CVE-2023-53649

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 wasnt 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.

Weakness

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

Affected Software

Potential Mitigations

• Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
• For example, glibc in Linux provides protection against free of invalid pointers.
• When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391].
• To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.

References

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