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| author | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2017-12-19 13:27:24 +0300 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2017-12-22 11:02:40 +0300 |
| commit | af955bf15d2c27496b0269b1f05c26f758c68314 (patch) | |
| tree | 93a46f7d3a6038882d956007e9b8a927df37b36c | |
| parent | e57121d08c38dabec15cf3e1e2ad46721af30cae (diff) | |
| download | linux-af955bf15d2c27496b0269b1f05c26f758c68314.tar.xz | |
crypto: af_alg - Fix race around ctx->rcvused by making it atomic_t
This variable was increased and decreased without any protection.
Result was an occasional misscount and negative wrap around resulting
in false resource allocation failures.
Fixes: 7d2c3f54e6f6 ("crypto: af_alg - remove locking in async callback")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| -rw-r--r-- | crypto/af_alg.c | 4 | ||||
| -rw-r--r-- | crypto/algif_aead.c | 2 | ||||
| -rw-r--r-- | crypto/algif_skcipher.c | 2 | ||||
| -rw-r--r-- | include/crypto/if_alg.h | 5 |
4 files changed, 7 insertions, 6 deletions
diff --git a/crypto/af_alg.c b/crypto/af_alg.c index f1a2caf1b59b..d3f1c431724b 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -664,7 +664,7 @@ void af_alg_free_areq_sgls(struct af_alg_async_req *areq) unsigned int i; list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) { - ctx->rcvused -= rsgl->sg_num_bytes; + atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused); af_alg_free_sg(&rsgl->sgl); list_del(&rsgl->list); if (rsgl != &areq->first_rsgl) @@ -1162,7 +1162,7 @@ int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags, areq->last_rsgl = rsgl; len += err; - ctx->rcvused += err; + atomic_add(err, &ctx->rcvused); rsgl->sg_num_bytes = err; iov_iter_advance(&msg->msg_iter, err); } diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c index b73db2b27656..20df8c1b6851 100644 --- a/crypto/algif_aead.c +++ b/crypto/algif_aead.c @@ -571,7 +571,7 @@ static int aead_accept_parent_nokey(void *private, struct sock *sk) INIT_LIST_HEAD(&ctx->tsgl_list); ctx->len = len; ctx->used = 0; - ctx->rcvused = 0; + atomic_set(&ctx->rcvused, 0); ctx->more = 0; ctx->merge = 0; ctx->enc = 0; diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c index baef9bfccdda..c5c47b680152 100644 --- a/crypto/algif_skcipher.c +++ b/crypto/algif_skcipher.c @@ -390,7 +390,7 @@ static int skcipher_accept_parent_nokey(void *private, struct sock *sk) INIT_LIST_HEAD(&ctx->tsgl_list); ctx->len = len; ctx->used = 0; - ctx->rcvused = 0; + atomic_set(&ctx->rcvused, 0); ctx->more = 0; ctx->merge = 0; ctx->enc = 0; diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h index 38d9c5861ed8..f38227a78eae 100644 --- a/include/crypto/if_alg.h +++ b/include/crypto/if_alg.h @@ -18,6 +18,7 @@ #include <linux/if_alg.h> #include <linux/scatterlist.h> #include <linux/types.h> +#include <linux/atomic.h> #include <net/sock.h> #include <crypto/aead.h> @@ -150,7 +151,7 @@ struct af_alg_ctx { struct crypto_wait wait; size_t used; - size_t rcvused; + atomic_t rcvused; bool more; bool merge; @@ -215,7 +216,7 @@ static inline int af_alg_rcvbuf(struct sock *sk) struct af_alg_ctx *ctx = ask->private; return max_t(int, max_t(int, sk->sk_rcvbuf & PAGE_MASK, PAGE_SIZE) - - ctx->rcvused, 0); + atomic_read(&ctx->rcvused), 0); } /** |