From: Eric Biggers <ebiggers@xxxxxxxxxx>
fscrypt_get_encryption_info() has never actually been safe to call in a
context that needs GFP_NOFS, since it calls crypto_alloc_skcipher().
crypto_alloc_skcipher() isn't GFP_NOFS-safe, even if called under
memalloc_nofs_save(). This is because it may load kernel modules, and
also because it internally takes crypto_alg_sem. Other tasks can do
GFP_KERNEL allocations while holding crypto_alg_sem for write.
The use of fscrypt_init_mutex isn't GFP_NOFS-safe either.
So, stop pretending that fscrypt_get_encryption_info() is nofs-safe.
I.e., when it allocates memory, just use GFP_KERNEL instead of GFP_NOFS.
Note, another reason to do this is that GFP_NOFS is deprecated in favor
of using memalloc_nofs_save() in the proper places.
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
fs/crypto/inline_crypt.c | 7 ++-----
fs/crypto/keysetup.c | 2 +-
fs/crypto/keysetup_v1.c | 8 ++++----
3 files changed, 7 insertions(+), 10 deletions(-)
diff --git a/fs/crypto/inline_crypt.c b/fs/crypto/inline_crypt.c
index faa25541ccb68..89bffa82ed74a 100644
--- a/fs/crypto/inline_crypt.c
+++ b/fs/crypto/inline_crypt.c
@@ -106,7 +106,7 @@ int fscrypt_select_encryption_impl(struct fscrypt_info *ci)
crypto_cfg.data_unit_size = sb->s_blocksize;
crypto_cfg.dun_bytes = fscrypt_get_dun_bytes(ci);
num_devs = fscrypt_get_num_devices(sb);
- devs = kmalloc_array(num_devs, sizeof(*devs), GFP_NOFS);
+ devs = kmalloc_array(num_devs, sizeof(*devs), GFP_KERNEL);
if (!devs)
return -ENOMEM;
fscrypt_get_devices(sb, num_devs, devs);
@@ -135,9 +135,8 @@ int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key,
struct fscrypt_blk_crypto_key *blk_key;
int err;
int i;
- unsigned int flags;
- blk_key = kzalloc(struct_size(blk_key, devs, num_devs), GFP_NOFS);
+ blk_key = kzalloc(struct_size(blk_key, devs, num_devs), GFP_KERNEL);
if (!blk_key)
return -ENOMEM;
@@ -166,10 +165,8 @@ int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key,
}
queue_refs++;
- flags = memalloc_nofs_save();
err = blk_crypto_start_using_key(&blk_key->base,
blk_key->devs[i]);
- memalloc_nofs_restore(flags);
if (err) {
fscrypt_err(inode,
"error %d starting to use blk-crypto", err);
diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c
index 6ac816d3e8478..ad64525ec6800 100644
--- a/fs/crypto/keysetup.c
+++ b/fs/crypto/keysetup.c
@@ -477,7 +477,7 @@ fscrypt_setup_encryption_info(struct inode *inode,
struct key *master_key = NULL;
int res;
- crypt_info = kmem_cache_zalloc(fscrypt_info_cachep, GFP_NOFS);
+ crypt_info = kmem_cache_zalloc(fscrypt_info_cachep, GFP_KERNEL);
if (!crypt_info)
return -ENOMEM;
diff --git a/fs/crypto/keysetup_v1.c b/fs/crypto/keysetup_v1.c
index a3cb52572b05c..2762c53504323 100644
--- a/fs/crypto/keysetup_v1.c
+++ b/fs/crypto/keysetup_v1.c
@@ -60,7 +60,7 @@ static int derive_key_aes(const u8 *master_key,
goto out;
}
crypto_skcipher_set_flags(tfm, CRYPTO_TFM_REQ_FORBID_WEAK_KEYS);
- req = skcipher_request_alloc(tfm, GFP_NOFS);
+ req = skcipher_request_alloc(tfm, GFP_KERNEL);
if (!req) {
res = -ENOMEM;
goto out;
@@ -99,7 +99,7 @@ find_and_lock_process_key(const char *prefix,
const struct user_key_payload *ukp;
const struct fscrypt_key *payload;
- description = kasprintf(GFP_NOFS, "%s%*phN", prefix,
+ description = kasprintf(GFP_KERNEL, "%s%*phN", prefix,
FSCRYPT_KEY_DESCRIPTOR_SIZE, descriptor);
if (!description)
return ERR_PTR(-ENOMEM);
@@ -228,7 +228,7 @@ fscrypt_get_direct_key(const struct fscrypt_info *ci, const u8 *raw_key)
return dk;
/* Nope, allocate one. */
- dk = kzalloc(sizeof(*dk), GFP_NOFS);
+ dk = kzalloc(sizeof(*dk), GFP_KERNEL);
if (!dk)
return ERR_PTR(-ENOMEM);
refcount_set(&dk->dk_refcount, 1);
@@ -272,7 +272,7 @@ static int setup_v1_file_key_derived(struct fscrypt_info *ci,
* This cannot be a stack buffer because it will be passed to the
* scatterlist crypto API during derive_key_aes().
*/
- derived_key = kmalloc(ci->ci_mode->keysize, GFP_NOFS);
+ derived_key = kmalloc(ci->ci_mode->keysize, GFP_KERNEL);
if (!derived_key)
return -ENOMEM;
--
2.28.0
