CVE-2026-52955

Summary

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().

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxf24e9980eb860d8600cbe5ef3d2fd9295320d229 < 6e70ef53e818c53eab28d7b0026b7fd03dddaba5affected
LinuxLinuxf24e9980eb860d8600cbe5ef3d2fd9295320d229 < ebe76d58a48a48031b98543d86c4cd30a825b622affected
LinuxLinuxf24e9980eb860d8600cbe5ef3d2fd9295320d229 < 3f42508191e129ee6b5ea96578d5cab14f2a013aaffected
LinuxLinuxf24e9980eb860d8600cbe5ef3d2fd9295320d229 < ea0d42137f0c06da71e37ffc647aab4c5309599aaffected
LinuxLinuxf24e9980eb860d8600cbe5ef3d2fd9295320d229 < cceb10023e76bc89f3fe9238ebd0ccab0fc7c7c5affected
LinuxLinuxf24e9980eb860d8600cbe5ef3d2fd9295320d229 < 0f3604cbe4df14c5e58288ac9f57511e726a222daffected
LinuxLinuxf24e9980eb860d8600cbe5ef3d2fd9295320d229 < fb176a99e4c1a5a8448a83d83d3606203ba81faaaffected
LinuxLinuxf24e9980eb860d8600cbe5ef3d2fd9295320d229 < 4c79fc2d598694bda845b46229c9d48b65042970affected
LinuxLinux2.6.34affected
LinuxLinux0 < 2.6.34unaffected
LinuxLinux5.10.258 <= 5.10.*unaffected
LinuxLinux5.15.209 <= 5.15.*unaffected
LinuxLinux6.1.175 <= 6.1.*unaffected
LinuxLinux6.6.141 <= 6.6.*unaffected
LinuxLinux6.12.91 <= 6.12.*unaffected
LinuxLinux6.18.33 <= 6.18.*unaffected
LinuxLinux7.0.10 <= 7.0.*unaffected
LinuxLinux7.1 <= *unaffected

Weaknesses

ADP Enrichment

kernel: libceph: Fix potential out-of-bounds access in crush_decode()

Additional References

References