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authorLinus Torvalds <torvalds@linux-foundation.org>2016-11-19 18:33:50 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-11-19 18:33:50 -0800
commitd117b9acaeada0b243f31e0fe83e111fcc9a6644 (patch)
tree3ba4fefa66b461127523bef71f2472b28e6d4342
parent50d438fb9e4229cb37ec89a22c066b626e30885c (diff)
parent8cdf3372fe8368f56315e66bea9f35053c418093 (diff)
Merge tag 'ext4_for_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 fixes from Ted Ts'o: "A security fix (so a maliciously corrupted file system image won't panic the kernel) and some fixes for CONFIG_VMAP_STACK" * tag 'ext4_for_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: sanity check the block and cluster size at mount time fscrypto: don't use on-stack buffer for key derivation fscrypto: don't use on-stack buffer for filename encryption
-rw-r--r--fs/crypto/fname.c53
-rw-r--r--fs/crypto/keyinfo.c16
-rw-r--r--fs/ext4/ext4.h1
-rw-r--r--fs/ext4/super.c17
4 files changed, 51 insertions, 36 deletions
diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c
index 9a28133ac3b8..9b774f4b50c8 100644
--- a/fs/crypto/fname.c
+++ b/fs/crypto/fname.c
@@ -39,65 +39,54 @@ static void fname_crypt_complete(struct crypto_async_request *req, int res)
static int fname_encrypt(struct inode *inode,
const struct qstr *iname, struct fscrypt_str *oname)
{
- u32 ciphertext_len;
struct skcipher_request *req = NULL;
DECLARE_FS_COMPLETION_RESULT(ecr);
struct fscrypt_info *ci = inode->i_crypt_info;
struct crypto_skcipher *tfm = ci->ci_ctfm;
int res = 0;
char iv[FS_CRYPTO_BLOCK_SIZE];
- struct scatterlist src_sg, dst_sg;
+ struct scatterlist sg;
int padding = 4 << (ci->ci_flags & FS_POLICY_FLAGS_PAD_MASK);
- char *workbuf, buf[32], *alloc_buf = NULL;
- unsigned lim;
+ unsigned int lim;
+ unsigned int cryptlen;
lim = inode->i_sb->s_cop->max_namelen(inode);
if (iname->len <= 0 || iname->len > lim)
return -EIO;
- ciphertext_len = max(iname->len, (u32)FS_CRYPTO_BLOCK_SIZE);
- ciphertext_len = round_up(ciphertext_len, padding);
- ciphertext_len = min(ciphertext_len, lim);
+ /*
+ * Copy the filename to the output buffer for encrypting in-place and
+ * pad it with the needed number of NUL bytes.
+ */
+ cryptlen = max_t(unsigned int, iname->len, FS_CRYPTO_BLOCK_SIZE);
+ cryptlen = round_up(cryptlen, padding);
+ cryptlen = min(cryptlen, lim);
+ memcpy(oname->name, iname->name, iname->len);
+ memset(oname->name + iname->len, 0, cryptlen - iname->len);
- if (ciphertext_len <= sizeof(buf)) {
- workbuf = buf;
- } else {
- alloc_buf = kmalloc(ciphertext_len, GFP_NOFS);
- if (!alloc_buf)
- return -ENOMEM;
- workbuf = alloc_buf;
- }
+ /* Initialize the IV */
+ memset(iv, 0, FS_CRYPTO_BLOCK_SIZE);
- /* Allocate request */
+ /* Set up the encryption request */
req = skcipher_request_alloc(tfm, GFP_NOFS);
if (!req) {
printk_ratelimited(KERN_ERR
- "%s: crypto_request_alloc() failed\n", __func__);
- kfree(alloc_buf);
+ "%s: skcipher_request_alloc() failed\n", __func__);
return -ENOMEM;
}
skcipher_request_set_callback(req,
CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
fname_crypt_complete, &ecr);
+ sg_init_one(&sg, oname->name, cryptlen);
+ skcipher_request_set_crypt(req, &sg, &sg, cryptlen, iv);
- /* Copy the input */
- memcpy(workbuf, iname->name, iname->len);
- if (iname->len < ciphertext_len)
- memset(workbuf + iname->len, 0, ciphertext_len - iname->len);
-
- /* Initialize IV */
