Home Home > GIT Browse
summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorThomas Hebb <tommyhebb@gmail.com>2015-04-16 12:47:18 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-05-13 05:14:31 -0700
commit2e15dca25908efb782320658fdd741fd9e04adc2 (patch)
tree18480e48a3ebc8a724100d5f0614cd71f098dae5
parente8ade718d9cfc32056ec78215b047aa764995b85 (diff)
hfsplus: don't store special "osx" xattr prefix on-disk
commit db579e76f06e78de011b2cb7e028740a82f5558c upstream. On Mac OS X, HFS+ extended attributes are not namespaced. Since we want to be compatible with OS X filesystems and yet still support the Linux namespacing system, the hfsplus driver implements a special "osx" namespace that is reported for any attribute that is not namespaced on-disk. However, the current code for getting and setting these unprefixed attributes is broken. hfsplus_osx_setattr() and hfsplus_osx_getattr() are passed names that have already had their "osx." prefixes stripped by the generic functions. The functions first, quite correctly, check those names to make sure that they aren't prefixed with a known namespace, which would allow namespace access restrictions to be bypassed. However, the functions then prepend "osx." to the name they're given before passing it on to hfsplus_getattr() and hfsplus_setattr(). Not only does this cause the "osx." prefix to be stored on-disk, defeating its purpose, it also breaks the check for the special "com.apple.FinderInfo" attribute, which is reported for all files, and as a consequence makes some userspace applications (e.g. GNU patch) fail even when extended attributes are not otherwise in use. There are five commits which have touched this particular code: 127e5f5ae51e ("hfsplus: rework functionality of getting, setting and deleting of extended attributes") b168fff72109 ("hfsplus: use xattr handlers for removexattr") bf29e886b242 ("hfsplus: correct usage of HFSPLUS_ATTR_MAX_STRLEN for non-English attributes") fcacbd95e121 ("fs/hfsplus: move xattr_name allocation in hfsplus_getxattr()") ec1bbd346f18 ("fs/hfsplus: move xattr_name allocation in hfsplus_setxattr()") The first commit creates the functions to begin with. The namespace is prepended by the original code, which I believe was correct at the time, since hfsplus_?etattr() stripped the prefix if found. The second commit removes this behavior from hfsplus_?etattr() and appears to have been intended to also remove the prefixing from hfsplus_osx_?etattr(). However, what it actually does is remove a necessary strncpy() call completely, breaking the osx namespace entirely. The third commit re-adds the strncpy() call as it was originally, but doesn't mention it in its commit message. The final two commits refactor the code and don't affect its functionality. This commit does what b168fff attempted to do (prevent the prefix from being added), but does it properly, instead of passing in an empty buffer (which is what b168fff actually did). Fixes: b168fff72109 ("hfsplus: use xattr handlers for removexattr") Signed-off-by: Thomas Hebb <tommyhebb@gmail.com> Cc: Hin-Tak Leung <htl10@users.sourceforge.net> Cc: Sergei Antonov <saproj@gmail.com> Cc: Anton Altaparmakov <anton@tuxera.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: Christian Kujau <lists@nerdbynature.de> Cc: Christoph Hellwig <hch@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Viacheslav Dubeyko <slava@dubeyko.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Hebb <tommyhebb@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/hfsplus/xattr.c38
1 files changed, 14 insertions, 24 deletions
diff --git a/fs/hfsplus/xattr.c b/fs/hfsplus/xattr.c
index d98094a9f476..ff10f3decbc9 100644
--- a/fs/hfsplus/xattr.c
+++ b/fs/hfsplus/xattr.c
@@ -806,9 +806,6 @@ end_removexattr:
static int hfsplus_osx_getxattr(struct dentry *dentry, const char *name,
void *buffer, size_t size, int type)
{
- char *xattr_name;
- int res;
-
if (!strcmp(name, ""))
return -EINVAL;
@@ -818,24 +815,19 @@ static int hfsplus_osx_getxattr(struct dentry *dentry, const char *name,
*/
if (is_known_namespace(name))
return -EOPNOTSUPP;
- xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN
- + XATTR_MAC_OSX_PREFIX_LEN + 1, GFP_KERNEL);
- if (!xattr_name)
- return -ENOMEM;
- strcpy(xattr_name, XATTR_MAC_OSX_PREFIX);
- strcpy(xattr_name + XATTR_MAC_OSX_PREFIX_LEN, name);
- res = hfsplus_getxattr(dentry, xattr_name, buffer, size);
- kfree(xattr_name);
- return res;
+ /*
+ * osx is the namespace we use to indicate an unprefixed
+ * attribute on the filesystem (like the ones that OS X
+ * creates), so we pass the name through unmodified (after
+ * ensuring it doesn't conflict with another namespace).
+ */
+ return hfsplus_getxattr(dentry, name, buffer, size);
}
static int hfsplus_osx_setxattr(struct dentry *dentry, const char *name,
const void *buffer, size_t size, int flags, int type)
{
- char *xattr_name;
- int res;
-
if (!strcmp(name, ""))
return -EINVAL;
@@ -845,16 +837,14 @@ static int hfsplus_osx_setxattr(struct dentry *dentry, const char *name,
*/
if (is_known_namespace(name))
return -EOPNOTSUPP;
- xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN
- + XATTR_MAC_OSX_PREFIX_LEN + 1, GFP_KERNEL);
- if (!xattr_name)
- return -ENOMEM;
- strcpy(xattr_name, XATTR_MAC_OSX_PREFIX);
- strcpy(xattr_name + XATTR_MAC_OSX_PREFIX_LEN, name);
- res = hfsplus_setxattr(dentry, xattr_name, buffer, size, flags);
- kfree(xattr_name);
- return res;
+ /*
+ * osx is the namespace we use to indicate an unprefixed
+ * attribute on the filesystem (like the ones that OS X
+ * creates), so we pass the name through unmodified (after
+ * ensuring it doesn't conflict with another namespace).
+ */
+ return hfsplus_setxattr(dentry, name, buffer, size, flags);
}
static size_t hfsplus_osx_listxattr(struct dentry *dentry, char *list,