Messages in this thread | | | From | Vakul Garg <> | Subject | RE: [PATCH] net: tls: fix a memory leak bug | Date | Thu, 25 Apr 2019 04:44:15 +0000 |
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> -----Original Message----- > From: Jakub Kicinski <jakub.kicinski@netronome.com> > Sent: Thursday, April 25, 2019 6:39 AM > To: Wenwen Wang <wang6495@umn.edu> > Cc: Boris Pismenny <borisp@mellanox.com>; Aviad Yehezkel > <aviadye@mellanox.com>; Dave Watson <davejwatson@fb.com>; John > Fastabend <john.fastabend@gmail.com>; Daniel Borkmann > <daniel@iogearbox.net>; David S. Miller <davem@davemloft.net>; open > list:NETWORKING [TLS] <netdev@vger.kernel.org>; open list <linux- > kernel@vger.kernel.org>; Vakul Garg <vakul.garg@nxp.com> > Subject: Re: [PATCH] net: tls: fix a memory leak bug > > 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
The patch is wrong. Valid reasons have been given against the patch.
> > > + } > > > > /* Release the pages in case iov was mapped to pages */ > > for (; pages > 0; pages--)
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