153 lines
4.5 KiB
Diff
153 lines
4.5 KiB
Diff
From 7d174f53539bfbfa9cdfa41ead605573d3f219eb Mon Sep 17 00:00:00 2001
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From: Florian Weimer <fweimer@redhat.com>
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Date: Tue, 28 Aug 2018 13:19:27 +0200
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Subject: [PATCH 41] nscd: Fix use-after-free in addgetnetgrentX [BZ #23520]
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addinnetgrX may use the heap-allocated buffer, so free the buffer
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in this function.
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(cherry picked from commit 745664bd798ec8fd50438605948eea594179fba1)
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---
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ChangeLog | 12 ++++++++++++
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nscd/netgroupcache.c | 42 +++++++++++++++++++++++++++++-------------
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2 files changed, 41 insertions(+), 13 deletions(-)
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diff --git a/ChangeLog b/ChangeLog
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index e81991066e..79d303e7b6 100644
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--- a/ChangeLog
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+++ b/ChangeLog
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@@ -1,3 +1,15 @@
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+2018-08-28 Florian Weimer <fweimer@redhat.com>
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+
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+ [BZ #23520]
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+ nscd: Fix use-after-free in addgetnetgrentX and its callers.
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+ * nscd/netgroupcache.c
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+ (addgetnetgrentX): Add tofreep parameter. Do not free
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+ heap-allocated buffer.
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+ (addinnetgrX): Free buffer allocated bt addgetnetgrentX.
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+ (addgetnetgrentX_ignore): New function.
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+ (addgetnetgrent): Call it.
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+ (readdgetnetgrent): Likewise.
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+
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2018-08-16 DJ Delorie <dj@delorie.com>
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* malloc/malloc.c (_int_free): Check for corrupt prev_size vs size.
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diff --git a/nscd/netgroupcache.c b/nscd/netgroupcache.c
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index 2b35389cc8..87059fb280 100644
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--- a/nscd/netgroupcache.c
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+++ b/nscd/netgroupcache.c
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@@ -113,7 +113,8 @@ do_notfound (struct database_dyn *db, int fd, request_header *req,
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static time_t
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addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
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const char *key, uid_t uid, struct hashentry *he,
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- struct datahead *dh, struct dataset **resultp)
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+ struct datahead *dh, struct dataset **resultp,
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+ void **tofreep)
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{
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if (__glibc_unlikely (debug_level > 0))
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{
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@@ -139,6 +140,7 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
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size_t group_len = strlen (key) + 1;
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struct name_list *first_needed
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= alloca (sizeof (struct name_list) + group_len);
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+ *tofreep = NULL;
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if (netgroup_database == NULL
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&& __nss_database_lookup ("netgroup", NULL, NULL, &netgroup_database))
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@@ -151,6 +153,7 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
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memset (&data, '\0', sizeof (data));
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buffer = xmalloc (buflen);
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+ *tofreep = buffer;
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first_needed->next = first_needed;
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memcpy (first_needed->name, key, group_len);
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data.needed_groups = first_needed;
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@@ -439,8 +442,6 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
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}
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out:
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- free (buffer);
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-
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*resultp = dataset;
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return timeout;
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@@ -477,8 +478,12 @@ addinnetgrX (struct database_dyn *db, int fd, request_header *req,
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group, group_len,
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db, uid);
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time_t timeout;
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+ void *tofree;
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if (result != NULL)
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- timeout = result->head.timeout;
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+ {
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+ timeout = result->head.timeout;
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+ tofree = NULL;
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+ }
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else
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{
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request_header req_get =
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@@ -487,7 +492,7 @@ addinnetgrX (struct database_dyn *db, int fd, request_header *req,
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.key_len = group_len
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};
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timeout = addgetnetgrentX (db, -1, &req_get, group, uid, NULL, NULL,
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- &result);
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+ &result, &tofree);
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}
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struct indataset
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@@ -560,7 +565,7 @@ addinnetgrX (struct database_dyn *db, int fd, request_header *req,
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++dh->nreloads;
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if (cacheable)
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pthread_rwlock_unlock (&db->lock);
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- return timeout;
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+ goto out;
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}
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if (he == NULL)
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@@ -596,17 +601,30 @@ addinnetgrX (struct database_dyn *db, int fd, request_header *req,
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dh->usable = false;
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}
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+ out:
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+ free (tofree);
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return timeout;
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}
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+static time_t
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+addgetnetgrentX_ignore (struct database_dyn *db, int fd, request_header *req,
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+ const char *key, uid_t uid, struct hashentry *he,
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+ struct datahead *dh)
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+{
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+ struct dataset *ignore;
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+ void *tofree;
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+ time_t timeout = addgetnetgrentX (db, fd, req, key, uid, he, dh,
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+ &ignore, &tofree);
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+ free (tofree);
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+ return timeout;
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+}
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+
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void
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addgetnetgrent (struct database_dyn *db, int fd, request_header *req,
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void *key, uid_t uid)
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{
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- struct dataset *ignore;
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-
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- addgetnetgrentX (db, fd, req, key, uid, NULL, NULL, &ignore);
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+ addgetnetgrentX_ignore (db, fd, req, key, uid, NULL, NULL);
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}
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@@ -619,10 +637,8 @@ readdgetnetgrent (struct database_dyn *db, struct hashentry *he,
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.type = GETNETGRENT,
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.key_len = he->len
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};
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- struct dataset *ignore;
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-
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- return addgetnetgrentX (db, -1, &req, db->data + he->key, he->owner, he, dh,
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- &ignore);
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+ return addgetnetgrentX_ignore
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+ (db, -1, &req, db->data + he->key, he->owner, he, dh);
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}
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