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authorDaniel Rosenberg <drosen@google.com>2020-01-20 14:31:56 -0800
committerEric Biggers <ebiggers@google.com>2020-01-22 14:47:15 -0800
commit6e1918cfb263acacd3fc9239127732b69de64695 (patch)
treef568fcd5fbed7df8ff441c664f18be933593ebd7 /fs/inode.c
parent1b3b827ee5230a73c8ed1b2cd8d53b4bd001268b (diff)
downloadlinux-6e1918cfb263acacd3fc9239127732b69de64695.tar.bz2
fscrypt: don't allow v1 policies with casefolding
Casefolded encrypted directories will use a new dirhash method that requires a secret key. If the directory uses a v2 encryption policy, it's easy to derive this key from the master key using HKDF. However, v1 encryption policies don't provide a way to derive additional keys. Therefore, don't allow casefolding on directories that use a v1 policy. Specifically, make it so that trying to enable casefolding on a directory that has a v1 policy fails, trying to set a v1 policy on a casefolded directory fails, and trying to open a casefolded directory that has a v1 policy (if one somehow exists on-disk) fails. Signed-off-by: Daniel Rosenberg <drosen@google.com> [EB: improved commit message, updated fscrypt.rst, and other cleanups] Link: https://lore.kernel.org/r/20200120223201.241390-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
Diffstat (limited to 'fs/inode.c')
-rw-r--r--fs/inode.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/inode.c b/fs/inode.c
index 96d62d97694e..ea15c6d9f274 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -12,6 +12,7 @@
#include <linux/security.h>
#include <linux/cdev.h>
#include <linux/memblock.h>
+#include <linux/fscrypt.h>
#include <linux/fsnotify.h>
#include <linux/mount.h>
#include <linux/posix_acl.h>
@@ -2252,7 +2253,7 @@ int vfs_ioc_setflags_prepare(struct inode *inode, unsigned int oldflags,
!capable(CAP_LINUX_IMMUTABLE))
return -EPERM;
- return 0;
+ return fscrypt_prepare_setflags(inode, oldflags, flags);
}
EXPORT_SYMBOL(vfs_ioc_setflags_prepare);