[SSSD] [sssd][patch] SYSDB: sysdb_getnetgr returns ENOENT

Pavel Reichl preichl at redhat.com
Tue Jun 24 15:28:23 UTC 2014


On Tue, 2014-06-24 at 16:18 +0200, Lukas Slebodnik wrote:
> On (24/06/14 13:33), Pavel Reichl wrote:
> >On Mon, 2014-06-23 at 13:50 +0200, Jakub Hrozek wrote:
> >> On Thu, Jun 19, 2014 at 05:53:37PM +0200, Pavel Reichl wrote:
> >> > From 6e2af6d696fd0e731467c50dbb715756a4bcb0a3 Mon Sep 17 00:00:00 2001
> >> > From: Pavel Reichl <preichl at redhat.com>
> >> > Date: Tue, 27 May 2014 19:11:20 +0100
> >> > Subject: [PATCH 1/4] SYSDB: sss_ldb_search - wrapper around ldb_search
> >> > 
> >> > Make sure that if no results were found ENOENT is returned rather than just
> >> > empty list of results.
> >> > 
> >> > Resolves:
> >> > https://fedorahosted.org/sssd/ticket/1991
> >> > ---
> >> >  src/db/sysdb.h     |  5 +++++
> >> >  src/db/sysdb_ops.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
> >> >  2 files changed, 52 insertions(+)
> >> > 
> >> > diff --git a/src/db/sysdb.h b/src/db/sysdb.h
> >> > index dd14190bfa156c6b2842e2af81d7b58efa3ea06f..634df049421586959531d8d1a365a2d50d15d1a6 100644
> >> > --- a/src/db/sysdb.h
> >> > +++ b/src/db/sysdb.h
> >> > @@ -480,6 +480,11 @@ int sysdb_get_netgroup_attr(TALLOC_CTX *mem_ctx,
> >> >                              const char **attributes,
> >> >                              struct ldb_result **res);
> >> >  
> >> > +errno_t sss_ldb_search(struct ldb_context *ldb, TALLOC_CTX *mem_ctx,
> >> > +                       struct ldb_result **_result, struct ldb_dn *base,
> >> > +                       enum ldb_scope scope, const char * const *attrs,
> >> > +                       const char *exp_fmt, ...);
> >> 
> >> You need to use SSS_ATTRIBUTE_PRINTF here.
> >
> >OK, but it didn't like "" being passed as fmt causing:
> >-Werror=format-zero-length. 
> >
> >To avoid this warning, NULL is passed instead of "". sss_ldb_search now
> >handles explicitly case when fmt is NULL because no filter processing is
> >required then.
> >
> And null caused warning in static analysers :-)
> 
> Error: PW.NON_CONST_PRINTF_FORMAT_STRING:
> sssd-1.11.92/src/db/sysdb_ops.c:109: non_const_printf_format_string: format string is not a string literal, potential security vulnerability if user controlled
> sssd-1.11.92/src/db/sysdb_ops.c:109: caretline:
> 
> I prefer to avoid compiler warnings. It will be better to use NULL.

(lret = ldb_search(ldb, mem_ctx, _result, base, scope, attrs, NULL);)

It's a common practice in SSSD anyway. 

