CVE-2026-23243

Summary

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

Affected Software

VendorProductVersion RangeStatus
LinuxLinux2be8e3ee8efd6f99ce454115c29d09750915021a < 1371ef6b1ecf3676b8942f5dfb3634fb0648128eaffected
LinuxLinux2be8e3ee8efd6f99ce454115c29d09750915021a < 362e45fd9069ffa1523f9f1633b606ebf72060d7affected
LinuxLinux2be8e3ee8efd6f99ce454115c29d09750915021a < 6eb2919474ca105c5b13d19574e25f0ddcf19ca2affected
LinuxLinux2be8e3ee8efd6f99ce454115c29d09750915021a < a6a3e4af10993cb9e4b8f0548680aba0ab5f3b0daffected
LinuxLinux2be8e3ee8efd6f99ce454115c29d09750915021a < 9c80d688f402539dfc8f336de1380d6b4ee14316affected
LinuxLinux2be8e3ee8efd6f99ce454115c29d09750915021a < 205955f29c26330b1dc7fdeadd5bb97c38e26f56affected
LinuxLinux2be8e3ee8efd6f99ce454115c29d09750915021a < 52ab82cc5cf8ada5c3fb6ffe8f32fdb2fc27a34baffected
LinuxLinux2be8e3ee8efd6f99ce454115c29d09750915021a < 5551b02fdbfd85a325bb857f3a8f9c9f33397ed2affected
LinuxLinux2.6.24affected
LinuxLinux0 < 2.6.24unaffected
LinuxLinux5.10.252 <= 5.10.*unaffected
LinuxLinux5.15.202 <= 5.15.*unaffected
LinuxLinux6.1.165 <= 6.1.*unaffected
LinuxLinux6.6.128 <= 6.6.*unaffected
LinuxLinux6.12.75 <= 6.12.*unaffected
LinuxLinux6.18.14 <= 6.18.*unaffected
LinuxLinux6.19.4 <= 6.19.*unaffected
LinuxLinux7.0 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: total

References