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authorMitchell Krome <mitchellkrome@gmail.com>2014-12-16 12:16:12 +1000
committerArnaldo Carvalho de Melo <acme@redhat.com>2014-12-17 11:58:17 -0300
commit7ad74b41e56e4f7f42c6b765bc44428cd09310d7 (patch)
treed8e8763a585680ce52245c93c764f3eff124f3df
parent91529834d1dea9afccb72843c3e547e703ec177f (diff)
perf symbols: Fix use after free in filename__read_build_id
In filename__read_build_id, phdr points to memory in buf, which gets realloced before a call to fseek that uses phdr->p_offset. This change stores the value of p_offset before buf is realloced, so the fseek can use the value safely. Signed-off-by: Mitchell Krome <mitchellkrome@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20141216021612.GA7199@mitchell Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-rw-r--r--tools/perf/util/symbol-minimal.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/tools/perf/util/symbol-minimal.c b/tools/perf/util/symbol-minimal.c
index fa585c63f56a..d7efb03b3f9a 100644
--- a/tools/perf/util/symbol-minimal.c
+++ b/tools/perf/util/symbol-minimal.c
@@ -129,6 +129,7 @@ int filename__read_build_id(const char *filename, void *bf, size_t size)
for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) {
void *tmp;
+ long offset;
if (need_swap) {
phdr->p_type = bswap_32(phdr->p_type);
@@ -140,12 +141,13 @@ int filename__read_build_id(const char *filename, void *bf, size_t size)
continue;
buf_size = phdr->p_filesz;
+ offset = phdr->p_offset;
tmp = realloc(buf, buf_size);
if (tmp == NULL)
goto out_free;
buf = tmp;
- fseek(fp, phdr->p_offset, SEEK_SET);
+ fseek(fp, offset, SEEK_SET);
if (fread(buf, buf_size, 1, fp) != 1)
goto out_free;
@@ -178,6 +180,7 @@ int filename__read_build_id(const char *filename, void *bf, size_t size)
for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) {
void *tmp;
+ long offset;
if (need_swap) {
phdr->p_type = bswap_32(phdr->p_type);
@@ -189,12 +192,13 @@ int filename__read_build_id(const char *filename, void *bf, size_t size)
continue;
buf_size = phdr->p_filesz;
+ offset = phdr->p_offset;
tmp = realloc(buf, buf_size);
if (tmp == NULL)
goto out_free;
buf = tmp;
- fseek(fp, phdr->p_offset, SEEK_SET);
+ fseek(fp, offset, SEEK_SET);
if (fread(buf, buf_size, 1, fp) != 1)
goto out_free;