[PATCH] s390/crypto: fix scatterwalk_unmap() callers in AES-GCM

Jann Horn
2022-05-17T14:31:14Z

The argument of scatterwalk_unmap() is supposed to be the void* that was
returned by the previous scatterwalk_map() call.
The s390 AES-GCM implementation was instead passing the pointer to the
struct scatter_walk.

This doesn't actually break anything because scatterwalk_unmap() only uses
its argument under CONFIG_HIGHMEM and ARCH_HAS_FLUSH_ON_KUNMAP.

Note that I have not tested this patch in any way, not even compile-tested
it.

Fixes: bf7fa038707c ("s390/crypto: add s390 platform specific aes gcm support.")
Signed-off-by: Jann Horn <jannh@google.com>
---
IDK which tree this has to go through - s390 or crypto?
maybe s390 is better, since they can actually test it?

arch/s390/crypto/aes_s390.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/s390/crypto/aes_s390.c b/arch/s390/crypto/aes_s390.c
index 54c7536f2482..1023e9d43d44 100644
--- a/arch/s390/crypto/aes_s390.c
+++ b/arch/s390/crypto/aes_s390.c
@@ -701,7 +701,7 @@ static inline void _gcm_sg_unmap_and_advance(struct gcm_sg_walk *gw,
unsigned int nbytes)
{
gw->walk_bytes_remain -= nbytes;
- scatterwalk_unmap(&gw->walk);
+ scatterwalk_unmap(gw->walk_ptr);
scatterwalk_advance(&gw->walk, nbytes);
scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain);
gw->walk_ptr = NULL;
@@ -776,7 +776,7 @@ static int gcm_out_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
goto out;
}

- scatterwalk_unmap(&gw->walk);
+ scatterwalk_unmap(gw->walk_ptr);
gw->walk_ptr = NULL;

gw->ptr = gw->buf;

base-commit: 42226c989789d8da4af1de0c31070c96726d990c
--
2.36.0.550.gb090851708-goog