[v2,iwl-net,2/3] ice: Don't process extts if PTP is disabled

Commit Message

Karol Kolacinski June 20, 2024, 12:27 p.m. UTC

From: Jacob Keller <[e-mail]>

The ice_ptp_extts_event() function can race with ice_ptp_release() and
result in a NULL pointer dereference which leads to a kernel panic.

Panic occurs because the ice_ptp_extts_event() function calls
ptp_clock_event() with a NULL pointer. The ice driver has already
released the PTP clock by the time the interrupt for the next external
timestamp event occurs.

To fix this, modify the ice_ptp_extts_event() function to check the
PTP state and bail early if PTP is not ready.

Fixes: 172db5f91d5f ("ice: add support for auxiliary input/output pins")
Reviewed-by: Przemek Kitszel <[e-mail]>
Signed-off-by: Jacob Keller <[e-mail]>
Signed-off-by: Karol Kolacinski <[e-mail]>
---
V1 -> V2: removed unnecessary hunk of code and adjusted commit message

 drivers/net/ethernet/intel/ice/ice_ptp.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Simon Horman June 21, 2024, 11:06 a.m. UTC | #1

On Thu, Jun 20, 2024 at 02:27:09PM +0200, Karol Kolacinski wrote:
> From: Jacob Keller <[e-mail]>
> 
> The ice_ptp_extts_event() function can race with ice_ptp_release() and
> result in a NULL pointer dereference which leads to a kernel panic.
> 
> Panic occurs because the ice_ptp_extts_event() function calls
> ptp_clock_event() with a NULL pointer. The ice driver has already
> released the PTP clock by the time the interrupt for the next external
> timestamp event occurs.
> 
> To fix this, modify the ice_ptp_extts_event() function to check the
> PTP state and bail early if PTP is not ready.
> 
> Fixes: 172db5f91d5f ("ice: add support for auxiliary input/output pins")
> Reviewed-by: Przemek Kitszel <[e-mail]>
> Signed-off-by: Jacob Keller <[e-mail]>
> Signed-off-by: Karol Kolacinski <[e-mail]>
> ---
> V1 -> V2: removed unnecessary hunk of code and adjusted commit message

Thanks for the update.

Reviewed-by: Simon Horman <[e-mail]>

Pucha, HimasekharX Reddy June 25, 2024, 7:08 a.m. UTC | #2

> -----Original Message-----
> From: Intel-wired-lan <[e-mail]> On Behalf Of Karol Kolacinski
> Sent: Thursday, June 20, 2024 5:57 PM
> To: [e-mail]
> Cc: Keller, Jacob E <[e-mail]>; [e-mail]; Kolacinski, Karol <[e-mail]>; Nguyen, Anthony L <[e-mail]>; Kitszel, Przemyslaw <[e-mail]>
> Subject: [Intel-wired-lan] [PATCH v2 iwl-net 2/3] ice: Don't process extts if PTP is disabled
>
> From: Jacob Keller <[e-mail]>
>
> The ice_ptp_extts_event() function can race with ice_ptp_release() and result in a NULL pointer dereference which leads to a kernel panic.
>
> Panic occurs because the ice_ptp_extts_event() function calls
> ptp_clock_event() with a NULL pointer. The ice driver has already released the PTP clock by the time the interrupt for the next external timestamp event occurs.
>
> To fix this, modify the ice_ptp_extts_event() function to check the PTP state and bail early if PTP is not ready.
>
> Fixes: 172db5f91d5f ("ice: add support for auxiliary input/output pins")
> Reviewed-by: Przemek Kitszel <[e-mail]>
> Signed-off-by: Jacob Keller <[e-mail]>
> Signed-off-by: Karol Kolacinski <[e-mail]>
> ---
> V1 -> V2: removed unnecessary hunk of code and adjusted commit message
>
>  drivers/net/ethernet/intel/ice/ice_ptp.c | 4 ++++
>  1 file changed, 4 insertions(+)
>

Tested-by: Pucha Himasekhar Reddy <[e-mail]> (A Contingent worker at Intel)

Patch

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index d8ff9f26010c..0500ced1adf8 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -1559,6 +1559,10 @@  void ice_ptp_extts_event(struct ice_pf *pf)
 	u8 chan, tmr_idx;
 	u32 hi, lo;
 
+	/* Don't process timestamp events if PTP is not ready */
+	if (pf->ptp.state != ICE_PTP_READY)
+		return;
+
 	tmr_idx = hw->func_caps.ts_func_info.tmr_index_owned;
 	/* Event time is captured by one of the two matched registers
 	 *      GLTSYN_EVNT_L: 32 LSB of sampled time event