[PATCH 1/3] dm integrity: do not filter algos with CRYPTO_ALG_ALLOCATES_MEMORY

From: Giovanni Cabiddu
Date: Wed Jul 05 2023 - 12:40:39 EST


The flag CRYPTO_ALG_ALLOCATES_MEMORY indicates that an algorithm might
allocate memory in the datapath and therefore sleep.
Dm-integrity is filtering out implementations of skcipher algorithms
that have this flag set. However, in the same function it does
allocations with GFP_KERNEL.
As dm-integrity is re-entrant and capable of handling sleeps that could
occur during allocations with GFP_KERNEL, then it is also capable of
using skcipher algorithm implementations that have
CRYPTO_ALG_ALLOCATES_MEMORY set.

Remove the filtering of skcipher implementations with the flag
CRYPTO_ALG_ALLOCATES_MEMORY set.

Suggested-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/linux-crypto/ZILvtASXQKLG43y9@xxxxxxxxxxxxxxxxxxx/
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@xxxxxxxxx>
Reviewed-by: Fiona Trahe <fiona.trahe@xxxxxxxxx>
---
drivers/md/dm-integrity.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index 31838b13ea54..a1013eff01b4 100644
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -3785,7 +3785,7 @@ static int create_journal(struct dm_integrity_c *ic, char **error)
struct journal_completion comp;

comp.ic = ic;
- ic->journal_crypt = crypto_alloc_skcipher(ic->journal_crypt_alg.alg_string, 0, CRYPTO_ALG_ALLOCATES_MEMORY);
+ ic->journal_crypt = crypto_alloc_skcipher(ic->journal_crypt_alg.alg_string, 0, 0);
if (IS_ERR(ic->journal_crypt)) {
*error = "Invalid journal cipher";
r = PTR_ERR(ic->journal_crypt);
--
2.40.1