The `vmac_update` function previously assumed that `p` was aligned,
which could lead to misaligned memory accesses when processing blocks.
This patch resolves the issue by,
introducing a temporary buffer to ensure alignment.
Changes include:
- Allocating a temporary buffer (`__le64 *data`) to store aligned blocks.
- Using `get_unaligned_le64` to safely read data into the temporary buffer.
- Iteratively processing blocks with the `vhash_blocks` function.
- Properly freeing the allocated temporary buffer after processing.
Signed-off-by: Atharva Tiwari <evepolonium@xxxxxxxxx>
---
crypto/vmac.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/crypto/vmac.c b/crypto/vmac.c
index 2ea384645ecf..513fbd5bc581 100644
--- a/crypto/vmac.c
+++ b/crypto/vmac.c
@@ -518,9 +518,19 @@ static int vmac_update(struct shash_desc *desc, const u8 *p, unsigned int len)
if (len >= VMAC_NHBYTES) {
n = round_down(len, VMAC_NHBYTES);
- /* TODO: 'p' may be misaligned here */
- vhash_blocks(tctx, dctx, (const __le64 *)p, n / VMAC_NHBYTES);
- p += n;
+ const u8 *end = p + n;
+ const uint16_t num_blocks = VMAC_NHBYTES/sizeof(__le64);
+ __le64 *data = kmalloc(num_blocks * sizeof(__le64), GFP_KERNEL);
+
+ while (p < end) {
+ for (unsigned short i = 0; i < num_blocks; i++) {
+ data[i] = get_unaligned_le64(p + i * sizeof(__le64));
+ }
+
+ vhash_blocks(tctx, dctx, data, 1);
+ p += VMAC_NHBYTES;
+ }
+ kfree(data);
len -= n;
}
--
2.39.5
