lkml.org 
[lkml]   [2017]   [Dec]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.14 006/178] crypto: af_alg - fix NULL pointer dereference in
    Date
    4.14-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Eric Biggers <ebiggers@google.com>

    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>

    ---
    crypto/af_alg.c | 13 +++++++------
    1 file changed, 7 insertions(+), 6 deletions(-)

    --- a/crypto/af_alg.c
    +++ b/crypto/af_alg.c
    @@ -699,14 +699,15 @@ void af_alg_free_areq_sgls(struct af_alg
    }

    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);


    \
     
     \ /
      Last update: 2017-12-18 17:52    [W:8.040 / U:0.076 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site