[PATCH v2 21/30] crypto: sa2ul - reject exhausted context IDs

[Manorit Chawdhry]

When every security-context ID is allocated, the bitmap search returns
SA_MAX_NUM_CTX. Setting that out-of-range bit can corrupt adjacent state
in the device structure. Reject allocation while still holding the lock
so no bitmap or context count is changed.

Fixes: 7694b6ca649f ("crypto: sa2ul - Add crypto driver")
Signed-off-by: Manorit Chawdhry <m-chawdhry@xxxxxx>
---
 drivers/crypto/sa2ul.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/crypto/sa2ul.c b/drivers/crypto/sa2ul.c
index ead12f77ff67..2964aa44d50e 100644
--- a/drivers/crypto/sa2ul.c
+++ b/drivers/crypto/sa2ul.c
@@ -717,6 +717,10 @@ static int sa_init_ctx_info(struct sa_ctx_info *ctx,
 
 	spin_lock(&data->scid_lock);
 	bn = find_first_zero_bit(data->ctx_bm, SA_MAX_NUM_CTX);
+	if (bn >= SA_MAX_NUM_CTX) {
+		spin_unlock(&data->scid_lock);
+		return -ENOSPC;
+	}
 	__set_bit(bn, data->ctx_bm);
 	data->sc_id++;
 	spin_unlock(&data->scid_lock);

-- 
2.43.0