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GNU C Library master sources branch ibm/2.20/master updated. glibc-2.20-53-g0a512fb
- From: tuliom at sourceware dot org
- To: glibc-cvs at sourceware dot org
- Date: 25 May 2015 19:17:10 -0000
- Subject: GNU C Library master sources branch ibm/2.20/master updated. glibc-2.20-53-g0a512fb
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http://sourceware.org/git/gitweb.cgi?p=glibc.git;a=commitdiff;h=0a512fb591621e2c26efaf5ecc95e87763978386
commit 0a512fb591621e2c26efaf5ecc95e87763978386
Author: Andreas Schwab <schwab@suse.de>
Date: Wed Mar 25 16:35:46 2015 +0100
Separate internal state between getXXent and getXXbyYY NSS calls (bug 18007)
Conflicts:
NEWS
diff --git a/ChangeLog b/ChangeLog
index 8b13f7b..f57928e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,41 @@
+2015-05-11 Andreas Schwab <schwab@suse.de>
+
+ [BZ #18007]
+ * nis/nss_compat/compat-grp.c (internal_endgrent): Don't call
+ nss_endgrent.
+ (_nss_compat_endgrent): Call nss_endgrent.
+ * nis/nss_compat/compat-pwd.c (internal_endpwent): Don't call
+ nss_endpwent.
+ (_nss_compat_endpwent): Call nss_endpwent.
+ * nis/nss_compat/compat-spwd.c (internal_setspent): Add parameter
+ needent, call nss_setspent only if non-zero.
+ (_nss_compat_setspent, _nss_compat_getspent_r): Pass non-zero.
+ (internal_endspent): Don't call nss_endspent.
+ (_nss_compat_endspent): Call nss_endspent.
+ * nss/nss_files/files-XXX.c (position, last_use, keep_stream):
+ Remove. All uses removed.
+ (internal_setent): Remove parameter stayopen, add parameter
+ stream. Use it instead of global variable.
+ (CONCAT(_nss_files_set,ENTNAME)): Pass global stream.
+ (internal_endent, internal_getent): Add parameter stream. Use it
+ instead of global variable.
+ (CONCAT(_nss_files_end,ENTNAME))
+ (CONCAT(_nss_files_get,ENTNAME_r)): Pass global stream.
+ (_nss_files_get##name##_r): Pass local stream. Remove locking.
+ * nss/nss_files/files-alias.c (position, last_use): Remove. All
+ uses removed.
+ (internal_setent, internal_endent): Add parameter stream. Use it
+ instead of global variable.
+ (_nss_files_setaliasent, _nss_files_endaliasent): Pass global
+ stream.
+ (get_next_alias): Add parameter stream.
+ (_nss_files_getaliasent_r): Pass global stream.
+ (_nss_files_getaliasbyname_r): Pass local stream. Remove locking.
+ * nss/nss_files/files-hosts.c (_nss_files_gethostbyname3_r)
+ (_nss_files_gethostbyname4_r): Pass local stream to
+ internal_setent, internal_getent and internal_endent. Remove
+ locking.
+
2015-04-29 Florian Weimer <fweimer@redhat.com>
[BZ #18007]
diff --git a/NEWS b/NEWS
index 8a63fb9..8e23536 100644
--- a/NEWS
+++ b/NEWS
@@ -19,10 +19,9 @@ Version 2.20.1
potentially arbitrary code execution, using crafted, but syntactically
valid DNS responses. (CVE-2015-1781)
-* CVE-2014-8121 The NSS files backend would reset the file pointer used by
- the get*ent functions if any of the query functions for the same database
- are used during the iteration, causing a denial-of-service condition in
- some applications.
+* CVE-2014-8121 The NSS backends shared internal state between the getXXent
+ and getXXbyYY NSS calls for the same database, causing a denial-of-service
+ condition in some applications.
