From: Xu Kuohai xukuohai@huawei.com
To be consistent with most LSM hooks, convert the return value of hook inode_listsecurity to 0 or a negative error code.
Before: - Hook inode_listsecurity returns number of bytes used/required on success or a negative error code on failure.
After: - Hook inode_listsecurity returns 0 on success or a negative error code on failure. An output parameter @bytes is introduced to hold the number of bytes used/required on success.
Signed-off-by: Xu Kuohai xukuohai@huawei.com --- fs/nfs/nfs4proc.c | 5 ++++- fs/xattr.c | 5 ++++- include/linux/lsm_hook_defs.h | 2 +- include/linux/security.h | 7 ++++--- net/socket.c | 9 +++++---- security/security.c | 29 +++++++++++++++++++++++++---- security/selinux/hooks.c | 8 +++++--- security/smack/smack_lsm.c | 6 ++++-- 8 files changed, 52 insertions(+), 19 deletions(-)
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index a691fa10b3e9..6d75758ba3d5 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -7848,10 +7848,13 @@ static int nfs4_xattr_get_nfs4_label(const struct xattr_handler *handler, static ssize_t nfs4_listxattr_nfs4_label(struct inode *inode, char *list, size_t list_len) { + size_t bytes; int len = 0;
if (nfs_server_capable(inode, NFS_CAP_SECURITY_LABEL)) { - len = security_inode_listsecurity(inode, list, list_len); + len = security_inode_listsecurity(inode, list, list_len, &bytes); + if (!len) + len = bytes; if (len >= 0 && list_len && len > list_len) return -ERANGE; } diff --git a/fs/xattr.c b/fs/xattr.c index f4e3bedf7272..ab7d7123a016 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -485,6 +485,7 @@ vfs_listxattr(struct dentry *dentry, char *list, size_t size) { struct inode *inode = d_inode(dentry); ssize_t error; + size_t bytes;
error = security_inode_listxattr(dentry); if (error) @@ -493,7 +494,9 @@ vfs_listxattr(struct dentry *dentry, char *list, size_t size) if (inode->i_op->listxattr) { error = inode->i_op->listxattr(dentry, list, size); } else { - error = security_inode_listsecurity(inode, list, size); + error = security_inode_listsecurity(inode, list, size, &bytes); + if (!error) + error = bytes; if (size && error > size) error = -ERANGE; } diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 4f056f2613af..1b7761ae2777 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -174,7 +174,7 @@ LSM_HOOK(int, -EOPNOTSUPP, inode_getsecurity, struct mnt_idmap *idmap, 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, - size_t buffer_size) + size_t buffer_size, size_t *bytes) LSM_HOOK(void, LSM_RET_VOID, inode_getsecid, struct inode *inode, u32 *secid) LSM_HOOK(int, 0, inode_copy_up, struct dentry *src, struct cred **new) LSM_HOOK(int, -EOPNOTSUPP, inode_copy_up_xattr, struct dentry *src, diff --git a/include/linux/security.h b/include/linux/security.h index b6d296d21438..0ed53e232c4d 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -395,7 +395,7 @@ int security_inode_getsecurity(struct mnt_idmap *idmap, struct inode *inode, const char *name, 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); +int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size, size_t *bytes); void security_inode_getsecid(struct inode *inode, u32 *secid); int security_inode_copy_up(struct dentry *src, struct cred **new); int security_inode_copy_up_xattr(struct dentry *src, const char *name); @@ -1007,9 +1007,10 @@ static inline int security_inode_setsecurity(struct inode *inode, const char *na return -EOPNOTSUPP; }
-static inline int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) +static inline int security_inode_listsecurity(struct inode *inode, char *buffer, + size_t buffer_size, size_t *bytes) { - return 0; + return *bytes = 0; }
static inline void security_inode_getsecid(struct inode *inode, u32 *secid) diff --git a/net/socket.c b/net/socket.c index e416920e9399..43f0e3c9a6e0 100644 --- a/net/socket.c +++ b/net/socket.c @@ -571,12 +571,13 @@ static struct socket *sockfd_lookup_light(int fd, int *err, int *fput_needed) static ssize_t sockfs_listxattr(struct dentry *dentry, char *buffer, size_t size) { - ssize_t len; + int err; + size_t len; ssize_t used = 0;
- len = security_inode_listsecurity(d_inode(dentry), buffer, size); - if (len < 0) - return len; + err = security_inode_listsecurity(d_inode(dentry), buffer, size, &len); + if (err < 0) + return err; used += len; if (buffer) { if (size < used) diff --git a/security/security.c b/security/security.c index 614f14cbfff7..26eea8f4cd74 100644 --- a/security/security.c +++ b/security/security.c @@ -2597,20 +2597,41 @@ int security_inode_setsecurity(struct inode *inode, const char *name, * @inode: inode * @buffer: buffer * @buffer_size: size of buffer + * @bytes: number of bytes used/required * * Copy the extended attribute names for the security labels associated with * @inode into @buffer. The maximum size of @buffer is specified by * @buffer_size. @buffer may be NULL to request the size of the buffer * required. * - * Return: Returns number of bytes used/required on success. + * Return: Returns 0 on success or a negative error code on failure. */ int security_inode_listsecurity(struct inode *inode, - char *buffer, size_t buffer_size) + char *buffer, size_t buffer_size, + size_t *bytes) { + int rc; + size_t used; + struct security_hook_list *hp; + if (unlikely(IS_PRIVATE(inode))) - return 0; - return call_int_hook(inode_listsecurity, inode, buffer, buffer_size); + return *bytes = 0; + + used = 0; + hlist_for_each_entry(hp, &security_hook_heads.inode_listsecurity, + list) { + rc = hp->hook.inode_listsecurity(inode, buffer, buffer_size, + &used); + if (rc < 0) + return rc; + if (used != 0) + break; + } + + *bytes = used; + + return 0; + } EXPORT_SYMBOL(security_inode_listsecurity);
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 70792bba24d9..5dedd3917d57 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3481,16 +3481,18 @@ static int selinux_inode_setsecurity(struct inode *inode, const char *name, return 0; }
-static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) +static int selinux_inode_listsecurity(struct inode *inode, char *buffer, + size_t buffer_size, size_t *bytes) { const int len = sizeof(XATTR_NAME_SELINUX);
if (!selinux_initialized()) - return 0; + return *bytes = 0;
if (buffer && len <= buffer_size) memcpy(buffer, XATTR_NAME_SELINUX, len); - return len; + *bytes = len; + return 0; }
static void selinux_inode_getsecid(struct inode *inode, u32 *secid) diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index e7a5f6fd9a2d..6f73906bf7ea 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -1611,16 +1611,18 @@ static int smack_inode_getsecurity(struct mnt_idmap *idmap, * @inode: the object * @buffer: where they go * @buffer_size: size of buffer + * @bytes: number of data bytes in buffer */ static int smack_inode_listsecurity(struct inode *inode, char *buffer, - size_t buffer_size) + size_t buffer_size, size_t *bytes) { int len = sizeof(XATTR_NAME_SMACK);
if (buffer != NULL && len <= buffer_size) memcpy(buffer, XATTR_NAME_SMACK, len);
- return len; + *bytes = len; + return 0; }
/**