[PATCH] tlshd: fix max config file size comparison

[PATCH] tlshd: fix max config file size comparison

[Jeff Layton]

gcc throws a warning on 32-bit x86 because of signedness mismatch:

config.c:155:52: error: comparison of integer expressions of different signedness: '__off_t' {aka 'long int'} and 'unsigned int' [-Werror=sign-compare]
  155 |         if (statbuf.st_size < 0 || statbuf.st_size > UINT_MAX) {
      |                                                    ^

st_size is a signed value (off_t), but UINT_MAX is unsigned.

Change it to compare against INT_MAX instead. This technically cuts the
max size of the config file in half to only 2GB, but I don't think we'll
miss it.

Cc: Steve Dickson <steved@redhat.com>
Reported-by: Petr Pisar <ppisar@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 src/tlshd/config.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tlshd/config.c b/src/tlshd/config.c
index 87cc4018733b..bdab98b9fba4 100644
--- a/src/tlshd/config.c
+++ b/src/tlshd/config.c
@@ -152,7 +152,7 @@ static bool tlshd_config_read_datum(const char *pathname, gnutls_datum_t *data,
 		tlshd_log_perror("stat");
 		goto out_close;
 	}
-	if (statbuf.st_size < 0 || statbuf.st_size > UINT_MAX) {
+	if (statbuf.st_size < 0 || statbuf.st_size > INT_MAX) {
 		tlshd_log_error("Bad config file size: %lld", statbuf.st_size);
 		goto out_close;
 	}
-- 
2.41.0

Re: [PATCH] tlshd: fix max config file size comparison

[Chuck Lever III]

> On Jun 20, 2023, at 1:20 PM, Jeff Layton <jlayton@kernel.org> wrote:
> 
> gcc throws a warning on 32-bit x86 because of signedness mismatch:
> 
> config.c:155:52: error: comparison of integer expressions of different signedness: '__off_t' {aka 'long int'} and 'unsigned int' [-Werror=sign-compare]
>  155 |         if (statbuf.st_size < 0 || statbuf.st_size > UINT_MAX) {
>      |                                                    ^
> 
> st_size is a signed value (off_t), but UINT_MAX is unsigned.
> 
> Change it to compare against INT_MAX instead. This technically cuts the
> max size of the config file in half to only 2GB, but I don't think we'll
> miss it.
> 
> Cc: Steve Dickson <steved@redhat.com>
> Reported-by: Petr Pisar <ppisar@redhat.com>
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
> src/tlshd/config.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/tlshd/config.c b/src/tlshd/config.c
> index 87cc4018733b..bdab98b9fba4 100644
> --- a/src/tlshd/config.c
> +++ b/src/tlshd/config.c
> @@ -152,7 +152,7 @@ static bool tlshd_config_read_datum(const char *pathname, gnutls_datum_t *data,
> tlshd_log_perror("stat");
> goto out_close;
> }
> - if (statbuf.st_size < 0 || statbuf.st_size > UINT_MAX) {
> + if (statbuf.st_size < 0 || statbuf.st_size > INT_MAX) {
> tlshd_log_error("Bad config file size: %lld", statbuf.st_size);
> goto out_close;
> }

Opened version ktls-utils-0.10-dev and applied this fix to oracle/ktls-utils.


--
Chuck Lever