> 
> 
> 
> >From: Pavel Reichl <preichl at redhat.com>
> >Date: Tue, 27 May 2014 19:11:20 +0100
> >Subject: [PATCH 1/5] SYSDB: sss_ldb_search - wrapper around ldb_search
> >
> >Make sure that if no results were found ENOENT is returned rather than just
> >empty list of results.
> >
> >Resolves:
> >https://fedorahosted.org/sssd/ticket/1991
> >---
> > src/db/sysdb.h     |  5 +++++
> > src/db/sysdb_ops.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
> > 2 files changed, 55 insertions(+)
> >
> >diff --git a/src/db/sysdb.h b/src/db/sysdb.h
> >index 911430eefcbf520ca04f123a3b6f1882dc25876b..17cd5110c9bdafd8d7b18e621188523ed41e5c8a 100644
> >--- a/src/db/sysdb.h
> >+++ b/src/db/sysdb.h
> >@@ -481,6 +481,11 @@ int sysdb_get_netgroup_attr(TALLOC_CTX *mem_ctx,
> >                             const char **attributes,
> >                             struct ldb_result **res);
> > 
> >+errno_t sss_ldb_search(struct ldb_context *ldb, TALLOC_CTX *mem_ctx,
> >+                       struct ldb_result **_result, struct ldb_dn *base,
> >+                       enum ldb_scope scope, const char * const *attrs,
> >+                       const char *exp_fmt, ...) SSS_ATTRIBUTE_PRINTF(7, 8);
> >+
> > /* functions that modify the databse
> >  * they have to be called within a transaction
> >  * See sysdb_transaction_send()/_recv() */
> >diff --git a/src/db/sysdb_ops.c b/src/db/sysdb_ops.c
> >index 4d31cb6a0e83370a2c49a666f9474d93baf430b0..25fccc5fdacd85416268e02632826fd87174e7f7 100644
> >--- a/src/db/sysdb_ops.c
> >+++ b/src/db/sysdb_ops.c
> >@@ -74,6 +74,56 @@ static uint32_t get_attr_as_uint32(struct ldb_message *msg, const char *attr)
> >     return l;
> > }
> > 
> >+
> >+/* Wrapper around ldb_search to ensure that if zero results are found then
> >+ * ENOENT is returned
> >+ */
> >+errno_t sss_ldb_search(struct ldb_context *ldb, TALLOC_CTX *mem_ctx,
> >+                       struct ldb_result **_result, struct ldb_dn *base,
> >+                       enum ldb_scope scope, const char * const *attrs,
> >+                       const char *exp_fmt, ...)
> >+{
> >+    char *s;
> >+    int lret;
> >+    va_list ap;
> >+    errno_t ret;
> >+    TALLOC_CTX *tmp_ctx = NULL;
> >+
> >+    if (exp_fmt != NULL) {
> >+        tmp_ctx = talloc_new(NULL);
> >+        if (tmp_ctx == NULL) {
> >+            ret = ENOMEM;
> >+            goto done;
> >+        }
> >+
> >+        va_start(ap, exp_fmt);
> >+        s = talloc_vasprintf(tmp_ctx, exp_fmt, ap);
> >+        if (s == NULL) {
> >+            DEBUG(SSSDBG_MINOR_FAILURE, "Failed to process filter.\n");
> >+            ret = ENOMEM;
> >+            goto done;
> va_end is not called in this case.
> It will be better to move va_end before if condition.
Yep, I missed that sorry. Fixed in attached patch set.

