crypto: api - Check spawn->alg under lock in crypto_drop_spawn

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...")
Cc: <>
Signed-off-by: Herbert Xu <>
Signed-off-by: Greg Kroah-Hartman <>
Signed-off-by: Lee Jones <>
Change-Id: If62968f4614045477fade39d65cbf6953e735731
1 file changed