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| author | Daniel Rosenberg <drosen@google.com> | 2020-01-20 14:31:56 -0800 |
|---|---|---|
| committer | Eric Biggers <ebiggers@google.com> | 2020-01-22 14:47:15 -0800 |
| commit | 6e1918cfb263acacd3fc9239127732b69de64695 (patch) | |
| tree | f568fcd5fbed7df8ff441c664f18be933593ebd7 /fs/inode.c | |
| parent | 1b3b827ee5230a73c8ed1b2cd8d53b4bd001268b (diff) | |
| download | linux-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.c | 3 |
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); |