CVE-2023-53649
Medium · 5.5CVSS
5.5
EPSS
0.2%
Published
Oct 7, 2025
CISA due date
—
Cloudanix analysis
A bug in a Linux performance diagnostic tool can cause small amounts of memory to be wasted each time the tool runs, eventually making the system slower or forcing restarts if the tool is used often.
- Exploitation
- Local Privilege
- Attacker needs
- Low Privilege
- Complexity
- Low
- Impact
- Denial Of Service
- Component
- Application
- Class
- Memory Corruption
- Remediation
- Upgrade
- Effort
- Medium
- Patch risk
- Low
What it actually does
Memory leak in perf trace where evsel->priv allocation for non-syscall tracepoints is never freed, leading to repeated small heap allocations that persist until process exit.
Why it matters to the business
Repeated execution of the affected perf trace command on systems with the vulnerable kernel tooling gradually increases memory usage; in long-running or automated diagnostic workflows this can contribute to resource pressure or force restarts, especially on systems where perf is invoked frequently.
How an attack unfolds
An attacker with local access runs 'perf trace' repeatedly against workloads that trigger non-syscall tracepoint initialization paths; each invocation leaks a small allocation because the conditional free logic only checked for the 'syscalls' system name while allocation occurred for all other systems, allowing gradual memory exhaustion without any special privileges beyond running perf.
How to fix it
Upgrade the perf tooling to a version containing commit 3cb4d5e00e037c70 and the follow-up fix that unconditionally frees evsel->priv when set and uses evsel_trace__delete(); for rswag (RubyGems) users, update to version 2.10.1 or later.
How to confirm the fix worked
Rebuild perf with -fsanitize=address and confirm 'perf trace sleep 1' no longer reports leaks from evsel_trace__new; inspect source to verify the free now occurs whenever evsel->priv is non-NULL regardless of tp_format->system name.
Typical attack path
- Obtain local shell or container access on a system with the vulnerable perf binary
- Invoke perf trace against arbitrary workloads or sleep commands to trigger evsel__init_raw_syscall_tp paths
- Repeat invocations to accumulate leaked 40-byte objects until memory pressure appears
- Combine with other local memory-exhaustion techniques if targeting availability
How to detect it
Search system logs and audit trails for repeated invocations of perf trace; use memory profiling tools on perf processes to detect growth in allocations originating from evsel_trace__new; review source history for the conditional strcmp check on tp_format->system before the fix.
What your security team should do
- Apply the upstream perf fix or distribution package update immediately on developer and CI systems that run perf trace
- Add memory-leak detection to automated perf regression tests using AddressSanitizer or valgrind
- Limit perf trace usage to trusted users via Unix permissions until patched
- Monitor memory usage of long-lived perf processes as a compensating control
The record
In the Linux kernel, the following vulnerability has been resolved: perf trace: Really free the evsel->priv area In 3cb4d5e00e037c70 ("perf trace: Free syscall tp fields in evsel->priv") it only was freeing if strcmp(evsel->tp_format->system, "syscalls") returned zero, while the corresponding initialization of evsel->priv was being performed if it was _not_ zero, i.e. if the tp system wasn't 'syscalls'. Just stop looking for that and free it if evsel->priv was set, which should be equivalent. Also use the pre-existing evsel_trace__delete() function. This resolves these leaks, detected with: $ make EXTRA_CFLAGS="-fsanitize=address" BUILD_BPF_SKEL=1 CORESIGHT=1 O=/tmp/build/perf-tools-next -C tools/perf install-bin ================================================================= ==481565==ERROR: LeakSanitizer: detected memory leaks Direct leak