From: Florian Weimer <fweimer@redhat.com>
To: libc-stable@sourceware.org
Subject: [2.30 COMMITTED] nss_compat: internal_end*ent may clobber errno, hiding ERANGE [BZ #25976]
Date: Tue, 19 May 2020 16:52:41 +0200 [thread overview]
Message-ID: <20200519145241.2A2B172C3413@oldenburg2.str.redhat.com> (raw)
During cleanup, before returning from get*_r functions, the end*ent
calls must not change errno. Otherwise, an ERANGE error from the
underlying implementation can be hidden, causing unexpected lookup
failures. This commit introduces an internal_end*ent_noerror
function which saves and restore errno, and marks the original
internal_end*ent function as warn_unused_result, so that it is used
only in contexts were errors from it can be handled explicitly.
Reviewed-by: DJ Delorie <dj@redhat.com>
(cherry picked from commit 790b8dda4455865cb8c3a47801f4304c1a43baf6)
diff --git a/NEWS b/NEWS
index 95d3446954..7a0cd14f80 100644
--- a/NEWS
+++ b/NEWS
@@ -55,6 +55,7 @@ The following bugs are resolved with this release:
[25896] Incorrect prctl
[25902] Bad LOADARGS_N
[25966] Incorrect access of __x86_shared_non_temporal_threshold for x32
+ [25976] nss_compat: internal_end*ent may clobber errno, hiding ERANGE
\f
Version 2.30
diff --git a/nss/nss_compat/compat-grp.c b/nss/nss_compat/compat-grp.c
index 8f01e44a72..32706d8301 100644
--- a/nss/nss_compat/compat-grp.c
+++ b/nss/nss_compat/compat-grp.c
@@ -142,7 +142,7 @@ _nss_compat_setgrent (int stayopen)
}
-static enum nss_status
+static enum nss_status __attribute_warn_unused_result__
internal_endgrent (ent_t *ent)
{
if (ent->stream != NULL)
@@ -163,6 +163,15 @@ internal_endgrent (ent_t *ent)
return NSS_STATUS_SUCCESS;
}
+/* Like internal_endgrent, but preserve errno in all cases. */
+static void
+internal_endgrent_noerror (ent_t *ent)
+{
+ int saved_errno = errno;
+ enum nss_status unused __attribute__ ((unused)) = internal_endgrent (ent);
+ __set_errno (saved_errno);
+}
+
enum nss_status
_nss_compat_endgrent (void)
{
@@ -483,7 +492,7 @@ _nss_compat_getgrnam_r (const char *name, struct group *grp,
if (result == NSS_STATUS_SUCCESS)
result = internal_getgrnam_r (name, grp, &ent, buffer, buflen, errnop);
- internal_endgrent (&ent);
+ internal_endgrent_noerror (&ent);
return result;
}
@@ -612,7 +621,7 @@ _nss_compat_getgrgid_r (gid_t gid, struct group *grp,
if (result == NSS_STATUS_SUCCESS)
result = internal_getgrgid_r (gid, grp, &ent, buffer, buflen, errnop);
- internal_endgrent (&ent);
+ internal_endgrent_noerror (&ent);
return result;
}
diff --git a/nss/nss_compat/compat-initgroups.c b/nss/nss_compat/compat-initgroups.c
index b1df6a4e43..1e6452e97a 100644
--- a/nss/nss_compat/compat-initgroups.c
+++ b/nss/nss_compat/compat-initgroups.c
@@ -133,7 +133,7 @@ internal_setgrent (ent_t *ent)
}
-static enum nss_status
+static enum nss_status __attribute_warn_unused_result__
internal_endgrent (ent_t *ent)
{
if (ent->stream != NULL)
@@ -157,6 +157,15 @@ internal_endgrent (ent_t *ent)
return NSS_STATUS_SUCCESS;
}
+/* Like internal_endgrent, but preserve errno in all cases. */
+static void
+internal_endgrent_noerror (ent_t *ent)
