[PATCH v2] blk-crypto: dynamically allocate fallback profile

Sweet Tea Dorminy
2023-08-09T13:06:07Z

blk_crypto_profile_init() calls lockdep_register_key(), which warns and
does not register if the provided memory is a static object.
blk-crypto-fallback currently has a static blk_crypto_profile and calls
blk_crypto_profile_init() thereupon, resulting in the warning and
failure to register.

Fortunately it is simple enough to use a dynamically allocated profile
and make lockdep function correctly.

Fixes: 2fb48d88e77f ("blk-crypto: use dynamic lock class for blk_crypto_profile::lock")
Cc: stable@vger.kernel.org
Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
---
v2: reworded commit message, fixed Fixes tag, as pointed out by Eric
Biggers.

block/blk-crypto-fallback.c | 27 +++++++++++++++------------
1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/block/blk-crypto-fallback.c b/block/blk-crypto-fallback.c
index ad9844c5b40c..de94e9bffec6 100644
--- a/block/blk-crypto-fallback.c
+++ b/block/blk-crypto-fallback.c
@@ -78,7 +78,7 @@ static struct blk_crypto_fallback_keyslot {
struct crypto_skcipher *tfms[BLK_ENCRYPTION_MODE_MAX];
} *blk_crypto_keyslots;

-static struct blk_crypto_profile blk_crypto_fallback_profile;
+static struct blk_crypto_profile *blk_crypto_fallback_profile;
static struct workqueue_struct *blk_crypto_wq;
static mempool_t *blk_crypto_bounce_page_pool;
static struct bio_set crypto_bio_split;
@@ -292,7 +292,7 @@ static bool blk_crypto_fallback_encrypt_bio(struct bio **bio_ptr)
* Get a blk-crypto-fallback keyslot that contains a crypto_skcipher for
* this bio's algorithm and key.
*/
- blk_st = blk_crypto_get_keyslot(&blk_crypto_fallback_profile,
+ blk_st = blk_crypto_get_keyslot(blk_crypto_fallback_profile,
bc->bc_key, &slot);
if (blk_st != BLK_STS_OK) {
src_bio->bi_status = blk_st;
@@ -395,7 +395,7 @@ static void blk_crypto_fallback_decrypt_bio(struct work_struct *work)
* Get a blk-crypto-fallback keyslot that contains a crypto_skcipher for
* this bio's algorithm and key.
*/
- blk_st = blk_crypto_get_keyslot(&blk_crypto_fallback_profile,
+ blk_st = blk_crypto_get_keyslot(blk_crypto_fallback_profile,
bc->bc_key, &slot);
if (blk_st != BLK_STS_OK) {
bio->bi_status = blk_st;
@@ -499,7 +499,7 @@ bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
return false;
}

- if (!__blk_crypto_cfg_supported(&blk_crypto_fallback_profile,
+ if (!__blk_crypto_cfg_supported(blk_crypto_fallback_profile,
&bc->bc_key->crypto_cfg)) {
bio->bi_status = BLK_STS_NOTSUPP;
return false;
@@ -526,7 +526,7 @@ bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)

int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key)
{
- return __blk_crypto_evict_key(&blk_crypto_fallback_profile, key);
+ return __blk_crypto_evict_key(blk_crypto_fallback_profile, key);
}

static bool blk_crypto_fallback_inited;
@@ -534,29 +534,32 @@ static int blk_crypto_fallback_init(void)
{
int i;
int err;
- struct blk_crypto_profile *profile = &blk_crypto_fallback_profile;

if (blk_crypto_fallback_inited)
return 0;

get_random_bytes(blank_key, BLK_CRYPTO_MAX_KEY_SIZE);

+ blk_crypto_fallback_profile =
+ kzalloc(sizeof(*blk_crypto_fallback_profile), GFP_KERNEL);
+
err = bioset_init(&crypto_bio_split, 64, 0, 0);
if (err)
goto out;

- err = blk_crypto_profile_init(profile, blk_crypto_num_keyslots);
+ err = blk_crypto_profile_init(blk_crypto_fallback_profile,
+ blk_crypto_num_keyslots);
if (err)
goto fail_free_bioset;
err = -ENOMEM;

- profile->ll_ops = blk_crypto_fallback_ll_ops;
- profile->max_dun_bytes_supported = BLK_CRYPTO_MAX_IV_SIZE;
+ blk_crypto_fallback_profile->ll_ops = blk_crypto_fallback_ll_ops;
+ blk_crypto_fallback_profile->max_dun_bytes_supported = BLK_CRYPTO_MAX_IV_SIZE;

/* All blk-crypto modes have a crypto API fallback. */
for (i = 0; i < BLK_ENCRYPTION_MODE_MAX; i++)
- profile->modes_supported[i] = 0xFFFFFFFF;
- profile->modes_supported[BLK_ENCRYPTION_MODE_INVALID] = 0;
+ blk_crypto_fallback_profile->modes_supported[i] = 0xFFFFFFFF;
+ blk_crypto_fallback_profile->modes_supported[BLK_ENCRYPTION_MODE_INVALID] = 0;

blk_crypto_wq = alloc_workqueue("blk_crypto_wq",
WQ_UNBOUND | WQ_HIGHPRI |
@@ -597,7 +600,7 @@ static int blk_crypto_fallback_init(void)
fail_free_wq:
destroy_workqueue(blk_crypto_wq);
fail_destroy_profile:
- blk_crypto_profile_destroy(profile);
+ blk_crypto_profile_destroy(blk_crypto_fallback_profile);
fail_free_bioset:
bioset_exit(&crypto_bio_split);
out:
--
2.41.0