CVE Catalog

CVE-2025-38544

MediumCVSS 5.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.15%

5th percentile - higher than 5% of all known CVEs

Summary

In the Linux kernel, the rxrpc subsystem has a prealloc collision bug. When userspace uses AF_RXRPC as a server, it preallocates incoming calls and assigns call IDs; attempting to preallocate a call with an in-use ID should return EBADSLT, but error handling triggers assertions in rxrpc_cleanup_call() because the call isn't marked complete or released. The fix sets the call state and marks it as being released before calling cleanup.

Risk Assessment

Potential kernel assertion (panic) triggered by a local application using AF_RXRPC, leading to denial of service.

Recommendation

Update the Linux kernel to a version containing the rxrpc fix.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix bug due to prealloc collision When userspace is using AF_RXRPC to provide a server, it has to preallocate incoming calls and assign to them call IDs that will be used to thread related recvmsg() and sendmsg() together. The preallocated call IDs will automatically be attached to calls as they come in until the pool is empty. To the kernel, the call IDs are just arbitrary numbers, but userspace can use the call ID to hold a pointer to prepared structs. In any case, the user isn't permitted to create two calls with the same call ID (call IDs become available again when the call ends) and EBADSLT should result from sendmsg() if an attempt is made to preallocate a call with an in-use call ID. However, the cleanup in the error handling will trigger both assertions in rxrpc_cleanup_call() because the call isn't marked complete and isn't marked as having been released. Fix this by setting the call state in rxrpc_service_prealloc_one() and then marking it as being released before calling the cleanup function.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS