[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen master] tools/xenstore: fix quota check in acc_fix_domains()
commit f6b801c36bd5e4ab22a9f80c8d57121b62b139af Author: Juergen Gross <jgross@xxxxxxxx> AuthorDate: Tue Mar 28 16:43:27 2023 +0200 Commit: Julien Grall <jgrall@xxxxxxxxxx> CommitDate: Wed Mar 29 22:02:36 2023 +0100 tools/xenstore: fix quota check in acc_fix_domains() Today when finalizing a transaction the number of node quota is checked to not being exceeded after the transaction. This check is always done, even if the transaction is being performed by a privileged connection, or if there were no nodes created in the transaction. Correct that by checking quota only if: - the transaction is being performed by an unprivileged guest, and - at least one node was created in the transaction Reported-by: Julien Grall <julien@xxxxxxx> Fixes: f2bebf72c4d5 ("xenstore: rework of transaction handling") Signed-off-by: Juergen Gross <jgross@xxxxxxxx> --- tools/xenstore/xenstored_core.c | 3 +++ tools/xenstore/xenstored_domain.c | 4 ++-- tools/xenstore/xenstored_domain.h | 7 ++++++- tools/xenstore/xenstored_transaction.c | 16 ++++++++++++++-- tools/xenstore/xenstored_transaction.h | 3 +++ 5 files changed, 28 insertions(+), 5 deletions(-) diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c index a61db2db2d..3ca68681e3 100644 --- a/tools/xenstore/xenstored_core.c +++ b/tools/xenstore/xenstored_core.c @@ -1472,6 +1472,9 @@ static struct node *create_node(struct connection *conn, const void *ctx, if (!node) return NULL; + if (conn && conn->transaction) + ta_node_created(conn->transaction); + node->data = data; node->datalen = datalen; diff --git a/tools/xenstore/xenstored_domain.c b/tools/xenstore/xenstored_domain.c index d7fc2fafc7..f62be2245c 100644 --- a/tools/xenstore/xenstored_domain.c +++ b/tools/xenstore/xenstored_domain.c @@ -544,7 +544,7 @@ static struct domain *find_domain_by_domid(unsigned int domid) return (d && d->introduced) ? d : NULL; } -int acc_fix_domains(struct list_head *head, bool update) +int acc_fix_domains(struct list_head *head, bool chk_quota, bool update) { struct changed_domain *cd; int cnt; @@ -552,7 +552,7 @@ int acc_fix_domains(struct list_head *head, bool update) list_for_each_entry(cd, head, list) { cnt = domain_nbentry_fix(cd->domid, cd->nbentry, update); if (!update) { - if (cnt >= quota_nb_entry_per_domain) + if (chk_quota && cnt >= quota_nb_entry_per_domain) return ENOSPC; if (cnt < 0) return ENOMEM; diff --git a/tools/xenstore/xenstored_domain.h b/tools/xenstore/xenstored_domain.h index dc4660861e..279cccb3ad 100644 --- a/tools/xenstore/xenstored_domain.h +++ b/tools/xenstore/xenstored_domain.h @@ -96,7 +96,12 @@ void domain_outstanding_dec(struct connection *conn); void domain_outstanding_domid_dec(unsigned int domid); int domain_get_quota(const void *ctx, struct connection *conn, unsigned int domid); -int acc_fix_domains(struct list_head *head, bool update); + +/* + * Update or check number of nodes per domain at the end of a transaction. + * If "update" is true, "chk_quota" is ignored. + */ +int acc_fix_domains(struct list_head *head, bool chk_quota, bool update); /* Write rate limiting */ diff --git a/tools/xenstore/xenstored_transaction.c b/tools/xenstore/xenstored_transaction.c index 1aa9d3cb3d..2b15506953 100644 --- a/tools/xenstore/xenstored_transaction.c +++ b/tools/xenstore/xenstored_transaction.c @@ -160,12 +160,20 @@ struct transaction /* List of changed domains - to record the changed domain entry number */ struct list_head changed_domains; + /* There was at least one node created in the transaction. */ + bool node_created; + /* Flag for letting transaction fail. */ bool fail; }; uint64_t generation; +void ta_node_created(struct transaction *trans) +{ + trans->node_created = true; +} + static struct accessed_node *find_accessed_node(struct transaction *trans, const char *name) { @@ -509,6 +517,7 @@ int do_transaction_end(const void *ctx, struct connection *conn, const char *arg = onearg(in); struct transaction *trans; bool is_corrupt = false; + bool chk_quota; int ret; if (!arg || (!streq(arg, "T") && !streq(arg, "F"))) @@ -523,13 +532,16 @@ int do_transaction_end(const void *ctx, struct connection *conn, if (!conn->transaction_started) conn->ta_start_time = 0; + chk_quota = trans->node_created && domain_is_unprivileged(conn); + /* Attach transaction to ctx for auto-cleanup */ talloc_steal(ctx, trans); if (streq(arg, "T")) { if (trans->fail) return ENOMEM; - ret = acc_fix_domains(&trans->changed_domains, false); + ret = acc_fix_domains(&trans->changed_domains, chk_quota, + false); if (ret) return ret; ret = finalize_transaction(conn, trans, &is_corrupt); @@ -539,7 +551,7 @@ int do_transaction_end(const void *ctx, struct connection *conn, wrl_apply_debit_trans_commit(conn); /* fix domain entry for each changed domain */ - acc_fix_domains(&trans->changed_domains, true); + acc_fix_domains(&trans->changed_domains, false, true); if (is_corrupt) corrupt(conn, "transaction inconsistency"); diff --git a/tools/xenstore/xenstored_transaction.h b/tools/xenstore/xenstored_transaction.h index b6f8cb7d0a..883145163f 100644 --- a/tools/xenstore/xenstored_transaction.h +++ b/tools/xenstore/xenstored_transaction.h @@ -36,6 +36,9 @@ int do_transaction_end(const void *ctx, struct connection *conn, struct transaction *transaction_lookup(struct connection *conn, uint32_t id); +/* Set flag for created node. */ +void ta_node_created(struct transaction *trans); + /* This node was accessed. */ int __must_check access_node(struct connection *conn, struct node *node, enum node_access_type type, TDB_DATA *key); -- generated by git-patchbot for /home/xen/git/xen.git#master
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