aboutsummaryrefslogtreecommitdiffstats
path: root/security/landlock/syscalls.c
diff options
context:
space:
mode:
Diffstat (limited to 'security/landlock/syscalls.c')
-rw-r--r--security/landlock/syscalls.c95
1 files changed, 50 insertions, 45 deletions
diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c
index 7e27ce394020..735a0865ea11 100644
--- a/security/landlock/syscalls.c
+++ b/security/landlock/syscalls.c
@@ -43,9 +43,10 @@
* @src: User space pointer or NULL.
* @usize: (Alleged) size of the data pointed to by @src.
*/
-static __always_inline int copy_min_struct_from_user(void *const dst,
- const size_t ksize, const size_t ksize_min,
- const void __user *const src, const size_t usize)
+static __always_inline int
+copy_min_struct_from_user(void *const dst, const size_t ksize,
+ const size_t ksize_min, const void __user *const src,
+ const size_t usize)
{
/* Checks buffer inconsistencies. */
BUILD_BUG_ON(!dst);
@@ -93,7 +94,7 @@ static void build_check_abi(void)
/* Ruleset handling */
static int fop_ruleset_release(struct inode *const inode,
- struct file *const filp)
+ struct file *const filp)
{
struct landlock_ruleset *ruleset = filp->private_data;
@@ -102,15 +103,15 @@ static int fop_ruleset_release(struct inode *const inode,
}
static ssize_t fop_dummy_read(struct file *const filp, char __user *const buf,
- const size_t size, loff_t *const ppos)
+ const size_t size, loff_t *const ppos)
{
/* Dummy handler to enable FMODE_CAN_READ. */
return -EINVAL;
}
static ssize_t fop_dummy_write(struct file *const filp,
- const char __user *const buf, const size_t size,
- loff_t *const ppos)
+ const char __user *const buf, const size_t size,
+ loff_t *const ppos)
{
/* Dummy handler to enable FMODE_CAN_WRITE. */
return -EINVAL;
@@ -128,7 +129,7 @@ static const struct file_operations ruleset_fops = {
.write = fop_dummy_write,
};
-#define LANDLOCK_ABI_VERSION 1
+#define LANDLOCK_ABI_VERSION 2
/**
* sys_landlock_create_ruleset - Create a new ruleset
@@ -168,22 +169,23 @@ SYSCALL_DEFINE3(landlock_create_ruleset,
return -EOPNOTSUPP;
if (flags) {
- if ((flags == LANDLOCK_CREATE_RULESET_VERSION)
- && !attr && !size)
+ if ((flags == LANDLOCK_CREATE_RULESET_VERSION) && !attr &&
+ !size)
return LANDLOCK_ABI_VERSION;
return -EINVAL;
}
/* Copies raw user space buffer. */
err = copy_min_struct_from_user(&ruleset_attr, sizeof(ruleset_attr),
- offsetofend(typeof(ruleset_attr), handled_access_fs),
- attr, size);
+ offsetofend(typeof(ruleset_attr),
+ handled_access_fs),
+ attr, size);
if (err)
return err;
/* Checks content (and 32-bits cast). */
if ((ruleset_attr.handled_access_fs | LANDLOCK_MASK_ACCESS_FS) !=
- LANDLOCK_MASK_ACCESS_FS)
+ LANDLOCK_MASK_ACCESS_FS)
return -EINVAL;
/* Checks arguments and transforms to kernel struct. */
@@ -193,7 +195,7 @@ SYSCALL_DEFINE3(landlock_create_ruleset,
/* Creates anonymous FD referring to the ruleset. */
ruleset_fd = anon_inode_getfd("[landlock-ruleset]", &ruleset_fops,
- ruleset, O_RDWR | O_CLOEXEC);
+ ruleset, O_RDWR | O_CLOEXEC);
if (ruleset_fd < 0)
landlock_put_ruleset(ruleset);
return ruleset_fd;
@@ -204,7 +206,7 @@ SYSCALL_DEFINE3(landlock_create_ruleset,
* landlock_put_ruleset() on the return value.
*/
static struct landlock_ruleset *get_ruleset_from_fd(const int fd,
- const fmode_t mode)
+ const fmode_t mode)
{
struct fd ruleset_f;
struct landlock_ruleset *ruleset;
@@ -244,8 +246,8 @@ static int get_path_from_fd(const s32 fd, struct path *const path)
struct fd f;
int err = 0;
- BUILD_BUG_ON(!__same_type(fd,
- ((struct landlock_path_beneath_attr *)NULL)->parent_fd));
+ BUILD_BUG_ON(!__same_type(
+ fd, ((struct landlock_path_beneath_attr *)NULL)->parent_fd));
/* Handles O_PATH. */
f = fdget_raw(fd);
@@ -257,10 +259,10 @@ static int get_path_from_fd(const s32 fd, struct path *const path)
* pipefs).