- memset(iv, 0, FS_CRYPTO_BLOCK_SIZE);
-
- /* Create encryption request */
- sg_init_one(&src_sg, workbuf, ciphertext_len);
- sg_init_one(&dst_sg, oname->name, ciphertext_len);
- skcipher_request_set_crypt(req, &src_sg, &dst_sg, ciphertext_len, iv);
+ /* Do the encryption */
res = crypto_skcipher_encrypt(req);
if (res == -EINPROGRESS || res == -EBUSY) {
+ /* Request is being completed asynchronously; wait for it */
wait_for_completion(&ecr.completion);
res = ecr.res;
}
- kfree(alloc_buf);
skcipher_request_free(req);
if (res < 0) {
printk_ratelimited(KERN_ERR
@@ -105,7 +94,7 @@ static int fname_encrypt(struct inode *inode,
return res;
}
- oname->len = ciphertext_len;
+ oname->len = cryptlen;
return 0;
}
diff --git a/fs/crypto/keyinfo.c b/fs/crypto/keyinfo.c
index 82f0285f5d08..67fb6d8876d0 100644
--- a/fs/crypto/keyinfo.c
+++ b/fs/crypto/keyinfo.c
@@ -185,7 +185,7 @@ int get_crypt_info(struct inode *inode)
struct crypto_skcipher *ctfm;
const char *cipher_str;
int keysize;
- u8 raw_key[FS_MAX_KEY_SIZE];
+ u8 *raw_key = NULL;
int res;
res = fscrypt_initialize();
@@ -238,6 +238,15 @@ retry:
if (res)
goto out;
+ /*
+ * This cannot be a stack buffer because it is passed to the scatterlist
+ * crypto API as part of key derivation.
+ */
+ res = -ENOMEM;
+ raw_key = kmalloc(FS_MAX_KEY_SIZE, GFP_NOFS);
+ if (!raw_key)
+ goto out;
+
if (fscrypt_dummy_context_enabled(inode)) {
memset(raw_key, 0x42, FS_AES_256_XTS_KEY_SIZE);
goto got_key;
@@ -276,7 +285,8 @@ got_key:
if (res)
goto out;
- memzero_explicit(raw_key, sizeof(raw_key));
+ kzfree(raw_key);
+ raw_key = NULL;
if (cmpxchg(&inode->i_crypt_info, NULL, crypt_info) != NULL) {
put_crypt_info(crypt_info);
goto retry;
@@ -287,7 +297,7 @@ out:
if (res == -ENOKEY)
res = 0;
put_crypt_info(crypt_info);
- memzero_explicit(raw_key, sizeof(raw_key));
+ kzfree(raw_key);
return res;
}
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 282a51b07c57..a8a750f59621 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -235,6 +235,7 @@ struct ext4_io_submit {
#define EXT4_MAX_BLOCK_SIZE 65536
#define EXT4_MIN_BLOCK_LOG_SIZE 10
#define EXT4_MAX_BLOCK_LOG_SIZE 16
+#define EXT4_MAX_CLUSTER_LOG_SIZE 30
#ifdef __KERNEL__
# define EXT4_BLOCK_SIZE(s) ((s)->s_blocksize)
#else
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 20da99da0a34..52b0530c5d65 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3565,7 +3565,15 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
if (blocksize < EXT4_MIN_BLOCK_SIZE ||
blocksize > EXT4_MAX_BLOCK_SIZE) {
ext4_msg(sb, KERN_ERR,
- "Unsupported filesystem blocksize %d", blocksize);
+ "Unsupported filesystem blocksize %d (%d log_block_size)",
+ blocksize, le32_to_cpu(es->s_log_block_size));
+ goto failed_mount;
+ }
+ if (le32_to_cpu(es->s_log_block_size) >
+ (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
+ ext4_msg(sb, KERN_ERR,
+ "Invalid log block size: %u",
+ le32_to_cpu(es->s_log_block_size));
goto failed_mount;
}
@@ -3697,6 +3705,13 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
"block size (%d)", clustersize, blocksize);
goto failed_mount;
}
+ if (le32_to_cpu(es->s_log_cluster_size) >
+ (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
+ ext4_msg(sb, KERN_ERR,
+ "Invalid log cluster size: %u",
+ le32_to_cpu(es->s_log_cluster_size));
+ goto failed_mount;
+ }
sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
le32_to_cpu(es->s_log_block_size);
sbi->s_clusters_per_group =