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| author | Ian Rogers <irogers@google.com> | 2025-09-18 10:24:16 -0700 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2025-09-19 16:53:09 -0300 |
| commit | 0dc96cae063cbf9ebf6631b33b08e9ba02324248 (patch) | |
| tree | 22c4e21aa0b5c8e40ae80aed97e113cacc8b1385 | |
| parent | perf evsel: Ensure the fallback message is always written to (diff) | |
| download | linux-0dc96cae063cbf9ebf6631b33b08e9ba02324248.tar.gz linux-0dc96cae063cbf9ebf6631b33b08e9ba02324248.zip | |
perf build-id: Ensure snprintf string is empty when size is 0
The string result of build_id__snprintf() is unconditionally used in
places like dsos__fprintf_buildid_cb(). If the build id has size 0 then
this creates a use of uninitialized memory. Add null termination for the
size 0 case.
A similar fix was written by Jiri Olsa in commit 6311951d4f8f28c4 ("perf
tools: Initialize output buffer in build_id__sprintf") but lost in the
transition to snprintf.
Fixes: fccaaf6fbbc59910 ("perf build-id: Change sprintf functions to snprintf")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/util/build-id.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c index bf7f3268b9a2..35505a1ffd11 100644 --- a/tools/perf/util/build-id.c +++ b/tools/perf/util/build-id.c @@ -86,6 +86,13 @@ int build_id__snprintf(const struct build_id *build_id, char *bf, size_t bf_size { size_t offs = 0; + if (build_id->size == 0) { + /* Ensure bf is always \0 terminated. */ + if (bf_size > 0) + bf[0] = '\0'; + return 0; + } + for (size_t i = 0; i < build_id->size && offs < bf_size; ++i) offs += snprintf(bf + offs, bf_size - offs, "%02x", build_id->data[i]); |