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authorAndreas Gruenbacher <agruenba@redhat.com>2015-12-02 14:44:36 +0100
committerAl Viro <viro@zeniv.linux.org.uk>2015-12-06 21:33:52 -0500
commit98e9cb5711c68223f0e4d5201b9a6add255ec550 (patch)
tree12fee55d296fc85a6e8188368ca4944fc4d913a8 /fs/xattr.c
parent97d79299223baab330b194437e676d301f12d5f6 (diff)
vfs: Distinguish between full xattr names and proper prefixes
Add an additional "name" field to struct xattr_handler. When the name is set, the handler matches attributes with exactly that name. When the prefix is set instead, the handler matches attributes with the given prefix and with a non-empty suffix. This patch should avoid bugs like the one fixed in commit c361016a in the future. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/xattr.c')
-rw-r--r--fs/xattr.c27
1 files changed, 17 insertions, 10 deletions
diff --git a/fs/xattr.c b/fs/xattr.c
index 58bdabcc9d35..418ad691cf4e 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -681,13 +681,20 @@ xattr_resolve_name(const struct xattr_handler **handlers, const char **name)
return NULL;
for_each_xattr_handler(handlers, handler) {
- const char *n = strcmp_prefix(*name, handler->prefix);
+ const char *n;
+
+ n = strcmp_prefix(*name, xattr_prefix(handler));
if (n) {
+ if (!handler->prefix ^ !*n) {
+ if (*n)
+ continue;
+ return ERR_PTR(-EINVAL);
+ }
*name = n;
- break;
+ return handler;
}
}
- return handler;
+ return ERR_PTR(-EOPNOTSUPP);
}
/*
@@ -699,8 +706,8 @@ generic_getxattr(struct dentry *dentry, const char *name, void *buffer, size_t s
const struct xattr_handler *handler;
handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name);
- if (!handler)
- return -EOPNOTSUPP;
+ if (IS_ERR(handler))
+ return PTR_ERR(handler);
return handler->get(handler, dentry, name, buffer, size);
}
@@ -746,8 +753,8 @@ generic_setxattr(struct dentry *dentry, const char *name, const void *value, siz
if (size == 0)
value = ""; /* empty EA, do not remove */
handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name);
- if (!handler)
- return -EOPNOTSUPP;
+ if (IS_ERR(handler))
+ return PTR_ERR(handler);
return handler->set(handler, dentry, name, value, size, flags);
}
@@ -761,8 +768,8 @@ generic_removexattr(struct dentry *dentry, const char *name)
const struct xattr_handler *handler;
handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name);
- if (!handler)
- return -EOPNOTSUPP;
+ if (IS_ERR(handler))
+ return PTR_ERR(handler);
return handler->set(handler, dentry, name, NULL, 0, XATTR_REPLACE);
}
@@ -789,7 +796,7 @@ EXPORT_SYMBOL(generic_removexattr);
const char *xattr_full_name(const struct xattr_handler *handler,
const char *name)
{
- size_t prefix_len = strlen(handler->prefix);
+ size_t prefix_len = strlen(xattr_prefix(handler));
return name - prefix_len;
}