{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-23243", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:37:45.989Z", "datePublished": "2026-03-18T10:05:05.826Z", "dateUpdated": "2026-08-05T12:20:53.089Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:20:53.089Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/umad: Reject negative data_len in ib_umad_write\n\nib_umad_write computes data_len from user-controlled count and the\nMAD header sizes. With a mismatched user MAD header size and RMPP\nheader length, data_len can become negative and reach ib_create_send_mad().\nThis can make the padding calculation exceed the segment size and trigger\nan out-of-bounds memset in alloc_send_rmpp_list().\n\nAdd an explicit check to reject negative data_len before creating the\nsend buffer.\n\nKASAN splat:\n[ 211.363464] BUG: KASAN: slab-out-of-bounds in ib_create_send_mad+0xa01/0x11b0\n[ 211.364077] Write of size 220 at addr ffff88800c3fa1f8 by task spray_thread/102\n[ 211.365867] ib_create_send_mad+0xa01/0x11b0\n[ 211.365887] ib_umad_write+0x853/0x1c80" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerability is in ib_umad_write(), the write handler for /dev/infiniband/umadX character device files, requiring local system access to open and write to the device.\nAC:L - The attacker reliably controls the count parameter passed to write() and can craft input to make data_len negative, triggering the OOB write deterministically with no race or special conditions.\nPR:L - The /dev/infiniband/umadX device has no capability checks in the code path. On RDMA-enabled systems (HPC clusters, cloud servers), udev rules commonly grant access to unprivileged users. An ioctl to register a MAD agent is needed first but requires no special privileges.\nUI:N - No user interaction is required. The attacker directly opens the device file, registers a MAD agent via ioctl, and triggers the bug by writing crafted data.\nS:U - The vulnerability operates within kernel space and does not cross a security boundary such as a VM or sandbox escape.\nC:H - The out-of-bounds memset write into slab memory can corrupt adjacent heap objects. In a controlled exploit, this memory corruption can be leveraged via heap spraying to gain arbitrary read primitives.\nI:H - KASAN confirmed a slab out-of-bounds write of 220 bytes. This heap corruption can be exploited to overwrite adjacent slab objects, enabling arbitrary write primitives and potential code execution.\nA:H - The out-of-bounds write corrupts slab memory, causing kernel crashes as confirmed by the KASAN splat. This is a reliable kernel panic/oops." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/infiniband/core/user_mad.c" ], "versions": [ { "version": "2be8e3ee8efd6f99ce454115c29d09750915021a", "lessThan": "1371ef6b1ecf3676b8942f5dfb3634fb0648128e", "status": "affected", "versionType": "git" }, { "version": "2be8e3ee8efd6f99ce454115c29d09750915021a", "lessThan": "362e45fd9069ffa1523f9f1633b606ebf72060d7", "status": "affected", "versionType": "git" }, { "version": "2be8e3ee8efd6f99ce454115c29d09750915021a", "lessThan": "6eb2919474ca105c5b13d19574e25f0ddcf19ca2", "status": "affected", "versionType": "git" }, { "version": "2be8e3ee8efd6f99ce454115c29d09750915021a", "lessThan": "a6a3e4af10993cb9e4b8f0548680aba0ab5f3b0d", "status": "affected", "versionType": "git" }, { "version": "2be8e3ee8efd6f99ce454115c29d09750915021a", "lessThan": "9c80d688f402539dfc8f336de1380d6b4ee14316", "status": "affected", "versionType": "git" }, { "version": "2be8e3ee8efd6f99ce454115c29d09750915021a", "lessThan": "205955f29c26330b1dc7fdeadd5bb97c38e26f56", "status": "affected", "versionType": "git" }, { "version": "2be8e3ee8efd6f99ce454115c29d09750915021a", "lessThan": "52ab82cc5cf8ada5c3fb6ffe8f32fdb2fc27a34b", "status": "affected", "versionType": "git" }, { "version": "2be8e3ee8efd6f99ce454115c29d09750915021a", "lessThan": "5551b02fdbfd85a325bb857f3a8f9c9f33397ed2", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/infiniband/core/user_mad.c" ], "versions": [ { "version": "2.6.24", "status": "affected" }, { "version": "0", "lessThan": "2.6.24", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.252", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.202", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.165", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.128", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.75", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.14", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.4", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.24", "versionEndExcluding": "5.10.252" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.24", "versionEndExcluding": "5.15.202" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.24", "versionEndExcluding": "6.1.165" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.24", "versionEndExcluding": "6.6.128" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.24", "versionEndExcluding": "6.12.75" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.24", "versionEndExcluding": "6.18.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.24", "versionEndExcluding": "6.19.4" }, { "vulnerable": true, "criteria": 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