In the Linux kernel, the following vulnerability has been resolved:
fs/omfs: reject s_sys_blocksize smaller than OMFS_DIR_START
omfs_fill_super() rejects oversized s_sys_blocksize values (> PAGE_SIZE),
but it does not reject values smaller than OMFS_DIR_START (0x1b8 = 440).
Later, omfs_make_empty() uses
sbi->s_sys_blocksize - OMFS_DIR_START
as the length argument to memset(). Since s_sys_blocksize is u32,
a crafted filesystem image with s_sys_blocksize < OMFS_DIR_START causes
an unsigned underflow there, wrapping to a value near 2^32. That drives
a ~4 GiB memset() from bh->b_data + OMFS_DIR_START and overwrites kernel
memory far beyond the backing block buffer.
Add the corresponding lower-bound check alongside the existing upper-bound
check in omfs_fill_super(), so that malformed images are rejected during
superblock validation before any filesystem data is processed.
fs/omfs: reject s_sys_blocksize smaller than OMFS_DIR_START
omfs_fill_super() rejects oversized s_sys_blocksize values (> PAGE_SIZE),
but it does not reject values smaller than OMFS_DIR_START (0x1b8 = 440).
Later, omfs_make_empty() uses
sbi->s_sys_blocksize - OMFS_DIR_START
as the length argument to memset(). Since s_sys_blocksize is u32,
a crafted filesystem image with s_sys_blocksize < OMFS_DIR_START causes
an unsigned underflow there, wrapping to a value near 2^32. That drives
a ~4 GiB memset() from bh->b_data + OMFS_DIR_START and overwrites kernel
memory far beyond the backing block buffer.
Add the corresponding lower-bound check alongside the existing upper-bound
check in omfs_fill_super(), so that malformed images are rejected during
superblock validation before any filesystem data is processed.
Advisories
| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-4664-1 | linux security update |
Debian DLA |
DLA-4665-1 | linux security update |
Debian DLA |
DLA-4671-1 | linux-6.1 security update |
Ubuntu USN |
USN-8566-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8567-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8568-1 | Linux kernel (OEM) vulnerabilities |
Ubuntu USN |
USN-8569-1 | Linux kernel (HWE) vulnerabilities |
Ubuntu USN |
USN-8574-1 | Linux kernel (GCP FIPS) vulnerabilities |
Ubuntu USN |
USN-8575-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8576-1 | Linux kernel (NVIDIA Tegra) vulnerabilities |
Ubuntu USN |
USN-8593-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8574-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8595-1 | Linux kernel (Oracle) vulnerabilities |
Ubuntu USN |
USN-8596-1 | Linux kernel (NVIDIA) vulnerabilities |
Ubuntu USN |
USN-8575-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8576-2 | Linux kernel (NVIDIA Tegra) vulnerabilities |
Ubuntu USN |
USN-8575-3 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8595-2 | Linux kernel (AWS) vulnerabilities |
Ubuntu USN |
USN-8603-1 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-8606-1 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-8607-1 | Linux kernel (Azure CVM) vulnerabilities |
Ubuntu USN |
USN-8608-1 | Linux kernel (Azure FIPS) vulnerabilities |
Ubuntu USN |
USN-8609-1 | Linux kernel (Azure CVM) vulnerabilities |
Ubuntu USN |
USN-8610-1 | Linux kernel (Azure CVM) vulnerabilities |
Ubuntu USN |
USN-8574-3 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8595-3 | Linux kernel (AWS) vulnerabilities |
Ubuntu USN |
USN-8618-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8619-1 | Linux kernel (HWE) vulnerabilities |
Ubuntu USN |
USN-8620-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8620-2 | Linux kernel (Azure FIPS) vulnerabilities |
Ubuntu USN |
USN-8620-3 | Linux kernel (Intel IoTG) vulnerabilities |
Ubuntu USN |
USN-8620-4 | Linux kernel (Intel IoTG) vulnerabilities |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Sun, 28 Jun 2026 13:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-787 |
Sun, 28 Jun 2026 11:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-122 CWE-680 |
Sun, 28 Jun 2026 08:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
cvssV3_1
|
Thu, 25 Jun 2026 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Wed, 24 Jun 2026 21:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-122 CWE-680 |
Wed, 24 Jun 2026 17:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: fs/omfs: reject s_sys_blocksize smaller than OMFS_DIR_START omfs_fill_super() rejects oversized s_sys_blocksize values (> PAGE_SIZE), but it does not reject values smaller than OMFS_DIR_START (0x1b8 = 440). Later, omfs_make_empty() uses sbi->s_sys_blocksize - OMFS_DIR_START as the length argument to memset(). Since s_sys_blocksize is u32, a crafted filesystem image with s_sys_blocksize < OMFS_DIR_START causes an unsigned underflow there, wrapping to a value near 2^32. That drives a ~4 GiB memset() from bh->b_data + OMFS_DIR_START and overwrites kernel memory far beyond the backing block buffer. Add the corresponding lower-bound check alongside the existing upper-bound check in omfs_fill_super(), so that malformed images are rejected during superblock validation before any filesystem data is processed. | |
| Title | fs/omfs: reject s_sys_blocksize smaller than OMFS_DIR_START | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-05T12:33:24.185Z
Reserved: 2026-06-09T07:44:35.386Z
Link: CVE-2026-53130
No data.
No data.
OpenCVE Enrichment
Updated: 2026-06-28T13:00:13Z
Weaknesses
Debian DLA
Ubuntu USN