tracing: Fix reading strings from synthetic events
In the Linux kernel, the following vulnerability has been resolved: tracing: Fix reading strings from synthetic events The follow commands caused a crash: # cd /sys/kernel/tracing # echo 's:open char file[]' > dynamic_events # echo 'hist:keys=common_pid:file=filename:onchange($file).trace(open,$file)' > events/syscalls/sys_enter_openat/trigger' # echo 1 > events/synthetic/open/enable BOOM! The problem is that the synthetic event field "char file[]" will read the value given to it as a string without any memory checks to make sure the address is valid. The above example will pass in the user space address and the sythetic event code will happily call strlen() on it and then strscpy() where either one will cause an oops when accessing user space addresses. Use the helper functions from trace_kprobe and trace_eprobe that can read strings safely (and actually succeed when the address is from user space and the memory is mapped in). Now the above can show: packagekitd-1721 [000] ...2. 104.597170: open: file=/usr/lib/rpm/fileattrs/cmake.attr in:imjournal-978 [006] ...2. 104.599642: open: file=/var/lib/rsyslog/imjournal.state.tmp packagekitd-1721 [000] ...2. 104.626308: open: file=/usr/lib/rpm/fileattrs/debuginfo.attr
CVE-2022-50255
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-2022-50255
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": "bd82631d7ccdc894af2738e47abcba2cb6e7dea9",
"lessThan": "d9c79fbcbdb6cb10c07c85040eaf615180b26c48",
"versionType": "git"
},
{
"status": "affected",
"version": "bd82631d7ccdc894af2738e47abcba2cb6e7dea9",
"lessThan": "149198d0b884e4606ed1d29b330c70016d878276",
"versionType": "git"
},
{
"status": "affected",
"version": "bd82631d7ccdc894af2738e47abcba2cb6e7dea9",
"lessThan": "f8bae1853196b52ede50950387f5b48cf83b9815",
"versionType": "git"
},
{
"status": "affected",
"version": "bd82631d7ccdc894af2738e47abcba2cb6e7dea9",
"lessThan": "0934ae9977c27133449b6dd8c6213970e7eece38",
"versionType": "git"
}
],
"programFiles": [
"kernel/trace/trace_events_synth.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.10"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.10",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.15.75",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "5.19.17",
"versionType": "semver",
"lessThanOrEqual": "5.19.*"
},
{
"status": "unaffected",
"version": "6.0.3",
"versionType": "semver",
"lessThanOrEqual": "6.0.*"
},
{
"status": "unaffected",
"version": "6.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"kernel/trace/trace_events_synth.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2022-50255
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #30209 · Revision 1
- Added to Heist Feed
- Publisher date