Le 4/01/19 à 16:11, Stephen Smalley a écrit :
On Wed, 2019-01-02 at 15:30 +0100, Laurent Bigonville wrote:
Le 2/01/19 à 14:46, Laurent Bigonville a écrit :
From: Laurent Bigonville <bigon@xxxxxxxx>
The manpage explicitly states that:
The getpwent() function returns a pointer to a passwd
structure, or
NULL if there are no more entries or an error occurred. If an
error
occurs, errno is set appropriately. If one wants to check errno
after
the call, it should be set to zero before the call.
Without this, genhomedircon can wrongly return the following:
libsemanage.get_home_dirs: Error while fetching
users. Returning list so far.
https://github.com/SELinuxProject/selinux/issues/121
Signed-off-by: Laurent Bigonville <bigon@xxxxxxxx>
---
libsemanage/src/genhomedircon.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/libsemanage/src/genhomedircon.c
b/libsemanage/src/genhomedircon.c
index 3e61b510..591941fb 100644
--- a/libsemanage/src/genhomedircon.c
+++ b/libsemanage/src/genhomedircon.c
@@ -361,7 +361,11 @@ static semanage_list_t
*get_home_dirs(genhomedircon_settings_t * s)
errno = 0;
setpwent();
- while ((pwbuf = getpwent()) != NULL) {
+ while (1) {
+ errno = 0;
+ pwbuf = getpwent();
+ if (pwbuf == NULL)
+ break;
if (pwbuf->pw_uid < minuid || pwbuf->pw_uid > maxuid)
continue;
if (!semanage_list_find(shells, pwbuf->pw_shell))
@@ -403,7 +407,6 @@ static semanage_list_t
*get_home_dirs(genhomedircon_settings_t * s)
}
free(path);
path = NULL;
- errno = 0;
Actually I'm wondering if this shouldn't stay there
Why?
According to strdup() manpage, it can also change errno, isn't there a
risk that errno is changed to an non-zero value and then causing the
warning below to be printed?
}
if (errno) {
@@ -1101,7 +1104,11 @@ static int
get_group_users(genhomedircon_settings_t * s,
}
setpwent();
- while ((pw = getpwent()) != NULL) {
+ while (1) {
+ errno = 0;
+ pw = getpwent();
+ if (pw == NULL)
+ break;
// skip users who also have this group as their
// primary group
if (lfind(pw->pw_name, group->gr_mem, &nmembers,
