crypto: af_alg - fix NULL pointer dereference in
commit 887207ed9e5812ed9239b6d07185a2d35dda91db upstream.
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>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index a72659f..e181073 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -699,14 +699,15 @@
}
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);