tools/perf/util/symbol-minimal.c | 34 +++++++++++++++++--------------- 1 file changed, 18 insertions(+), 16 deletions(-)
Running the "perf script task-analyzer tests" with address sanitizer
showed a double free:
```
FAIL: "test_csv_extended_times" Error message: "Failed to find required string:'Out-Out;'."
=================================================================
==19190==ERROR: AddressSanitizer: attempting double-free on 0x50b000017b10 in thread T0:
#0 0x55da9601c78a in free (perf+0x26078a) (BuildId: e7ef50e08970f017a96fde6101c5e2491acc674a)
#1 0x55da96640c63 in filename__read_build_id tools/perf/util/symbol-minimal.c:221:2
0x50b000017b10 is located 0 bytes inside of 112-byte region [0x50b000017b10,0x50b000017b80)
freed by thread T0 here:
#0 0x55da9601ce40 in realloc (perf+0x260e40) (BuildId: e7ef50e08970f017a96fde6101c5e2491acc674a)
#1 0x55da96640ad6 in filename__read_build_id tools/perf/util/symbol-minimal.c:204:10
previously allocated by thread T0 here:
#0 0x55da9601ca23 in malloc (perf+0x260a23) (BuildId: e7ef50e08970f017a96fde6101c5e2491acc674a)
#1 0x55da966407e7 in filename__read_build_id tools/perf/util/symbol-minimal.c:181:9
SUMMARY: AddressSanitizer: double-free (perf+0x26078a) (BuildId: e7ef50e08970f017a96fde6101c5e2491acc674a) in free
==19190==ABORTING
FAIL: "invocation of perf script report task-analyzer --csv-summary csvsummary --summary-extended command failed" Error message: ""
FAIL: "test_csvsummary_extended" Error message: "Failed to find required string:'Out-Out;'."
---- end(-1) ----
132: perf script task-analyzer tests : FAILED!
```
The buf_size if always set to phdr->p_filesz, but that may be 0
causing a free and realloc to return NULL. This is treated in
filename__read_build_id like a failure and the buffer is freed again.
To avoid this problem only grow buf, meaning the buf_size will never
be 0. This also reduces the number of memory (re)allocations.
Fixes: b691f64360ec ("perf symbols: Implement poor man's ELF parser")
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/util/symbol-minimal.c | 34 +++++++++++++++++---------------
1 file changed, 18 insertions(+), 16 deletions(-)
diff --git a/tools/perf/util/symbol-minimal.c b/tools/perf/util/symbol-minimal.c
index c6f369b5d893..d8da3da01fe6 100644
--- a/tools/perf/util/symbol-minimal.c
+++ b/tools/perf/util/symbol-minimal.c
@@ -147,18 +147,19 @@ int filename__read_build_id(const char *filename, struct build_id *bid)
if (phdr->p_type != PT_NOTE)
continue;
- buf_size = phdr->p_filesz;
offset = phdr->p_offset;
- tmp = realloc(buf, buf_size);
- if (tmp == NULL)
- goto out_free;
-
- buf = tmp;
+ if (phdr->p_filesz > buf_size) {
+ buf_size = phdr->p_filesz;
+ tmp = realloc(buf, buf_size);
+ if (tmp == NULL)
+ goto out_free;
+ buf = tmp;
+ }
fseek(fp, offset, SEEK_SET);
- if (fread(buf, buf_size, 1, fp) != 1)
+ if (fread(buf, phdr->p_filesz, 1, fp) != 1)
goto out_free;
- ret = read_build_id(buf, buf_size, bid, need_swap);
+ ret = read_build_id(buf, phdr->p_filesz, bid, need_swap);
if (ret == 0) {
ret = bid->size;
break;
@@ -199,18 +200,19 @@ int filename__read_build_id(const char *filename, struct build_id *bid)
if (phdr->p_type != PT_NOTE)
continue;
- buf_size = phdr->p_filesz;
offset = phdr->p_offset;
- tmp = realloc(buf, buf_size);
- if (tmp == NULL)
- goto out_free;
-
- buf = tmp;
+ if (phdr->p_filesz > buf_size) {
+ buf_size = phdr->p_filesz;
+ tmp = realloc(buf, buf_size);
+ if (tmp == NULL)
+ goto out_free;
+ buf = tmp;
+ }
fseek(fp, offset, SEEK_SET);
- if (fread(buf, buf_size, 1, fp) != 1)
+ if (fread(buf, phdr->p_filesz, 1, fp) != 1)
goto out_free;
- ret = read_build_id(buf, buf_size, bid, need_swap);
+ ret = read_build_id(buf, phdr->p_filesz, bid, need_swap);
if (ret == 0) {
ret = bid->size;
break;
--
2.49.0.967.g6a0df3ecc3-googHi Ian,
On Thu, May 01, 2025 at 12:00:03AM -0700, Ian Rogers wrote:
> Running the "perf script task-analyzer tests" with address sanitizer
> showed a double free:
> ```
> FAIL: "test_csv_extended_times" Error message: "Failed to find required string:'Out-Out;'."
