diff options
Diffstat (limited to '0092-tools-xenstore-simplify-and-fix-per-domain-node-acco.patch')
-rw-r--r-- | 0092-tools-xenstore-simplify-and-fix-per-domain-node-acco.patch | 336 |
1 files changed, 0 insertions, 336 deletions
diff --git a/0092-tools-xenstore-simplify-and-fix-per-domain-node-acco.patch b/0092-tools-xenstore-simplify-and-fix-per-domain-node-acco.patch deleted file mode 100644 index 01f29b1..0000000 --- a/0092-tools-xenstore-simplify-and-fix-per-domain-node-acco.patch +++ /dev/null @@ -1,336 +0,0 @@ -From 8ee7ed7c1ef435f43edc08be07c036d81642d8e1 Mon Sep 17 00:00:00 2001 -From: Juergen Gross <jgross@suse.com> -Date: Tue, 13 Sep 2022 07:35:08 +0200 -Subject: [PATCH 092/126] tools/xenstore: simplify and fix per domain node - accounting - -The accounting of nodes can be simplified now that each connection -holds the associated domid. - -Fix the node accounting to cover nodes created for a domain before it -has been introduced. This requires to react properly to an allocation -failure inside domain_entry_inc() by returning an error code. - -Especially in error paths the node accounting has to be fixed in some -cases. - -This is part of XSA-326 / CVE-2022-42313. - -Signed-off-by: Juergen Gross <jgross@suse.com> -Reviewed-by: Julien Grall <jgrall@amazon.com> -(cherry picked from commit dbef1f7482894c572d90cd73d99ed689c891e863) ---- - tools/xenstore/xenstored_core.c | 43 ++++++++-- - tools/xenstore/xenstored_domain.c | 105 ++++++++++++++++--------- - tools/xenstore/xenstored_domain.h | 4 +- - tools/xenstore/xenstored_transaction.c | 8 +- - 4 files changed, 109 insertions(+), 51 deletions(-) - -diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c -index 6ea06e20df91..85c0d2f38fac 100644 ---- a/tools/xenstore/xenstored_core.c -+++ b/tools/xenstore/xenstored_core.c -@@ -603,7 +603,7 @@ struct node *read_node(struct connection *conn, const void *ctx, - - /* Permissions are struct xs_permissions. */ - node->perms.p = hdr->perms; -- if (domain_adjust_node_perms(node)) { -+ if (domain_adjust_node_perms(conn, node)) { - talloc_free(node); - return NULL; - } -@@ -625,7 +625,7 @@ int write_node_raw(struct connection *conn, TDB_DATA *key, struct node *node, - void *p; - struct xs_tdb_record_hdr *hdr; - -- if (domain_adjust_node_perms(node)) -+ if (domain_adjust_node_perms(conn, node)) - return errno; - - data.dsize = sizeof(*hdr) -@@ -1238,13 +1238,17 @@ nomem: - return NULL; - } - --static int destroy_node(struct connection *conn, struct node *node) -+static void destroy_node_rm(struct node *node) - { - if (streq(node->name, "/")) - corrupt(NULL, "Destroying root node!"); - - tdb_delete(tdb_ctx, node->key); -+} - -+static int destroy_node(struct connection *conn, struct node *node) -+{ -+ destroy_node_rm(node); - domain_entry_dec(conn, node); - - /* -@@ -1294,8 +1298,12 @@ static struct node *create_node(struct connection *conn, const void *ctx, - goto err; - - /* Account for new node */ -- if (i->parent) -- domain_entry_inc(conn, i); -+ if (i->parent) { -+ if (domain_entry_inc(conn, i)) { -+ destroy_node_rm(i); -+ return NULL; -+ } -+ } - } - - return node; -@@ -1580,10 +1588,27 @@ static int do_set_perms(struct connection *conn, struct buffered_data *in) - old_perms = node->perms; - domain_entry_dec(conn, node); - node->perms = perms; -- domain_entry_inc(conn, node); -+ if (domain_entry_inc(conn, node)) { -+ node->perms = old_perms; -+ /* -+ * This should never fail because we had a reference on the -+ * domain before and Xenstored