> -----Original Message-----
> From: Kitszel, Przemyslaw <[email protected]>
> Sent: Friday, March 20, 2026 11:13 AM
> To: Loktionov, Aleksandr <[email protected]>; Bart Van
> Assche <[email protected]>
> Cc: [email protected]; [email protected];
> Wieczerzycka, Katarzyna <[email protected]>; Nguyen,
> Anthony L <[email protected]>
> Subject: Re: [Intel-wired-lan] [PATCH iwl-next] ice: call mutex_lock()
> before mutex_unlock() in ice_dcb_rebuild()
> 
> On 3/20/26 06:05, Aleksandr Loktionov wrote:
> > From: Katarzyna Wieczerzycka <[email protected]>
> >
> > In ice_dcb_rebuild(), the first call to ice_query_port_ets() is
> > checked for error, and on failure jumps to the 'dcb_error' label.
> The
> > error path always calls mutex_unlock(&pf->tc_mutex), but at this
> point
> > in the code the mutex has never been locked -- mutex_lock() came
> after the check.
> >
> > Releasing a mutex that was not locked is undefined behaviour and can
> > cause a deadlock or crash. Fix this by moving mutex_lock() to before
> > the error check, so that 'dcb_error' always pairs with a prior lock.
> >
> > Fixes: 242b5e068b25 ("ice: Fix DCB rebuild after reset")
> > Signed-off-by: Katarzyna Wieczerzycka
> > <[email protected]>
> > Signed-off-by: Aleksandr Loktionov <[email protected]>
> 
> NACK
> 
> there is a better fix proposed by community, we are awaiting v2
> https://patchew.org/linux/20260223220102.2158611-1-
> [email protected]/20260223220102.2158611-20-
> [email protected]/
> 
> > ---
> >   drivers/net/ethernet/intel/ice/ice_dcb_lib.c | 3 +--
> >   1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/intel/ice/ice_dcb_lib.c
> > b/drivers/net/ethernet/intel/ice/ice_dcb_lib.c
> > index bd77f1c..d516734 100644
> > --- a/drivers/net/ethernet/intel/ice/ice_dcb_lib.c
> > +++ b/drivers/net/ethernet/intel/ice/ice_dcb_lib.c
> > @@ -538,12 +538,11 @@ void ice_dcb_rebuild(struct ice_pf *pf)
> >     int ret;
> >
> >     ret = ice_query_port_ets(pf->hw.port_info, &buf, sizeof(buf),
> > NULL);
> 
> the difference is to move mutex_lock() over ice_query_port_ets()
> 
> > +   mutex_lock(&pf->tc_mutex);
> >     if (ret) {
> >             dev_err(dev, "Query Port ETS failed\n");
> >             goto dcb_error;
> >     }
> >
> > -   mutex_lock(&pf->tc_mutex);
> > -
> >     if (!pf->hw.port_info->qos_cfg.is_sw_lldp)
> >             ice_cfg_etsrec_defaults(pf->hw.port_info);
> >

Withdrawing this patch (just in case NACK is not enough).

Bart Van Assche's series covers the same fix with a more complete
approach (moving mutex_lock() above ice_query_port_ets()). His v4
has been reviewed and accepted.

With the best regards
Alex

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