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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-11-20 03:33:50 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-11-20 03:33:50 +0100 |
commit | d117b9acaeada0b243f31e0fe83e111fcc9a6644 (patch) | |
tree | 3ba4fefa66b461127523bef71f2472b28e6d4342 /fs | |
parent | Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/g... (diff) | |
parent | ext4: sanity check the block and cluster size at mount time (diff) | |
download | linux-d117b9acaeada0b243f31e0fe83e111fcc9a6644.tar.xz linux-d117b9acaeada0b243f31e0fe83e111fcc9a6644.zip |
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
Diffstat (limited to 'fs')
-rw-r--r-- | fs/crypto/fname.c | 53 | ||||
-rw-r--r-- | fs/crypto/keyinfo.c | 16 | ||||
-rw-r--r-- | fs/ext4/ext4.h | 1 | ||||
-rw-r--r-- | fs/ext4/super.c | 17 |
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 = |