* Added support for TSX lock elision of pthread mutexes on powerpc32, powerpc64
and powerpc64le. This may improve lock scaling of existing programs on
diff --git a/nis/nss_compat/compat-grp.c b/nis/nss_compat/compat-grp.c
index 78e14d6..c241e82 100644
--- a/nis/nss_compat/compat-grp.c
+++ b/nis/nss_compat/compat-grp.c
@@ -194,9 +194,6 @@ _nss_compat_setgrent (int stayopen)
static enum nss_status
internal_endgrent (ent_t *ent)
{
- if (nss_endgrent)
- nss_endgrent ();
-
if (ent->stream != NULL)
{
fclose (ent->stream);
@@ -222,6 +219,9 @@ _nss_compat_endgrent (void)
__libc_lock_lock (lock);
+ if (nss_endgrent)
+ nss_endgrent ();
+
result = internal_endgrent (&ext_ent);
__libc_lock_unlock (lock);
diff --git a/nis/nss_compat/compat-pwd.c b/nis/nss_compat/compat-pwd.c
index 127673c..f6b8d80 100644
--- a/nis/nss_compat/compat-pwd.c
+++ b/nis/nss_compat/compat-pwd.c
@@ -311,9 +311,6 @@ _nss_compat_setpwent (int stayopen)
static enum nss_status
internal_endpwent (ent_t *ent)
{
- if (nss_endpwent)
- nss_endpwent ();
-
if (ent->stream != NULL)
{
fclose (ent->stream);
@@ -346,6 +343,9 @@ _nss_compat_endpwent (void)
__libc_lock_lock (lock);
+ if (nss_endpwent)
+ nss_endpwent ();
+
result = internal_endpwent (&ext_ent);
__libc_lock_unlock (lock);
diff --git a/nis/nss_compat/compat-spwd.c b/nis/nss_compat/compat-spwd.c
index 4890ce6..e404841 100644
--- a/nis/nss_compat/compat-spwd.c
+++ b/nis/nss_compat/compat-spwd.c
@@ -169,7 +169,7 @@ copy_spwd_changes (struct spwd *dest, struct spwd *src,
}
static enum nss_status
-internal_setspent (ent_t *ent, int stayopen)
+internal_setspent (ent_t *ent, int stayopen, int needent)
{
enum nss_status status = NSS_STATUS_SUCCESS;
@@ -239,7 +239,7 @@ internal_setspent (ent_t *ent, int stayopen)
give_spwd_free (&ent->pwd);
- if (status == NSS_STATUS_SUCCESS && nss_setspent)
+ if (needent && status == NSS_STATUS_SUCCESS && nss_setspent)
ent->setent_status = nss_setspent (stayopen);
return status;
@@ -256,7 +256,7 @@ _nss_compat_setspent (int stayopen)
if (ni == NULL)
init_nss_interface ();
- result = internal_setspent (&ext_ent, stayopen);
+ result = internal_setspent (&ext_ent, stayopen, 1);
__libc_lock_unlock (lock);
@@ -267,9 +267,6 @@ _nss_compat_setspent (int stayopen)
static enum nss_status
internal_endspent (ent_t *ent)
{
- if (nss_endspent)
- nss_endspent ();
-
if (ent->stream != NULL)
{
fclose (ent->stream);
@@ -303,6 +300,9 @@ _nss_compat_endspent (void)
__libc_lock_lock (lock);
+ if (nss_endspent)
+ nss_endspent ();
+
result = internal_endspent (&ext_ent);
__libc_lock_unlock (lock);
@@ -658,7 +658,7 @@ _nss_compat_getspent_r (struct spwd *pwd, char *buffer, size_t buflen,
init_nss_interface ();
if (ext_ent.stream == NULL)
- result = internal_setspent (&ext_ent, 1);
+ result = internal_setspent (&ext_ent, 1, 1);
if (result == NSS_STATUS_SUCCESS)
result = internal_getspent_r (pwd, &ext_ent, buffer, buflen, errnop);
@@ -830,7 +830,7 @@ _nss_compat_getspnam_r (const char *name, struct spwd *pwd,
__libc_lock_unlock (lock);
- result = internal_setspent (&ent, 0);
+ result = internal_setspent (&ent, 0, 0);
if (result == NSS_STATUS_SUCCESS)
result = internal_getspnam_r (name, pwd, &ent, buffer, buflen, errnop);
diff --git a/nss/nss_files/files-XXX.c b/nss/nss_files/files-XXX.c
index cc38174..2d66024 100644
--- a/nss/nss_files/files-XXX.c
+++ b/nss/nss_files/files-XXX.c
@@ -60,24 +60,23 @@
/* Locks the static variables in this file. */
