lkml.org 
[lkml]   [2020]   [May]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Date
    Subject[PATCH 3.16 17/99] crypto: api - Check spawn->alg under lock in crypto_drop_spawn
    3.16.84-rc1 review patch.  If anyone has any objections, please let me know.

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

    From: Herbert Xu <herbert@gondor.apana.org.au>

    commit 7db3b61b6bba4310f454588c2ca6faf2958ad79f upstream.

    We need to check whether spawn->alg is NULL under lock as otherwise
    the algorithm could be removed from under us after we have checked
    it and found it to be non-NULL. This could cause us to remove the
    spawn from a non-existent list.

    Fixes: 7ede5a5ba55a ("crypto: api - Fix crypto_drop_spawn crash...")
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
    Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
    ---
    crypto/algapi.c | 6 ++----
    1 file changed, 2 insertions(+), 4 deletions(-)

    --- a/crypto/algapi.c
    +++ b/crypto/algapi.c
    @@ -618,11 +618,9 @@ EXPORT_SYMBOL_GPL(crypto_init_spawn2);

    void crypto_drop_spawn(struct crypto_spawn *spawn)
    {
    - if (!spawn->alg)
    - return;
    -
    down_write(&crypto_alg_sem);
    - list_del(&spawn->list);
    + if (spawn->alg)
    + list_del(&spawn->list);
    up_write(&crypto_alg_sem);
    }
    EXPORT_SYMBOL_GPL(crypto_drop_spawn);
    \
     
     \ /
      Last update: 2020-05-20 16:23    [W:2.233 / U:0.188 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site