> 
> >+        }
> >+        va_end(ap);
> >+        lret = ldb_search(ldb, mem_ctx, _result, base, scope, attrs, "%s", s);
> >+    } else {
> >+        lret = ldb_search(ldb, mem_ctx, _result, base, scope, attrs, NULL);
> >+    }
> >+
> >+    ret = sysdb_error_to_errno(lret);
> >+    if (ret != EOK) {
> >+        goto done;
> >+    }
> >+
> >+    if ((*_result)->count == 0) {
> >+        ret = ENOENT;
> >+        goto done;
> >+    }
> >+
> >+done:
> >+    talloc_free(tmp_ctx);
> >+    return ret;
> >+}
> >+
> > /*
> >  * The wrapper around ldb_modify that uses LDB_CONTROL_PERMISSIVE_MODIFY_OID
> >  * so that on adds entries that already exist are skipped and similarly
> >-- 
> >1.8.4.2
> >
> 
> >From cd9f7ed48017516d01c79d59af6af63d87a4a31f Mon Sep 17 00:00:00 2001
> >From: Pavel Reichl <preichl at redhat.com>
> >Date: Thu, 19 Jun 2014 15:38:59 +0100
> >Subject: [PATCH 2/5] TESTS: add tests for sss_ldb_search
> >
> >Resolves:
> >https://fedorahosted.org/sssd/ticket/1991
> >---
> > src/tests/sysdb-tests.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 97 insertions(+)
> >
> >diff --git a/src/tests/sysdb-tests.c b/src/tests/sysdb-tests.c
> >index ac78f368f04b5138eecb6b121b43ac45bc3c32a3..650219d266ca052d941343321608fadf3c76872d 100644
> >--- a/src/tests/sysdb-tests.c
> >+++ b/src/tests/sysdb-tests.c
> >@@ -3979,6 +3979,87 @@ START_TEST(test_odd_characters)
> > }
> > END_TEST
> > 
> >+START_TEST(test_sss_ldb_search)
> >+{
> >+    errno_t ret;
> >+    struct sysdb_test_ctx *test_ctx;
> >+    struct ldb_dn *group_dn, *nonexist_dn;
> >+    struct ldb_result *res;
> >+    const char groupname[] = "test_group";
> >+    const char *received_group;
> >+
> >+    /* Setup */
> >+    ret = setup_sysdb_tests(&test_ctx);
> >+    if (ret != EOK) {
> >+        fail("Could not set up the test");
> >+        return;
> >+    }
> >+
> >+    check_leaks_push(test_ctx);
> >+
> >+    group_dn = sysdb_group_dn(test_ctx, test_ctx->domain, groupname);
> >+    fail_if(group_dn == NULL, "sysdb_group_dn failed");
> >+
> >+    nonexist_dn = sysdb_group_dn(test_ctx, test_ctx->domain,
> >+                                 "non-existing-group");
> >+    fail_if(nonexist_dn == NULL, "sysdb_group_dn failed");
> >+
> >+    /* Add */
> >+    ret = sysdb_add_incomplete_group(test_ctx->domain,
> >+                                     groupname, 20000, NULL, NULL, true, 0);
> >+    fail_unless(ret == EOK, "sysdb_add_incomplete_group error [%d][%s]",
> >+                ret, strerror(ret));
> >+
> >+    /* Retrieve */
> >+
> >+    /* Empty filter */
> >+    ret = sss_ldb_search(test_ctx->sysdb->ldb, test_ctx, &res, group_dn,
> >+                         LDB_SCOPE_BASE, NULL, NULL);
> >+
> >+    fail_unless(ret == EOK, "sss_ldb_search error [%d][%s]",
> >+                ret, strerror(ret));
> >+
> >+    fail_unless(res->count == 1, "Received [%d] responses",
> >+                                 res->count);
> >+
> >+    received_group = ldb_msg_find_attr_as_string(res->msgs[0], SYSDB_NAME,
> >+                                                 NULL);
> >+    fail_unless(strcmp(received_group, groupname) == 0,
> >+                "Expected [%s], got [%s]", groupname, received_group);
> >+
> >+    talloc_zfree(res);
> >+
> >+    /* Non-empty filter */
> >+    ret = sss_ldb_search(test_ctx->sysdb->ldb, test_ctx, &res, group_dn,
> >+                         LDB_SCOPE_BASE, NULL, "objectClass=group");
> >+
> >+    fail_unless(ret == EOK, "sss_ldb_search error [%d][%s]",
> >+                ret, strerror(ret));
> >+    talloc_zfree(res);
> >+
> >+    /* Filter yeilding no results */
> >+    ret = sss_ldb_search(test_ctx->sysdb->ldb, test_ctx, &res, group_dn,
> >+                         LDB_SCOPE_BASE, NULL,
> >+                         "objectClass=nonExistingObjectClass");
> >+
> >+    fail_unless(ret == ENOENT, "sss_ldb_search error [%d][%s]",
> >+                ret, strerror(ret));
> >+    talloc_zfree(res);
> >+
> >+    /* Non-existing dn */
> >+    ret = sss_ldb_search(test_ctx->sysdb->ldb, test_ctx, &res, nonexist_dn,
> >+                         LDB_SCOPE_BASE, NULL, NULL);
> >+
> >+    fail_unless(ret == ENOENT, "sss_ldb_search error [%d][%s]",
