diff options
| author | Stephan Mueller <smueller@chronox.de> | 2017-08-16 11:56:24 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-09-07 08:34:10 +0200 |
| commit | d95827490c39d20c148b3c4c3d250f9cce294eb5 (patch) | |
| tree | 26a0c9cb81c7f05fcb2c461cbc7e95b18ca6ce0f /crypto | |
| parent | ab3ee6b53d678b37b90934fb67b01d5fc7aa3a85 (diff) | |
crypto: algif_skcipher - only call put_page on referenced and used pages
commit 445a582738de6802669aeed9c33ca406c23c3b1f upstream.
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.
Signed-off-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>
Diffstat (limited to 'crypto')
| -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 f5e9f9310b48..b3b0004ea8ac 100644 --- a/crypto/algif_skcipher.c +++ b/crypto/algif_skcipher.c @@ -86,8 +86,13 @@ 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 && atomic_read(&page->_count)) + put_page(page); + } kfree(sreq->tsg); } |