CVE-2026-23243RDMA/umad: Reject negative data_len in ib_umad_write
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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
- CVSS
- 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Modified
- Record last updated
- Oct 15, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 2be8e3ee8efd6f99ce454115c29d09750915021a before 1371ef6b1ecf3676b8942f5dfb3634fb0648128e; from 2be8e3ee8efd6f99ce454115c29d09750915021a before 362e45fd9069ffa1523f9f1633b606ebf72060d7; from 2be8e3ee8efd6f99ce454115c29d09750915021a before 6eb2919474ca105c5b13d19574e25f0ddcf19ca2; from 2be8e3ee8efd6f99ce454115c29d09750915021a before a6a3e4af10993cb9e4b8f0548680aba0ab5f3b0d; from 2be8e3ee8efd6f99ce454115c29d09750915021a before 9c80d688f402539dfc8f336de1380d6b4ee14316; from 2be8e3ee8efd6f99ce454115c29d09750915021a before 205955f29c26330b1dc7fdeadd5bb97c38e26f56; from 2be8e3ee8efd6f99ce454115c29d09750915021a before 52ab82cc5cf8ada5c3fb6ffe8f32fdb2fc27a34b; from 2be8e3ee8efd6f99ce454115c29d09750915021a before 5551b02fdbfd85a325bb857f3a8f9c9f33397ed2 | CNA record |
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.6 | CISA ADP |
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name) | from V3.1.6 | CISA ADP |
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.6 | CISA ADP |
linux linux_kernel linux:linux_kernel | from 2.6.24.1 before 5.10.252; from 5.11 before 5.15.202; from 5.16 before 6.1.165; from 6.2 before 6.6.128; from 6.7 before 6.12.75; from 6.13 before 6.18.14; from 6.19 before 6.19.4; 2.6.24 | NVD |
References
- https://git.kernel.org/stable/c/1371ef6b1ecf3676b8942f5dfb3634fb0648128epatch
- https://git.kernel.org/stable/c/362e45fd9069ffa1523f9f1633b606ebf72060d7patch
- https://git.kernel.org/stable/c/6eb2919474ca105c5b13d19574e25f0ddcf19ca2patch
- https://git.kernel.org/stable/c/a6a3e4af10993cb9e4b8f0548680aba0ab5f3b0dpatch
- https://git.kernel.org/stable/c/9c80d688f402539dfc8f336de1380d6b4ee14316patch
- https://git.kernel.org/stable/c/205955f29c26330b1dc7fdeadd5bb97c38e26f56patch
- https://git.kernel.org/stable/c/52ab82cc5cf8ada5c3fb6ffe8f32fdb2fc27a34bpatch
- https://git.kernel.org/stable/c/5551b02fdbfd85a325bb857f3a8f9c9f33397ed2patch
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.