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| author | Eric Biggers <ebiggers@google.com> | 2017-11-28 00:46:24 -0800 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2017-11-29 13:39:14 +1100 |
| commit | 887207ed9e5812ed9239b6d07185a2d35dda91db (patch) | |
| tree | cadb413b15f8fd9699ad3f48638795a7bb9fb31e /crypto | |
| parent | b32a7dc8aef1882fbf983eb354837488cc9d54dc (diff) | |
| download | lwn-887207ed9e5812ed9239b6d07185a2d35dda91db.tar.gz lwn-887207ed9e5812ed9239b6d07185a2d35dda91db.zip | |
crypto: af_alg - fix NULL pointer dereference in
af_alg_free_areq_sgls()
If allocating the ->tsgl member of 'struct af_alg_async_req' failed,
during cleanup we dereferenced the NULL ->tsgl pointer in
af_alg_free_areq_sgls(), because ->tsgl_entries was nonzero.
Fix it by only freeing the ->tsgl list if it is non-NULL.
This affected both algif_skcipher and algif_aead.
Fixes: e870456d8e7c ("crypto: algif_skcipher - overhaul memory management")
Fixes: d887c52d6ae4 ("crypto: algif_aead - overhaul memory management")
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: <stable@vger.kernel.org> # v4.14+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/af_alg.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/crypto/af_alg.c b/crypto/af_alg.c index 85cea9de324a..1e5353f62067 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -672,14 +672,15 @@ void af_alg_free_areq_sgls(struct af_alg_async_req *areq) } tsgl = areq->tsgl; - for_each_sg(tsgl, sg, areq->tsgl_entries, i) { - if (!sg_page(sg)) - continue; - put_page(sg_page(sg)); - } + if (tsgl) { + for_each_sg(tsgl, sg, areq->tsgl_entries, i) { + if (!sg_page(sg)) + continue; + put_page(sg_page(sg)); + } - if (areq->tsgl && areq->tsgl_entries) sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl)); + } } EXPORT_SYMBOL_GPL(af_alg_free_areq_sgls); |