io_uring: fix task_work add use-after-free with SQPOLL
In the Linux kernel, the following vulnerability has been resolved: io_uring: fix task_work add use-after-free with SQPOLL For SQPOLL, the sqpoll thread runs task_work off its own list and doesn't need to be told about it, so it can pop and complete a request as soon as mpscq_push() has published it. If that was the last request holding the ring alive, io_ring_exit_work() then frees the ctx, stops the thread, and with it the tctx, while io_req_normal_work_add() is still looking at both after the push: BUG: KASAN: slab-use-after-free in io_req_normal_work_add+0x439/0x510 Read of size 4 at addr ff11000000ca0000 by task repro/55 (...) BUG: KASAN: slab-use-after-free in queue_work_on+0x25/0x70 Write of size 8 at addr ff11000000c3bd00 by task repro/55 Hold an RCU read lock across the add, like io_req_local_work_add() already does, and have io_ring_exit_work() wait for a grace period for SQPOLL rings as well before freeing the ctx.
CVE-2026-98858
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-2026-98858
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": "af5d68f8892f8ee8f137648b79ceb2abc153a19b",
"lessThan": "42b3332efacfd2140be4cd0dedad4fb96b8ae90e",
"versionType": "git"
},
{
"status": "affected",
"version": "af5d68f8892f8ee8f137648b79ceb2abc153a19b",
"lessThan": "891bd8335a0de3bb15c3b797ce3026bbb0dbef6c",
"versionType": "git"
},
{
"status": "affected",
"version": "af5d68f8892f8ee8f137648b79ceb2abc153a19b",
"lessThan": "395b25968fe854d4efaa19a8e9b7a5b6d1b3eea3",
"versionType": "git"
},
{
"status": "affected",
"version": "af5d68f8892f8ee8f137648b79ceb2abc153a19b",
"lessThan": "a92193c91e8839fe5fc209616ea95465ae4b919d",
"versionType": "git"
}
],
"programFiles": [
"io_uring/io_uring.c",
"io_uring/tw.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.9"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.9",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.113",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.56",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.10",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"io_uring/io_uring.c",
"io_uring/tw.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98858
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #38754 · Revision 1
- Added to Heist Feed
- Publisher date