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| 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 | 445a582738de6802669aeed9c33ca406c23c3b1f (patch) | |
| tree | 0d07bd2145a3444c51f59e8a8db9095e0e9ceac5 /crypto | |
| parent | 549f64153c354e69fc19534f7d7e867de1992f95 (diff) | |
| download | linux-stable-445a582738de6802669aeed9c33ca406c23c3b1f.tar.gz linux-stable-445a582738de6802669aeed9c33ca406c23c3b1f.tar.bz2 linux-stable-445a582738de6802669aeed9c33ca406c23c3b1f.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>
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 43839b00fe6c..903605dbc1a5 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); } |