Handle memory allocation errors in landlock_create_object() call. This prevent to inadvertently hold an inode. Also, make get_inode_object() more readable. Cc: James Morris <jmorris@xxxxxxxxx> Cc: Jann Horn <jannh@xxxxxxxxxx> Cc: Serge E. Hallyn <serge@xxxxxxxxxx> Signed-off-by: Mickaël Salaün <mic@xxxxxxxxxxx> --- security/landlock/fs.c | 5 +++++ security/landlock/object.c | 5 +++-- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/security/landlock/fs.c b/security/landlock/fs.c index d8c5d19ac2af..b67c821bb40b 100644 --- a/security/landlock/fs.c +++ b/security/landlock/fs.c @@ -9,6 +9,7 @@ #include <linux/atomic.h> #include <linux/compiler_types.h> #include <linux/dcache.h> +#include <linux/err.h> #include <linux/fs.h> #include <linux/init.h> #include <linux/kernel.h> @@ -98,6 +99,8 @@ static struct landlock_object *get_inode_object(struct inode *const inode) * holding any locks). */ new_object = landlock_create_object(&landlock_fs_underops, inode); + if (IS_ERR(new_object)) + return new_object; spin_lock(&inode->i_lock); object = rcu_dereference_protected(inode_sec->object, @@ -145,6 +148,8 @@ int landlock_append_fs_rule(struct landlock_ruleset *const ruleset, access_rights |= _LANDLOCK_ACCESS_FS_MASK & ~ruleset->fs_access_mask; rule.access = access_rights; rule.object = get_inode_object(d_backing_inode(path->dentry)); + if (IS_ERR(rule.object)) + return PTR_ERR(rule.object); mutex_lock(&ruleset->lock); err = landlock_insert_rule(ruleset, &rule, false); mutex_unlock(&ruleset->lock); diff --git a/security/landlock/object.c b/security/landlock/object.c index a71644ee72a7..54ba0327002a 100644 --- a/security/landlock/object.c +++ b/security/landlock/object.c @@ -8,6 +8,7 @@ #include <linux/bug.h> #include <linux/compiler_types.h> +#include <linux/err.h> #include <linux/kernel.h> #include <linux/rcupdate.h> #include <linux/refcount.h> @@ -23,10 +24,10 @@ struct landlock_object *landlock_create_object( struct landlock_object *new_object; if (WARN_ON_ONCE(!underops || !underobj)) - return NULL; + return ERR_PTR(-ENOENT); new_object = kzalloc(sizeof(*new_object), GFP_KERNEL_ACCOUNT); if (!new_object) - return NULL; + return ERR_PTR(-ENOMEM); refcount_set(&new_object->usage, 1); spin_lock_init(&new_object->lock); new_object->underops = underops; -- 2.29.2
