RDMA/rxe: Reject non-8-byte ATOMIC_WRITE payloads
In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Reject non-8-byte ATOMIC_WRITE payloads atomic_write_reply() at drivers/infiniband/sw/rxe/rxe_resp.c unconditionally dereferences 8 bytes at payload_addr(pkt): value = *(u64 *)payload_addr(pkt); check_rkey() previously accepted an ATOMIC_WRITE request with pktlen == resid == 0 because the length validation only compared pktlen against resid. A remote initiator that sets the RETH length to 0 therefore reaches atomic_write_reply() with a zero-byte logical payload, and the responder reads sizeof(u64) bytes from past the logical end of the packet into skb->head tailroom, then writes those 8 bytes into the attacker's MR via rxe_mr_do_atomic_write(). That is a remote disclosure of 4 bytes of kernel tailroom per probe (the other 4 bytes are the packet's own trailing ICRC). IBA oA19-28 defines ATOMIC_WRITE as exactly 8 bytes. Anything else is protocol-invalid. Hoist a strict length check into check_rkey() so the responder never reaches the unchecked dereference, and keep the existing WRITE-family length logic for the normal RDMA WRITE path. Reproduced on mainline with an unmodified rxe driver: a sustained zero-length ATOMIC_WRITE probe repeatedly leaks adjacent skb head-buffer bytes into the attacker's MR, including recognisable kernel strings and partial kernel-direct-map pointer words. With this patch applied the responder rejects the PDU and the MR stays all-zero.
CVE-2026-46114
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-46114
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "034e285f8b99062a0cf29112e1232154a6a44aa5",
"lessThan": "539cabb7b2d8ba70f55bba91db55faef11c2a6d7",
"versionType": "git"
},
{
"status": "affected",
"version": "034e285f8b99062a0cf29112e1232154a6a44aa5",
"lessThan": "d415fce3fcde6d7aeea6c25362a395b905811452",
"versionType": "git"
},
{
"status": "affected",
"version": "034e285f8b99062a0cf29112e1232154a6a44aa5",
"lessThan": "105bf79a23b85cf3a761d18a4f3e10ce88526bc1",
"versionType": "git"
},
{
"status": "affected",
"version": "034e285f8b99062a0cf29112e1232154a6a44aa5",
"lessThan": "7ec1ed4747f5f99f8b797bb438c5efd36079fad5",
"versionType": "git"
},
{
"status": "affected",
"version": "034e285f8b99062a0cf29112e1232154a6a44aa5",
"lessThan": "1114c87aa6f195cf07da55a27b2122ae26557b26",
"versionType": "git"
}
],
"programFiles": [
"drivers/infiniband/sw/rxe/rxe_resp.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.2"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.2",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.140",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.88",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.30",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.7",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/infiniband/sw/rxe/rxe_resp.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-46114
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #40121 · Revision 1
- Added to Heist Feed
- Publisher date