of 40 byte(s) in 1 object(s) allocated from: #0 0x7f7343cba097 in calloc (/lib64/libasan.so.8+0xba097) #1 0x987966 in zalloc (/home/acme/bin/perf+0x987966) #2 0x52f9b9 in evsel_trace__new /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:307 #3 0x52f9b9 in evsel__syscall_tp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:333 #4 0x52f9b9 in evsel__init_raw_syscall_tp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:458 #5 0x52f9b9 in perf_evsel__raw_syscall_newtp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:480 #6 0x540e8b in trace__add_syscall_newtp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3212 #7 0x540e8b in trace__run /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3891 #8 0x540e8b in cmd_trace /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:5156 #9 0x5ef262 in run_builtin /home/acme/git/perf-tools-next/tools/perf/perf.c:323 #10 0x4196da in handle_internal_command /home/acme/git/perf-tools-next/tools/perf/perf.c:377 #11 0x4196da in run_argv /home/acme/git/perf-tools-next/tools/perf/perf.c:421 #12 0x4196da in main /home/acme/git/perf-tools-next/tools/perf/perf.c:537 #13 0x7f7342c4a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f) Direct leak of 40 byte(s) in 1 object(s) allocated from: #0 0x7f7343cba097 in calloc (/lib64/libasan.so.8+0xba097) #1 0x987966 in zalloc (/home/acme/bin/perf+0x987966) #2 0x52f9b9 in evsel_trace__new /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:307 #3 0x52f9b9 in evsel__syscall_tp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:333 #4 0x52f9b9 in evsel__init_raw_syscall_tp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:458 #5 0x52f9b9 in perf_evsel__raw_syscall_newtp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:480 #6 0x540dd1 in trace__add_syscall_newtp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3205 #7 0x540dd1 in trace__run /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3891 #8 0x540dd1 in cmd_trace /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:5156 #9 0x5ef262 in run_builtin /home/acme/git/perf-tools-next/tools/perf/perf.c:323 #10 0x4196da in handle_internal_command /home/acme/git/perf-tools-next/tools/perf/perf.c:377 #11 0x4196da in run_argv /home/acme/git/perf-tools-next/tools/perf/perf.c:421 #12 0x4196da in main /home/acme/git/perf-tools-next/tools/perf/perf.c:537 #13 0x7f7342c4a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f) SUMMARY: AddressSanitizer: 80 byte(s) leaked in 2 allocation(s). [root@quaco ~]# With this we plug all leaks with "perf trace sleep 1".
Affected packages
| Ecosystem | Package | Introduced | Fixed |
|---|---|---|---|
| Linux | Kernel | 5.14.0 | 5.15.132 |
| SUSE:Linux Enterprise High Availability Extension 15 SP6 | kernel-default | 0 | 6.4.0-150600.23.78.1 |
| SUSE:Linux Enterprise High Availability Extension 15 SP7 | kernel-default | 0 | 6.4.0-150700.53.22.1 |
| SUSE:Linux Enterprise Live Patching 15 SP6 | kernel-default | 0 | 6.4.0-150600.23.78.1 |
| SUSE:Linux Enterprise Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6-RT_Update_17 | 0 | 1-150600.1.3.1 |
| SUSE:Linux Enterprise Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_17 | 0 | 1-150600.13.5.1 |
| SUSE:Linux Enterprise Live Patching 15 SP7 | kernel-default | 0 | 6.4.0-150700.53.22.1 |
| SUSE:Linux Enterprise Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_6 | 0 | 1-150700.15.3.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP6 | kernel-64kb | 0 | 6.4.0-150600.23.78.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP6 | kernel-default | 0 | 6.4.0-150600.23.78.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP6 | kernel-default-base | 0 | 6.4.0-150600.23.78.1.150600.12.34.2 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP6 | kernel-source | 0 | 6.4.0-150600.23.78.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP6 | kernel-zfcpdump | 0 | 6.4.0-150600.23.78.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP7 | kernel-64kb | 0 | 6.4.0-150700.53.22.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP7 | kernel-default | 0 | 6.4.0-150700.53.22.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP7 | kernel-default-base | 0 | 6.4.0-150700.53.22.1.150700.17.15.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP7 | kernel-source | 0 | 6.4.0-150700.53.22.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP7 | kernel-zfcpdump | 0 | 6.4.0-150700.53.22.1 |