__libc_lock_define_initialized (static, lock)
-/* Maintenance of the shared stream open on the database file. */
+/* Maintenance of the stream open on the database file. For getXXent
+ operations the stream needs to be held open across calls, the other
+ getXXbyYY operations all use their own stream. */
static FILE *stream;
-static fpos_t position;
-static enum { nouse, getent, getby } last_use;
-static int keep_stream;
/* Open database file if not already opened. */
static enum nss_status
-internal_setent (int stayopen)
+internal_setent (FILE **stream)
{
enum nss_status status = NSS_STATUS_SUCCESS;
- if (stream == NULL)
+ if (*stream == NULL)
{
- stream = fopen (DATAFILE, "rce");
+ *stream = fopen (DATAFILE, "rce");
- if (stream == NULL)
+ if (*stream == NULL)
status = errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
else
{
@@ -90,7 +89,7 @@ internal_setent (int stayopen)
int result;
int flags;
- result = flags = fcntl (fileno (stream), F_GETFD, 0);
+ result = flags = fcntl (fileno (*stream), F_GETFD, 0);
if (result >= 0)
{
# ifdef O_CLOEXEC
@@ -100,15 +99,15 @@ internal_setent (int stayopen)
# endif
{
flags |= FD_CLOEXEC;
- result = fcntl (fileno (stream), F_SETFD, flags);
+ result = fcntl (fileno (*stream), F_SETFD, flags);
}
}
if (result < 0)
{
/* Something went wrong. Close the stream and return a
failure. */
- fclose (stream);
- stream = NULL;
+ fclose (*stream);
+ *stream = NULL;
status = NSS_STATUS_UNAVAIL;
}
}
@@ -116,11 +115,7 @@ internal_setent (int stayopen)
}
}
else
- rewind (stream);
-
- /* Remember STAYOPEN flag. */
- if (stream != NULL)
- keep_stream |= stayopen;
+ rewind (*stream);
return status;
}
@@ -134,16 +129,7 @@ CONCAT(_nss_files_set,ENTNAME) (int stayopen)
__libc_lock_lock (lock);
- status = internal_setent (1);
-
- if (status == NSS_STATUS_SUCCESS && fgetpos (stream, &position) < 0)
- {
- fclose (stream);
- stream = NULL;
- status = NSS_STATUS_UNAVAIL;
- }
-
- last_use = getent;
+ status = internal_setent (&stream);
__libc_lock_unlock (lock);
@@ -153,12 +139,12 @@ CONCAT(_nss_files_set,ENTNAME) (int stayopen)
/* Close the database file. */
static void
-internal_endent (void)
+internal_endent (FILE **stream)
{
- if (stream != NULL)
+ if (*stream != NULL)
{
- fclose (stream);
- stream = NULL;
+ fclose (*stream);
+ *stream = NULL;
}
}
@@ -169,10 +155,7 @@ CONCAT(_nss_files_end,ENTNAME) (void)
{
__libc_lock_lock (lock);
- internal_endent ();
-
- /* Reset STAYOPEN flag. */
- keep_stream = 0;
+ internal_endent (&stream);
__libc_lock_unlock (lock);
@@ -227,7 +210,7 @@ get_contents (char *linebuf, size_t len, FILE *stream)
/* Parsing the database file into `struct STRUCTURE' data structures. */
static enum nss_status
-internal_getent (struct STRUCTURE *result,
+internal_getent (FILE *stream, struct STRUCTURE *result,
char *buffer, size_t buflen, int *errnop H_ERRNO_PROTO
EXTRA_ARGS_DECL)
{
@@ -300,45 +283,14 @@ CONCAT(_nss_files_get,ENTNAME_r) (struct STRUCTURE *result, char *buffer,
{
int save_errno = errno;
- status = internal_setent (0);
+ status = internal_setent (&stream);
__set_errno (save_errno);
-
- if (status == NSS_STATUS_SUCCESS && fgetpos (stream, &position) < 0)
- {
- fclose (stream);
- stream = NULL;
- status = NSS_STATUS_UNAVAIL;
- }
}
if (status == NSS_STATUS_SUCCESS)
- {
- /* If the last use was not by the getent function we need the
- position the stream. */
- if (last_use != getent)
- {
