From: Xu Kuohai <xukuohai@xxxxxxxxxx> To be consistent with most LSM hooks, convert the return value of hook inode_getsecurity to 0 or a negative error code. Before: - Hook inode_getsecurity returns size of buffer on success or a negative error code on failure. After: - Hook inode_getsecurity returns 0 on success or a negative error code on failure. An output parameter @len is introduced to hold the buffer size on success. Signed-off-by: Xu Kuohai <xukuohai@xxxxxxxxxx> --- fs/xattr.c | 19 ++++++++++--------- include/linux/lsm_hook_defs.h | 3 ++- include/linux/security.h | 12 ++++++------ security/commoncap.c | 9 ++++++--- security/security.c | 11 ++++++----- security/selinux/hooks.c | 16 ++++++---------- security/smack/smack_lsm.c | 14 +++++++------- 7 files changed, 43 insertions(+), 41 deletions(-) diff --git a/fs/xattr.c b/fs/xattr.c index f8b643f91a98..f4e3bedf7272 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -339,27 +339,28 @@ xattr_getsecurity(struct mnt_idmap *idmap, struct inode *inode, const char *name, void *value, size_t size) { void *buffer = NULL; - ssize_t len; + int error; + u32 len; if (!value || !size) { - len = security_inode_getsecurity(idmap, inode, name, - &buffer, false); + error = security_inode_getsecurity(idmap, inode, name, + false, &buffer, &len); goto out_noalloc; } - len = security_inode_getsecurity(idmap, inode, name, &buffer, - true); - if (len < 0) - return len; + error = security_inode_getsecurity(idmap, inode, name, true, + &buffer, &len); + if (error) + return error; if (size < len) { - len = -ERANGE; + error = -ERANGE; goto out; } memcpy(value, buffer, len); out: kfree(buffer); out_noalloc: - return len; + return error < 0 ? error : len; } /* diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 964849de424b..4f056f2613af 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -169,7 +169,8 @@ LSM_HOOK(int, 0, inode_need_killpriv, struct dentry *dentry, bool *need) LSM_HOOK(int, 0, inode_killpriv, struct mnt_idmap *idmap, struct dentry *dentry) LSM_HOOK(int, -EOPNOTSUPP, inode_getsecurity, struct mnt_idmap *idmap, - struct inode *inode, const char *name, void **buffer, bool alloc) + struct inode *inode, const char *name, bool alloc, void **buffer, + u32 *len) LSM_HOOK(int, -EOPNOTSUPP, inode_setsecurity, struct inode *inode, const char *name, const void *value, size_t size, int flags) LSM_HOOK(int, 0, inode_listsecurity, struct inode *inode, char *buffer, diff --git a/include/linux/security.h b/include/linux/security.h index 1614ef5b2dd2..b6d296d21438 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -164,8 +164,8 @@ int cap_inode_removexattr(struct mnt_idmap *idmap, int cap_inode_need_killpriv(struct dentry *dentry, bool *need); int cap_inode_killpriv(struct mnt_idmap *idmap, struct dentry *dentry); int cap_inode_getsecurity(struct mnt_idmap *idmap, - struct inode *inode, const char *name, void **buffer, - bool alloc); + struct inode *inode, const char *name, bool alloc, + void **buffer, u32 *len); extern int cap_mmap_addr(unsigned long addr); extern int cap_mmap_file(struct file *file, unsigned long reqprot, unsigned long prot, unsigned long flags); @@ -393,7 +393,7 @@ int security_inode_need_killpriv(struct dentry *dentry, int *attr); int security_inode_killpriv(struct mnt_idmap *idmap, struct dentry *dentry); int security_inode_getsecurity(struct mnt_idmap *idmap, struct inode *inode, const char *name, - void **buffer, bool alloc); + bool alloc, void **buffer, u32 *len); int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags); int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size); void security_inode_getsecid(struct inode *inode, u32 *secid); @@ -996,10 +996,10 @@ static inline int security_inode_killpriv(struct mnt_idmap *idmap, static inline int security_inode_getsecurity(struct mnt_idmap *idmap, struct inode *inode, - const char *name, void **buffer, - bool alloc) + const char *name, bool alloc, + void **buffer, u32 *len) { - return cap_inode_getsecurity(idmap, inode, name, buffer, alloc); + return cap_inode_getsecurity(idmap, inode, name, alloc, buffer, len); } static inline int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags) diff --git a/security/commoncap.c b/security/commoncap.c index 17d6188d22cf..ff82e2ab6f8f 