io_uring: defer eventfd signaling when queued from a wakeup handler
In the Linux kernel, the following vulnerability has been resolved: io_uring: defer eventfd signaling when queued from a wakeup handler io_req_local_work_add() signals the CQ ring eventfd inline when it is the one to push the first entry onto ->work_list. For DEFER_TASKRUN rings that add is frequently done from a waitqueue wakeup handler, where an arbitrary waitqueue lock is held. eventfd_signal_mask() only refuses to recurse when current->in_eventfd is set, but that bit is set by eventfd_signal_mask() itself. If the wake chain starts somewhere else, signal goes out inline and can feed back into epoll. Add IOU_F_TWQ_IN_WAKE, set it on the task_work add done from the three waitqueue callbacks, and use it to force io_eventfd_signal() down the existing call_rcu_hurry() deferral instead of signaling inline.
CVE-2026-80920
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-2026-80920
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": "21a091b970cdbcf3e8ff829234b51be6f9192766",
"lessThan": "d0c240f25e654442a72af5ca021a02165ccce638",
"versionType": "git"
},
{
"status": "affected",
"version": "21a091b970cdbcf3e8ff829234b51be6f9192766",
"lessThan": "9d984451baf768ecd9e1fdad4637b729fcb2c9d5",
"versionType": "git"
},
{
"status": "affected",
"version": "21a091b970cdbcf3e8ff829234b51be6f9192766",
"lessThan": "e22f4494cc9487d326e5e3067f33dea7c1e442b2",
"versionType": "git"
},
{
"status": "affected",
"version": "21a091b970cdbcf3e8ff829234b51be6f9192766",
"lessThan": "b6bb334b0e9348887e3e55e1f494b0c3b8fbf59f",
"versionType": "git"
},
{
"status": "affected",
"version": "21a091b970cdbcf3e8ff829234b51be6f9192766",
"lessThan": "40b6ccf68731809ceb85c6e9f0f8f2ed61c7aa5a",
"versionType": "git"
},
{
"status": "affected",
"version": "21a091b970cdbcf3e8ff829234b51be6f9192766",
"lessThan": "cd305ee3633a45fcf5f3a5d83f99f3cb77d87b6e",
"versionType": "git"
}
],
"programFiles": [
"include/linux/io_uring_types.h",
"io_uring/eventfd.c",
"io_uring/eventfd.h",
"io_uring/futex.c",
"io_uring/io_uring.c",
"io_uring/poll.c",
"io_uring/tw.c",
"io_uring/waitid.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.1"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.1",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.114",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.49",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.11",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2.1",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"include/linux/io_uring_types.h",
"io_uring/eventfd.c",
"io_uring/eventfd.h",
"io_uring/futex.c",
"io_uring/io_uring.c",
"io_uring/poll.c",
"io_uring/tw.c",
"io_uring/waitid.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-80920
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #46646 · Revision 1
- Added to Heist Feed
- Publisher date