diff options
Diffstat (limited to 'grp/compat-initgroups.c')
| -rw-r--r-- | grp/compat-initgroups.c | 33 |
1 files changed, 28 insertions, 5 deletions
diff --git a/grp/compat-initgroups.c b/grp/compat-initgroups.c index efd875a689..7bcc203fe4 100644 --- a/grp/compat-initgroups.c +++ b/grp/compat-initgroups.c @@ -8,13 +8,19 @@ typedef enum nss_status (*end_function) (void); typedef enum nss_status (*get_function) (struct group *, char *, size_t, int *); +/* This file is also used in nscd where __libc_alloca_cutoff is not + available. */ +#ifdef NOT_IN_libc +# define __libc_use_alloca(size) ((size) < __MAX_ALLOCA_CUTOFF * 4) +#endif + + static enum nss_status compat_call (service_user *nip, const char *user, gid_t group, long int *start, long int *size, gid_t **groupsp, long int limit, int *errnop) { struct group grpbuf; size_t buflen = __sysconf (_SC_GETGR_R_SIZE_MAX); - char *tmpbuf; enum nss_status status; set_function setgrent_fct; get_function getgrent_fct; @@ -35,7 +41,9 @@ compat_call (service_user *nip, const char *user, gid_t group, long int *start, endgrent_fct = __nss_lookup_function (nip, "endgrent"); - tmpbuf = __alloca (buflen); + char *tmpbuf = __alloca (buflen); + bool use_malloc = false; + enum nss_status result = NSS_STATUS_SUCCESS; do { @@ -44,8 +52,20 @@ compat_call (service_user *nip, const char *user, gid_t group, long int *start, status == NSS_STATUS_TRYAGAIN) && *errnop == ERANGE) { - buflen *= 2; - tmpbuf = __alloca (buflen); + if (__libc_use_alloca (buflen * 2)) + tmpbuf = extend_alloca (tmpbuf, buflen, buflen * 2); + else + { + buflen *= 2; + char *newbuf = realloc (use_malloc ? tmpbuf : NULL, buflen); + if (newbuf == NULL) + { + result = NSS_STATUS_TRYAGAIN; + goto done; + } + use_malloc = true; + tmpbuf = newbuf; + } } if (status != NSS_STATUS_SUCCESS) @@ -102,8 +122,11 @@ compat_call (service_user *nip, const char *user, gid_t group, long int *start, while (status == NSS_STATUS_SUCCESS); done: + if (use_malloc) + free (tmpbuf); + if (endgrent_fct) DL_CALL_FCT (endgrent_fct, ()); - return NSS_STATUS_SUCCESS; + return result; } |