linux-stable.git/fs/ecryptfs/crypto.c, branch linux-4.19.y

Revert "ecryptfs: replace BUG_ON with error handling code"

2021-05-26T09:48:34+00:00

commit e1436df2f2550bc89d832ffd456373fdf5d5b5d7 upstream.

This reverts commit 2c2a7552dd6465e8fde6bc9cccf8d66ed1c1eb72.

Because of recent interactions with developers from @umn.edu, all
commits from them have been recently re-reviewed to ensure if they were
correct or not.

Upon review, this commit was found to be incorrect for the reasons
below, so it must be reverted.  It will be fixed up "correctly" in a
later kernel change.

The original commit log for this change was incorrect, no "error
handling code" was added, things will blow up just as badly as before if
any of these cases ever were true.  As this BUG_ON() never fired, and
most of these checks are "obviously" never going to be true, let's just
revert to the original code for now until this gets unwound to be done
correctly in the future.

Cc: Aditya Pakki 
Fixes: 2c2a7552dd64 ("ecryptfs: replace BUG_ON with error handling code")
Cc: stable 
Acked-by: Tyler Hicks 
Link: https://lore.kernel.org/r/20210503115736.2104747-49-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman

ecryptfs: replace BUG_ON with error handling code

2020-02-28T15:38:59+00:00

commit 2c2a7552dd6465e8fde6bc9cccf8d66ed1c1eb72 upstream.

In crypt_scatterlist, if the crypt_stat argument is not set up
correctly, the kernel crashes. Instead, by returning an error code
upstream, the error is handled safely.

The issue is detected via a static analysis tool written by us.

Fixes: 237fead619984 (ecryptfs: fs/Makefile and fs/Kconfig)
Signed-off-by: Aditya Pakki 
Signed-off-by: Tyler Hicks 
Signed-off-by: Greg Kroah-Hartman

eCryptfs: fix a couple type promotion bugs

2019-07-26T07:14:29+00:00

commit 0bdf8a8245fdea6f075a5fede833a5fcf1b3466c upstream.

ECRYPTFS_SIZE_AND_MARKER_BYTES is type size_t, so if "rc" is negative
that gets type promoted to a high positive value and treated as success.

Fixes: 778aeb42a708 ("eCryptfs: Cleanup and optimize ecryptfs_lookup_interpose()")
Signed-off-by: Dan Carpenter 
[tyhicks: Use "if/else if" rather than "if/if"]
Cc: stable@vger.kernel.org
Signed-off-by: Tyler Hicks 
Signed-off-by: Greg Kroah-Hartman

eCryptfs: don't pass up plaintext names when using filename encryption

2018-04-16T18:51:22+00:00

Both ecryptfs_filldir() and ecryptfs_readlink_lower() use
ecryptfs_decode_and_decrypt_filename() to translate lower filenames to
upper filenames. The function correctly passes up lower filenames,
unchanged, when filename encryption isn't in use. However, it was also
passing up lower filenames when the filename wasn't encrypted or
when decryption failed. Since 88ae4ab9802e, eCryptfs refuses to lookup
lower plaintext names when filename encryption is enabled so this
resulted in a situation where userspace would see lower plaintext
filenames in calls to getdents(2) but then not be able to lookup those
filenames.

An example of this can be seen when enabling filename encryption on an
eCryptfs mount at the root directory of an Ext4 filesystem:

$ ls -1i /lower
12 ECRYPTFS_FNEK_ENCRYPTED.FWYZD8TcW.5FV-TKTEYOHsheiHX9a-w.NURCCYIMjI8pn5BDB9-h3fXwrE--
11 lost+found
$ ls -1i /upper
ls: cannot access '/upper/lost+found': No such file or directory
 ? lost+found
12 test

With this change, the lower lost+found dentry is ignored:

$ ls -1i /lower
12 ECRYPTFS_FNEK_ENCRYPTED.FWYZD8TcW.5FV-TKTEYOHsheiHX9a-w.NURCCYIMjI8pn5BDB9-h3fXwrE--
11 lost+found
$ ls -1i /upper
12 test

Additionally, some potentially noisy error/info messages in the related
code paths are turned into debug messages so that the logs can't be
easily filled.

Fixes: 88ae4ab9802e ("ecryptfs_lookup(): try either only encrypted or plaintext name")
Reported-by: Guenter Roeck 
Cc: Al Viro 
Signed-off-by: Tyler Hicks

ecryptfs: use ARRAY_SIZE

2017-11-06T18:23:59+00:00

Using the ARRAY_SIZE macro improves the readability of the code.

Found with Coccinelle with the following semantic patch:
@r depends on (org || report)@
type T;
T[] E;
position p;
@@
(
 (sizeof(E)@p /sizeof(*E))
|
 (sizeof(E)@p /sizeof(E[...]))
|
 (sizeof(E)@p /sizeof(T))
)

Signed-off-by: Jérémy Lefaure 
Signed-off-by: Tyler Hicks

ecryptfs: Adjust four checks for null pointers

2017-11-06T18:23:48+00:00

The script “checkpatch.pl” pointed information out like the following.

Comparison to NULL could be written …

Thus fix the affected source code places.

Signed-off-by: Markus Elfring 
Signed-off-by: Tyler Hicks

ecryptfs: Delete 21 error messages for a failed memory allocation

2017-11-06T18:23:29+00:00

Omit extra messages for a memory allocation failure in these functions.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring 
Signed-off-by: Tyler Hicks

ecryptfs: remove private bin2hex implementation

2017-11-04T22:16:41+00:00

Calling sprintf in a loop is not very efficient, and in any case, we
already have an implementation of bin-to-hex conversion in lib/ which
we might as well use.

Note that ecryptfs_to_hex used to nul-terminate the destination (and
the kernel doc was wrong about the required output size), while
bin2hex doesn't. [All but one user of ecryptfs_to_hex explicitly
nul-terminates the result anyway.]

Signed-off-by: Rasmus Villemoes 
[tyhicks: Include  in ecryptfs_kernel.h]
Signed-off-by: Tyler Hicks

ecryptfs: fix spelling mistakes

2016-06-20T15:02:35+00:00

Noticed some minor spelling errors when looking through the code.

Signed-off-by: Chris J Arges 
Signed-off-by: Tyler Hicks

eCryptfs: fix typos in comment

2016-06-20T15:02:23+00:00

Signed-off-by: Weiyuan 
Signed-off-by: Tyler Hicks