[PATCH AUTOSEL 5.5 052/121] crypto: chelsio - This fixes the kernel panic which occurs during a libkcapi test

Sasha Levin
2020-04-11T23:38:02Z

From: Ayush Sawal <ayush.sawal@chelsio.com>

[ Upstream commit 9195189e00a7db55e7d448cee973cae87c5a3c71 ]

The libkcapi test which causes kernel panic is
aead asynchronous vmsplice multiple test.

./bin/kcapi -v -d 4 -x 10 -c "ccm(aes)"
-q 4edb58e8d5eb6bc711c43a6f3693daebde2e5524f1b55297abb29f003236e43d
-t a7877c99 -n 674742abd0f5ba -k 2861fd0253705d7875c95ba8a53171b4
-a fb7bc304a3909e66e2e0c5ef952712dd884ce3e7324171369f2c5db1adc48c7d

This patch avoids dma_mapping of a zero length sg which causes the panic,
by using sg_nents_for_len which maps only upto a specific length

Signed-off-by: Ayush Sawal <ayush.sawal@chelsio.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/crypto/chelsio/chcr_algo.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/chelsio/chcr_algo.c b/drivers/crypto/chelsio/chcr_algo.c
index 722c5f65b66b3..4ace6dfe3a688 100644
--- a/drivers/crypto/chelsio/chcr_algo.c
+++ b/drivers/crypto/chelsio/chcr_algo.c
@@ -2481,8 +2481,9 @@ int chcr_aead_dma_map(struct device *dev,
else
reqctx->b0_dma = 0;
if (req->src == req->dst) {
- error = dma_map_sg(dev, req->src, sg_nents(req->src),
- DMA_BIDIRECTIONAL);
+ error = dma_map_sg(dev, req->src,
+ sg_nents_for_len(req->src, dst_size),
+ DMA_BIDIRECTIONAL);
if (!error)
goto err;
} else {
--
2.20.1