* RE: [PATCH 4/4] tty: n_gsm: fix missing corner cases in gsmld_poll()
@ 2022-07-07 7:00 Starke, Daniel
2022-07-07 7:34 ` Jiri Slaby
0 siblings, 1 reply; 3+ messages in thread
From: Starke, Daniel @ 2022-07-07 7:00 UTC (permalink / raw)
To: Jiri Slaby, linux-serial, gregkh; +Cc: linux-kernel
> > @@ -3051,14 +3051,20 @@ static __poll_t gsmld_poll(struct tty_struct *tty, struct file *file,
> > __poll_t mask = 0;
> > struct gsm_mux *gsm = tty->disc_data;
> >
> > + if (!gsm)
> > + return EPOLLHUP;
>
> Hmm, how can this happen? It's a tty bug if it calls ld ops after NULLing
> disc_data.
I can remove this check if it is redundant. Should I?
Best regards,
Daniel Starke
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 4/4] tty: n_gsm: fix missing corner cases in gsmld_poll()
2022-07-07 7:00 [PATCH 4/4] tty: n_gsm: fix missing corner cases in gsmld_poll() Starke, Daniel
@ 2022-07-07 7:34 ` Jiri Slaby
0 siblings, 0 replies; 3+ messages in thread
From: Jiri Slaby @ 2022-07-07 7:34 UTC (permalink / raw)
To: Starke, Daniel, linux-serial, gregkh; +Cc: linux-kernel
On 07. 07. 22, 9:00, Starke, Daniel wrote:
>>> @@ -3051,14 +3051,20 @@ static __poll_t gsmld_poll(struct tty_struct *tty, struct file *file,
>>> __poll_t mask = 0;
>>> struct gsm_mux *gsm = tty->disc_data;
>>>
>>> + if (!gsm)
>>> + return EPOLLHUP;
>>
>> Hmm, how can this happen? It's a tty bug if it calls ld ops after NULLing
>> disc_data.
>
> I can remove this check if it is redundant. Should I?
Sure as it makes little sense anyway. Even if gsm was non-NULL here, the
backing disc_data would be freed on the accesses further.
thanks,
--
js
suse labs
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 4/4] tty: n_gsm: fix missing corner cases in gsmld_poll()
[not found] ` <20220706054452.3663-4-daniel.starke@siemens.com>
@ 2022-07-07 6:48 ` Jiri Slaby
0 siblings, 0 replies; 3+ messages in thread
From: Jiri Slaby @ 2022-07-07 6:48 UTC (permalink / raw)
To: D. Starke, linux-serial, gregkh; +Cc: linux-kernel
On 06. 07. 22, 7:44, D. Starke wrote:
> From: Daniel Starke <daniel.starke@siemens.com>
>
> gsmld_poll() currently fails to handle some corner cases correctly:
> - tty ldisc association lost
> - remote party closed the associated tty
>
> Add the missing checks and map those to EPOLLHUP.
> Reorder the checks to group them by their reaction.
>
> Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
> Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
> ---
> drivers/tty/n_gsm.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> Based on tty-testing.
>
> diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
> index 51447ccccbab..47566bd2ed6e 100644
> --- a/drivers/tty/n_gsm.c
> +++ b/drivers/tty/n_gsm.c
> @@ -3051,14 +3051,20 @@ static __poll_t gsmld_poll(struct tty_struct *tty, struct file *file,
> __poll_t mask = 0;
> struct gsm_mux *gsm = tty->disc_data;
>
> + if (!gsm)
> + return EPOLLHUP;
Hmm, how can this happen? It's a tty bug if it calls ld ops after
NULLing disc_data.
thanks,
--
js
suse labs
^ permalink raw reply [flat|nested] 3+ messages in thread
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2022-07-07 7:00 [PATCH 4/4] tty: n_gsm: fix missing corner cases in gsmld_poll() Starke, Daniel
2022-07-07 7:34 ` Jiri Slaby
[not found] <20220706054452.3663-1-daniel.starke@siemens.com>
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