- if (fsetpos (stream, &position) < 0)
- status = NSS_STATUS_UNAVAIL;
- else
- last_use = getent;
- }
-
- if (status == NSS_STATUS_SUCCESS)
- {
- status = internal_getent (result, buffer, buflen, errnop
- H_ERRNO_ARG EXTRA_ARGS_VALUE);
-
- /* Remember this position if we were successful. If the
- operation failed we give the user a chance to repeat the
- operation (perhaps the buffer was too small). */
- if (status == NSS_STATUS_SUCCESS)
- fgetpos (stream, &position);
- else
- /* We must make sure we reposition the stream the next call. */
- last_use = nouse;
- }
- }
+ status = internal_getent (stream, result, buffer, buflen, errnop
+ H_ERRNO_ARG EXTRA_ARGS_VALUE);
__libc_lock_unlock (lock);
@@ -364,27 +316,20 @@ _nss_files_get##name##_r (proto, \
size_t buflen, int *errnop H_ERRNO_PROTO) \
{ \
enum nss_status status; \
+ FILE *stream = NULL; \
\
- __libc_lock_lock (lock); \
- \
- /* Reset file pointer to beginning or open file. */ \
- status = internal_setent (keep_stream); \
+ /* Open file. */ \
+ status = internal_setent (&stream); \
\
if (status == NSS_STATUS_SUCCESS) \
{ \
- /* Tell getent function that we have repositioned the file pointer. */ \
- last_use = getby; \
- \
- while ((status = internal_getent (result, buffer, buflen, errnop \
+ while ((status = internal_getent (stream, result, buffer, buflen, errnop \
H_ERRNO_ARG EXTRA_ARGS_VALUE)) \
== NSS_STATUS_SUCCESS) \
{ break_if_match } \
\
- if (! keep_stream) \
- internal_endent (); \
+ internal_endent (&stream); \
} \
\
- __libc_lock_unlock (lock); \
- \
return status; \
}
diff --git a/nss/nss_files/files-alias.c b/nss/nss_files/files-alias.c
index 53088f6..4b085d3 100644
--- a/nss/nss_files/files-alias.c
+++ b/nss/nss_files/files-alias.c
@@ -33,23 +33,23 @@
/* Locks the static variables in this file. */
__libc_lock_define_initialized (static, lock)
-/* Maintenance of the shared stream open on the database file. */
+/* Maintenance of the stream open on the database file. For getXXent
+ operations the stream needs to be held open across calls, the other
+ getXXbyYY operations all use their own stream. */
static FILE *stream;
-static fpos_t position;
-static enum { nouse, getent, getby } last_use;
static enum nss_status
-internal_setent (void)
+internal_setent (FILE **stream)
{
enum nss_status status = NSS_STATUS_SUCCESS;
- if (stream == NULL)
+ if (*stream == NULL)
{
- stream = fopen ("/etc/aliases", "rce");
+ *stream = fopen ("/etc/aliases", "rce");
- if (stream == NULL)
+ if (*stream == NULL)
status = errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
else
{
@@ -62,7 +62,7 @@ internal_setent (void)
int result;
int flags;
- result = flags = fcntl (fileno (stream), F_GETFD, 0);
+ result = flags = fcntl (fileno (*stream), F_GETFD, 0);
if (result >= 0)
{
# ifdef O_CLOEXEC
@@ -72,14 +72,14 @@ internal_setent (void)
# endif
{
flags |= FD_CLOEXEC;
- result = fcntl (fileno (stream), F_SETFD, flags);
+ result = fcntl (fileno (*stream), F_SETFD, flags);
}
}
if (result < 0)
{
/* Something went wrong. Close the stream and return a
failure. */
- fclose (stream);
+ fclose (*stream);
stream = NULL;
status = NSS_STATUS_UNAVAIL;
}
@@ -88,7 +88,7 @@ internal_setent (void)
}
}
else
- rewind (stream);
+ rewind (*stream);
return status;
}
@@ -102,16 +102,7 @@ _nss_files_setaliasent (void)
__libc_lock_lock (lock);
- status = internal_setent ();
-
- if (status == NSS_STATUS_SUCCESS && fgetpos (stream, &position) < 0)
