diff options
Diffstat (limited to 'security/landlock/syscalls.c')
-rw-r--r-- | security/landlock/syscalls.c | 95 |
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)) |