Messages in this thread | | | Subject | Re: [PATCH][V2] selftests/resctrl: Fix null pointer dereference on open failed | From | Shuah Khan <> | Date | Tue, 26 Apr 2022 09:21:55 -0600 |
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On 4/26/22 6:25 AM, Colin Ian King wrote: > 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> > --- > > V2: Add cppcheck analysis information > > --- > tools/testing/selftests/resctrl/fill_buf.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > 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); > >
Thank you. Applied to linux-kselftest next for Linux 5.19-rc1
thanks, -- Shuah
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