2026:3268 https://access.redhat.com/errata/RHSA-2026:3268 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions Via RHSA-2026:3267 https://access.redhat.com/errata/RHSA-2026:3267 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions Red Hat Enterprise Linux 8.8 Telecommunications Update Service Via RHSA-2026:3277 https://access.redhat.com/errata/RHSA-2026:3277 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions Via RHSA-2026:3293 https://access.redhat.com/errata/RHSA-2026:3293 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions Via RHSA-2026:3358 https://access.redhat.com/errata/RHSA-2026:3358 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On Via RHSA-2026:3360 https://access.redhat.com/errata/RHSA-2026:3360 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions Via RHSA-2026:3375 https://access.redhat.com/errata/RHSA-2026:3375 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.2 Advanced Update Support Via RHSA-2026:3388 https://access.redhat.com/errata/RHSA-2026:3388 This issue has been addressed in the following products: Red Hat Enterprise Linux 10.0 Extended Update Support Via RHSA-2026:3579 https://access.redhat.com/errata/RHSA-2026:3579 This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Extended Lifecycle Support Via RHSA-2026:3634 https://access.redhat.com/errata/RHSA-2026:3634 This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Extended Lifecycle Support Via RHSA-2026:3685 https://access.redhat.com/errata/RHSA-2026:3685 |
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().