CVE-2026-45999

erofs: fix unsigned underflow in z_erofs_lz4_handle_overlap()

HIGH

7.1

CVSS Score

Published: May 27, 2026 at 12:55 PM UTC

Updated: August 5, 2026 at 01:24 PM UTC

1 product affected across 1 vendorLinux Kernel

Using Linux by Linux?

Get instant alerts when new vulnerabilities affect Linux - before attackers find them.

Real-time alertsTrack your software stackFree plan available

Start Free Sign In

Severity

HIGH7.1

Exploit prediction

EPSS 0.1%

Description

In the Linux kernel, the following vulnerability has been resolved: erofs: fix unsigned underflow in z_erofs_lz4_handle_overlap() Some crafted images can have illegal (!partial_decoding && m_llen < m_plen) extents, and the LZ4 inplace decompression path can be wrongly hit, but it cannot handle (outpages < inpages) properly: "outpages - inpages" wraps to a large value and the subsequent rq->out[] access reads past the decompressed_pages array. However, such crafted cases can correctly result in a corruption report in the normal LZ4 non-inplace path. Let's add an additional check to fix this for backporting. Reproducible image (base64-encoded gzipped blob): H4sIAJGR12kCA+3SPUoDQRgG4MkmkkZk8QRbRFIIi9hbpEjrHQI5ghfwCN5BLCzTGtLbBI+g dilSJo1CnIm7GEXFxhT6PDDwfrs73/ywIQD/1ePD4r7Ou6ETsrq4mu7XcWfj++Pb58nJU/9i PNtbjhan04/9GtX4qVYc814WDqt6FaX5s+ZwXXeq52lndT6IuVvlblytLMvh4Gzwaf90nsvz 2DF/21+20T/ldgp5s1jXRaN4t/8izsy/OUB6e/Qa79r+JwAAAAAAAL52vQVuGQAAAP6+my1w ywAAAAAAAADwu14ATsEYtgBQAAA= $ mount -t erofs -o cache_strategy=disabled foo.erofs /mnt $ dd if=/mnt/data of=/dev/null bs=4096 count=1

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Linux Kernel · Linux

95%

5.13 ≤ v < 5.15.2105.13 ≤ v < 6.1.1765.13 ≤ v < 6.12.885.13 ≤ v < 6.18.305.13 ≤ v < 6.6.1405.13 ≤ v < 7.0.45.13 ≤ v < 7.16.13 ≤ v < 6.18.306.19 ≤ v < 7.0.46.7 ≤ v < 6.12.885.13598162d050801e556750defff4ddab499e5d76ed

Vendor states this is fixed in 118ff71ff09ebaf323a09af9e911517321a299f4 (fixed)

Vendor states this is fixed in 21e161de2dc660b1bb70ef5b156ab8e6e1cca3ab (fixed)

Vendor states this is fixed in 43a878639b90e9721ffa5eb616a7e6d8454adef3 (fixed)

Vendor states this is fixed in 778acd52e9497806fbd2cea7f770c41d6850fc48 (fixed)

Vendor states this is fixed in bbbbb3f0d7864238a8da2a94cd6ec013fee06a2e (fixed)

Vendor states this is fixed in c9ce18e6bb2c467ec85756dc7989b547b7584fee (fixed)

Vendor states this is fixed in f1374fa6e57fd836623668d782ded9244cfd2938 (fixed)

Vendor states this is fixed in 5.13 (unaffected)

Vendor states this is fixed in 5.15.210 (unaffected)

Vendor states this is fixed in 6.1.176 (unaffected)

Vendor states this is fixed in 6.12.88 (unaffected)

Vendor states this is fixed in 6.18.30 (unaffected)