CVE-2026-52955

Description

In the Linux kernel, the following vulnerability has been resolved: libceph: Fix potential out-of-bounds access in crush_decode() A message of type CEPH_MSG_OSD_MAP containing a crush map with at least one bucket has two fields holding the bucket algorithm. If the values in these two fields differ, an out-of-bounds access can occur. This is the case because the first algorithm field (alg) is used to allocate the correct amount of memory for a bucket of this type, while the second algorithm field inside the bucket (b->alg) is used in the subsequent processing. This patch fixes the issue by adding a check that compares alg and b->alg and aborts the processing in case they differ. Furthermore, b->alg is set to 0 in this case, because the destruction of the crush map also uses this field to determine the bucket type, which can again result in an out-of-bounds access when trying to free the memory pointed to by the fields of the bucket. To correctly free the memory allocated for the bucket in such a case, the corresponding call to kfree is moved from the algorithm-specific crush_destroy_bucket functions to the generic crush_destroy_bucket().

CVSS breakdown

Affected products

• Linux / Linux7.0.10 – 7.0.*
• Linux / Linux7.1 – *
• Linux / Linux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – 6e70ef53e818c53eab28d7b0026b7fd03dddaba5
• Linux / Linux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – ebe76d58a48a48031b98543d86c4cd30a825b622
• Linux / Linux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – 3f42508191e129ee6b5ea96578d5cab14f2a013a
• Linux / Linux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – ea0d42137f0c06da71e37ffc647aab4c5309599a
• Linux / Linux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – cceb10023e76bc89f3fe9238ebd0ccab0fc7c7c5
• Linux / Linux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – 0f3604cbe4df14c5e58288ac9f57511e726a222d
• Linux / Linux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – fb176a99e4c1a5a8448a83d83d3606203ba81faa
• Linux / Linux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – 4c79fc2d598694bda845b46229c9d48b65042970
• Linux / Linux0 – 5.10.258
• Linux / Linux0 – 5.15.209
• Linux / Linux0 – 6.1.175
• Linux / Linux0 – 6.6.141
• Linux / Linux0 – 6.12.91
• Linux / Linux0 – 6.18.33
• Linux / Linux0 – 7.0.10
• Linux / Linux5.10.258 – 5.10.*
• Linux / Linux5.15.209 – 5.15.*
• Linux / Linux6.1.175 – 6.1.*
• Linux / Linux6.6.141 – 6.6.*
• Linux / Linux6.12.91 – 6.12.*
• Linux / Linux6.18.33 – 6.18.*

References

• MISChttps://git.kernel.org/stable/c/6e70ef53e818c53eab28d7b0026b7fd03dddaba5
• MISChttps://git.kernel.org/stable/c/ebe76d58a48a48031b98543d86c4cd30a825b622
• MISChttps://git.kernel.org/stable/c/3f42508191e129ee6b5ea96578d5cab14f2a013a
• MISChttps://git.kernel.org/stable/c/ea0d42137f0c06da71e37ffc647aab4c5309599a
• MISChttps://git.kernel.org/stable/c/cceb10023e76bc89f3fe9238ebd0ccab0fc7c7c5
• MISChttps://git.kernel.org/stable/c/0f3604cbe4df14c5e58288ac9f57511e726a222d
• MISChttps://git.kernel.org/stable/c/fb176a99e4c1a5a8448a83d83d3606203ba81faa
• MISChttps://git.kernel.org/stable/c/4c79fc2d598694bda845b46229c9d48b65042970