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| author | Jeff Mahoney <jeffm@suse.com> | 2010-04-23 19:17:37 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-04-24 20:31:24 +0200 |
| commit | cac36f707119b792b2396aed371d6b5cdc194890 (patch) | |
| tree | ccb19a68ce1c1aa066d6d13dde51657cba906de6 /fs/reiserfs/dir.c | |
| parent | Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiw... (diff) | |
| download | linux-cac36f707119b792b2396aed371d6b5cdc194890.tar.xz linux-cac36f707119b792b2396aed371d6b5cdc194890.zip | |
reiserfs: fix permissions on .reiserfs_priv
Commit 677c9b2e393a0cd203bd54e9c18b012b2c73305a ("reiserfs: remove
privroot hiding in lookup") removed the magic from the lookup code to hide
the .reiserfs_priv directory since it was getting loaded at mount-time
instead. The intent was that the entry would be hidden from the user via
a poisoned d_compare, but this was faulty.
This introduced a security issue where unprivileged users could access and
modify extended attributes or ACLs belonging to other users, including
root.
This patch resolves the issue by properly hiding .reiserfs_priv. This was
the intent of the xattr poisoning code, but it appears to have never
worked as expected. This is fixed by using d_revalidate instead of
d_compare.
This patch makes -oexpose_privroot a no-op. I'm fine leaving it this way.
The effort involved in working out the corner cases wrt permissions and
caching outweigh the benefit of the feature.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Acked-by: Edward Shishkin <edward.shishkin@gmail.com>
Reported-by: Matt McCutchen <matt@mattmccutchen.net>
Tested-by: Matt McCutchen <matt@mattmccutchen.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/reiserfs/dir.c')
| -rw-r--r-- | fs/reiserfs/dir.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/fs/reiserfs/dir.c b/fs/reiserfs/dir.c index f8a6075abf50..07930449a958 100644 --- a/fs/reiserfs/dir.c +++ b/fs/reiserfs/dir.c @@ -46,8 +46,6 @@ static inline bool is_privroot_deh(struct dentry *dir, struct reiserfs_de_head *deh) { struct dentry *privroot = REISERFS_SB(dir->d_sb)->priv_root; - if (reiserfs_expose_privroot(dir->d_sb)) - return 0; return (dir == dir->d_parent && privroot->d_inode && deh->deh_objectid == INODE_PKEY(privroot->d_inode)->k_objectid); } |