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -383,8 +383,8 @@ static bool is_v3header(int size, const struct vfs_cap_data *cap) * so that's good. */ int cap_inode_getsecurity(struct mnt_idmap *idmap, - struct inode *inode, const char *name, void **buffer, - bool alloc) + struct inode *inode, const char *name, + bool alloc, void **buffer, u32 *len) { int size; kuid_t kroot; @@ -485,7 +485,10 @@ int cap_inode_getsecurity(struct mnt_idmap *idmap, } out_free: kfree(tmpbuf); - return size; + if (size < 0) + return size; + *len = size; + return 0; } /** diff --git a/security/security.c b/security/security.c index a4abcd86eb36..614f14cbfff7 100644 --- a/security/security.c +++ b/security/security.c @@ -2544,8 +2544,9 @@ int security_inode_killpriv(struct mnt_idmap *idmap, * @idmap: idmap of the mount * @inode: inode * @name: xattr name - * @buffer: security label buffer * @alloc: allocation flag + * @buffer: security label buffer + * @len: security label length * * Retrieve a copy of the extended attribute representation of the security * label associated with @name for @inode via @buffer. Note that @name is the @@ -2553,17 +2554,17 @@ int security_inode_killpriv(struct mnt_idmap *idmap, * @alloc is used to specify if the call should return a value via the buffer * or just the value length. * - * Return: Returns size of buffer on success. + * Return: Returns 0 on success or a negative error code on failure. */ int security_inode_getsecurity(struct mnt_idmap *idmap, struct inode *inode, const char *name, - void **buffer, bool alloc) + bool alloc, void **buffer, u32 *len) { if (unlikely(IS_PRIVATE(inode))) return LSM_RET_DEFAULT(inode_getsecurity); - return call_int_hook(inode_getsecurity, idmap, inode, name, buffer, - alloc); + return call_int_hook(inode_getsecurity, idmap, inode, name, alloc, + buffer, len); } /** diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 9cd5a8f1f6a3..70792bba24d9 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3407,7 +3407,7 @@ static int selinux_path_notify(const struct path *path, u64 mask, */ static int selinux_inode_getsecurity(struct mnt_idmap *idmap, struct inode *inode, const char *name, - void **buffer, bool alloc) + bool alloc, void **buffer, u32 *len) { u32 size; int error; @@ -3440,14 +3440,14 @@ static int selinux_inode_getsecurity(struct mnt_idmap *idmap, &context, &size); if (error) return error; - error = size; + *len = size; if (alloc) { *buffer = context; goto out_nofree; } kfree(context); out_nofree: - return error; + return 0; } static int selinux_inode_setsecurity(struct inode *inode, const char *name, @@ -6644,13 +6644,9 @@ static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) { - int len = 0; - len = selinux_inode_getsecurity(&nop_mnt_idmap, inode, - XATTR_SELINUX_SUFFIX, ctx, true); - if (len < 0) - return len; - *ctxlen = len; - return 0; + return selinux_inode_getsecurity(&nop_mnt_idmap, inode, + XATTR_SELINUX_SUFFIX, + true, ctx, ctxlen); } #ifdef CONFIG_KEYS diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index f5cbec1e6a92..e7a5f6fd9a2d 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -1543,14 +1543,15 @@ static int smack_inode_remove_acl(struct mnt_idmap *idmap, * @idmap: idmap of the mount * @inode: the object * @name: attribute name - * @buffer: where to put the result * @alloc: duplicate memory + * @buffer: where to put the result + * @len: where to put the result length * - * Returns the size of the attribute or an error code + * Returns 0 on success or a negative error code on failure */ static int smack_inode_getsecurity(struct mnt_idmap *idmap, struct inode *inode, const char *name, - void **buffer, bool alloc) + bool alloc, void **buffer, u32 *len) { struct socket_smack *ssp; struct socket *sock; @@ -1558,7 +1559,6 @@ static int smack_inode_getsecurity(struct mnt_idmap *idmap, struct inode *ip = inode; struct smack_known *isp; struct inode_smack *ispp; - size_t label_len; char *label = NULL; if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { @@ -1594,15 +1594,15 @@ static int smack_inode_getsecurity(struct mnt_idmap *idmap, if (!label) label = isp->smk_known; - label_len = strlen(label); - if (alloc) { *buffer = kstrdup(label, GFP_KERNEL); if (*buffer == NULL) return -ENOMEM; } - return label_len; + *len = strlen(label); + + return 0; } -- 2.30.2