tools/perf: use local variable for segment file offset

PATCH New Romeo Cane 1 participant 1 message Oct 2, 2014 perf events

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Romeo Cane

author

2014-10-02 14:59 UTC #0 lore raw

PATCH 1/1 tools/perf: use local variable for segment file offset

The value of phdr->p_offset is stored inside a buffer that gets reallocated, so it could become corrupted if the new size isn't big enough to contain it

Signed-off-by Romeo Cane <[email protected]>

---
 tools/perf/util/symbol-minimal.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

tools/perf/util/symbol-minimal.c +6 -2

index c9541fe..bf13e46 100644
@@ -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;
+			Elf32_Off tmp_off;
 
 			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;
+			tmp_off = 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, tmp_off, 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;
+			Elf64_Off tmp_off;
 
 			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;
+			tmp_off = 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, tmp_off, SEEK_SET);
 			if (fread(buf, buf_size, 1, fp) != 1)
 				goto out_free;

Signature · 1 line

1.8.3.2