is single-threaded. -+ */ -+ domain_entry_inc(conn, node); -+ return ENOMEM; -+ } - -- if (write_node(conn, node, false)) -+ if (write_node(conn, node, false)) { -+ int saved_errno = errno; -+ -+ domain_entry_dec(conn, node); -+ node->perms = old_perms; -+ /* No failure possible as above. */ -+ domain_entry_inc(conn, node); -+ -+ errno = saved_errno; - return errno; -+ } - - fire_watches(conn, in, name, node, false, &old_perms); - send_ack(conn, XS_SET_PERMS); -@@ -3003,7 +3028,9 @@ void read_state_node(const void *ctx, const void *state) - set_tdb_key(name, &key); - if (write_node_raw(NULL, &key, node, true)) - barf("write node error restoring node"); -- domain_entry_inc(&conn, node); -+ -+ if (domain_entry_inc(&conn, node)) -+ barf("node accounting error restoring node"); - - talloc_free(node); - } -diff --git a/tools/xenstore/xenstored_domain.c b/tools/xenstore/xenstored_domain.c -index 979f8c629835..3c27973fb836 100644 ---- a/tools/xenstore/xenstored_domain.c -+++ b/tools/xenstore/xenstored_domain.c -@@ -16,6 +16,7 @@ - along with this program; If not, see <http://www.gnu.org/licenses/>. - */ - -+#include <assert.h> - #include <stdio.h> - #include <sys/mman.h> - #include <unistd.h> -@@ -369,6 +370,18 @@ static struct domain *find_or_alloc_domain(const void *ctx, unsigned int domid) - return domain ? : alloc_domain(ctx, domid); - } - -+static struct domain *find_or_alloc_existing_domain(unsigned int domid) -+{ -+ struct domain *domain; -+ xc_dominfo_t dominfo; -+ -+ domain = find_domain_struct(domid); -+ if (!domain && get_domain_info(domid, &dominfo)) -+ domain = alloc_domain(NULL, domid); -+ -+ return domain; -+} -+ - static int new_domain(struct domain *domain, int port, bool restore) - { - int rc; -@@ -788,30 +801,28 @@ void domain_deinit(void) - xenevtchn_unbind(xce_handle, virq_port); - } - --void domain_entry_inc(struct connection *conn, struct node *node) -+int domain_entry_inc(struct connection *conn, struct node *node) - { - struct domain *d; -+ unsigned int domid; - - if (!conn) -- return; -+ return 0; - -- if (node->perms.p && node->perms.p[0].id != conn->id) { -- if (conn->transaction) { -- transaction_entry_inc(conn->transaction, -- node->perms.p[0].id); -- } else { -- d = find_domain_by_domid(node->perms.p[0].id); -- if (d) -- d->nbentry++; -- } -- } else if (conn->domain) { -- if (conn->transaction) { -- transaction_entry_inc(conn->transaction, -- conn->domain->domid); -- } else { -- conn->domain->nbentry++; -- } -+ domid = node->perms.p ? node->perms.p[0].id : conn->id; -+ -+ if (conn->transaction) { -+ transaction_entry_inc(conn->transaction, domid); -+ } else { -+ d = (domid == conn->id && conn->domain) ? conn->domain -+ : find_or_alloc_existing_domain(domid); -+ if (d) -+ d->nbentry++; -+ else -+ return ENOMEM; - } -+ -+ return 0; - } - - /* -@@ -847,7 +858,7 @@ static int chk_domain_generation(unsigned int domid, uint64_t gen) - * Remove permissions for no longer existing domains in order to avoid a new - * domain with the same domid inheriting the permissions. - */ --int domain_adjust_node_perms(struct node *node) -+int domain_adjust_node_perms(struct connection *conn, struct node *node) - { - unsigned int i; - int ret; -@@ -857,8 +868,14 @@ int domain_adjust_node_perms(struct node *node) - return errno; - - /* If the owner doesn't exist any longer give it to priv domain. */ -- if (!ret) -+ if (!ret) { -+ /* -+ * In theory we'd need to update the number of dom0 nodes here, -+ * but we could be called for a read of the