答复: [????] Re: [PATCH] af_unix: Fix wrong socket tested in the symmetric half of unix_state_lock_cmp_fn().

[Li,Rongqing]

> > [PATCH] af_unix: Fix wrong socket tested in the symmetric half
> 
> This is net-next material, so it should be
> 
>   [PATCH net-next vX] af_unix: ...
> 
> see Documentation/process/maintainer-netdev.rst.
> 
> 
> On Sat, 07 Nov 2026 04:18:22 +0800, lirongqing wrote:
> > From: Li RongQing <lirongqing@xxxxxxxxx>
> >
> > The second half of unix_state_lock_cmp_fn() is meant to mirror the
> > first one with the roles of a and b swapped, but it switches on b's
> > state again:
> >
> > 	if (b->sk.sk_state == TCP_LISTEN) {
> > 		switch (b->sk.sk_state) {
> > 		case TCP_CLOSE:
> > 		case TCP_ESTABLISHED:
> > 			return 1;
> >
> > The enclosing if already established that b is TCP_LISTEN, so the
> > switch can only reach the default label and the branch always returns
> > 0, "no order known", instead of the intended 1.
> >
> > Test a's state, as the first half does.  The code is only compiled
> > with CONFIG_PROVE_LOCKING, so there is no runtime memory-safety
> > impact; the effect is that lockdep cannot validate this nesting order
> > of unix_state_lock().
> >
> > Fixes: 98f706de445b ("af_unix: Define locking order for U_LOCK_SECOND
> > in unix_stream_connect().")
> 
> Please drop the tag.
> 
> As commented, the branch never hits and no real issue exists, not worth
> backporting.
> 

Ok, I will send v2

[Li,Rongqing] 

> 
> > Signed-off-by: Li RongQing <lirongqing@xxxxxxxxx>
> > ---
> >  net/unix/af_unix.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index
> > e7a0582..501e693 100644
> > --- a/net/unix/af_unix.c
> > +++ b/net/unix/af_unix.c
> > @@ -163,7 +163,7 @@ static int unix_state_lock_cmp_fn(const struct
> > lockdep_map *_a,
> >
> >  	/* Should never happen.  Just to be symmetric. */
> >  	if (b->sk.sk_state == TCP_LISTEN) {
> > -		switch (b->sk.sk_state) {
> > +		switch (a->sk.sk_state) {
> >  		case TCP_CLOSE:
> >  		case TCP_ESTABLISHED:
> >  			return 1;
> > --
> > 2.9.4
> >