From f71ece9712b7712df98871eea9aeb60e49ca5239 Mon Sep 17 00:00:00 2001 From: Stephen Smalley Date: Mon, 28 Apr 2025 15:50:19 -0400 Subject: security,fs,nfs,net: update security_inode_listsecurity() interface 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@gmail.com Signed-off-by: Stephen Smalley [PM: forward porting to bring this patch up to v7.1-rc1+] Signed-off-by: Paul Moore --- fs/nfs/nfs4proc.c | 7 ++----- fs/xattr.c | 11 +++++++---- include/linux/lsm_hook_defs.h | 4 ++-- include/linux/security.h | 5 +++-- security/security.c | 16 ++++++++-------- security/selinux/hooks.c | 10 +++------- security/smack/smack_lsm.c | 13 ++++--------- 7 files changed, 29 insertions(+), 37 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index a9b8d482d289..a16342056ae5 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -10562,13 +10562,10 @@ static ssize_t nfs4_listxattr(struct dentry *dentry, char *list, size_t size) left -= error; } - error2 = security_inode_listsecurity(d_inode(dentry), list, left); + error2 = security_inode_listsecurity(d_inode(dentry), &list, &left); if (error2 < 0) return error2; - if (list) { - list += error2; - left -= error2; - } + error2 = size - error - left; error3 = nfs4_listxattr_nfs4_user(d_inode(dentry), list, left); if (error3 < 0) diff --git a/fs/xattr.c b/fs/xattr.c index 09ecbaaa1660..0bc3b47e6936 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -510,9 +510,12 @@ 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; + ssize_t remaining = size; + + error = security_inode_listsecurity(inode, &list, &remaining); + if (error) + return error; + error = size - remaining; } return error; } @@ -1540,7 +1543,7 @@ ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, if (err) return err; - err = security_inode_listsecurity(inode, buffer, remaining_size); + err = security_inode_listsecurity(inode, &buffer, &remaining_size); if (err < 0) return err; diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 2b8dfb35caed..65c9609ec207 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -176,8 +176,8 @@ 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 41d7367cf403..153e9043058f 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -459,7 +459,7 @@ 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); @@ -1097,7 +1097,8 @@ 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/security/security.c b/security/security.c index 4e999f023651..71aea8fdf014 100644 --- a/security/security.c +++ b/security/security.c @@ -2258,22 +2258,22 @@ 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 97801966bf32..4ae736755557 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3684,16 +3684,12 @@ 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 3f9ae05039a2..ff115068c5c0 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -1665,17 +1665,12 @@ 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); } /** -- cgit v1.2.3