[PATCH] shash: fix unaligned calculation with short length

[Yehuda Sadeh]

When the total length is shorter than the calculated number of unaligned bytes, the call to shash->update breaks. For example, calling crc32c on unaligned buffer with length of 1 can result in a system crash.

Signed-off-by: Yehuda Sadeh <yehuda@xxxxxxxxxxxxxxx>
---
 crypto/shash.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/crypto/shash.c b/crypto/shash.c
index d5a2b61..6792a67 100644
--- a/crypto/shash.c
+++ b/crypto/shash.c
@@ -82,6 +82,9 @@ static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
 	u8 buf[shash_align_buffer_size(unaligned_len, alignmask)]
 		__attribute__ ((aligned));
 
+	if (unaligned_len > len)
+		unaligned_len = len;
+
 	memcpy(buf, data, unaligned_len);
 
 	return shash->update(desc, buf, unaligned_len) ?:
-- 
1.5.6.5

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