xsk: fix buffer leak in xsk_drop_skb() for AF_XDP multi-buffer Tx
In the Linux kernel, the following vulnerability has been resolved: xsk: fix buffer leak in xsk_drop_skb() for AF_XDP multi-buffer Tx This patch is inspired by the check[1] from sashiko. It says when overflow happens, the address of cq to be published is invalid. Actually the severer thing is the whole process of publishing the address of cq in this particular case is not right: it should truely publish the address and advance the cached_prod in cq as long as it reads descriptors from txq. The following is the full analysis. xsk_drop_skb() is called in three places, which all discard a partially built multi-buffer skb: 1) xsk_build_skb() -EOVERFLOW error path: packet exceeds MAX_SKB_FRAGS 2) __xsk_generic_xmit() post-loop cleanup: an invalid descriptor in the TX ring prevents the partial packet from completing 3) xsk_release(): socket close while xs->skb holds an incomplete packet In all three cases, the TX descriptors for the already-processed frags have been consumed from the TX ring (xskq_cons_release), and CQ slots have been reserved. However, xsk_drop_skb() calls xsk_consume_skb() which cancels the CQ reservations via xsk_cq_cancel_locked(). Since the buffer addresses never appear in the completion queue, userspace permanently loses track of these buffers. Fix this by letting consume_skb() trigger the existing xsk_destruct_skb destructor, which already submits buffer addresses to the CQ via xsk_cq_submit_addr_locked(). Note that cancelling the descriptors back to the TX
CVE-2026-74560
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-2026-74560
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": "cf24f5a5feeaae34c1a34d1e04f8ac697290427a",
"lessThan": "c24b3379c0ff00101b9ede54d36f7138d8a02c43",
"versionType": "git"
},
{
"status": "affected",
"version": "cf24f5a5feeaae34c1a34d1e04f8ac697290427a",
"lessThan": "05e283466b86e0b25a5209a3eafe87aa9886064a",
"versionType": "git"
},
{
"status": "affected",
"version": "cf24f5a5feeaae34c1a34d1e04f8ac697290427a",
"lessThan": "a0528ab6af62bf57153caaf8ea28e5fcb0e18fd4",
"versionType": "git"
},
{
"status": "affected",
"version": "cf24f5a5feeaae34c1a34d1e04f8ac697290427a",
"lessThan": "a3c8382ebce4780c6b3ace2c09bc342313ac0186",
"versionType": "git"
}
],
"programFiles": [
"net/xdp/xsk.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.6"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.6",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.18.44",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.8",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/xdp/xsk.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-74560
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #46577 · Revision 1
- Added to Heist Feed
- Publisher date