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path: root/fs/ext4/crypto.c
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Diffstat (limited to 'fs/ext4/crypto.c')
-rw-r--r--fs/ext4/crypto.c98
1 files changed, 82 insertions, 16 deletions
diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c
index 1a0835073663..1bb67391225a 100644
--- a/fs/ext4/crypto.c
+++ b/fs/ext4/crypto.c
@@ -93,7 +93,8 @@ 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 +121,7 @@ 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 +258,8 @@ 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];
@@ -309,9 +311,10 @@ 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 +337,8 @@ 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 +346,17 @@ 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 +384,8 @@ 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 +406,11 @@ 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 +418,12 @@ 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;
@@ -453,7 +458,8 @@ errout:
bool ext4_valid_contents_enc_mode(uint32_t mode)
{
- return (mode == EXT4_ENCRYPTION_MODE_AES_256_XTS);
+ return (mode == EXT4_ENCRYPTION_MODE_AES_256_XTS ||
+ mode == EXT4_ENCRYPTION_MODE_PRIVATE);
}
/**
@@ -469,3 +475,63 @@ 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;
+
+ dir = dget_parent(dentry);
+ if (!ext4_encrypted_inode(d_inode(dir))) {
+ dput(dir);
+ return 0;
+ }
+ ci = EXT4_I(d_inode(dir))->i_crypt_info;
+ if (ci && ci->ci_keyring_key &&
+ (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) |
+ (1 << KEY_FLAG_REVOKED) |
+ (1 << KEY_FLAG_DEAD))))
+ ci = NULL;
+
+ /* 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,
+};
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-23 01:54:56 +0000