GHSA-JJ8V-VRFX-WP8W
Vulnerability from github – Published: 2026-09-11 21:31 – Updated: 2026-09-13 09:32In the Linux kernel, the following vulnerability has been resolved:
svcrdma: Validate Read chunk positions before reconstruction
The RPC/RDMA Read chunk position field is supplied by the remote client and stored verbatim in the parsed chunk list. xdr_count_read_segments() checks only 4-byte alignment; it never compares the position against the received inline body length.
In the single-chunk path, svc_rdma_read_complete_one() splits the head and tail kvecs at ch_position. A position past the inline body underflows the tail length, exposing adjacent slab memory to the upper XDR decoder.
In the multi-chunk path, svc_rdma_read_multiple_chunks() computes gap lengths between chunks as unsigned subtractions from ch_position. Overlapping Read chunks cause these subtractions to underflow. A final position past the inline body likewise underflows the trailing gap length. svc_rdma_copy_inline_range() then copies past the receive buffer into request pages that are returned to the client through the Reply channel.
Bound inline-range copies in svc_rdma_copy_inline_range() against the decoded inline RPC body saved in rc_saved_arg. Reject a single Read chunk positioned beyond that body, and reject multi-chunk lists where accumulated read bytes exceed the next chunk's position. Apply the same position and overlap checks in the call-chunk interleaving path.
{
"affected": [],
"aliases": [
"CVE-2026-89526"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-11T20:19:35Z",
"severity": "CRITICAL"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nsvcrdma: Validate Read chunk positions before reconstruction\n\nThe RPC/RDMA Read chunk position field is supplied by the remote\nclient and stored verbatim in the parsed chunk list.\nxdr_count_read_segments() checks only 4-byte alignment; it never\ncompares the position against the received inline body length.\n\nIn the single-chunk path, svc_rdma_read_complete_one() splits the\nhead and tail kvecs at ch_position. A position past the inline\nbody underflows the tail length, exposing adjacent slab memory to\nthe upper XDR decoder.\n\nIn the multi-chunk path, svc_rdma_read_multiple_chunks() computes\ngap lengths between chunks as unsigned subtractions from\nch_position. Overlapping Read chunks cause these subtractions to\nunderflow. A final position past the inline body likewise\nunderflows the trailing gap length. svc_rdma_copy_inline_range()\nthen copies past the receive buffer into request pages that are\nreturned to the client through the Reply channel.\n\nBound inline-range copies in svc_rdma_copy_inline_range() against\nthe decoded inline RPC body saved in rc_saved_arg. Reject a\nsingle Read chunk positioned beyond that body, and reject\nmulti-chunk lists where accumulated read bytes exceed the next\nchunk\u0027s position. Apply the same position and overlap checks in\nthe call-chunk interleaving path.",
"id": "GHSA-jj8v-vrfx-wp8w",
"modified": "2026-09-13T09:32:17Z",
"published": "2026-09-11T21:31:30Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89526"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3779b7b9e7d1c8ba4738f9d327de3b0288cefe9b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/577097455d084610fc31e91e6a61c5793b6f04ba"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5ab3f6d882fe07ae5e61d0bcfeea00b9409155c2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f84ec84d8d4bc65f9ae23372570349687f66fa39"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
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