- {
- fclose (stream);
- stream = NULL;
- status = NSS_STATUS_UNAVAIL;
- }
-
- last_use = getent;
+ status = internal_setent (&stream);
__libc_lock_unlock (lock);
@@ -121,12 +112,12 @@ _nss_files_setaliasent (void)
/* Close the database file. */
static void
-internal_endent (void)
+internal_endent (FILE **stream)
{
- if (stream != NULL)
+ if (*stream != NULL)
{
- fclose (stream);
- stream = NULL;
+ fclose (*stream);
+ *stream = NULL;
}
}
@@ -137,7 +128,7 @@ _nss_files_endaliasent (void)
{
__libc_lock_lock (lock);
- internal_endent ();
+ internal_endent (&stream);
__libc_lock_unlock (lock);
@@ -146,7 +137,7 @@ _nss_files_endaliasent (void)
/* Parsing the database file into `struct aliasent' data structures. */
static enum nss_status
-get_next_alias (const char *match, struct aliasent *result,
+get_next_alias (FILE *stream, const char *match, struct aliasent *result,
char *buffer, size_t buflen, int *errnop)
{
enum nss_status status = NSS_STATUS_NOTFOUND;
@@ -397,35 +388,16 @@ _nss_files_getaliasent_r (struct aliasent *result, char *buffer, size_t buflen,
/* Be prepared that the set*ent function was not called before. */
if (stream == NULL)
- status = internal_setent ();
+ status = internal_setent (&stream);
if (status == NSS_STATUS_SUCCESS)
{
- /* If the last use was not by the getent function we need the
- position the stream. */
- if (last_use != getent)
- {
- if (fsetpos (stream, &position) < 0)
- status = NSS_STATUS_UNAVAIL;
- else
- last_use = getent;
- }
+ result->alias_local = 1;
- if (status == NSS_STATUS_SUCCESS)
- {
- result->alias_local = 1;
-
- /* Read lines until we get a definite result. */
- do
- status = get_next_alias (NULL, result, buffer, buflen, errnop);
- while (status == NSS_STATUS_RETURN);
-
- /* If we successfully read an entry remember this position. */
- if (status == NSS_STATUS_SUCCESS)
- fgetpos (stream, &position);
- else
- last_use = nouse;
- }
+ /* Read lines until we get a definite result. */
+ do
+ status = get_next_alias (stream, NULL, result, buffer, buflen, errnop);
+ while (status == NSS_STATUS_RETURN);
}
__libc_lock_unlock (lock);
@@ -440,6 +412,7 @@ _nss_files_getaliasbyname_r (const char *name, struct aliasent *result,
{
/* Return next entry in host file. */
enum nss_status status = NSS_STATUS_SUCCESS;
+ FILE *stream = NULL;
if (name == NULL)
{
@@ -447,11 +420,8 @@ _nss_files_getaliasbyname_r (const char *name, struct aliasent *result,
return NSS_STATUS_UNAVAIL;
}
- __libc_lock_lock (lock);
-
- /* Open the stream or rest it. */
- status = internal_setent ();
- last_use = getby;
+ /* Open the stream. */
+ status = internal_setent (&stream);
if (status == NSS_STATUS_SUCCESS)
{
@@ -459,13 +429,11 @@ _nss_files_getaliasbyname_r (const char *name, struct aliasent *result,
/* Read lines until we get a definite result. */
do
- status = get_next_alias (name, result, buffer, buflen, errnop);
+ status = get_next_alias (stream, name, result, buffer, buflen, errnop);
while (status == NSS_STATUS_RETURN);
}
- internal_endent ();
-
- __libc_lock_unlock (lock);
+ internal_endent (&stream);
return status;
}
diff --git a/nss/nss_files/files-hosts.c b/nss/nss_files/files-hosts.c
index ab64ead..8de4b1b 100644
--- a/nss/nss_files/files-hosts.c
+++ b/nss/nss_files/files-hosts.c
@@ -120,14 +120,13 @@ _nss_files_gethostbyname3_r (const char *name, int af, struct hostent *result,
char *buffer, size_t buflen, int *errnop,