node. So better -+ * avoid the risk to overflow the node count of dom0. -+ */ - node->perms.p[0].id = priv_domid; -+ } - - for (i = 1; i < node->perms.num; i++) { - if (node->perms.p[i].perms & XS_PERM_IGNORE) -@@ -877,25 +894,25 @@ int domain_adjust_node_perms(struct node *node) - void domain_entry_dec(struct connection *conn, struct node *node) - { - struct domain *d; -+ unsigned int domid; - - if (!conn) - return; - -- if (node->perms.p && node->perms.p[0].id != conn->id) { -- if (conn->transaction) { -- transaction_entry_dec(conn->transaction, -- node->perms.p[0].id); -+ domid = node->perms.p ? node->perms.p[0].id : conn->id; -+ -+ if (conn->transaction) { -+ transaction_entry_dec(conn->transaction, domid); -+ } else { -+ d = (domid == conn->id && conn->domain) ? conn->domain -+ : find_domain_struct(domid); -+ if (d) { -+ d->nbentry--; - } else { -- d = find_domain_by_domid(node->perms.p[0].id); -- if (d && d->nbentry) -- d->nbentry--; -- } -- } else if (conn->domain && conn->domain->nbentry) { -- if (conn->transaction) { -- transaction_entry_dec(conn->transaction, -- conn->domain->domid); -- } else { -- conn->domain->nbentry--; -+ errno = ENOENT; -+ corrupt(conn, -+ "Node \"%s\" owned by non-existing domain %u\n", -+ node->name, domid); - } - } - } -@@ -905,13 +922,23 @@ int domain_entry_fix(unsigned int domid, int num, bool update) - struct domain *d; - int cnt; - -- d = find_domain_by_domid(domid); -- if (!d) -- return 0; -+ if (update) { -+ d = find_domain_struct(domid); -+ assert(d); -+ } else { -+ /* -+ * We are called first with update == false in order to catch -+ * any error. So do a possible allocation and check for error -+ * only in this case, as in the case of update == true nothing -+ * can go wrong anymore as the allocation already happened. -+ */ -+ d = find_or_alloc_existing_domain(domid); -+ if (!d) -+ return -1; -+ } - - cnt = d->nbentry + num; -- if (cnt < 0) -- cnt = 0; -+ assert(cnt >= 0); - - if (update) - d->nbentry = cnt; -diff --git a/tools/xenstore/xenstored_domain.h b/tools/xenstore/xenstored_domain.h -index 5757a6557146..cce13d14f016 100644 ---- a/tools/xenstore/xenstored_domain.h -+++ b/tools/xenstore/xenstored_domain.h -@@ -58,10 +58,10 @@ bool domain_can_write(struct connection *conn); - bool domain_is_unprivileged(struct connection *conn); - - /* Remove node permissions for no longer existing domains. */ --int domain_adjust_node_perms(struct node *node); -+int domain_adjust_node_perms(struct connection *conn, struct node *node); - - /* Quota manipulation */ --void domain_entry_inc(struct connection *conn, struct node *); -+int domain_entry_inc(struct connection *conn, struct node *); - void domain_entry_dec(struct connection *conn, struct node *); - int domain_entry_fix(unsigned int domid, int num, bool update); - int domain_entry(struct connection *conn); -diff --git a/tools/xenstore/xenstored_transaction.c b/tools/xenstore/xenstored_transaction.c -index ee1b09031a3b..86caf6c398be 100644 ---- a/tools/xenstore/xenstored_transaction.c -+++ b/tools/xenstore/xenstored_transaction.c -@@ -519,8 +519,12 @@ static int transaction_fix_domains(struct transaction *trans, bool update) - - list_for_each_entry(d, &trans->changed_domains, list) { - cnt = domain_entry_fix(d->domid, d->nbentry, update); -- if (!update && cnt >= quota_nb_entry_per_domain) -- return ENOSPC; -+ if (!update) { -+ if (cnt >= quota_nb_entry_per_domain) -+ return ENOSPC; -+ if (cnt < 0) -+ return ENOMEM; -+ } - } - - return 0; --- -2.37.4 - |