On Thu, Apr 03, 2025 at 09:04:43PM +0200, Stefano Brivio wrote:After 3d41e4d83895 ("passt-repair: Correct off-by-one error verifying name"), Coverity Scan isn't convinced anymore about the fact that the ev->name used in the snprintf() is NULL-terminated.Aww, man :(It comes from a read() call, and read() of course doesn't terminate it, but we already check that the byte at ev->len - 1 is a NULL terminator, so this is actually a false positive.Indeed. I'm kind of baffled that it's able to reason it out with the off-by-one, but not without.In any case, the logic ensuring that ev->name is NULL-terminated isn't necessarily obvious, and additionally checking that the last byte in the buffer we read is a NULL terminator is harmless, so do that explicitly, even if it's redundant. Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com>Vexing that it's necessary, but Reviewed-by: David Gibson <david(a)gibson.dropbear.id.au>--- passt-repair.c | 1 + 1 file changed, 1 insertion(+) diff --git a/passt-repair.c b/passt-repair.c index 440c77a..256a8c9 100644 --- a/passt-repair.c +++ b/passt-repair.c @@ -137,6 +137,7 @@ int main(int argc, char **argv) fprintf(stderr, "inotify read: %i", errno); _exit(1); } + buf[n - 1] = '\0'; if (n < (ssize_t)sizeof(*ev)) { fprintf(stderr, "Short inotify read: %zi", n);-- David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson