Messages in this thread | | | Date | Wed, 24 Apr 2019 18:08:40 -0700 | From | Jakub Kicinski <> | Subject | Re: [PATCH] net: tls: fix a memory leak bug |
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On Wed, 24 Apr 2019 15:18:07 -0500, Wenwen Wang wrote: > In decrypt_internal(), a memory block 'mem' is allocated through kmalloc() > to hold aead_req, sgin[], sgout[], aad, and iv. This memory block should be > freed after it is used, before this function is returned. However, if the > return value of the function invocation of tls_do_decryption() is > -EINPROGRESS, this memory block is actually not freed, which is a memory > leak bug. > > To fix this issue, free the allocated block before the error code > -EINPROGRESS is returned. > > Signed-off-by: Wenwen Wang <wang6495@umn.edu>
Did you find this by code inspection or is this provable at runtime (kmemleak or such)?
> diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c > index b50ced8..22445bb 100644 > --- a/net/tls/tls_sw.c > +++ b/net/tls/tls_sw.c > @@ -1445,8 +1445,10 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb, > /* Prepare and submit AEAD request */ > err = tls_do_decryption(sk, skb, sgin, sgout, iv, > data_len, aead_req, async); > - if (err == -EINPROGRESS) > + if (err == -EINPROGRESS) { > + kfree(mem); > return err;
Mm... don't think so.
-EINPROGRESS is special, it means something is working on the request asynchronously here.
I think this memory is freed in tls_decrypt_done():
kfree(aead_req);
Note that aead_req is the first member of the allocated buffer.
CCing Vakul
> + } > > /* Release the pages in case iov was mapped to pages */ > for (; pages > 0; pages--)
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