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perf tools: Check for null when copying nsinfo.

PATCH Applied Benno Evers 3 participants 3 messages Aug 10, 2018 – Aug 18, 2018 perf events

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Benno Evers

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#0 lore raw

PATCH v2 1/1 perf tools: Check for null when copying nsinfo.

The argument to nsinfo__copy() was assumed to be valid, but some code paths exist that will lead to NULL being passed.

In particular, running 'perf script -D' on a perf.data file containing an PERF_RECORD_MMAP event associating the '[vdso]' dso with pid 0 earlier in the event stream will lead to a segfault.

Since all calling code is already checking for a non-null return value, just return NULL for this case as well.

Acked-by Namhyung Kim <[email protected]>
Signed-off-by Benno Evers <[email protected]>

---
Changes from v1:
Added Signed-off-by line.

 tools/perf/util/namespaces.c | 3 +++
 1 file changed, 3 insertions(+)
tools/perf/util/namespaces.c +3 -0
index 5be021701f34..cf8bd123cf73 100644
@@ -139,6 +139,9 @@ struct nsinfo *nsinfo__copy(struct nsinfo *nsi)
 {
 	struct nsinfo *nnsi;
 
+	if (nsi == NULL)
+		return NULL;
+
 	nnsi = calloc(1, sizeof(*nnsi));
 	if (nnsi != NULL) {
 		nnsi->pid = nsi->pid;
Signature · 1 line
2.17.1
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#1 lore raw

Em Fri, Aug 10, 2018 at 03:36:13PM +0200, Benno Evers escreveu:

Quoted 7 lines

The argument to nsinfo__copy() was assumed to be valid, but some code paths exist that will lead to NULL being passed.

In particular, running 'perf script -D' on a perf.data file containing an PERF_RECORD_MMAP event associating the '[vdso]' dso with pid 0 earlier in the event stream will lead to a segfault.

Quoted 5 lines

Since all calling code is already checking for a non-null return value, just return NULL for this case as well.

Acked-by Namhyung Kim <[email protected]>
Signed-off-by Benno Evers <[email protected]>

Thanks, applied.

- Arnaldo

merge bot
#2 lore raw
In reply to Benno Evers
perf tools: Check for null when copying nsinfo.
Commit-ID:  3f4417d693b43fa240ac8bde4487f67745ca23d8
Gitweb:     https://git.kernel.org/tip/3f4417d693b43fa240ac8bde4487f67745ca23d8
Author:     Benno Evers <[email protected]>
AuthorDate: Fri, 10 Aug 2018 15:36:13 +0200
Committer:  Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Mon, 13 Aug 2018 15:39:09 -0300

perf tools: Check for null when copying nsinfo.

The argument to nsinfo__copy() was assumed to be valid, but some code paths exist that will lead to NULL being passed.

In particular, running 'perf script -D' on a perf.data file containing an PERF_RECORD_MMAP event associating the '[vdso]' dso with pid 0 earlier in the event stream will lead to a segfault.

Since all calling code is already checking for a non-null return value, just return NULL for this case as well.

Signed-off-by Benno Evers <[email protected]>
Acked-by Namhyung Kim <[email protected]>
Cc Alexander Shishkin <[email protected]>
Cc Jiri Olsa <[email protected]>
Cc Krister Johansen <[email protected]>
Cc Peter Zijlstra <[email protected]>
Link http://lkml.kernel.org/r/[email protected] open here
Signed-off-by Arnaldo Carvalho de Melo <[email protected]>
---
 tools/perf/util/namespaces.c | 3 +++
 1 file changed, 3 insertions(+)
tools/perf/util/namespaces.c +3 -0
index 5be021701f34..cf8bd123cf73 100644
@@ -139,6 +139,9 @@ struct nsinfo *nsinfo__copy(struct nsinfo *nsi)
 {
 	struct nsinfo *nnsi;
 
+	if (nsi == NULL)
+		return NULL;
+
 	nnsi = calloc(1, sizeof(*nnsi));
 	if (nnsi != NULL) {
 		nnsi->pid = nsi->pid;