ring-buffer: Fix subbuf resize race with ring buffer readers
In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Fix subbuf resize race with ring buffer readers trace_buffer subbuf_size is read lockless in ring_buffer_read_page() and ring_buffer_read_start(), while it can simultaneously be resized with ring_buffer_subbuf_order_set(). Instead of trace_buffer::subbuf_size, use bpage::order in ring_buffer_read_start() and ring_buffer_read_page(). In ring_buffer_read_start(), even with resize_disabled, there is still a possibility of a race with a buffer modification. Hold the trace_buffer mutex to synchronise with any pending ring buffer order modification. trace_buffer::subbuf_size is now actually useless, remove it. Also, create accessors rb_subbuf_capacity() and rb_page_capacity() which return the actual size available for storing events, while rb_subbuf_size() returns the actual subbuf page-size.
CVE-2026-89771
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-2026-89771
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": "f9b94daa542a8d2532f0930f01cd9aec2d19621b",
"lessThan": "6d666f0b8b36c0765cf19fbe6de5a7ba5a73aad9",
"versionType": "git"
},
{
"status": "affected",
"version": "f9b94daa542a8d2532f0930f01cd9aec2d19621b",
"lessThan": "50f4a793c4ff24826efb0ac700989a5063cc53df",
"versionType": "git"
},
{
"status": "affected",
"version": "f9b94daa542a8d2532f0930f01cd9aec2d19621b",
"lessThan": "0c7c517827a453128a8f58bfd849546a29813b27",
"versionType": "git"
},
{
"status": "affected",
"version": "f9b94daa542a8d2532f0930f01cd9aec2d19621b",
"lessThan": "8a5f63637890f03177146efddaba5ec7a1b4d61f",
"versionType": "git"
}
],
"programFiles": [
"kernel/trace/ring_buffer.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.8"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.8",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.109",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.50",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.4",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"kernel/trace/ring_buffer.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-89771
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #35239 · Revision 1
- Added to Heist Feed
- Publisher date