CVE-2026-23243

RDMA/umad: Reject negative data_len in ib_umad_write

State: Published
Severity: 7.8 High
Published: Mar 18, 2026
Updated: Oct 19, 2026
Reserved: Jan 13, 2026

Description

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

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

CWE-190 Integer Overflow or Wraparound

Affected Products

Product	Versions
LinuxLinux	2be8e3ee8efd6f99ce454115c29d09750915021a to before 1371ef6b1ecf3676b8942f5dfb3634fb0648128eAffected 2be8e3ee8efd6f99ce454115c29d09750915021a to before 362e45fd9069ffa1523f9f1633b606ebf72060d7Affected 2be8e3ee8efd6f99ce454115c29d09750915021a to before 6eb2919474ca105c5b13d19574e25f0ddcf19ca2Affected 2be8e3ee8efd6f99ce454115c29d09750915021a to before a6a3e4af10993cb9e4b8f0548680aba0ab5f3b0dAffected 2be8e3ee8efd6f99ce454115c29d09750915021a to before 9c80d688f402539dfc8f336de1380d6b4ee14316Affected 2be8e3ee8efd6f99ce454115c29d09750915021a to before 205955f29c26330b1dc7fdeadd5bb97c38e26f56Affected 2be8e3ee8efd6f99ce454115c29d09750915021a to before 52ab82cc5cf8ada5c3fb6ffe8f32fdb2fc27a34bAffected 2be8e3ee8efd6f99ce454115c29d09750915021a to before 5551b02fdbfd85a325bb857f3a8f9c9f33397ed2Affected
LinuxLinux	2.6.24Affected before 2.6.24Not affected 5.10.252 through 5.10.Not affected 5.15.202 through 5.15.Not affected 6.1.165 through 6.1.Not affected 6.6.128 through 6.6.Not affected 6.12.75 through 6.12.Not affected 6.18.14 through 6.18.Not affected 6.19.4 through 6.19.*Not affected 7.0 and laterNot affected

Product

Versions

LinuxLinux

2be8e3ee8efd6f99ce454115c29d09750915021a to before 1371ef6b1ecf3676b8942f5dfb3634fb0648128eAffected
2be8e3ee8efd6f99ce454115c29d09750915021a to before 362e45fd9069ffa1523f9f1633b606ebf72060d7Affected
2be8e3ee8efd6f99ce454115c29d09750915021a to before 6eb2919474ca105c5b13d19574e25f0ddcf19ca2Affected
2be8e3ee8efd6f99ce454115c29d09750915021a to before a6a3e4af10993cb9e4b8f0548680aba0ab5f3b0dAffected
2be8e3ee8efd6f99ce454115c29d09750915021a to before 9c80d688f402539dfc8f336de1380d6b4ee14316Affected
2be8e3ee8efd6f99ce454115c29d09750915021a to before 205955f29c26330b1dc7fdeadd5bb97c38e26f56Affected
2be8e3ee8efd6f99ce454115c29d09750915021a to before 52ab82cc5cf8ada5c3fb6ffe8f32fdb2fc27a34bAffected
2be8e3ee8efd6f99ce454115c29d09750915021a to before 5551b02fdbfd85a325bb857f3a8f9c9f33397ed2Affected

LinuxLinux

2.6.24Affected
before 2.6.24Not affected
5.10.252 through 5.10.*Not affected
5.15.202 through 5.15.*Not affected
6.1.165 through 6.1.*Not affected
6.6.128 through 6.6.*Not affected
6.12.75 through 6.12.*Not affected
6.18.14 through 6.18.*Not affected
6.19.4 through 6.19.*Not affected
7.0 and laterNot affected

References

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