int *herrnop, int32_t *ttlp, char **canonp)
{
+ FILE *stream = NULL;
uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct hostent_data);
buffer += pad;
buflen = buflen > pad ? buflen - pad : 0;
- __libc_lock_lock (lock);
-
- /* Reset file pointer to beginning or open file. */
- enum nss_status status = internal_setent (keep_stream);
+ /* Open file. */
+ enum nss_status status = internal_setent (&stream);
if (status == NSS_STATUS_SUCCESS)
{
@@ -135,10 +134,7 @@ _nss_files_gethostbyname3_r (const char *name, int af, struct hostent *result,
addresses to IPv6 addresses really the right thing to do? */
int flags = ((_res.options & RES_USE_INET6) ? AI_V4MAPPED : 0);
- /* Tell getent function that we have repositioned the file pointer. */
- last_use = getby;
-
- while ((status = internal_getent (result, buffer, buflen, errnop,
+ while ((status = internal_getent (stream, result, buffer, buflen, errnop,
herrnop, af, flags))
== NSS_STATUS_SUCCESS)
{
@@ -165,7 +161,7 @@ _nss_files_gethostbyname3_r (const char *name, int af, struct hostent *result,
bufferend = (char *) &result->h_aliases[naliases + 1];
again:
- while ((status = internal_getent (&tmp_result_buf, tmp_buffer,
+ while ((status = internal_getent (stream, &tmp_result_buf, tmp_buffer,
tmp_buflen, errnop, herrnop, af,
flags))
== NSS_STATUS_SUCCESS)
@@ -341,15 +337,12 @@ _nss_files_gethostbyname3_r (const char *name, int af, struct hostent *result,
free (tmp_buffer);
}
- if (! keep_stream)
- internal_endent ();
+ internal_endent (&stream);
}
if (canonp && status == NSS_STATUS_SUCCESS)
*canonp = result->h_name;
- __libc_lock_unlock (lock);
-
return status;
}
@@ -378,16 +371,13 @@ _nss_files_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat,
char *buffer, size_t buflen, int *errnop,
int *herrnop, int32_t *ttlp)
{
- __libc_lock_lock (lock);
+ FILE *stream = NULL;
- /* Reset file pointer to beginning or open file. */
- enum nss_status status = internal_setent (keep_stream);
+ /* Open file. */
+ enum nss_status status = internal_setent (&stream);
if (status == NSS_STATUS_SUCCESS)
{
- /* Tell getent function that we have repositioned the file pointer. */
- last_use = getby;
-
bool any = false;
bool got_canon = false;
while (1)
@@ -399,7 +389,7 @@ _nss_files_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat,
buflen = buflen > pad ? buflen - pad : 0;
struct hostent result;
- status = internal_getent (&result, buffer, buflen, errnop,
+ status = internal_getent (stream, &result, buffer, buflen, errnop,
herrnop, AF_UNSPEC, 0);
if (status != NSS_STATUS_SUCCESS)
break;
@@ -475,8 +465,7 @@ _nss_files_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat,
status = NSS_STATUS_SUCCESS;
}
- if (! keep_stream)
- internal_endent ();
+ internal_endent (&stream);
}
else if (status == NSS_STATUS_TRYAGAIN)
{
@@ -489,7 +478,5 @@ _nss_files_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat,
*herrnop = NO_DATA;
}
- __libc_lock_unlock (lock);
-
return status;
}
http://sourceware.org/git/gitweb.cgi?p=glibc.git;a=commitdiff;h=9dc3dd905a5612717ed4b577b7f07294bff614f4
commit 9dc3dd905a5612717ed4b577b7f07294bff614f4
Author: Florian Weimer <fweimer@redhat.com>
Date: Wed Apr 29 14:41:25 2015 +0200
CVE-2014-8121: Do not close NSS files database during iteration [BZ #18007]
Robin Hack discovered Samba would enter an infinite loop processing
certain quota-related requests. We eventually tracked this down to a
glibc issue.
