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authorHerbert Xu <herbert@gondor.apana.org.au>2019-09-06 13:13:06 +1000
committerHerbert Xu <herbert@gondor.apana.org.au>2019-09-09 17:35:27 +1000
commit0ba3c026e685573bd3534c17e27da7c505ac99c4 (patch)
tree62a5c9b06044d73c4b004c2000ec87b24c319a36 /crypto
parentcrypto: arm64/aes - Use PTR_ERR_OR_ZERO rather than its implementation. (diff)
downloadlinux-dev-0ba3c026e685573bd3534c17e27da7c505ac99c4.tar.xz
linux-dev-0ba3c026e685573bd3534c17e27da7c505ac99c4.zip
crypto: skcipher - Unmap pages after an external error
skcipher_walk_done may be called with an error by internal or external callers. For those internal callers we shouldn't unmap pages but for external callers we must unmap any pages that are in use. This patch distinguishes between the two cases by checking whether walk->nbytes is zero or not. For internal callers, we now set walk->nbytes to zero prior to the call. For external callers, walk->nbytes has always been non-zero (as zero is used to indicate the termination of a walk). Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Fixes: 5cde0af2a982 ("[CRYPTO] cipher: Added block cipher type") Cc: <stable@vger.kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto')
-rw-r--r--crypto/skcipher.c42
1 files changed, 23 insertions, 19 deletions
diff --git a/crypto/skcipher.c b/crypto/skcipher.c
index 5d836fc3df3e..22753c1c7202 100644
--- a/crypto/skcipher.c
+++ b/crypto/skcipher.c
@@ -90,7 +90,7 @@ static inline u8 *skcipher_get_spot(u8 *start, unsigned int len)
return max(start, end_page);
}
-static void skcipher_done_slow(struct skcipher_walk *walk, unsigned int bsize)
+static int skcipher_done_slow(struct skcipher_walk *walk, unsigned int bsize)
{
u8 *addr;
@@ -98,19 +98,21 @@ static void skcipher_done_slow(struct skcipher_walk *walk, unsigned int bsize)
addr = skcipher_get_spot(addr, bsize);
scatterwalk_copychunks(addr, &walk->out, bsize,
(walk->flags & SKCIPHER_WALK_PHYS) ? 2 : 1);
+ return 0;
}
int skcipher_walk_done(struct skcipher_walk *walk, int err)
{
- unsigned int n; /* bytes processed */
- bool more;
+ unsigned int n = walk->nbytes;
+ unsigned int nbytes = 0;
- if (unlikely(err < 0))
+ if (!n)
goto finish;
- n = walk->nbytes - err;
- walk->total -= n;
- more = (walk->total != 0);
+ if (likely(err >= 0)) {
+ n -= err;
+ nbytes = walk->total - n;
+ }
if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS |
SKCIPHER_WALK_SLOW |
@@ -126,7 +128,7 @@ unmap_src:
memcpy(walk->dst.virt.addr, walk->page, n);
skcipher_unmap_dst(walk);
} else if (unlikely(walk->flags & SKCIPHER_WALK_SLOW)) {
- if (err) {
+ if (err > 0) {
/*
* Didn't process all bytes. Either the algorithm is
* broken, or this was the last step and it turned out
@@ -134,27 +136,29 @@ unmap_src:
* the algorithm requires it.
*/
err = -EINVAL;
- goto finish;
- }
- skcipher_done_slow(walk, n);
- goto already_advanced;
+ nbytes = 0;
+ } else
+ n = skcipher_done_slow(walk, n);
}
+ if (err > 0)
+ err = 0;
+
+ walk->total = nbytes;
+ walk->nbytes = 0;
+
scatterwalk_advance(&walk->in, n);
scatterwalk_advance(&walk->out, n);
-already_advanced:
- scatterwalk_done(&walk->in, 0, more);
- scatterwalk_done(&walk->out, 1, more);
+ scatterwalk_done(&walk->in, 0, nbytes);
+ scatterwalk_done(&walk->out, 1, nbytes);
- if (more) {
+ if (nbytes) {
crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ?
CRYPTO_TFM_REQ_MAY_SLEEP : 0);
return skcipher_walk_next(walk);
}
- err = 0;
-finish:
- walk->nbytes = 0;
+finish:
/* Short-circuit for the common/fast path. */
if (!((unsigned long)walk->buffer | (unsigned long)walk->page))
goto out;