RDMA/rxe: Reject unknown opcodes before ICRC processing
In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Reject unknown opcodes before ICRC processing Even after applying commit 7244491dab34 ("RDMA/rxe: Validate pad and ICRC before payload_size() in rxe_rcv"), a single unauthenticated UDP packet can still trigger panic. That patch handled payload_size() underflow only for valid opcodes with short packets, not for packets carrying an unknown opcode. The unknown-opcode OOB read described below predates that commit and reaches back to the initial Soft RoCE driver. The check added there reads pkt->paylen < header_size(pkt) + bth_pad(pkt) + RXE_ICRC_SIZE where header_size(pkt) expands to rxe_opcode[pkt->opcode].length. The rxe_opcode[] array has 256 entries but is only populated for defined IB opcodes; any other entry (for example opcode 0xff) is zero-initialized, so length == 0 and the check degenerates to pkt->paylen < 0 + bth_pad(pkt) + RXE_ICRC_SIZE which does not constrain pkt->paylen enough. rxe_icrc_hdr() then computes rxe_opcode[pkt->opcode].length - RXE_BTH_BYTES which underflows when length == 0 and passes a huge value to rxe_crc32(), causing an out-of-bounds read of the skb payload. Reproduced on v7.0-rc7 with that fix applied, QEMU/KVM with CONFIG_RDMA_RXE=y and CONFIG_KASAN=y, after rdma link add rxe0 type rxe netdev eth0 A single 48-byte UDP packet to port 4791 with BTH opcode=0xff and QPN=IB_MULTICAST_QPN triggers: BUG: KASAN: slab-out-of-bounds in crc32_le+0x115/0x170 Read of size 1 at addr
CVE-2026-46133
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-2026-46133
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": "8700e3e7c4857d28ebaa824509934556da0b3e76",
"lessThan": "318787fa7193bd79691f2ebce4e80cb6abd0faef",
"versionType": "git"
},
{
"status": "affected",
"version": "8700e3e7c4857d28ebaa824509934556da0b3e76",
"lessThan": "6a79b1ea0fcb2c998fda6a793050f66146e9cc42",
"versionType": "git"
},
{
"status": "affected",
"version": "8700e3e7c4857d28ebaa824509934556da0b3e76",
"lessThan": "599cfdf44c1701c581cd4a21f1e1e03f8dc3840b",
"versionType": "git"
},
{
"status": "affected",
"version": "8700e3e7c4857d28ebaa824509934556da0b3e76",
"lessThan": "e3dc3a2fb05f4ed49c7f20594c4c52350d032189",
"versionType": "git"
},
{
"status": "affected",
"version": "8700e3e7c4857d28ebaa824509934556da0b3e76",
"lessThan": "f8ee926431a7bbec2b10c1290664af2cb290b983",
"versionType": "git"
},
{
"status": "affected",
"version": "8700e3e7c4857d28ebaa824509934556da0b3e76",
"lessThan": "006a3a5f75345c6a0dbf13fd3ee01406e93b6733",
"versionType": "git"
},
{
"status": "affected",
"version": "8700e3e7c4857d28ebaa824509934556da0b3e76",
"lessThan": "6fa18025e5782afff91415fd5217b39c1e4837d7",
"versionType": "git"
},
{
"status": "affected",
"version": "8700e3e7c4857d28ebaa824509934556da0b3e76",
"lessThan": "4c6f86d85d03cdb33addce86aa69aa795ca6c47a",
"versionType": "git"
}
],
"programFiles": [
"drivers/infiniband/sw/rxe/rxe_recv.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.8"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.8",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.258",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.209",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.175",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"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_recv.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-46133
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #40138 · Revision 1
- Added to Heist Feed
- Publisher date