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authorSohom Datta <sohomdatta1@gmail.com>2022-12-04 16:28:35 +0530
committerArnaldo Carvalho de Melo <acme@redhat.com>2023-01-18 10:33:00 -0300
commit85c44913969bd27f15229c39383da1291800d7e9 (patch)
tree491b75227f34dd06a6012d4ab502ba3dc72f874c
parentc905ecfbb8e5d54bbcdd2a1706b925baf1728cfe (diff)
downloadlinux-85c44913969bd27f15229c39383da1291800d7e9.tar.bz2
perf expr: Prevent normalize() from reading into undefined memory in the expression lexer
The current implementation does not account for a trailing backslash followed by a null-byte. If a null-byte is encountered following a backslash, normalize() will continue reading (and potentially writing) into garbage memory ignoring the EOS null-byte. Signed-off-by: Sohom Datta <sohomdatta1+git@gmail.com> Acked-by: Ian Rogers <irogers@google.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20221204105836.1012885-1-sohomdatta1+git@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-rw-r--r--tools/perf/util/expr.l5
1 files changed, 4 insertions, 1 deletions
diff --git a/tools/perf/util/expr.l b/tools/perf/util/expr.l
index 0168a9637330..d47de5f270a8 100644
--- a/tools/perf/util/expr.l
+++ b/tools/perf/util/expr.l
@@ -42,8 +42,11 @@ static char *normalize(char *str, int runtime)
char *dst = str;
while (*str) {
- if (*str == '\\')
+ if (*str == '\\') {
*dst++ = *++str;
+ if (!*str)
+ break;
+ }
else if (*str == '?') {
char *paramval;
int i = 0;