[PATCH 0/2] perf kvm: Fix memory leaks
From: Michalis Niarchos via B4 Relay
Date: Fri Aug 07 2026 - 11:25:36 EST
Running ./perf kvm stat report with ASan, revealed some memory leaks:
==206006==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 72 byte(s) in 3 object(s) allocated from:
#0 0x7ff86bf2bea9 in calloc (/usr/lib/libasan.so.8+0x12bea9) (BuildId: 7f2845989b820f536270e19ec47df085ae89a675)
#1 0x55f42795a0d5 in zalloc ../../lib/zalloc.c:8
#2 0x55f42782d7f4 in per_vcpu_record /home/mike/git/linux/tools/perf/builtin-kvm.c:929
#3 0x55f42782dab7 in handle_kvm_event /home/mike/git/linux/tools/perf/builtin-kvm.c:950
#4 0x55f42782fa80 in process_sample_event /home/mike/git/linux/tools/perf/builtin-kvm.c:1159
...
#14 0x55f42783236c in read_events /home/mike/git/linux/tools/perf/builtin-kvm.c:1591
#15 0x55f4278326f8 in kvm_events_report_vcpu /home/mike/git/linux/tools/perf/builtin-kvm.c:1636
Direct leak of 8 byte(s) in 1 object(s) allocated from:
#0 0x7ff86bf2c0c1 in malloc (/usr/lib/libasan.so.8+0x12c0c1) (BuildId: 7f2845989b820f536270e19ec47df085ae89a675)
#1 0x55f427d78fe5 in thread__get util/thread.c:137
#2 0x55f427c4f1fc in thread__find_map util/event.c:703
#3 0x55f427c5001e in machine__resolve util/event.c:819
#4 0x55f42782f84a in process_sample_event /home/mike/git/linux/tools/perf/builtin-kvm.c:1145
...
#14 0x55f42783236c in read_events /home/mike/git/linux/tools/perf/builtin-kvm.c:1591
#15 0x55f4278326f8 in kvm_events_report_vcpu /home/mike/git/linux/tools/perf/builtin-kvm.c:1636
Indirect leak of 256 byte(s) in 1 object(s) allocated from:
#0 0x7ff86bf2bea9 in calloc (/usr/lib/libasan.so.8+0x12bea9) (BuildId: 7f2845989b820f536270e19ec47df085ae89a675)
#1 0x55f42795a0d5 in zalloc ../../lib/zalloc.c:8
#2 0x55f427d78857 in thread__new util/thread.c:46
#3 0x55f427d7c083 in threads__findnew util/threads.c:116
#4 0x55f427d2957c in __machine__findnew_thread util/machine.c:553
#5 0x55f427d29734 in machine__findnew_thread util/machine.c:577
#6 0x55f427d29a07 in machine__process_comm_event util/machine.c:616
...
#16 0x55f42783236c in read_events /home/mike/git/linux/tools/perf/builtin-kvm.c:1591
#17 0x55f4278326f8 in kvm_events_report_vcpu /home/mike/git/linux/tools/perf/builtin-kvm.c:1636
Indirect leak of 112 byte(s) in 1 object(s) allocated from:
#0 0x7ff86bf2bea9 in calloc (/usr/lib/libasan.so.8+0x12bea9) (BuildId: 7f2845989b820f536270e19ec47df085ae89a675)
#1 0x55f42795a0d5 in zalloc ../../lib/zalloc.c:8
#2 0x55f427d40e37 in maps__new util/maps.c:270
#3 0x55f427d78718 in thread__init_maps util/thread.c:30
#4 0x55f427d295d8 in __machine__findnew_thread util/machine.c:563
#5 0x55f427d29734 in machine__findnew_thread util/machine.c:577
#6 0x55f427d29a07 in machine__process_comm_event util/machine.c:616
...
#16 0x55f42783236c in read_events /home/mike/git/linux/tools/perf/builtin-kvm.c:1591
#17 0x55f4278326f8 in kvm_events_report_vcpu /home/mike/git/linux/tools/perf/builtin-kvm.c:1636
Indirect leak of 48 byte(s) in 1 object(s) allocated from:
#0 0x7ff86bf2bea9 in calloc (/usr/lib/libasan.so.8+0x12bea9) (BuildId: 7f2845989b820f536270e19ec47df085ae89a675)
#1 0x55f42795a0d5 in zalloc ../../lib/zalloc.c:8
#2 0x55f427d75f07 in comm__new util/comm.c:194
#3 0x55f427d78a2f in thread__new util/thread.c:67
#4 0x55f427d7c083 in threads__findnew util/threads.c:116
#5 0x55f427d2957c in __machine__findnew_thread util/machine.c:553
#6 0x55f427d29734 in machine__findnew_thread util/machine.c:577
#7 0x55f427d29a07 in machine__process_comm_event util/machine.c:616
...
