Bug 2514446 (CVE-2026-68433)

Summary: CVE-2026-68433 kernel: libceph: bound get_version reply decode to front len
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the `libceph` component of the Linux kernel. This vulnerability occurs because the system incorrectly processes replies, using an allocated buffer size rather than the actual received data length. A specially crafted, truncated reply can lead to the system reading uninitialized memory. This could result in the disclosure of sensitive information or cause system instability.
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Description OSIDB Bzimport 2026-08-12 00:21:51 UTC 
In the Linux kernel, the following vulnerability has been resolved:

libceph: bound get_version reply decode to front len

handle_get_version_reply() uses msg->front_alloc_len as the decode
boundary for MON_GET_VERSION_REPLY.  That is the size of the reused
reply buffer, not the number of bytes actually received.

A truncated reply can therefore pass ceph_decode_need() and decode the
second u64 from stale tail bytes left in the buffer by an earlier
message, causing an uninitialized memory read.

Use msg->front.iov_len as the receive-side decode boundary, matching
other libceph reply handlers and limiting decoding to the bytes that
were actually read from the wire.
Comment 1 Mauro Matteo Cascella 2026-08-12 15:28:02 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081254-CVE-2026-68433-c891@gregkh/T