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author | Marcel Ziswiler <marcel.ziswiler@toradex.com> | 2017-06-17 17:01:11 +0200 |
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committer | Marcel Ziswiler <marcel.ziswiler@toradex.com> | 2017-06-17 17:01:11 +0200 |
commit | c1d5fe2d54551b95b812143d94d8168da2220dd8 (patch) | |
tree | fdde4472ab2b19fcadaae22d68a0c9b008f74373 /fs/ext4/crypto.c | |
parent | 0068a1b36d309f22698f7de7478b72e672360129 (diff) | |
parent | 1bd30958ec55d80ca72d2ca4e7e5c3d9fbf3173e (diff) |
Merge tag 'v4.4.73' into toradex_vf_4.4-nextColibri-VF_LXDE-Image_2.7b3-20170630
This is the 4.4.73 stable release
Diffstat (limited to 'fs/ext4/crypto.c')
-rw-r--r-- | fs/ext4/crypto.c | 96 |
1 files changed, 80 insertions, 16 deletions
diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c index 1a0835073663..f240cef8b326 100644 --- a/fs/ext4/crypto.c +++ b/fs/ext4/crypto.c @@ -34,6 +34,7 @@ #include <linux/random.h> #include <linux/scatterlist.h> #include <linux/spinlock_types.h> +#include <linux/namei.h> #include "ext4_extents.h" #include "xattr.h" @@ -93,7 +94,8 @@ void ext4_release_crypto_ctx(struct ext4_crypto_ctx *ctx) * Return: An allocated and initialized encryption context on success; error * value or NULL otherwise. */ -struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode) +struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode, + gfp_t gfp_flags) { struct ext4_crypto_ctx *ctx = NULL; int res = 0; @@ -120,7 +122,7 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode) list_del(&ctx->free_list); spin_unlock_irqrestore(&ext4_crypto_ctx_lock, flags); if (!ctx) { - ctx = kmem_cache_zalloc(ext4_crypto_ctx_cachep, GFP_NOFS); + ctx = kmem_cache_zalloc(ext4_crypto_ctx_cachep, gfp_flags); if (!ctx) { res = -ENOMEM; goto out; @@ -257,7 +259,8 @@ static int ext4_page_crypto(struct inode *inode, ext4_direction_t rw, pgoff_t index, struct page *src_page, - struct page *dest_page) + struct page *dest_page, + gfp_t gfp_flags) { u8 xts_tweak[EXT4_XTS_TWEAK_SIZE]; @@ -268,7 +271,7 @@ static int ext4_page_crypto(struct inode *inode, struct crypto_ablkcipher *tfm = ci->ci_ctfm; int res = 0; - req = ablkcipher_request_alloc(tfm, GFP_NOFS); + req = ablkcipher_request_alloc(tfm, gfp_flags); if (!req) { printk_ratelimited(KERN_ERR "%s: crypto_request_alloc() failed\n", @@ -309,9 +312,10 @@ static int ext4_page_crypto(struct inode *inode, return 0; } -static struct page *alloc_bounce_page(struct ext4_crypto_ctx *ctx) +static struct page *alloc_bounce_page(struct ext4_crypto_ctx *ctx, + gfp_t gfp_flags) { - ctx->w.bounce_page = mempool_alloc(ext4_bounce_page_pool, GFP_NOWAIT); + ctx->w.bounce_page = mempool_alloc(ext4_bounce_page_pool, gfp_flags); if (ctx->w.bounce_page == NULL) return ERR_PTR(-ENOMEM); ctx->flags |= EXT4_WRITE_PATH_FL; @@ -334,7 +338,8 @@ static struct page *alloc_bounce_page(struct ext4_crypto_ctx *ctx) * error value or NULL. */ struct page *ext4_encrypt(struct inode *inode, - struct page *plaintext_page) + struct page *plaintext_page, + gfp_t gfp_flags) { struct ext4_crypto_ctx *ctx; struct page *ciphertext_page = NULL; @@ -342,17 +347,17 @@ struct page *ext4_encrypt(struct inode *inode, BUG_ON(!PageLocked(plaintext_page)); - ctx = ext4_get_crypto_ctx(inode); + ctx = ext4_get_crypto_ctx(inode, gfp_flags); if (IS_ERR(ctx)) return (struct page *) ctx; /* The encryption operation will require a bounce page. */ - ciphertext_page = alloc_bounce_page(ctx); + ciphertext_page = alloc_bounce_page(ctx, gfp_flags); if (IS_ERR(ciphertext_page)) goto errout; ctx->w.control_page = plaintext_page; err = ext4_page_crypto(inode, EXT4_ENCRYPT, plaintext_page->index, - plaintext_page, ciphertext_page); + plaintext_page, ciphertext_page, gfp_flags); if (err) { ciphertext_page = ERR_PTR(err); errout: @@ -380,8 +385,8 @@ int ext4_decrypt(struct page *page) { BUG_ON(!PageLocked(page)); - return ext4_page_crypto(page->mapping->host, - EXT4_DECRYPT, page->index, page, page); + return ext4_page_crypto(page->mapping->host, EXT4_DECRYPT, + page->index, page, page, GFP_NOFS); } int ext4_encrypted_zeroout(struct inode *inode, struct ext4_extent *ex) @@ -402,11 +407,11 @@ int ext4_encrypted_zeroout(struct inode *inode, struct ext4_extent *ex) BUG_ON(inode->i_sb->s_blocksize != PAGE_CACHE_SIZE); - ctx = ext4_get_crypto_ctx(inode); + ctx = ext4_get_crypto_ctx(inode, GFP_NOFS); if (IS_ERR(ctx)) return PTR_ERR(ctx); - ciphertext_page = alloc_bounce_page(ctx); + ciphertext_page = alloc_bounce_page(ctx, GFP_NOWAIT); if (IS_ERR(ciphertext_page)) { err = PTR_ERR(ciphertext_page); goto errout; @@ -414,11 +419,12 @@ int ext4_encrypted_zeroout(struct inode *inode, struct ext4_extent *ex) while (len--) { err = ext4_page_crypto(inode, EXT4_ENCRYPT, lblk, - ZERO_PAGE(0), ciphertext_page); + ZERO_PAGE(0), ciphertext_page, + GFP_NOFS); if (err) goto errout; - bio = bio_alloc(GFP_KERNEL, 1); + bio = bio_alloc(GFP_NOWAIT, 1); if (!bio) { err = -ENOMEM; goto errout; @@ -469,3 +475,61 @@ uint32_t ext4_validate_encryption_key_size(uint32_t mode, uint32_t size) return size; return 0; } + +/* + * Validate dentries for encrypted directories to make sure we aren't + * potentially caching stale data after a key has been added or + * removed. + */ +static int ext4_d_revalidate(struct dentry *dentry, unsigned int flags) +{ + struct dentry *dir; + struct ext4_crypt_info *ci; + int dir_has_key, cached_with_key; + + if (flags & LOOKUP_RCU) + return -ECHILD; + + dir = dget_parent(dentry); + if (!ext4_encrypted_inode(d_inode(dir))) { + dput(dir); + return 0; + } + ci = EXT4_I(d_inode(dir))->i_crypt_info; + + /* this should eventually be an flag in d_flags */ + cached_with_key = dentry->d_fsdata != NULL; + dir_has_key = (ci != NULL); + dput(dir); + + /* + * If the dentry was cached without the key, and it is a + * negative dentry, it might be a valid name. We can't check + * if the key has since been made available due to locking + * reasons, so we fail the validation so ext4_lookup() can do + * this check. + * + * We also fail the validation if the dentry was created with + * the key present, but we no longer have the key, or vice versa. + */ + if ((!cached_with_key && d_is_negative(dentry)) || + (!cached_with_key && dir_has_key) || + (cached_with_key && !dir_has_key)) { +#if 0 /* Revalidation debug */ + char buf[80]; + char *cp = simple_dname(dentry, buf, sizeof(buf)); + + if (IS_ERR(cp)) + cp = (char *) "???"; + pr_err("revalidate: %s %p %d %d %d\n", cp, dentry->d_fsdata, + cached_with_key, d_is_negative(dentry), + dir_has_key); +#endif + return 0; + } + return 1; +} + +const struct dentry_operations ext4_encrypted_d_ops = { + .d_revalidate = ext4_d_revalidate, +}; |