CVE-2026-23243

High

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

SeverityHigh
CVSS7.8
Exploit probability—
ProductLinux Kernel
PublishedMar 18, 2026
First seenMar 18, 2026

How to fix

Update
  • linux linux_kernel5.10.252, 5.15.202, 6.1.165, 6.6.128, 6.12.75, 6.18.14, 6.19.4 or later

Affected products

ProductAffected versionsFixed in
linux linux_kernel2.6.24.1 ≤ v < 5.10.252, 5.11 ≤ v < 5.15.202, 5.16 ≤ v < 6.1.165, 6.2 ≤ v < 6.6.128, 6.7 ≤ v < 6.12.75, 6.13 ≤ v < 6.18.14, 6.19 ≤ v < 6.19.4, 2.6.245.10.252, 5.15.202, 6.1.165, 6.6.128, 6.12.75, 6.18.14, 6.19.4

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