tracing: Fix use-after-free with same-name named triggers
In the Linux kernel, the following vulnerability has been resolved: tracing: Fix use-after-free with same-name named triggers When two hist triggers on different events are registered with the same name=, the second one reuses the first as named_data. Both are added to tr->hist_vars by save_hist_vars() during event_hist_trigger_parse(), because save_hist_vars() is called before event_trigger_register() while the named reuse is only detected later, in hist_register_trigger(). In the named-data branch hist_register_trigger() then frees the second histogram's hist_data via destroy_hist_data(), but never removes its tr->hist_vars list entry, leaving a dangling pointer and leaking the trace_array reference it holds. A later hist trigger that references a variable makes find_var_file() walk tr->hist_vars and dereference the freed hist_data. The bug is reproducible from userspace by writing three hist triggers to tracefs: cd /sys/kernel/tracing echo 'hist:keys=common_pid:x=common_pid:name=mh' > events/sched/sched_switch/trigger echo 'hist:keys=common_pid:x=common_pid:name=mh' > events/sched/sched_process_fork/trigger echo 'hist:keys=common_pid:vals=$x' > events/sched/sched_process_exit/trigger The third write panics the kernel: BUG: KASAN: slab-use-after-free in find_var_file.part.0+0x272/0x290 Read of size 8 at addr ffff888001f8a0e0 by task sh/1 CPU: 1 UID: 0 PID: 1 Comm: sh Tainted: G D N Call Trace: find_var_file.part.0 find_event_var parse_atom parse_expr __create_val_field even
CVE-2026-89746
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-2026-89746
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": "5ae1b18f05ee2b849dc03b6c15d7da0c1c6efa77",
"lessThan": "441aa6742dff70297b5f64533a07a6189a026e91",
"versionType": "git"
},
{
"status": "affected",
"version": "43b254d46c740bf9dbe65709afa021dd726dfa99",
"lessThan": "3a8534664426c071c2dfb5b4ffa36b18a2abfd79",
"versionType": "git"
},
{
"status": "affected",
"version": "435d2964af815aae456db554c62963b4515f19d0",
"lessThan": "477d762be4b0ffaf01429ccd88859e93b0ec28cc",
"versionType": "git"
},
{
"status": "affected",
"version": "6f86bdeab633a56d5c6dccf1a2c5989b6a5e323e",
"lessThan": "b1a49c22de01faf176d44e5caa765e237353a579",
"versionType": "git"
},
{
"status": "affected",
"version": "6f86bdeab633a56d5c6dccf1a2c5989b6a5e323e",
"lessThan": "83d1ae0406d8eade219a81b401e201702dd9dc55",
"versionType": "git"
},
{
"status": "affected",
"version": "6f86bdeab633a56d5c6dccf1a2c5989b6a5e323e",
"lessThan": "a7318172aa332a161fb9618286e64454c827f8fd",
"versionType": "git"
},
{
"status": "affected",
"version": "f1ae50cfb818ce1ac7a674406dfadb7653e2552d",
"versionType": "git"
},
{
"status": "affected",
"version": "6.1.130",
"lessThan": "6.1.188",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.6.81",
"lessThan": "6.6.157",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.12.18",
"lessThan": "6.12.109",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.13.6",
"lessThan": "6.14",
"versionType": "semver"
}
],
"programFiles": [
"kernel/trace/trace_events_hist.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.14"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.14",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.188",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"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/trace_events_hist.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-89746
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #35222 · Revision 1
- Added to Heist Feed
- Publisher date