mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-11 04:18:39 +08:00
b5639bb431
Tryng to rename a directory that has all following properties fails with
EINVAL and triggers the 'WARN_ON_ONCE(!fscrypt_has_encryption_key(dir))'
in f2fs_match_ci_name():
- The directory is casefolded
- The directory is encrypted
- The directory's encryption key is not yet set up
- The parent directory is *not* encrypted
The problem is incorrect handling of the lookup of ".." to get the
parent reference to update. fscrypt_setup_filename() treats ".." (and
".") specially, as it's never encrypted. It's passed through as-is, and
setting up the directory's key is not attempted. As the name isn't a
no-key name, f2fs treats it as a "normal" name and attempts a casefolded
comparison. That breaks the assumption of the WARN_ON_ONCE() in
f2fs_match_ci_name() which assumes that for encrypted directories,
casefolded comparisons only happen when the directory's key is set up.
We could just remove this WARN_ON_ONCE(). However, since casefolding is
always a no-op on "." and ".." anyway, let's instead just not casefold
these names. This results in the standard bytewise comparison.
Fixes: 7ad08a58bf ("f2fs: Handle casefolding with Encryption")
Cc: <stable@vger.kernel.org> # v5.11+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
138 lines
3.0 KiB
C
138 lines
3.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* fs/f2fs/hash.c
|
|
*
|
|
* Copyright (c) 2012 Samsung Electronics Co., Ltd.
|
|
* http://www.samsung.com/
|
|
*
|
|
* Portions of this code from linux/fs/ext3/hash.c
|
|
*
|
|
* Copyright (C) 2002 by Theodore Ts'o
|
|
*/
|
|
#include <linux/types.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/f2fs_fs.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/unicode.h>
|
|
|
|
#include "f2fs.h"
|
|
|
|
/*
|
|
* Hashing code copied from ext3
|
|
*/
|
|
#define DELTA 0x9E3779B9
|
|
|
|
static void TEA_transform(unsigned int buf[4], unsigned int const in[])
|
|
{
|
|
__u32 sum = 0;
|
|
__u32 b0 = buf[0], b1 = buf[1];
|
|
__u32 a = in[0], b = in[1], c = in[2], d = in[3];
|
|
int n = 16;
|
|
|
|
do {
|
|
sum += DELTA;
|
|
b0 += ((b1 << 4)+a) ^ (b1+sum) ^ ((b1 >> 5)+b);
|
|
b1 += ((b0 << 4)+c) ^ (b0+sum) ^ ((b0 >> 5)+d);
|
|
} while (--n);
|
|
|
|
buf[0] += b0;
|
|
buf[1] += b1;
|
|
}
|
|
|
|
static void str2hashbuf(const unsigned char *msg, size_t len,
|
|
unsigned int *buf, int num)
|
|
{
|
|
unsigned pad, val;
|
|
int i;
|
|
|
|
pad = (__u32)len | ((__u32)len << 8);
|
|
pad |= pad << 16;
|
|
|
|
val = pad;
|
|
if (len > num * 4)
|
|
len = num * 4;
|
|
for (i = 0; i < len; i++) {
|
|
if ((i % 4) == 0)
|
|
val = pad;
|
|
val = msg[i] + (val << 8);
|
|
if ((i % 4) == 3) {
|
|
*buf++ = val;
|
|
val = pad;
|
|
num--;
|
|
}
|
|
}
|
|
if (--num >= 0)
|
|
*buf++ = val;
|
|
while (--num >= 0)
|
|
*buf++ = pad;
|
|
}
|
|
|
|
static u32 TEA_hash_name(const u8 *p, size_t len)
|
|
{
|
|
__u32 in[8], buf[4];
|
|
|
|
/* Initialize the default seed for the hash checksum functions */
|
|
buf[0] = 0x67452301;
|
|
buf[1] = 0xefcdab89;
|
|
buf[2] = 0x98badcfe;
|
|
buf[3] = 0x10325476;
|
|
|
|
while (1) {
|
|
str2hashbuf(p, len, in, 4);
|
|
TEA_transform(buf, in);
|
|
p += 16;
|
|
if (len <= 16)
|
|
break;
|
|
len -= 16;
|
|
}
|
|
return buf[0] & ~F2FS_HASH_COL_BIT;
|
|
}
|
|
|
|
/*
|
|
* Compute @fname->hash. For all directories, @fname->disk_name must be set.
|
|
* For casefolded directories, @fname->usr_fname must be set, and also
|
|
* @fname->cf_name if the filename is valid Unicode and is not "." or "..".
|
|
*/
|
|
void f2fs_hash_filename(const struct inode *dir, struct f2fs_filename *fname)
|
|
{
|
|
const u8 *name = fname->disk_name.name;
|
|
size_t len = fname->disk_name.len;
|
|
|
|
WARN_ON_ONCE(!name);
|
|
|
|
if (is_dot_dotdot(name, len)) {
|
|
fname->hash = 0;
|
|
return;
|
|
}
|
|
|
|
#if IS_ENABLED(CONFIG_UNICODE)
|
|
if (IS_CASEFOLDED(dir)) {
|
|
/*
|
|
* If the casefolded name is provided, hash it instead of the
|
|
* on-disk name. If the casefolded name is *not* provided, that
|
|
* should only be because the name wasn't valid Unicode or was
|
|
* "." or "..", so fall back to treating the name as an opaque
|
|
* byte sequence. Note that to handle encrypted directories,
|
|
* the fallback must use usr_fname (plaintext) rather than
|
|
* disk_name (ciphertext).
|
|
*/
|
|
WARN_ON_ONCE(!fname->usr_fname->name);
|
|
if (fname->cf_name.name) {
|
|
name = fname->cf_name.name;
|
|
len = fname->cf_name.len;
|
|
} else {
|
|
name = fname->usr_fname->name;
|
|
len = fname->usr_fname->len;
|
|
}
|
|
if (IS_ENCRYPTED(dir)) {
|
|
struct qstr tmp = QSTR_INIT(name, len);
|
|
|
|
fname->hash =
|
|
cpu_to_le32(fscrypt_fname_siphash(dir, &tmp));
|
|
return;
|
|
}
|
|
}
|
|
#endif
|
|
fname->hash = cpu_to_le32(TEA_hash_name(name, len));
|
|
}
|