CVE Catalog

CVE-2026-23243

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.13%

3th percentile - higher than 3% of all known CVEs

Summary

In the Linux kernel, a vulnerability in the RDMA/umad driver was found where ib_umad_write computed data_len from user-controlled values, potentially resulting in a negative value. A negative data_len caused incorrect padding calculations in alloc_send_rmpp_list, leading to an out-of-bounds write (slab-out-of-bounds).

Risk Assessment

An attacker with local access could exploit this vulnerability to write beyond buffer boundaries, potentially causing a system crash (kernel panic) or privilege escalation.

Recommendation

Immediately update the Linux kernel to a version containing the fix (commit adding a check for negative data_len). For production systems, apply the security patch from your distributor.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: RDMA/umad: Reject negative data_len in ib_umad_write ib_umad_write computes data_len from user-controlled count and the MAD header sizes. With a mismatched user MAD header size and RMPP header length, data_len can become negative and reach ib_create_send_mad(). This can make the padding calculation exceed the segment size and trigger an out-of-bounds memset in alloc_send_rmpp_list(). Add an explicit check to reject negative data_len before creating the send buffer. KASAN splat: [ 211.363464] BUG: KASAN: slab-out-of-bounds in ib_create_send_mad+0xa01/0x11b0 [ 211.364077] Write of size 220 at addr ffff88800c3fa1f8 by task spray_thread/102 [ 211.365867] ib_create_send_mad+0xa01/0x11b0 [ 211.365887] ib_umad_write+0x853/0x1c80

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