Re: [PATCH FINAL] SCTP: fix race between sctp_bind_addr_free() and sctp_bind_addr_conflict()

[Eric Dumazet <eric.dumazet@gmail.com>]

Le jeudi 19 mai 2011 à 21:55 +0200, Jacek Luczak a écrit :
> During the sctp_close() call, we do not use rcu primitives to
> destroy the address list attached to the endpoint.  At the same
> time, we do the removal of addresses from this list before
> attempting to remove the socket from the port hash
> 
> As a result, it is possible for another process to find the socket
> in the port hash that is in the process of being closed.  It then
> proceeds to traverse the address list to find the conflict, only
> to have that address list suddenly disappear without rcu() critical
> section.
> 
> Fix issue by closing address list removal inside RCU critical
> section.
> 
> Race can result in a kernel crash with general protection fault or
> kernel NULL pointer dereference:
> 

> Signed-off-by: Jacek Luczak <luczak.jacek@gmail.com>
> Acked-by: Vlad Yasevich <vladislav.yasevich@hp.com>
> CC: Eric Dumazet <eric.dumazet@gmail.com>
> 
> ---
>  net/sctp/bind_addr.c |   10 ++++------
>  1 files changed, 4 insertions(+), 6 deletions(-)
> 

Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>