From: Guenter Roeck <linux@xxxxxxxxxxxx>
commit 88d02c9ba2e83fc22d37ccb1f11c62ea6fc9ae50 upstream.
TCPM may receive PD messages associated with unknown or unsupported
alternate modes. If that happens, calls to typec_match_altmode()
will return NULL. The tcpm code does not currently take this into
account. This results in crashes.
Unable to handle kernel NULL pointer dereference at virtual address 000001f0
pgd = 41dad9a1
[000001f0] *pgd=00000000
Internal error: Oops: 5 [#1] THUMB2
Modules linked in: tcpci tcpm
CPU: 0 PID: 2338 Comm: kworker/u2:0 Not tainted 5.1.18-sama5-armv7-r2 #6
Hardware name: Atmel SAMA5
Workqueue: 2-0050 tcpm_pd_rx_handler [tcpm]
PC is at typec_altmode_attention+0x0/0x14
LR is at tcpm_pd_rx_handler+0xa3b/0xda0 [tcpm]
...
[<c03fbee8>] (typec_altmode_attention) from [<bf8030fb>]
(tcpm_pd_rx_handler+0xa3b/0xda0 [tcpm])
[<bf8030fb>] (tcpm_pd_rx_handler [tcpm]) from [<c012082b>]
(process_one_work+0x123/0x2a8)
[<c012082b>] (process_one_work) from [<c0120a6d>]
(worker_thread+0xbd/0x3b0)
[<c0120a6d>] (worker_thread) from [<c012431f>] (kthread+0xcf/0xf4)
[<c012431f>] (kthread) from [<c01010f9>] (ret_from_fork+0x11/0x38)
Ignore PD messages if the associated alternate mode is not supported.
Fixes: e9576fe8e605c ("usb: typec: tcpm: Support for Alternate Modes")
Cc: stable <stable@xxxxxxxxxxxxxxx>
Reported-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
Cc: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
Acked-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Tested-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/1564761822-13984-1-git-send-email-linux@xxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/typec/tcpm/tcpm.c | 36 +++++++++++++++++++++++-------------
1 file changed, 23 insertions(+), 13 deletions(-)
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -1109,7 +1109,8 @@ static int tcpm_pd_svdm(struct tcpm_port
break;
case CMD_ATTENTION:
/* Attention command does not have response */
- typec_altmode_attention(adev, p[1]);
+ if (adev)
+ typec_altmode_attention(adev, p[1]);
return 0;
default:
break;
@@ -1161,20 +1162,26 @@ static int tcpm_pd_svdm(struct tcpm_port
}
break;
case CMD_ENTER_MODE:
- typec_altmode_update_active(pdev, true);
+ if (adev && pdev) {
+ typec_altmode_update_active(pdev, true);
- if (typec_altmode_vdm(adev, p[0], &p[1], cnt)) {
- response[0] = VDO(adev->svid, 1, CMD_EXIT_MODE);
- response[0] |= VDO_OPOS(adev->mode);
- return 1;
+ if (typec_altmode_vdm(adev, p[0], &p[1], cnt)) {
+ response[0] = VDO(adev->svid, 1,
+ CMD_EXIT_MODE);
+ response[0] |= VDO_OPOS(adev->mode);
+ return 1;
+ }
}
return 0;
case CMD_EXIT_MODE:
- typec_altmode_update_active(pdev, false);
+ if (adev && pdev) {
+ typec_altmode_update_active(pdev, false);
- /* Back to USB Operation */
- WARN_ON(typec_altmode_notify(adev, TYPEC_STATE_USB,
- NULL));
+ /* Back to USB Operation */
+ WARN_ON(typec_altmode_notify(adev,
+ TYPEC_STATE_USB,
+ NULL));
+ }
break;
default:
break;
@@ -1184,8 +1191,10 @@ static int tcpm_pd_svdm(struct tcpm_port
switch (cmd) {
case CMD_ENTER_MODE:
/* Back to USB Operation */
- WARN_ON(typec_altmode_notify(adev, TYPEC_STATE_USB,
- NULL));
+ if (adev)
+ WARN_ON(typec_altmode_notify(adev,
+ TYPEC_STATE_USB,
+ NULL));
break;
default:
break;
@@ -1196,7 +1205,8 @@ static int tcpm_pd_svdm(struct tcpm_port
}
/* Informing the alternate mode drivers about everything */
- typec_altmode_vdm(adev, p[0], &p[1], cnt);
+ if (adev)
+ typec_altmode_vdm(adev, p[0], &p[1], cnt);
return rlen;
}
