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https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git
synced 2026-10-30 03:27:44 -04:00
[PATCH] add vfs_* helpers for xattr operations
Add vfs_getxattr, vfs_setxattr and vfs_removexattr helpers for common checks around invocation of the xattr methods. NFSD already was missing some of the checks and there will be more soon. Signed-off-by: Christoph Hellwig <[email protected]> Cc: James Morris <[email protected]> (James, I haven't touched selinux yet because it's doing various odd things and I'm not sure how it would interact with the security attribute fallbacks you added. Could you investigate whether it could use vfs_getxattr or if not add a __vfs_getxattr helper to share the bits it is fine with?) For NFSv4: instead of just converting it add an nfsd_getxattr helper for the code shared by NFSv2/3 and NFSv4 ACLs. In fact that code isn't even NFS-specific, but I'll wait for more users to pop up first before moving it to common code. Signed-off-by: Christoph Hellwig <[email protected]> Acked-by: Dave Kleikamp <[email protected]> Signed-off-by: Adrian Bunk <[email protected]> Signed-off-by: Neil Brown <[email protected]> Cc: Trond Myklebust <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
parent
a7e670d828
commit
5be196e5f9
3 changed files with 145 additions and 130 deletions
146
fs/xattr.c
146
fs/xattr.c
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@ -19,6 +19,96 @@
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#include <linux/fsnotify.h>
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#include <asm/uaccess.h>
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int
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vfs_setxattr(struct dentry *dentry, char *name, void *value,
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size_t size, int flags)
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{
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struct inode *inode = dentry->d_inode;
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int error;
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mutex_lock(&inode->i_mutex);
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error = security_inode_setxattr(dentry, name, value, size, flags);
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if (error)
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goto out;
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error = -EOPNOTSUPP;
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if (inode->i_op->setxattr) {
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error = inode->i_op->setxattr(dentry, name, value, size, flags);
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if (!error) {
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fsnotify_xattr(dentry);
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security_inode_post_setxattr(dentry, name, value,
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size, flags);
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}
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} else if (!strncmp(name, XATTR_SECURITY_PREFIX,
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sizeof XATTR_SECURITY_PREFIX - 1)) {
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const char *suffix = name + sizeof XATTR_SECURITY_PREFIX - 1;
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error = security_inode_setsecurity(inode, suffix, value,
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size, flags);
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if (!error)
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fsnotify_xattr(dentry);
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}
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out:
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mutex_unlock(&inode->i_mutex);
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return error;
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}
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EXPORT_SYMBOL_GPL(vfs_setxattr);
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ssize_t
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vfs_getxattr(struct dentry *dentry, char *name, void *value, size_t size)
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{
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struct inode *inode = dentry->d_inode;
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int error;
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error = security_inode_getxattr(dentry, name);
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if (error)
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return error;
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if (inode->i_op->getxattr)
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error = inode->i_op->getxattr(dentry, name, value, size);
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else
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error = -EOPNOTSUPP;
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if (!strncmp(name, XATTR_SECURITY_PREFIX,
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sizeof XATTR_SECURITY_PREFIX - 1)) {
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const char *suffix = name + sizeof XATTR_SECURITY_PREFIX - 1;
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int ret = security_inode_getsecurity(inode, suffix, value,
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size, error);
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/*
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* Only overwrite the return value if a security module
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* is actually active.
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*/
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if (ret != -EOPNOTSUPP)
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error = ret;
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}
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return error;
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}
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EXPORT_SYMBOL_GPL(vfs_getxattr);
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int
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vfs_removexattr(struct dentry *dentry, char *name)
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{
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struct inode *inode = dentry->d_inode;
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int error;
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if (!inode->i_op->removexattr)
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return -EOPNOTSUPP;
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error = security_inode_removexattr(dentry, name);
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if (error)
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return error;
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mutex_lock(&inode->i_mutex);
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error = inode->i_op->removexattr(dentry, name);
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mutex_unlock(&inode->i_mutex);
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if (!error)
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fsnotify_xattr(dentry);
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return error;
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}
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EXPORT_SYMBOL_GPL(vfs_removexattr);
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/*
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* Extended attribute SET operations
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*/
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@ -51,29 +141,7 @@ setxattr(struct dentry *d, char __user *name, void __user *value,
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}
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}
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mutex_lock(&d->d_inode->i_mutex);
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error = security_inode_setxattr(d, kname, kvalue, size, flags);
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if (error)
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goto out;
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error = -EOPNOTSUPP;
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if (d->d_inode->i_op && d->d_inode->i_op->setxattr) {
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error = d->d_inode->i_op->setxattr(d, kname, kvalue,
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size, flags);
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if (!error) {
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fsnotify_xattr(d);
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security_inode_post_setxattr(d, kname, kvalue,
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size, flags);
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}
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} else if (!strncmp(kname, XATTR_SECURITY_PREFIX,
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sizeof XATTR_SECURITY_PREFIX - 1)) {
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const char *suffix = kname + sizeof XATTR_SECURITY_PREFIX - 1;
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error = security_inode_setsecurity(d->d_inode, suffix, kvalue,
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size, flags);
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if (!error)
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fsnotify_xattr(d);
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}
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out:
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mutex_unlock(&d->d_inode->i_mutex);
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error = vfs_setxattr(d, kname, kvalue, size, flags);
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kfree(kvalue);
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return error;
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}
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@ -147,22 +215,7 @@ getxattr(struct dentry *d, char __user *name, void __user *value, size_t size)
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return -ENOMEM;
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}
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error = security_inode_getxattr(d, kname);
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if (error)
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goto out;
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error = -EOPNOTSUPP;
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if (d->d_inode->i_op && d->d_inode->i_op->getxattr)
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error = d->d_inode->i_op->getxattr(d, kname, kvalue, size);
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if (!strncmp(kname, XATTR_SECURITY_PREFIX,
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sizeof XATTR_SECURITY_PREFIX - 1)) {
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const char *suffix = kname + sizeof XATTR_SECURITY_PREFIX - 1;
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int rv = security_inode_getsecurity(d->d_inode, suffix, kvalue,
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size, error);
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/* Security module active: overwrite error value */
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if (rv != -EOPNOTSUPP)
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error = rv;
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}
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error = vfs_getxattr(d, kname, kvalue, size);
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if (error > 0) {
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if (size && copy_to_user(value, kvalue, error))
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error = -EFAULT;
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@ -171,7 +224,6 @@ getxattr(struct dentry *d, char __user *name, void __user *value, size_t size)
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than XATTR_SIZE_MAX bytes. Not possible. */
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error = -E2BIG;
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}
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out:
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kfree(kvalue);
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return error;
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}
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@ -318,19 +370,7 @@ removexattr(struct dentry *d, char __user *name)
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if (error < 0)
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return error;
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error = -EOPNOTSUPP;
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if (d->d_inode->i_op && d->d_inode->i_op->removexattr) {
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error = security_inode_removexattr(d, kname);
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if (error)
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goto out;
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mutex_lock(&d->d_inode->i_mutex);
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error = d->d_inode->i_op->removexattr(d, kname);
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mutex_unlock(&d->d_inode->i_mutex);
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if (!error)
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fsnotify_xattr(d);
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}
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out:
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return error;
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return vfs_removexattr(d, kname);
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}
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asmlinkage long
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