+{
+ int saved_errno = errno;
+ enum nss_status unused __attribute__ ((unused)) = internal_endgrent (ent);
+ __set_errno (saved_errno);
+}
+
/* Add new group record. */
static void
add_group (long int *start, long int *size, gid_t **groupsp, long int limit,
@@ -501,7 +510,7 @@ _nss_compat_initgroups_dyn (const char *user, gid_t group, long int *start,
done:
scratch_buffer_free (&tmpbuf);
- internal_endgrent (&intern);
+ internal_endgrent_noerror (&intern);
return status;
}
diff --git a/nss/nss_compat/compat-pwd.c b/nss/nss_compat/compat-pwd.c
index 37f883f35a..d24addef5b 100644
--- a/nss/nss_compat/compat-pwd.c
+++ b/nss/nss_compat/compat-pwd.c
@@ -259,7 +259,7 @@ _nss_compat_setpwent (int stayopen)
}
-static enum nss_status
+static enum nss_status __attribute_warn_unused_result__
internal_endpwent (ent_t *ent)
{
if (ent->stream != NULL)
@@ -287,6 +287,15 @@ internal_endpwent (ent_t *ent)
return NSS_STATUS_SUCCESS;
}
+/* Like internal_endpwent, but preserve errno in all cases. */
+static void
+internal_endpwent_noerror (ent_t *ent)
+{
+ int saved_errno = errno;
+ enum nss_status unused __attribute__ ((unused)) = internal_endpwent (ent);
+ __set_errno (saved_errno);
+}
+
enum nss_status
_nss_compat_endpwent (void)
{
@@ -822,7 +831,7 @@ _nss_compat_getpwnam_r (const char *name, struct passwd *pwd,
if (result == NSS_STATUS_SUCCESS)
result = internal_getpwnam_r (name, pwd, &ent, buffer, buflen, errnop);
- internal_endpwent (&ent);
+ internal_endpwent_noerror (&ent);
return result;
}
@@ -1061,7 +1070,7 @@ _nss_compat_getpwuid_r (uid_t uid, struct passwd *pwd,
if (result == NSS_STATUS_SUCCESS)
result = internal_getpwuid_r (uid, pwd, &ent, buffer, buflen, errnop);
- internal_endpwent (&ent);
+ internal_endpwent_noerror (&ent);
return result;
}
diff --git a/nss/nss_compat/compat-spwd.c b/nss/nss_compat/compat-spwd.c
index bd310ab9aa..6c4d958a40 100644
--- a/nss/nss_compat/compat-spwd.c
+++ b/nss/nss_compat/compat-spwd.c
@@ -215,7 +215,7 @@ _nss_compat_setspent (int stayopen)
}
-static enum nss_status
+static enum nss_status __attribute_warn_unused_result__
internal_endspent (ent_t *ent)
{
if (ent->stream != NULL)
@@ -244,6 +244,15 @@ internal_endspent (ent_t *ent)
return NSS_STATUS_SUCCESS;
}
+/* Like internal_endspent, but preserve errno in all cases. */
+static void
+internal_endspent_noerror (ent_t *ent)
+{
+ int saved_errno = errno;
+ enum nss_status unused __attribute__ ((unused)) = internal_endspent (ent);
+ __set_errno (saved_errno);
+}
+
enum nss_status
_nss_compat_endspent (void)
{
@@ -261,7 +270,6 @@ _nss_compat_endspent (void)
return result;
}
-
static enum nss_status
getspent_next_nss_netgr (const char *name, struct spwd *result, ent_t *ent,
char *group, char *buffer, size_t buflen,
@@ -786,7 +794,7 @@ _nss_compat_getspnam_r (const char *name, struct spwd *pwd,
if (result == NSS_STATUS_SUCCESS)
result = internal_getspnam_r (name, pwd, &ent, buffer, buflen, errnop);
- internal_endspent (&ent);
+ internal_endspent_noerror (&ent);
return result;
}
reply other threads:[~2020-05-19 14:53 UTC|newest]
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