> >+                ret, strerror(ret));
> >+    talloc_zfree(res);
> >+
> >+    talloc_zfree(nonexist_dn);
> >+    talloc_zfree(group_dn);
> >+    fail_unless(check_leaks_pop(test_ctx) == true, "Memory leak");
> >+}
> >+END_TEST
> >+
> > /* == SERVICE TESTS == */
> > void services_check_match(struct sysdb_test_ctx *test_ctx,
> >                           bool by_name,
> >@@ -4539,6 +4620,18 @@ START_TEST (test_sysdb_search_return_ENOENT)
> >     talloc_zfree(msgs);
> >     talloc_zfree(user_dn);
> > 
> >+    /* sss_ldb_search */
> >+    user_dn = sysdb_user_dn(test_ctx, test_ctx->domain, "nonexisting_user");
> >+    fail_if(user_dn == NULL, "sysdb_user_dn failed");
> >+    ret = sss_ldb_search(test_ctx->sysdb->ldb, test_ctx, &res, user_dn,
> >+                         LDB_SCOPE_BASE, NULL, "objectClass=user");
> >+
> >+    fail_unless(ret == ENOENT, "sss_ldb_search failed: %d, %s",
> >+                               ret, strerror(ret));
> >+
> >+    talloc_zfree(res);
> >+    talloc_zfree(user_dn);
> >+
> >     /* TODO: test sysdb_search_selinux_config */
> > 
> >     fail_unless(check_leaks_pop(test_ctx) == true, "Memory leak");
> >@@ -5786,6 +5879,10 @@ Suite *create_sysdb_suite(void)
> >                         MBO_GROUP_BASE , MBO_GROUP_BASE + 10);
> >     tcase_add_loop_test(tc_memberof, test_sysdb_memberof_check_nested_double_ghosts,
> >                         MBO_GROUP_BASE , MBO_GROUP_BASE + 10);
> >+
> >+    /* sss_ldb_search */
> >+    tcase_add_test(tc_sysdb, test_sss_ldb_search);
> >+
> >     /* This loop counts backwards so the indexing is a little odd */
> >     tcase_add_loop_test(tc_memberof, test_sysdb_memberof_mod_replace_keep,
> >                         1 , 11);
> >-- 
> >1.8.4.2
> >
> 
> >From 7954ad8ee3310d7e7bc9ac12c3b764786c052a4d Mon Sep 17 00:00:00 2001
> >From: Pavel Reichl <preichl at redhat.com>
> >Date: Wed, 26 Feb 2014 16:52:26 +0000
> >Subject: [PATCH 3/5] SYSDB: sysdb_getnetgr returns ENOENT
> >
> >Replace call of ldb_search by sss_ldb_search to make sure that ENOENT is
> >returned if no results were found.
> >
> >Resolves:
> >https://fedorahosted.org/sssd/ticket/1991
> >---
> > src/db/sysdb_search.c | 20 ++++++++------------
> > 1 file changed, 8 insertions(+), 12 deletions(-)
> >
> >diff --git a/src/db/sysdb_search.c b/src/db/sysdb_search.c
> >index 60ad61368d92d12bca3833bc08b0673c581ab882..608277ab34c3280659cb2cf04ea57721bd9790f5 100644
> >--- a/src/db/sysdb_search.c
> >+++ b/src/db/sysdb_search.c
> >@@ -786,7 +786,6 @@ errno_t sysdb_getnetgr(TALLOC_CTX *mem_ctx,
> >     char *sanitized_netgroup;
> >     char *lc_sanitized_netgroup;
> >     char *netgroup_dn;
> >-    int lret;
> >     errno_t ret;
> > 
> >     tmp_ctx = talloc_new(NULL);
> >@@ -816,18 +815,15 @@ errno_t sysdb_getnetgr(TALLOC_CTX *mem_ctx,
> >         goto done;
> >     }
> > 
> >-    lret = ldb_search(domain->sysdb->ldb, tmp_ctx, &result, base_dn,
> >-                     LDB_SCOPE_SUBTREE, attrs,
> >-                     SYSDB_NETGR_TRIPLES_FILTER, lc_sanitized_netgroup,
> >-                     sanitized_netgroup, sanitized_netgroup,
> >-                     netgroup_dn);
> >-    ret = sysdb_error_to_errno(lret);
> >-    if (ret != EOK) {
> >-        goto done;
> >-    }
> >+    ret = sss_ldb_search(domain->sysdb->ldb, tmp_ctx, &result, base_dn,
> >+                         LDB_SCOPE_SUBTREE, attrs,
> >+                         SYSDB_NETGR_TRIPLES_FILTER, lc_sanitized_netgroup,
> >+                         sanitized_netgroup, sanitized_netgroup,
> >+                         netgroup_dn);
> > 
> >-    *res = talloc_steal(mem_ctx, result);
> >-    ret = EOK;
> >+    if (ret == EOK || ret == ENOENT) {
> >+        *res = talloc_steal(mem_ctx, result);
> There is a warning from coverity
> Error: UNINIT (CWE-457):
> sssd-1.11.92/src/db/sysdb_search.c:785: var_decl: Declaring variable "result" without initializer.
> sssd-1.11.92/src/db/sysdb_search.c:825: uninit_use_in_call: Using uninitialized value "result" when calling "_talloc_steal_loc".
> 
> I think it is false positive.
So do I. But I wonder if initiating result to NULL would make coverity
to be quiet. (done in attached patch).

