On Thu, May 04, 2023 at 03:40:15PM +0000, Chuck Lever III wrote:
>
>
> > On May 3, 2023, at 7:31 AM, Dan Carpenter <[email protected]> wrote:
> >
> > I changed the CC list from netdev to linux-nfs.
> >
> > On Tue, Mar 07, 2023 at 02:37:07PM -0300, Thadeu Lima de Souza Cascardo wrote:
> >> When sock_alloc_file fails to allocate a file, it will call sock_release.
> >> __sys_socket_file should then not call sock_release again, otherwise there
> >> will be a double free.
> >>
> >
> > It's just a one liner to make Smatch warn about these sorts of user
> > after free bugs.
> >
> > { "sock_release", PARAM_FREED, 0, "$" },
> >
> > Smatch found a related bug in nfs.
> >
> > net/sunrpc/svcsock.c:938 svc_tcp_accept() warn: 'newsock' was already freed.
> > net/sunrpc/svcsock.c:1633 svc_create_socket() warn: 'sock' was already freed.
> > net/sunrpc/svcsock.c:1555 svc_addsock() error: dereferencing freed memory 'so'
> > net/sunrpc/svcsock.c:1633 svc_create_socket() warn: passing freed memory 'sock'
> > net/sunrpc/svcsock.c:938 svc_tcp_accept() warn: passing freed memory 'newsock'
> >
> > I guess the svc_setup_socket() function should free sock on every error
> > path? It seems kind of gnarly.
>
> I'm looking at current upstream, and I don't see svc_setup_socket()
> releasing @sock on any return path. What am I missing?
The sock_alloc_file() function releases it on error...
>
> Does your tree have "SUNRPC: Ensure server-side sockets have a sock->file" ?
Ah, that's the commit that introduces the call sock_alloc_file().
regards,
dan carpenter