| SUSE:Linux Enterprise Module for Development Tools 15 SP6 | kernel-docs | 0 | 6.4.0-150600.23.78.1 |
| SUSE:Linux Enterprise Module for Development Tools 15 SP6 | kernel-obs-build | 0 | 6.4.0-150600.23.78.1 |
| SUSE:Linux Enterprise Module for Development Tools 15 SP6 | kernel-source | 0 | 6.4.0-150600.23.78.1 |
| SUSE:Linux Enterprise Module for Development Tools 15 SP6 | kernel-syms | 0 | 6.4.0-150600.23.78.1 |
| SUSE:Linux Enterprise Module for Development Tools 15 SP7 | kernel-docs | 0 | 6.4.0-150700.53.22.1 |
| SUSE:Linux Enterprise Module for Development Tools 15 SP7 | kernel-obs-build | 0 | 6.4.0-150700.53.22.1 |
| SUSE:Linux Enterprise Module for Development Tools 15 SP7 | kernel-source | 0 | 6.4.0-150700.53.22.1 |
| SUSE:Linux Enterprise Module for Development Tools 15 SP7 | kernel-syms | 0 | 6.4.0-150700.53.22.1 |
| SUSE:Linux Enterprise Module for Legacy 15 SP6 | kernel-default | 0 | 6.4.0-150600.23.78.1 |
| SUSE:Linux Enterprise Module for Legacy 15 SP7 | kernel-default | 0 | 6.4.0-150700.53.22.1 |
| SUSE:Linux Enterprise Module for Public Cloud 15 SP6 | kernel-azure | 0 | 6.4.0-150600.8.55.1 |
| SUSE:Linux Enterprise Module for Public Cloud 15 SP6 | kernel-source-azure | 0 | 6.4.0-150600.8.55.1 |
| SUSE:Linux Enterprise Module for Public Cloud 15 SP6 | kernel-syms-azure | 0 | 6.4.0-150600.8.55.1 |
| SUSE:Linux Enterprise Module for Public Cloud 15 SP7 | kernel-azure | 0 | 6.4.0-150700.20.18.1 |
| SUSE:Linux Enterprise Module for Public Cloud 15 SP7 | kernel-source-azure | 0 | 6.4.0-150700.20.18.1 |
| SUSE:Linux Enterprise Module for Public Cloud 15 SP7 | kernel-syms-azure | 0 | 6.4.0-150700.20.18.1 |
| SUSE:Linux Enterprise Workstation Extension 15 SP6 | kernel-default | 0 | 6.4.0-150600.23.78.1 |
| SUSE:Linux Enterprise Workstation Extension 15 SP7 | kernel-default | 0 | 6.4.0-150700.53.22.1 |
| SUSE:Real Time Module 15 SP6 | kernel-rt | 0 | 6.4.0-150600.10.58.1 |
| SUSE:Real Time Module 15 SP6 | kernel-rt_debug | 0 | 6.4.0-150600.10.58.1 |
| SUSE:Real Time Module 15 SP6 | kernel-source-rt | 0 | 6.4.0-150600.10.58.1 |
| SUSE:Real Time Module 15 SP6 | kernel-syms-rt | 0 | 6.4.0-150600.10.58.1 |
| openSUSE:Leap 15.6 | dtb-aarch64 | 0 | 6.4.0-150600.23.78.1 |
| openSUSE:Leap 15.6 | kernel-64kb | 0 | 6.4.0-150600.23.78.1 |
| openSUSE:Leap 15.6 | kernel-azure | 0 | 6.4.0-150600.8.55.1 |
| openSUSE:Leap 15.6 | kernel-debug | 0 | 6.4.0-150600.23.78.1 |
| openSUSE:Leap 15.6 | kernel-default | 0 | 6.4.0-150600.23.78.1 |
| openSUSE:Leap 15.6 | kernel-default-base | 0 | 6.4.0-150600.23.78.1.150600.12.34.2 |
| openSUSE:Leap 15.6 | kernel-docs | 0 | 6.4.0-150600.23.78.1 |
| openSUSE:Leap 15.6 | kernel-kvmsmall | 0 | 6.4.0-150600.23.78.1 |
| openSUSE:Leap 15.6 | kernel-obs-build | 0 | 6.4.0-150600.23.78.1 |
| openSUSE:Leap 15.6 | kernel-obs-qa | 0 | 6.4.0-150600.23.78.1 |
| openSUSE:Leap 15.6 | kernel-rt | 0 | 6.4.0-150600.10.58.1 |
| openSUSE:Leap 15.6 | kernel-rt_debug | 0 | 6.4.0-150600.10.58.1 |
| openSUSE:Leap 15.6 | kernel-source | 0 | 6.4.0-150600.23.78.1 |
| openSUSE:Leap 15.6 | kernel-source-azure | 0 | 6.4.0-150600.8.55.1 |
| openSUSE:Leap 15.6 | kernel-source-rt | 0 | 6.4.0-150600.10.58.1 |
| openSUSE:Leap 15.6 | kernel-syms | 0 | 6.4.0-150600.23.78.1 |
| openSUSE:Leap 15.6 | kernel-syms-azure | 0 | 6.4.0-150600.8.55.1 |
| openSUSE:Leap 15.6 | kernel-syms-rt | 0 | 6.4.0-150600.10.58.1 |
| openSUSE:Leap 15.6 | kernel-zfcpdump | 0 | 6.4.0-150600.23.78.1 |
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