Running a (simplified) test case under strace shows that /etc/passwd
is continuously opened and closed:
â?¦
open("/etc/passwd", O_RDONLY|O_CLOEXEC) = 3
lseek(3, 0, SEEK_CUR) = 0
read(3, "root:x:0:0:root:/root:/bin/bash\n"..., 4096) = 2717
lseek(3, 2717, SEEK_SET) = 2717
close(3) = 0
open("/etc/passwd", O_RDONLY|O_CLOEXEC) = 3
lseek(3, 0, SEEK_CUR) = 0
lseek(3, 0, SEEK_SET) = 0
read(3, "root:x:0:0:root:/root:/bin/bash\n"..., 4096) = 2717
lseek(3, 2717, SEEK_SET) = 2717
close(3) = 0
open("/etc/passwd", O_RDONLY|O_CLOEXEC) = 3
lseek(3, 0, SEEK_CUR) = 0
â?¦
The lookup function implementation in
nss/nss_files/files-XXX.c:DB_LOOKUP has code to prevent that. It is
supposed skip closing the input file if it was already open.
/* Reset file pointer to beginning or open file. */ \
status = internal_setent (keep_stream); \
\
if (status == NSS_STATUS_SUCCESS) \
{ \
/* Tell getent function that we have repositioned the file pointer. */ \
last_use = getby; \
\
while ((status = internal_getent (result, buffer, buflen, errnop \
H_ERRNO_ARG EXTRA_ARGS_VALUE)) \
== NSS_STATUS_SUCCESS) \
{ break_if_match } \
\
if (! keep_stream) \
internal_endent (); \
} \
keep_stream is initialized from the stayopen flag in internal_setent.
internal_setent is called from the set*ent implementation as:
status = internal_setent (stayopen);
However, for non-host database, this flag is always 0, per the
STAYOPEN magic in nss/getXXent_r.c.
Thus, the fix is this:
- status = internal_setent (stayopen);
+ status = internal_setent (1);
This is not a behavioral change even for the hosts database (where the
application can specify the stayopen flag) because with a call to
sethostent(0), the file handle is still not closed in the
implementation of gethostent.
Conflicts:
NEWS
diff --git a/ChangeLog b/ChangeLog
index 22f2017..8b13f7b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2015-04-29 Florian Weimer <fweimer@redhat.com>
+
+ [BZ #18007]
+ * nss/nss_files/files-XXX.c (CONCAT): Always enable stayopen.
+ (CVE-2014-8121)
+ * nss/tst-nss-getpwent.c: New file.
+ * nss/Makefile (tests): Add new test.
+
2015-04-21 Arjun Shankar <arjun.is@lostca.se>
[BZ #18287]
diff --git a/NEWS b/NEWS
index 8160427..8a63fb9 100644
--- a/NEWS
+++ b/NEWS
@@ -10,7 +10,7 @@ Version 2.20.1
* The following bugs are resolved with this release:
16009, 16617, 16618, 17266, 17370, 17371, 17460, 17485, 17555, 17625,
- 17630, 17801, 18287
+ 17630, 17801, 18007, 18287.
* A buffer overflow in gethostbyname_r and related functions performing DNS
requests has been fixed. If the NSS functions were called with a
@@ -19,6 +19,11 @@ Version 2.20.1
potentially arbitrary code execution, using crafted, but syntactically
valid DNS responses. (CVE-2015-1781)
+* CVE-2014-8121 The NSS files backend would reset the file pointer used by
+ the get*ent functions if any of the query functions for the same database
+ are used during the iteration, causing a denial-of-service condition in
+ some applications.
+
* Added support for TSX lock elision of pthread mutexes on powerpc32, powerpc64
and powerpc64le. This may improve lock scaling of existing programs on
HTM capable systems. The lock elision code is only enabled with
diff --git a/nss/Makefile b/nss/Makefile
index 1fa7f1f..d6f0139 100644
--- a/nss/Makefile
+++ b/nss/Makefile
@@ -39,7 +39,7 @@ install-bin := getent makedb
makedb-modules = xmalloc hash-string
extra-objs += $(makedb-modules:=.o)
