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| author | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2017-12-19 10:27:24 +0000 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2017-12-22 19:02:40 +1100 |
| commit | af955bf15d2c27496b0269b1f05c26f758c68314 (patch) | |
| tree | 93a46f7d3a6038882d956007e9b8a927df37b36c /crypto/af_alg.c | |
| parent | e57121d08c38dabec15cf3e1e2ad46721af30cae (diff) | |
| download | lwn-af955bf15d2c27496b0269b1f05c26f758c68314.tar.gz lwn-af955bf15d2c27496b0269b1f05c26f758c68314.zip | |
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>
Diffstat (limited to 'crypto/af_alg.c')
| -rw-r--r-- | crypto/af_alg.c | 4 |
1 files changed, 2 insertions, 2 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); } |