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
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Fri, 19 Jun 2026 12:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
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Sat, 30 May 2026 13:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-193 CWE-20 CWE-680 |
Sat, 30 May 2026 11:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
cvssV3_1
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cvssV3_1
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Thu, 28 May 2026 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-191 | |
| References |
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| Metrics |
threat_severity
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cvssV3_1
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Wed, 27 May 2026 19:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-193 CWE-20 CWE-680 |
Wed, 27 May 2026 14:15:00 +0000
| Type | Values Removed | Values Added |
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| 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 | |
| Title | erofs: fix unsigned underflow in z_erofs_lz4_handle_overlap() | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-06-19T11:58:54.176Z
Reserved: 2026-05-13T15:03:33.091Z
Link: CVE-2026-45999
No data.
Status : Analyzed
Published: 2026-05-27T14:17:17.517
Modified: 2026-06-17T10:52:52.463
Link: CVE-2026-45999
OpenCVE Enrichment
Updated: 2026-05-30T14:45:25Z