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authorColin Ian King <colin.i.king@gmail.com>2022-04-26 13:25:31 +0100
committerShuah Khan <skhan@linuxfoundation.org>2022-04-26 09:20:00 -0600
commitc7b607fa9325ccc94982774c505176677117689c (patch)
tree33b334994df733d8f2a6f69acdca66d1312c0072 /tools/testing/selftests/resctrl
parent68c4844985d1f8c1b1a71dfcdbfacb5a30babc95 (diff)
selftests/resctrl: Fix null pointer dereference on open failed
Currently if opening /dev/null fails to open then file pointer fp is null and further access to fp via fprintf will cause a null pointer dereference. Fix this by returning a negative error value when a null fp is detected. Detected using cppcheck static analysis: tools/testing/selftests/resctrl/fill_buf.c:124:6: note: Assuming that condition '!fp' is not redundant if (!fp) ^ tools/testing/selftests/resctrl/fill_buf.c:126:10: note: Null pointer dereference fprintf(fp, "Sum: %d ", ret); Fixes: a2561b12fe39 ("selftests/resctrl: Add built in benchmark") Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Diffstat (limited to 'tools/testing/selftests/resctrl')
-rw-r--r--tools/testing/selftests/resctrl/fill_buf.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/tools/testing/selftests/resctrl/fill_buf.c b/tools/testing/selftests/resctrl/fill_buf.c
index 51e5cf22632f..56ccbeae0638 100644
--- a/tools/testing/selftests/resctrl/fill_buf.c
+++ b/tools/testing/selftests/resctrl/fill_buf.c
@@ -121,8 +121,10 @@ static int fill_cache_read(unsigned char *start_ptr, unsigned char *end_ptr,
/* Consume read result so that reading memory is not optimized out. */
fp = fopen("/dev/null", "w");
- if (!fp)
+ if (!fp) {
perror("Unable to write to /dev/null");
+ return -1;
+ }
fprintf(fp, "Sum: %d ", ret);
fclose(fp);