diff options
| author | Stephan Mueller <smueller@chronox.de> | 2017-08-16 11:56:24 +0200 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2017-08-22 14:45:48 +0800 |
| commit | 4f673910a79f5cb0e7dd87bf807eebb24834cea3 (patch) | |
| tree | 37dfb734828424b7992df6161939c240241125b0 | |
| parent | 9f05533bf0bb1efd537387be541e8c617827ba1e (diff) | |
| download | linux-crypto-4f673910a79f5cb0e7dd87bf807eebb24834cea3.tar.gz linux-crypto-4f673910a79f5cb0e7dd87bf807eebb24834cea3.zip | |
crypto: algif_skcipher - only call put_page on referenced and used pages
For asynchronous operation, SGs are allocated without a page mapped to
them or with a page that is not used (ref-counted). If the SGL is freed,
the code must only call put_page for an SG if there was a page assigned
and ref-counted in the first place.
This fixes a kernel crash when using io_submit with more than one iocb
using the sendmsg and sendpage (vmsplice/splice) interface.
Cc: <stable@vger.kernel.org>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| -rw-r--r-- | crypto/algif_skcipher.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c index 43839b00..903605db 100644 --- a/crypto/algif_skcipher.c +++ b/crypto/algif_skcipher.c @@ -87,8 +87,13 @@ static void skcipher_free_async_sgls(struct skcipher_async_req *sreq) } sgl = sreq->tsg; n = sg_nents(sgl); - for_each_sg(sgl, sg, n, i) - put_page(sg_page(sg)); + for_each_sg(sgl, sg, n, i) { + struct page *page = sg_page(sg); + + /* some SGs may not have a page mapped */ + if (page && page_ref_count(page)) + put_page(page); + } kfree(sreq->tsg); } |