perf trace: Really free the evsel->priv area

Vulnerability Description

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".

References

• https://git.kernel.org/stable/c/c3bc668581e71e7c3bc7eb1d647f25f8db222163
• https://git.kernel.org/stable/c/62dd514c34be63d3d5cae1f52a7e8b96c6dd6630
• https://git.kernel.org/stable/c/27f396f64537b1ae48d0644d7cbf0d250b3c0b33
• https://git.kernel.org/stable/c/7962ef13651a9163f07b530607392ea123482e8a