*/
if ((f.file->f_op == &ruleset_fops) ||
- (f.file->f_path.mnt->mnt_flags & MNT_INTERNAL) ||
- (f.file->f_path.dentry->d_sb->s_flags & SB_NOUSER) ||
- d_is_negative(f.file->f_path.dentry) ||
- IS_PRIVATE(d_backing_inode(f.file->f_path.dentry))) {
+ (f.file->f_path.mnt->mnt_flags & MNT_INTERNAL) ||
+ (f.file->f_path.dentry->d_sb->s_flags & SB_NOUSER) ||
+ d_is_negative(f.file->f_path.dentry) ||
+ IS_PRIVATE(d_backing_inode(f.file->f_path.dentry))) {
err = -EBADFD;
goto out_fdput;
}
@@ -290,19 +292,18 @@ out_fdput:
*
* - EOPNOTSUPP: Landlock is supported by the kernel but disabled at boot time;
* - EINVAL: @flags is not 0, or inconsistent access in the rule (i.e.
- * &landlock_path_beneath_attr.allowed_access is not a subset of the rule's
- * accesses);
+ * &landlock_path_beneath_attr.allowed_access is not a subset of the
+ * ruleset handled accesses);
* - ENOMSG: Empty accesses (e.g. &landlock_path_beneath_attr.allowed_access);
* - EBADF: @ruleset_fd is not a file descriptor for the current thread, or a
* member of @rule_attr is not a file descriptor as expected;
* - EBADFD: @ruleset_fd is not a ruleset file descriptor, or a member of
- * @rule_attr is not the expected file descriptor type (e.g. file open
- * without O_PATH);
+ * @rule_attr is not the expected file descriptor type;
* - EPERM: @ruleset_fd has no write access to the underlying ruleset;
* - EFAULT: @rule_attr inconsistency.
*/
-SYSCALL_DEFINE4(landlock_add_rule,
- const int, ruleset_fd, const enum landlock_rule_type, rule_type,
+SYSCALL_DEFINE4(landlock_add_rule, const int, ruleset_fd,
+ const enum landlock_rule_type, rule_type,
const void __user *const, rule_attr, const __u32, flags)
{
struct landlock_path_beneath_attr path_beneath_attr;
@@ -317,20 +318,24 @@ SYSCALL_DEFINE4(landlock_add_rule,
if (flags)
return -EINVAL;
- if (rule_type != LANDLOCK_RULE_PATH_BENEATH)
- return -EINVAL;
-
- /* Copies raw user space buffer, only one type for now. */
- res = copy_from_user(&path_beneath_attr, rule_attr,
- sizeof(path_beneath_attr));
- if (res)
- return -EFAULT;
-
/* Gets and checks the ruleset. */
ruleset = get_ruleset_from_fd(ruleset_fd, FMODE_CAN_WRITE);
if (IS_ERR(ruleset))
return PTR_ERR(ruleset);
+ if (rule_type != LANDLOCK_RULE_PATH_BENEATH) {
+ err = -EINVAL;
+ goto out_put_ruleset;
+ }
+
+ /* Copies raw user space buffer, only one type for now. */
+ res = copy_from_user(&path_beneath_attr, rule_attr,
+ sizeof(path_beneath_attr));
+ if (res) {
+ err = -EFAULT;
+ goto out_put_ruleset;
+ }
+
/*
* Informs about useless rule: empty allowed_access (i.e. deny rules)
* are ignored in path walks.
@@ -344,7 +349,7 @@ SYSCALL_DEFINE4(landlock_add_rule,
* (ruleset->fs_access_masks[0] is automatically upgraded to 64-bits).
*/
if ((path_beneath_attr.allowed_access | ruleset->fs_access_masks[0]) !=
- ruleset->fs_access_masks[0]) {
+ ruleset->fs_access_masks[0]) {
err = -EINVAL;
goto out_put_ruleset;
}
@@ -356,7 +361,7 @@ SYSCALL_DEFINE4(landlock_add_rule,
/* Imports the new rule. */
err = landlock_append_fs_rule(ruleset, &path,
- path_beneath_attr.allowed_access);
+ path_beneath_attr.allowed_access);
path_put(&path);
out_put_ruleset:
@@ -389,8 +394,8 @@ out_put_ruleset:
* - E2BIG: The maximum number of stacked rulesets is reached for the current
* thread.
*/
-SYSCALL_DEFINE2(landlock_restrict_self,
- const int, ruleset_fd, const __u32, flags)
+SYSCALL_DEFINE2(landlock_restrict_self, const int, ruleset_fd, const __u32,
+ flags)
{
struct landlock_ruleset *new_dom, *ruleset;
struct cred *new_cred;
@@ -400,18 +405,18 @@ SYSCALL_DEFINE2(landlock_restrict_self,
if (!landlock_initialized)
return -EOPNOTSUPP;
- /* No flag for now. */
- if (flags)
- return -EINVAL;
-
/*
* Similar checks as for seccomp(2), except that an -EPERM may be
* returned.
*/
if (!task_no_new_privs(current) &&
- !ns_capable_noaudit(current_user_ns(), CAP_SYS_ADMIN))
+ !ns_capable_noaudit(current_user_ns(), CAP_SYS_ADMIN))
return -EPERM;
+ /* No flag for now. */
+ if (flags)
+ return -EINVAL;
+
/* Gets and checks the ruleset. */
ruleset = get_ruleset_from_fd(ruleset_fd, FMODE_CAN_READ);
if (IS_ERR(ruleset))
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.