Hi Martin, On Thu, Jan 16, 2025 at 3:44 PM Martin Storsjö <mar...@martin.st> wrote: > > On Thu, 16 Jan 2025, Sean McGovern wrote: > > > The POSIX specification for strncmp()[1] leaves this behaviour as > > undefined if either pointer argument is NULL. > > > > Prevent a segmentation fault by ensuring 'arg' is non-NULL. > > > > [1] https://pubs.opengroup.org/onlinepubs/9799919799/functions/strncmp.html > > --- > > tests/checkasm/checkasm.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/tests/checkasm/checkasm.c b/tests/checkasm/checkasm.c > > index 14742081ca..4270ed170a 100644 > > --- a/tests/checkasm/checkasm.c > > +++ b/tests/checkasm/checkasm.c > > @@ -952,7 +952,7 @@ int main(int argc, char *argv[]) > > } > > > > for (i = 1; i < argc; i++) { > > - const char *arg = argv[i]; > > + const char *arg = argv[i] != NULL ? argv[i] : ""; > > unsigned long l; > > This feels like less of an issue with strncmp, and more of an issue with > the spec for main() and argc/argv; how do you do to end up with a NULL > entry in argv[i] for 0 <= i < argc?
If 'checkasm' is run without arguments, argv[i] would be NULL since argc == 1. It only really tripped up on GCC with Address Sanitizer enabled, but the comment regarding how POSIX does not require a length check on either argument means we should be defensive. In fact, even 'checkasm --test=blah' triggered the segmentation fault under ASan. -- Sean McGovern _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
