CVE-2026-99264
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: io_uring/net: don't retry recv on uncommitted buffers Commit 41b70df5b38b ("io_uring/net: commit partial buffers on retry") commits ring provided buffers when a receive is going to be retried after a partial transfer, so that another request using the same buffer group can't be handed the memory the first one keeps receiving into. It commits the number of bytes received so far. That does the job for a single buffer which is consumed as a whole, but the request hangs on to all it has mapped: - For a buffer ring with IOU_PBUF_RING_INC only these bytes are consumed. The rest of the buffer stays at the head of the ring. - For a bundle only the buffers which hold these bytes are consumed, the others that were peeked stay in the ring. In both cases the next receive with that buffer group gets memory that the retried request is still going to write to, and whoever comes last overwrites the data of the other. What the retry fills isn't committed at all, as the buffer list isn't known any more at that point. So the kernel hands it out again later on, while the CQE tells the application that it was used, and for an incremental buffer that it is done with. The remainder can't be committed in advance: if the request ends up receiving less, there is no way to tell the application that more was consumed than the CQE accounts for. Complete the request with what it has got instead of retrying it. MSG_WAITALL is no longer honoured for receives into incremental buffers or multi buffer bundles, they can return a short count, with the request marked as failed like for other short MSG_WAITALL transfers.
View original CVE JSON
{
"id": "CVE-2026-99264",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-11-03T12:17:33.490",
"lastModified": "2026-11-03T12:17:33.490",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/net: don't retry recv on uncommitted buffers\n\nCommit 41b70df5b38b (\"io_uring/net: commit partial buffers on retry\")\ncommits ring provided buffers when a receive is going to be retried after\na partial transfer, so that another request using the same buffer group\ncan't be handed the memory the first one keeps receiving into. It commits\nthe number of bytes received so far. That does the job for a single\nbuffer which is consumed as a whole, but the request hangs on to all it\nhas mapped:\n\n- For a buffer ring with IOU_PBUF_RING_INC only these bytes are consumed.\n The rest of the buffer stays at the head of the ring.\n- For a bundle only the buffers which hold these bytes are consumed, the\n others that were peeked stay in the ring.\n\nIn both cases the next receive with that buffer group gets memory that\nthe retried request is still going to write to, and whoever comes last\noverwrites the data of the other. What the retry fills isn't committed at\nall, as the buffer list isn't known any more at that point. So the kernel\nhands it out again later on, while the CQE tells the application that it\nwas used, and for an incremental buffer that it is done with.\n\nThe remainder can't be committed in advance: if the request ends up\nreceiving less, there is no way to tell the application that more was\nconsumed than the CQE accounts for. Complete the request with what it has\ngot instead of retrying it. MSG_WAITALL is no longer honoured for\nreceives into incremental buffers or multi buffer bundles, they can\nreturn a short count, with the request marked as failed like for other\nshort MSG_WAITALL transfers."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"io_uring/net.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "fe9da1812f8697a38f7e30991d568ec199e16059",
"lessThan": "21cb1770a56a51266ab96d4ed2a3b6979db59694",
"versionType": "git",
"status": "affected"
},
{
"version": "41b70df5b38bc80967d2e0ed55cc3c3896bba781",
"lessThan": "fc8506eea4498ecba26ef8bf6dbbd74af3dc891d",
"versionType": "git",
"status": "affected"
},
{
"version": "41b70df5b38bc80967d2e0ed55cc3c3896bba781",
"lessThan": "97b8dc36ba3cb176b74a7929140aeaeb40d5cdc0",
"versionType": "git",
"status": "affected"
},
{
"version": "3b53dc1c641f2884d4750fc25aaf6c36b90db606",
"versionType": "git",
"status": "affected"
},
{
"version": "21a4ddb0f5e933f372808c10b9ac704505751bb1",
"versionType": "git",
"status": "affected"
},
{
"version": "2eb7937b5fc7fcd90eab7bebb0181214b61b9283",
"versionType": "git",
"status": "affected"
},
{
"version": "6.12.44",
"lessThan": "6.12.115",
"versionType": "semver",
"status": "affected"
},
{
"version": "6.6.103",
"lessThan": "6.7",
"versionType": "semver",
"status": "affected"
},
{
"version": "6.15.11",
"lessThan": "6.16",
"versionType": "semver",
"status": "affected"
},
{
"version": "6.16.2",
"lessThan": "6.17",
"versionType": "semver",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"io_uring/net.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "6.17",
"status": "affected"
},
{
"version": "0",
"lessThan": "6.17",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.115",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.60",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.14",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {},
"references": [
{
"url": "https://git.kernel.org/stable/c/21cb1770a56a51266ab96d4ed2a3b6979db59694",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/97b8dc36ba3cb176b74a7929140aeaeb40d5cdc0",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/fc8506eea4498ecba26ef8bf6dbbd74af3dc891d",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}