#17 0x55f42783236c in read_events /home/mike/git/linux/tools/perf/builtin-kvm.c:1591
#18 0x55f4278326f8 in kvm_events_report_vcpu /home/mike/git/linux/tools/perf/builtin-kvm.c:1636
Indirect leak of 32 byte(s) in 1 object(s) allocated from:
#0 0x7ff86bf2bea9 in calloc (/usr/lib/libasan.so.8+0x12bea9) (BuildId: 7f2845989b820f536270e19ec47df085ae89a675)
#1 0x55f427d731a1 in nsinfo__alloc util/namespaces.c:146
#2 0x55f427d73275 in nsinfo__new util/namespaces.c:160
#3 0x55f427d78ac9 in thread__new util/thread.c:74
#4 0x55f427d7c083 in threads__findnew util/threads.c:116
#5 0x55f427d2957c in __machine__findnew_thread util/machine.c:553
#6 0x55f427d29734 in machine__findnew_thread util/machine.c:577
#7 0x55f427d29a07 in machine__process_comm_event util/machine.c:616
...
#18 0x55f4278326f8 in kvm_events_report_vcpu /home/mike/git/linux/tools/perf/builtin-kvm.c:1636
#19 0x55f427833d77 in kvm_events_report /home/mike/git/linux/tools/perf/builtin-kvm.c:1764
Indirect leak of 24 byte(s) in 1 object(s) allocated from:
#0 0x7ff86bf2bea9 in calloc (/usr/lib/libasan.so.8+0x12bea9) (BuildId: 7f2845989b820f536270e19ec47df085ae89a675)
#1 0x55f42795a0d5 in zalloc ../../lib/zalloc.c:8
#2 0x55f42782d7f4 in per_vcpu_record /home/mike/git/linux/tools/perf/builtin-kvm.c:929
#3 0x55f42782dab7 in handle_kvm_event /home/mike/git/linux/tools/perf/builtin-kvm.c:950
#4 0x55f42782fa80 in process_sample_event /home/mike/git/linux/tools/perf/builtin-kvm.c:1159
...
#14 0x55f42783236c in read_events /home/mike/git/linux/tools/perf/builtin-kvm.c:1591
#15 0x55f4278326f8 in kvm_events_report_vcpu /home/mike/git/linux/tools/perf/builtin-kvm.c:1636
Indirect leak of 8 byte(s) in 1 object(s) allocated from:
#0 0x7ff86bf2c0c1 in malloc (/usr/lib/libasan.so.8+0x12c0c1) (BuildId: 7f2845989b820f536270e19ec47df085ae89a675)
#1 0x55f427d7540f in comm_str__get util/comm.c:58
#2 0x55f427d75ec5 in comm_strs__findnew util/comm.c:189
#3 0x55f427d76056 in comm__override util/comm.c:215
#4 0x55f427d796d1 in ____thread__set_comm util/thread.c:259
#5 0x55f427d797c2 in __thread__set_comm util/thread.c:283
#6 0x55f427d29b7a in machine__process_comm_event util/machine.c:629
...
#16 0x55f42783236c in read_events /home/mike/git/linux/tools/perf/builtin-kvm.c:1591
#17 0x55f4278326f8 in kvm_events_report_vcpu /home/mike/git/linux/tools/perf/builtin-kvm.c:1636
Indirect leak of 8 byte(s) in 1 object(s) allocated from:
#0 0x7ff86bf2c0c1 in malloc (/usr/lib/libasan.so.8+0x12c0c1) (BuildId: 7f2845989b820f536270e19ec47df085ae89a675)
#1 0x55f427d40f8d in maps__get util/maps.c:288
#2 0x55f427d7875f in thread__init_maps util/thread.c:35
#3 0x55f427d295d8 in __machine__findnew_thread util/machine.c:563
#4 0x55f427d29734 in machine__findnew_thread util/machine.c:577
#5 0x55f427d29a07 in machine__process_comm_event util/machine.c:616
...
#15 0x55f42783236c in read_events /home/mike/git/linux/tools/perf/builtin-kvm.c:1591
#16 0x55f4278326f8 in kvm_events_report_vcpu /home/mike/git/linux/tools/perf/builtin-kvm.c:1636
Indirect leak of 8 byte(s) in 1 object(s) allocated from:
#0 0x7ff86bf2c0c1 in malloc (/usr/lib/libasan.so.8+0x12c0c1) (BuildId: 7f2845989b820f536270e19ec47df085ae89a675)
#1 0x55f427d731b6 in nsinfo__alloc util/namespaces.c:147
#2 0x55f427d73275 in nsinfo__new util/namespaces.c:160
#3 0x55f427d78ac9 in thread__new util/thread.c:74
#4 0x55f427d7c083 in threads__findnew util/threads.c:116
#5 0x55f427d2957c in __machine__findnew_thread util/machine.c:553
#6 0x55f427d29734 in machine__findnew_thread util/machine.c:577
#7 0x55f427d29a07 in machine__process_comm_event util/machine.c:616
...
#17 0x55f42783236c in read_events /home/mike/git/linux/tools/perf/builtin-kvm.c:1591
#18 0x55f4278326f8 in kvm_events_report_vcpu /home/mike/git/linux/tools/perf/builtin-kvm.c:1636
SUMMARY: AddressSanitizer: 576 byte(s) leaked in 12 allocation(s).
Signed-off-by: Michalis Niarchos <michael.niarchos@xxxxxxxxx>
---
Michalis Niarchos (2):
perf kvm: Fix memory leak in process_sample_event()
perf kvm: Fix memory leak in cmd_kvm()
tools/perf/builtin-kvm.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
---
base-commit: 7c39d92d52c28686e7ae21eb726dc008fa1b2f0b
change-id: 20260807-perf-kvm-leaks-feca9044a3db
Best regards,
--
Michalis Niarchos <michael.niarchos@xxxxxxxxx>