diff options
| -rw-r--r-- | mm/shmem.c | 88 |
1 files changed, 72 insertions, 16 deletions
diff --git a/mm/shmem.c b/mm/shmem.c index b7e19557186..7cc80833b74 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1178,6 +1178,12 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode static const struct inode_operations shmem_symlink_inode_operations; static const struct inode_operations shmem_short_symlink_operations; +#ifdef CONFIG_TMPFS_XATTR +static int shmem_initxattrs(struct inode *, const struct xattr *, void *); +#else +#define shmem_initxattrs NULL +#endif + static int shmem_write_begin(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned flags, @@ -1490,7 +1496,7 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) if (inode) { error = security_inode_init_security(inode, dir, &dentry->d_name, - NULL, NULL); + shmem_initxattrs, NULL); if (error) { if (error != -EOPNOTSUPP) { iput(inode); @@ -1630,7 +1636,7 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s return -ENOSPC; error = security_inode_init_security(inode, dir, &dentry->d_name, - NULL, NULL); + shmem_initxattrs, NULL); if (error) { if (error != -EOPNOTSUPP) { iput(inode); @@ -1704,6 +1710,66 @@ static void shmem_put_link(struct dentry *dentry, struct nameidata *nd, void *co * filesystem level, though. */ +/* + * Allocate new xattr and copy in the value; but leave the name to callers. + */ +static struct shmem_xattr *shmem_xattr_alloc(const void *value, size_t size) +{ + struct shmem_xattr *new_xattr; + size_t len; + + /* wrap around? */ + len = sizeof(*new_xattr) + size; + if (len <= sizeof(*new_xattr)) + return NULL; + + new_xattr = kmalloc(len, GFP_KERNEL); + if (!new_xattr) + return NULL; + + new_xattr->size = size; + memcpy(new_xattr->value, value, size); + return new_xattr; +} + +/* + * Callback for security_inode_init_security() for acquiring xattrs. + */ +static int shmem_initxattrs(struct inode *inode, + const struct xattr *xattr_array, + void *fs_info) +{ + struct shmem_inode_info *info = SHMEM_I(inode); + const struct xattr *xattr; + struct shmem_xattr *new_xattr; + size_t len; + + for (xattr = xattr_array; xattr->name != NULL; xattr++) { + new_xattr = shmem_xattr_alloc(xattr->value, xattr->value_len); + if (!new_xattr) + return -ENOMEM; + + len = strlen(xattr->name) + 1; + new_xattr->name = kmalloc(XATTR_SECURITY_PREFIX_LEN + len, + GFP_KERNEL); + if (!new_xattr->name) { + kfree(new_xattr); + return -ENOMEM; + } + + memcpy(new_xattr->name, XATTR_SECURITY_PREFIX, + XATTR_SECURITY_PREFIX_LEN); + memcpy(new_xattr->name + XATTR_SECURITY_PREFIX_LEN, + xattr->name, len); + + spin_lock(&info->lock); + list_add(&new_xattr->list, &info->xattr_list); + spin_unlock(&info->lock); + } + + return 0; +} + static int shmem_xattr_get(struct dentry *dentry, const char *name, void *buffer, size_t size) { @@ -1731,24 +1797,17 @@ static int shmem_xattr_get(struct dentry *dentry, const char *name, return ret; } -static int shmem_xattr_set(struct dentry *dentry, const char *name, +static int shmem_xattr_set(struct inode *inode, const char *name, const void *value, size_t size, int flags) { - struct inode *inode = dentry->d_inode; struct shmem_inode_info *info = SHMEM_I(inode); struct shmem_xattr *xattr; struct shmem_xattr *new_xattr = NULL; - size_t len; int err = 0; /* value == NULL means remove */ if (value) { - /* wrap around? */ - len = sizeof(*new_xattr) + size; - if (len <= sizeof(*new_xattr)) - return -ENOMEM; - - new_xattr = kmalloc(len, GFP_KERNEL); + new_xattr = shmem_xattr_alloc(value, size); if (!new_xattr) return -ENOMEM; @@ -1757,9 +1816,6 @@ static int shmem_xattr_set(struct dentry *dentry, const char *name, kfree(new_xattr); return -ENOMEM; } - - new_xattr->size = size; - memcpy(new_xattr->value, value, size); } spin_lock(&info->lock); @@ -1858,7 +1914,7 @@ static int shmem_setxattr(struct dentry *dentry, const char *name, if (size == 0) value = ""; /* empty EA, do not remove */ - return shmem_xattr_set(dentry, name, value, size, flags); + return shmem_xattr_set(dentry->d_inode, name, value, size, flags); } @@ -1878,7 +1934,7 @@ static int shmem_removexattr(struct dentry *dentry, const char *name) if (err) return err; - return shmem_xattr_set(dentry, name, NULL, 0, XATTR_REPLACE); + return shmem_xattr_set(dentry->d_inode, name, NULL, 0, XATTR_REPLACE); } static bool xattr_is_trusted(const char *name) |