Update the security_inode_listsecurity() interface to allow use of the xattr_list_one() helper and update the hook implementations. Link: https://lore.kernel.org/selinux/20250424152822.2719-1-stephen.smalley.work@xxxxxxxxx/ Signed-off-by: Stephen Smalley <stephen.smalley.work@xxxxxxxxx> --- This patch is relative to the one linked above, which in theory is on vfs.fixes but doesn't appear to have been pushed when I looked. fs/nfs/nfs4proc.c | 9 +++++---- fs/xattr.c | 20 ++++++++------------ include/linux/lsm_hook_defs.h | 4 ++-- include/linux/security.h | 5 +++-- net/socket.c | 8 +------- security/security.c | 16 ++++++++-------- security/selinux/hooks.c | 10 +++------- security/smack/smack_lsm.c | 13 ++++--------- 8 files changed, 34 insertions(+), 51 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 970f28dbf253..a1d7cb0acb5e 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -8023,12 +8023,13 @@ 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) { - int len = 0; + ssize_t len = 0; + int err; if (nfs_server_capable(inode, NFS_CAP_SECURITY_LABEL)) { - len = security_inode_listsecurity(inode, list, list_len); - if (len >= 0 && list_len && len > list_len) - return -ERANGE; + err = security_inode_listsecurity(inode, &list, &len); + if (err) + len = err; } return len; } diff --git a/fs/xattr.c b/fs/xattr.c index 2fc314b27120..fdd2f387bfd5 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -492,9 +492,12 @@ 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); - if (size && error > size) - error = -ERANGE; + char *buffer = list; + ssize_t len = 0; + + error = security_inode_listsecurity(inode, &buffer, &len); + if (!error) + error = len; } return error; } @@ -1469,17 +1472,10 @@ ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, if (err) return err; - err = security_inode_listsecurity(inode, buffer, remaining_size); - if (err < 0) + err = security_inode_listsecurity(inode, &buffer, &remaining_size); + if (err) return err; - if (buffer) { - if (remaining_size < err) - return -ERANGE; - buffer += err; - } - remaining_size -= err; - read_lock(&xattrs->lock); for (rbp = rb_first(&xattrs->rb_root); rbp; rbp = rb_next(rbp)) { xattr = rb_entry(rbp, struct simple_xattr, rb_node); diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index bf3bbac4e02a..3c3919dcdebc 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -174,8 +174,8 @@ LSM_HOOK(int, -EOPNOTSUPP, inode_getsecurity, struct mnt_idmap *idmap, struct inode *inode, const char *name, void **buffer, bool alloc) 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) +LSM_HOOK(int, 0, inode_listsecurity, struct inode *inode, char **buffer, + ssize_t *remaining_size) LSM_HOOK(void, LSM_RET_VOID, inode_getlsmprop, struct inode *inode, struct lsm_prop *prop) LSM_HOOK(int, 0, inode_copy_up, struct dentry *src, struct cred **new) diff --git a/include/linux/security.h b/include/linux/security.h index cc9b54d95d22..0efc6a0ab56d 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -457,7 +457,7 @@ int security_inode_getsecurity(struct mnt_idmap *idmap, struct inode *inode, const char *name, void **buffer, bool alloc); 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, ssize_t *remaining_size); void security_inode_getlsmprop(struct inode *inode, struct lsm_prop *prop); int security_inode_copy_up(struct dentry *src, struct cred **new); int security_inode_copy_up_xattr(struct dentry *src, const char *name); @@ -1077,7 +1077,8 @@ 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, ssize_t *remaining_size) { return 0; } diff --git a/net/socket.c b/net/socket.c index 9a0e720f0859..52e3670dc89b 100644 --- a/net/socket.c +++ b/net/socket.c @@ -562,15 +562,9 @@ static ssize_t sockfs_listxattr(struct dentry *dentry, char *buffer, ssize_t len; ssize_t used = 0; - len = security_inode_listsecurity(d_inode(dentry), buffer, size); + len = security_inode_listsecurity(d_inode(dentry), &buffer, &used); if (len < 0) return len; - used += len; - if (buffer) { - if (size < used) - return -ERANGE; - buffer += len; - } len = (XATTR_NAME_SOCKPROTONAME_LEN + 1); used += len; diff --git a/security/security.c b/security/security.c index fb57e8fddd91..3985d040d5a9 100644 --- a/security/security.c +++ b/security/security.c @@ -2710,22 +2710,22 @@ int security_inode_setsecurity(struct inode *inode, const char *name, /** * security_inode_listsecurity() - List the xattr security label names * @inode: inode - * @buffer: buffer - * @buffer_size: size of buffer + * @buffer: pointer to buffer + * @remaining_size: pointer to remaining size of buffer * * 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. + * @inode into *(@buffer). The remaining size of @buffer is specified by + * *(@remaining_size). *(@buffer) may be NULL to request the size of the + * buffer required. Updates *(@buffer) and *(@remaining_size). * - * Return: Returns number of bytes used/required on success. + * Return: Returns 0 on success, or -errno on failure. */ int security_inode_listsecurity(struct inode *inode, - char *buffer, size_t buffer_size) + char **buffer, ssize_t *remaining_size) { if (unlikely(IS_PRIVATE(inode))) return 0; - return call_int_hook(inode_listsecurity, inode, buffer, buffer_size); + return call_int_hook(inode_listsecurity, inode, buffer, remaining_size); } EXPORT_SYMBOL(security_inode_listsecurity); diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index b8115df536ab..e6c98ebbf7bc 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3612,16 +3612,12 @@ 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, + ssize_t *remaining_size) { - const int len = sizeof(XATTR_NAME_SELINUX); - if (!selinux_initialized()) return 0; - - if (buffer && len <= buffer_size) - memcpy(buffer, XATTR_NAME_SELINUX, len); - return len; + return xattr_list_one(buffer, remaining_size, XATTR_NAME_SELINUX); } static void selinux_inode_getlsmprop(struct inode *inode, struct lsm_prop *prop) diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 99833168604e..3f7ac865532e 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -1619,17 +1619,12 @@ static int smack_inode_getsecurity(struct mnt_idmap *idmap, * smack_inode_listsecurity - list the Smack attributes * @inode: the object * @buffer: where they go - * @buffer_size: size of buffer + * @remaining_size: size of buffer */ -static int smack_inode_listsecurity(struct inode *inode, char *buffer, - size_t buffer_size) +static int smack_inode_listsecurity(struct inode *inode, char **buffer, + ssize_t *remaining_size) { - int len = sizeof(XATTR_NAME_SMACK); - - if (buffer != NULL && len <= buffer_size) - memcpy(buffer, XATTR_NAME_SMACK, len); - - return len; + return xattr_list_one(buffer, remaining_size, XATTR_NAME_SMACK); } /** -- 2.49.0
