In Chrome OS, a large number of crashes is observed due to corrupted timer
lists. Steven Rostedt pointed out that this usually happens when a timer
is freed while still active, and that the problem is often triggered
by code calling del_timer() instead of del_timer_sync() just before
freeing.
Steven also identified the iwlwifi driver as one of the possible culprits
since it does exactly that.
Reported-by: Steven Rostedt <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Johannes Berg <[email protected]>
Cc: Gregory Greenman <[email protected]>
Fixes: 60e8abd9d3e91 ("iwlwifi: dbg_ini: add periodic trigger new API support")
Signed-off-by: Guenter Roeck <[email protected]>
---
v1 (from RFC):
Removed Shahar S Matityahu from Cc: and added Gregory Greenman.
No functional change.
I thought about the need to add a mutex to protect the timer list, but
I convinced myself that it is not necessary because the code adding
the timer list and the code removing it should never be never executed
in parallel.
drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c b/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
index 866a33f49915..3237d4b528b5 100644
--- a/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
@@ -371,7 +371,7 @@ void iwl_dbg_tlv_del_timers(struct iwl_trans *trans)
struct iwl_dbg_tlv_timer_node *node, *tmp;
list_for_each_entry_safe(node, tmp, timer_list, list) {
- del_timer(&node->timer);
+ del_timer_sync(&node->timer);
list_del(&node->list);
kfree(node);
}
--
2.35.1
On Mon, 2022-04-11 at 08:42 -0700, Guenter Roeck wrote:
> In Chrome OS, a large number of crashes is observed due to corrupted
> timer
> lists. Steven Rostedt pointed out that this usually happens when a
> timer
> is freed while still active, and that the problem is often triggered
> by code calling del_timer() instead of del_timer_sync() just before
> freeing.
>
> Steven also identified the iwlwifi driver as one of the possible
> culprits
> since it does exactly that.
>
> Reported-by: Steven Rostedt <[email protected]>
> Cc: Steven Rostedt <[email protected]>
> Cc: Johannes Berg <[email protected]>
> Cc: Gregory Greenman <[email protected]>
> Fixes: 60e8abd9d3e91 ("iwlwifi: dbg_ini: add periodic trigger new API
> support")
> Signed-off-by: Guenter Roeck <[email protected]>
> ---
> v1 (from RFC):
> Removed Shahar S Matityahu from Cc: and added Gregory Greenman.
> No functional change.
>
> I thought about the need to add a mutex to protect the timer list,
> but
> I convinced myself that it is not necessary because the code adding
> the timer list and the code removing it should never be never
> executed
> in parallel.
>
> drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
> b/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
> index 866a33f49915..3237d4b528b5 100644
> --- a/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
> +++ b/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
> @@ -371,7 +371,7 @@ void iwl_dbg_tlv_del_timers(struct iwl_trans
> *trans)
> struct iwl_dbg_tlv_timer_node *node, *tmp;
>
> list_for_each_entry_safe(node, tmp, timer_list, list) {
> - del_timer(&node->timer);
> + del_timer_sync(&node->timer);
> list_del(&node->list);
> kfree(node);
> }
Hi Kalle,
Can you please pick it up to wireless-drivers for the next rc?
It is an important fix.
Luca has already assigned it to you in patchwork.
Thanks!
Acked-by: Gregory Greenman <[email protected]>
On Wed, Apr 13, 2022 at 11:56 AM Greenman, Gregory
<[email protected]> wrote:
>
>
> On Mon, 2022-04-11 at 08:42 -0700, Guenter Roeck wrote:
> > In Chrome OS, a large number of crashes is observed due to corrupted
> > timer
> > lists. Steven Rostedt pointed out that this usually happens when a
> > timer
> > is freed while still active, and that the problem is often triggered
> > by code calling del_timer() instead of del_timer_sync() just before
> > freeing.
> >
> > Steven also identified the iwlwifi driver as one of the possible
> > culprits
> > since it does exactly that.
> >
> > Reported-by: Steven Rostedt <[email protected]>
> > Cc: Steven Rostedt <[email protected]>
> > Cc: Johannes Berg <[email protected]>
> > Cc: Gregory Greenman <[email protected]>
> > Fixes: 60e8abd9d3e91 ("iwlwifi: dbg_ini: add periodic trigger new API
> > support")
> > Signed-off-by: Guenter Roeck <[email protected]>
> > ---
> > v1 (from RFC):
> > Removed Shahar S Matityahu from Cc: and added Gregory Greenman.
> > No functional change.
> >
> > I thought about the need to add a mutex to protect the timer list,
> > but
> > I convinced myself that it is not necessary because the code adding
> > the timer list and the code removing it should never be never
> > executed
> > in parallel.
> >
> > drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
> > b/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
> > index 866a33f49915..3237d4b528b5 100644
> > --- a/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
> > +++ b/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
> > @@ -371,7 +371,7 @@ void iwl_dbg_tlv_del_timers(struct iwl_trans
> > *trans)
> > struct iwl_dbg_tlv_timer_node *node, *tmp;
> >
> > list_for_each_entry_safe(node, tmp, timer_list, list) {
> > - del_timer(&node->timer);
> > + del_timer_sync(&node->timer);
> > list_del(&node->list);
> > kfree(node);
> > }
>
> Hi Kalle,
>
> Can you please pick it up to wireless-drivers for the next rc?
> It is an important fix.
> Luca has already assigned it to you in patchwork.
>
> Thanks!
>
> Acked-by: Gregory Greenman <[email protected]>
I have tested this on top of Linux v5.17.3-rc1.
Feel free to add my...
Tested-by: Sedat Dilek <[email protected]> # Linux v5.17.3-rc1 and
Debian LLVM-14
- Sedat -