> 
> >+    }
> > 
> > done:
> >     talloc_zfree(tmp_ctx);
> >-- 
> >1.8.4.2
> >
> 
> >From 94a3501fa6d0f238c889e2e05858c0a42579815d Mon Sep 17 00:00:00 2001
> >From: Pavel Reichl <preichl at redhat.com>
> >Date: Thu, 19 Jun 2014 16:18:12 +0100
> >Subject: [PATCH 4/5] TESTS: sysdb_getnetgr - return ENOENT
> >
> >Resolves:
> >https://fedorahosted.org/sssd/ticket/1991
> >---
> BTW 3rd and 4th patch are small.
> 
> I am used to sending a fix and an unit test in single patch. Small benefit is
> that we don't forgot to backport a test. I don't have strong preferences.
> I just want to start discussion what should be prefered way
>     a) to send a fix and an unit test in two patches
>     b) to send a fix and an unit test in single patch
> (of course there can be exceptions :-)
I don't have strong preferences either as I'm not paid per commit so far.

I agree with your statement about 'forgetting to back-port'. On the
other hand I believe that patch should do just one thing and one thing
only. Either to fix the bug or introduce a test. 

Direct advantage of separate patches is possibility to run test before
applying patch with bug fix and then to see if it really fixes the
issue.



> >From 44c4d576c840c01bade8f7f7aa6c980793d79505 Mon Sep 17 00:00:00 2001
> >From: Pavel Reichl <preichl at redhat.com>
> >Date: Tue, 24 Jun 2014 09:47:09 +0100
> >Subject: [PATCH 5/5] NSS: lookup_netgr_step don't access result on ENOENT
> >
> >Don't access result if return value is not EOK.
> >---
> > src/responder/nss/nsssrv_netgroup.c | 45 +++++++++++++++++++------------------
> > 1 file changed, 23 insertions(+), 22 deletions(-)
> >
> >diff --git a/src/responder/nss/nsssrv_netgroup.c b/src/responder/nss/nsssrv_netgroup.c
> >index 1c9b72ae30c6ef1115d1ed972a12dc554db04bbe..d60f72a743157066dffca86493dfebf40bb451f6 100644
> >--- a/src/responder/nss/nsssrv_netgroup.c
> >+++ b/src/responder/nss/nsssrv_netgroup.c
> >@@ -514,30 +514,31 @@ static errno_t lookup_netgr_step(struct setent_step_ctx *step_ctx)
> > 
> >         /* Look up the netgroup in the cache */
> >         ret = sysdb_getnetgr(step_ctx->dctx, dom, name, &step_ctx->dctx->res);
> >-        if (ret == ENOENT) {
> >-            /* This netgroup was not found in this domain */
> >-            if (!step_ctx->dctx->check_provider) {
> >-                if (step_ctx->check_next) {
> >-                    dom = get_next_domain(dom, false);
> >-                    continue;
> >+        if (ret == EOK) {
> >+            if (step_ctx->dctx->res->count > 1) {
> >+                DEBUG(SSSDBG_FATAL_FAILURE,
> >+                      "getnetgr call returned more than one result !?!\n");
> >+                ret = EMSGSIZE;
> >+                goto done;
> >+            }
> >+        } else {
> >+            if (ret == ENOENT) {
> >+                /* This netgroup was not found in this domain */
> >+                if (!step_ctx->dctx->check_provider) {
> >+                    if (step_ctx->check_next) {
> >+                        dom = get_next_domain(dom, false);
> >+                        continue;
> >+                    } else {
> >+                        break;
> >+                    }
> >                 }
> >-                else break;
> >+                ret = EOK;
>                   warning: Value stored to 'ret' is never read
> I think conditionc could be more flatten
> if (ret == EOK) {
> ...
> } else if (ret == ENOENT) {
> ...
> } else {
> ...
> }
OK.

> 
> Or switch/case/default.
> 
> LS
> _______________________________________________
> sssd-devel mailing list
> sssd-devel at lists.fedorahosted.org
> https://lists.fedorahosted.org/mailman/listinfo/sssd-devel

-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-SYSDB-sss_ldb_search-wrapper-around-ldb_search.patch
Type: text/x-patch
Size: 3116 bytes
Desc: not available
URL: <https://lists.fedorahosted.org/pipermail/sssd-devel/attachments/20140624/3a566326/attachment.bin>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0002-TESTS-add-tests-for-sss_ldb_search.patch
Type: text/x-patch
Size: 4833 bytes
Desc: not available
URL: <https://lists.fedorahosted.org/pipermail/sssd-devel/attachments/20140624/3a566326/attachment-0001.bin>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0003-SYSDB-sysdb_getnetgr-returns-ENOENT.patch
Type: text/x-patch
Size: 2075 bytes
Desc: not available
URL: <https://lists.fedorahosted.org/pipermail/sssd-devel/attachments/20140624/3a566326/attachment-0002.bin>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0004-TESTS-sysdb_getnetgr-return-ENOENT.patch
Type: text/x-patch
Size: 1084 bytes
Desc: not available
URL: <https://lists.fedorahosted.org/pipermail/sssd-devel/attachments/20140624/3a566326/attachment-0003.bin>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0005-NSS-lookup_netgr_step-don-t-access-result-on-ENOENT.patch
Type: text/x-patch
Size: 2210 bytes
Desc: not available
URL: <https://lists.fedorahosted.org/pipermail/sssd-devel/attachments/20140624/3a566326/attachment-0004.bin>


More information about the sssd-devel mailing list