> =================================================================
> ==19190==ERROR: AddressSanitizer: attempting double-free on 0x50b000017b10 in thread T0:
> #0 0x55da9601c78a in free (perf+0x26078a) (BuildId: e7ef50e08970f017a96fde6101c5e2491acc674a)
> #1 0x55da96640c63 in filename__read_build_id tools/perf/util/symbol-minimal.c:221:2
>
> 0x50b000017b10 is located 0 bytes inside of 112-byte region [0x50b000017b10,0x50b000017b80)
> freed by thread T0 here:
> #0 0x55da9601ce40 in realloc (perf+0x260e40) (BuildId: e7ef50e08970f017a96fde6101c5e2491acc674a)
> #1 0x55da96640ad6 in filename__read_build_id tools/perf/util/symbol-minimal.c:204:10
>
> previously allocated by thread T0 here:
> #0 0x55da9601ca23 in malloc (perf+0x260a23) (BuildId: e7ef50e08970f017a96fde6101c5e2491acc674a)
> #1 0x55da966407e7 in filename__read_build_id tools/perf/util/symbol-minimal.c:181:9
>
> SUMMARY: AddressSanitizer: double-free (perf+0x26078a) (BuildId: e7ef50e08970f017a96fde6101c5e2491acc674a) in free
> ==19190==ABORTING
> FAIL: "invocation of perf script report task-analyzer --csv-summary csvsummary --summary-extended command failed" Error message: ""
> FAIL: "test_csvsummary_extended" Error message: "Failed to find required string:'Out-Out;'."
> ---- end(-1) ----
> 132: perf script task-analyzer tests : FAILED!
> ```
>
> The buf_size if always set to phdr->p_filesz, but that may be 0
> causing a free and realloc to return NULL. This is treated in
> filename__read_build_id like a failure and the buffer is freed again.
>
> To avoid this problem only grow buf, meaning the buf_size will never
> be 0. This also reduces the number of memory (re)allocations.
Thanks for fixing this!