-tests = test-netdb tst-nss-test1 test-digits-dots
+tests = test-netdb tst-nss-test1 test-digits-dots tst-nss-getpwent
xtests = bug-erange
# Specify rules for the nss_* modules. We have some services.
diff --git a/nss/nss_files/files-XXX.c b/nss/nss_files/files-XXX.c
index 212b938..cc38174 100644
--- a/nss/nss_files/files-XXX.c
+++ b/nss/nss_files/files-XXX.c
@@ -134,7 +134,7 @@ CONCAT(_nss_files_set,ENTNAME) (int stayopen)
__libc_lock_lock (lock);
- status = internal_setent (stayopen);
+ status = internal_setent (1);
if (status == NSS_STATUS_SUCCESS && fgetpos (stream, &position) < 0)
{
diff --git a/nss/tst-nss-getpwent.c b/nss/tst-nss-getpwent.c
new file mode 100644
index 0000000..f2e8abc
--- /dev/null
+++ b/nss/tst-nss-getpwent.c
@@ -0,0 +1,118 @@
+/* Copyright (C) 2015 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <pwd.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int
+do_test (void)
+{
+ /* Count the number of entries in the password database, and fetch
+ data from the first and last entries. */
+ size_t count = 0;
+ struct passwd * pw;
+ char *first_name = NULL;
+ uid_t first_uid = 0;
+ char *last_name = NULL;
+ uid_t last_uid = 0;
+ setpwent ();
+ while ((pw = getpwent ()) != NULL)
+ {
+ if (first_name == NULL)
+ {
+ first_name = strdup (pw->pw_name);
+ if (first_name == NULL)
+ {
+ printf ("strdup: %m\n");
+ return 1;
+ }
+ first_uid = pw->pw_uid;
+ }
+
+ free (last_name);
+ last_name = strdup (pw->pw_name);
+ if (last_name == NULL)
+ {
+ printf ("strdup: %m\n");
+ return 1;
+ }
+ last_uid = pw->pw_uid;
+ ++count;
+ }
+ endpwent ();
+
+ if (count == 0)
+ {
+ printf ("No entries in the password database.\n");
+ return 0;
+ }
+
+ /* Try again, this time interleaving with name-based and UID-based
+ lookup operations. The counts do not match if the interleaved
+ lookups affected the enumeration. */
+ size_t new_count = 0;
+ setpwent ();
+ while ((pw = getpwent ()) != NULL)
+ {
+ if (new_count == count)
+ {
+ printf ("Additional entry in the password database.\n");
+ return 1;
+ }
+ ++new_count;
+ struct passwd *pw2 = getpwnam (first_name);
+ if (pw2 == NULL)
+ {
+ printf ("getpwnam (%s) failed: %m\n", first_name);
+ return 1;
+ }
+ pw2 = getpwnam (last_name);
+ if (pw2 == NULL)
+ {
+ printf ("getpwnam (%s) failed: %m\n", last_name);
+ return 1;
+ }
+ pw2 = getpwuid (first_uid);
+ if (pw2 == NULL)
+ {
+ printf ("getpwuid (%llu) failed: %m\n",
+ (unsigned long long) first_uid);
+ return 1;
+ }
+ pw2 = getpwuid (last_uid);
+ if (pw2 == NULL)
+ {
+ printf ("getpwuid (%llu) failed: %m\n",
+ (unsigned long long) last_uid);
+ return 1;
+ }
+ }
+ endpwent ();
+ if (new_count < count)
+ {
+ printf ("Missing entry in the password database.\n");
+ return 1;
+ }
+
+ return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
-----------------------------------------------------------------------
Summary of changes:
ChangeLog | 46 ++++++++++++++++
NEWS | 6 ++-
nis/nss_compat/compat-grp.c | 6 +-
nis/nss_compat/compat-pwd.c | 6 +-
nis/nss_compat/compat-spwd.c | 16 +++---
nss/Makefile | 2 +-
nss/nss_files/files-XXX.c | 109 ++++++++++-----------------------------
nss/nss_files/files-alias.c | 90 ++++++++++----------------------
nss/nss_files/files-hosts.c | 35 ++++---------
nss/tst-nss-getpwent.c | 118 ++++++++++++++++++++++++++++++++++++++++++
10 files changed, 251 insertions(+), 183 deletions(-)
create mode 100644 nss/tst-nss-getpwent.c
hooks/post-receive
--
GNU C Library master sources