from getpwnam_r(3): "The call sysconf(_SC_GETPW_R_SIZE_MAX) returns
either -1, without changing errno, or an initial suggested size for buf.
(If this size is too small, the call fails with ERANGE, in which case
the caller can retry with a larger buffer.)"
The same can happen for _SC_GETGR_R_SIZE_MAX. 1024 appears to be a good
fallback but may need revisiting in the future.
This triggered an error on musl libc but could happen other places too.
Signed-off-by: Jason Zaman <ja...@perfinion.com>
---
libsemanage/src/genhomedircon.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/libsemanage/src/genhomedircon.c b/libsemanage/src/genhomedircon.c
index d09d82ff..3e61b510 100644
--- a/libsemanage/src/genhomedircon.c
+++ b/libsemanage/src/genhomedircon.c
@@ -972,9 +972,13 @@ static int add_user(genhomedircon_settings_t * s,
char uid[11];
char gid[11];
+ errno = 0;
/* Allocate space for the getpwnam_r buffer */
rbuflen = sysconf(_SC_GETPW_R_SIZE_MAX);
- if (rbuflen <= 0)
+ if (rbuflen == -1 && errno == 0)
+ /* sysconf returning -1 with no errno means indeterminate size
*/
+ rbuflen = 1024;
+ else if (rbuflen <= 0)
goto cleanup;
rbuf = malloc(rbuflen);
if (rbuf == NULL)
@@ -1057,8 +1061,12 @@ static int get_group_users(genhomedircon_settings_t * s,
struct group grstorage, *group = NULL;
struct passwd *pw = NULL;
+ errno = 0;
grbuflen = sysconf(_SC_GETGR_R_SIZE_MAX);
- if (grbuflen <= 0)
+ if (grbuflen == -1 && errno == 0)
+ /* sysconf returning -1 with no errno means indeterminate size
*/
+ grbuflen = 1024;
+ else if (grbuflen <= 0)
goto cleanup;
grbuf = malloc(grbuflen);
if (grbuf == NULL)
--
2.16.1