Acked-by: Namhyung Kim <namhyung@kernel.org>
Thanks,
Namhyung
>
> Fixes: b691f64360ec ("perf symbols: Implement poor man's ELF parser")
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
> tools/perf/util/symbol-minimal.c | 34 +++++++++++++++++---------------
> 1 file changed, 18 insertions(+), 16 deletions(-)
>
> diff --git a/tools/perf/util/symbol-minimal.c b/tools/perf/util/symbol-minimal.c
> index c6f369b5d893..d8da3da01fe6 100644
> --- a/tools/perf/util/symbol-minimal.c
> +++ b/tools/perf/util/symbol-minimal.c
> @@ -147,18 +147,19 @@ int filename__read_build_id(const char *filename, struct build_id *bid)
> if (phdr->p_type != PT_NOTE)
> continue;
>
> - buf_size = phdr->p_filesz;
> offset = phdr->p_offset;
> - tmp = realloc(buf, buf_size);
> - if (tmp == NULL)
> - goto out_free;
> -
> - buf = tmp;
> + if (phdr->p_filesz > buf_size) {
> + buf_size = phdr->p_filesz;
> + tmp = realloc(buf, buf_size);
> + if (tmp == NULL)
> + goto out_free;
> + buf = tmp;
> + }
> fseek(fp, offset, SEEK_SET);
> - if (fread(buf, buf_size, 1, fp) != 1)
> + if (fread(buf, phdr->p_filesz, 1, fp) != 1)
> goto out_free;
>
> - ret = read_build_id(buf, buf_size, bid, need_swap);
> + ret = read_build_id(buf, phdr->p_filesz, bid, need_swap);
> if (ret == 0) {
> ret = bid->size;
> break;
> @@ -199,18 +200,19 @@ int filename__read_build_id(const char *filename, struct build_id *bid)
> if (phdr->p_type != PT_NOTE)
> continue;
>
> - buf_size = phdr->p_filesz;
> offset = phdr->p_offset;
> - tmp = realloc(buf, buf_size);
> - if (tmp == NULL)
> - goto out_free;
> -
> - buf = tmp;
> + if (phdr->p_filesz > buf_size) {
> + buf_size = phdr->p_filesz;
> + tmp = realloc(buf, buf_size);
> + if (tmp == NULL)
> + goto out_free;
> + buf = tmp;
> + }
> fseek(fp, offset, SEEK_SET);
> - if (fread(buf, buf_size, 1, fp) != 1)
> + if (fread(buf, phdr->p_filesz, 1, fp) != 1)
> goto out_free;
>
> - ret = read_build_id(buf, buf_size, bid, need_swap);
> + ret = read_build_id(buf, phdr->p_filesz, bid, need_swap);
> if (ret == 0) {
> ret = bid->size;
> break;
> --
> 2.49.0.967.g6a0df3ecc3-goog
>
On Thu, May 01, 2025 at 01:25:27PM -0700, Namhyung Kim wrote: > Hi Ian, > > On Thu, May 01, 2025 at 12:00:03AM -0700, Ian Rogers wrote: > > Running the "perf script task-analyzer tests" with address sanitizer > > showed a double free: > > ``` > > FAIL: "test_csv_extended_times" Error message: "Failed to find required string:'Out-Out;'." > > ================================================================= > > ==19190==ERROR: AddressSanitizer: attempting double-free on 0x50b000017b10 in thread T0: > > #0 0x55da9601c78a in free (perf+0x26078a) (BuildId: e7ef50e08970f017a96fde6101c5e2491acc674a) > > #1 0x55da96640c63 in filename__read_build_id tools/perf/util/symbol-minimal.c:221:2 > > > > 0x50b000017b10 is located 0 bytes inside of 112-byte region [0x50b000017b10,0x50b000017b80) > > freed by thread T0 here: > > #0 0x55da9601ce40 in realloc (perf+0x260e40) (BuildId: e7ef50e08970f017a96fde6101c5e2491acc674a) > > #1 0x55da96640ad6 in filename__read_build_id tools/perf/util/symbol-minimal.c:204:10 > > > > previously allocated by thread T0 here: > > #0 0x55da9601ca23 in malloc (perf+0x260a23) (BuildId: e7ef50e08970f017a96fde6101c5e2491acc674a) > > #1 0x55da966407e7 in filename__read_build_id tools/perf/util/symbol-minimal.c:181:9 > > > > SUMMARY: AddressSanitizer: double-free (perf+0x26078a) (BuildId: e7ef50e08970f017a96fde6101c5e2491acc674a) in free > > ==19190==ABORTING > > FAIL: "invocation of perf script report task-analyzer --csv-summary csvsummary --summary-extended command failed" Error message: "" > > FAIL: "test_csvsummary_extended" Error message: "Failed to find required string:'Out-Out;'." > > ---- end(-1) ---- > > 132: perf script task-analyzer tests : FAILED! > > ``` > > > > The buf_size if always set to phdr->p_filesz, but that may be 0 > > causing a free and realloc to return NULL. This is treated in > > filename__read_build_id like a failure and the buffer is freed again. > > > > To avoid this problem only grow buf, meaning the buf_size will never > > be 0. This also reduces the number of memory (re)allocations. > > Thanks for fixing this! > > Acked-by: Namhyung Kim <namhyung@kernel.org> Thanks, applied to perf-tools-next, - Arnaldo
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