diff mbox series

Fix array overruns in ucsi.c partner_altmode[]

Message ID alpine.DEB.2.21.2008131842080.26061@montezuma.home (mailing list archive)
State New, archived
Headers show
Series Fix array overruns in ucsi.c partner_altmode[] | expand

Commit Message

Zwane Mwaikambo Aug. 14, 2020, 1:56 a.m. UTC 
Plugging in a USB type C dock causes an Oops due to an array 
overrun of ->partner_altmode[].

con->partner_altmode[i] ends up with the value 0x2 in the call and it's
because the array has been accessed out of bounds resulting in random 
contents of memory being checked. The patch was generated and tested 
against 5.8.0-rc6.


[  565.452023] BUG: kernel NULL pointer dereference, address: 00000000000002fe
[  565.452025] #PF: supervisor read access in kernel mode
[  565.452026] #PF: error_code(0x0000) - not-present page
[  565.452026] PGD 0 P4D 0 
[  565.452028] Oops: 0000 [#1] PREEMPT SMP NOPTI
[  565.452030] CPU: 0 PID: 502 Comm: kworker/0:3 Not tainted 5.8.0-rc3+ #1
[  565.452031] Hardware name: LENOVO 20RD002VUS/20RD002VUS, 
BIOS R16ET25W (1.11 ) 04/21/2020
[  565.452034] Workqueue: events ucsi_handle_connector_change [typec_ucsi]
[  565.452039] RIP: 0010:typec_altmode_update_active+0x1f/0x100 [typec]
[  565.452040] Code: 0f 1f 84 00 00 00 00 00 0f 1f 00 0f 1f 44 00 00 55 48 
89 e5 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 45 e8 31 c0 
<0f> b6 87 fc 02 00 00 83 e0 01 40 38 f0 0f 84 95 00 00 00 48 8b 47
[  565.452041] RSP: 0018:ffffb729c066bdb0 EFLAGS: 00010246
[  565.452042] RAX: 0000000000000000 RBX: ffffa067c3e64a70 RCX: 0000000000000000
[  565.452043] RDX: ffffb729c066bd20 RSI: 0000000000000000 RDI: 0000000000000002
[  565.452044] RBP: ffffb729c066bdd0 R08: 00000083a7910a4f R09: 0000000000000000
[  565.452044] R10: ffffffffa106a220 R11: 0000000000000000 R12: 0000000000000000
[  565.452045] R13: ffffa067c3e64a98 R14: ffffa067c3e64810 R15: ffffa067c3e64800
[  565.452046] FS:  0000000000000000(0000) GS:ffffa067d1400000(0000)
knlGS:0000000000000000
[  565.452047] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  565.452048] CR2: 00000000000002fe CR3: 00000001b060a003 CR4: 00000000003606f0
[  565.452048] Call Trace:
[  565.452052]  ucsi_altmode_update_active+0x83/0xd0 [typec_ucsi]
[  565.452054]  ucsi_handle_connector_change+0x1dc/0x320 [typec_ucsi]
[  565.452057]  process_one_work+0x1df/0x3d0
[  565.452059]  worker_thread+0x4d/0x3d0
[  565.452060]  ? process_one_work+0x3d0/0x3d0
[  565.452062]  kthread+0x127/0x170
[  565.452063]  ? kthread_park+0x90/0x90
[  565.452065]  ret_from_fork+0x1f/0x30

The failing instruction is;

0x0000000000000380 <+0>:     callq  0x385 <typec_altmode_update_active+5>
0x0000000000000385 <+5>:     push   %rbp
0x0000000000000386 <+6>:     mov    %rsp,%rbp
0x0000000000000389 <+9>:     push   %r12
0x000000000000038b <+11>:    push   %rbx
0x000000000000038c <+12>:    sub    $0x10,%rsp
0x0000000000000390 <+16>:    mov    %gs:0x28,%rax
0x0000000000000399 <+25>:    mov    %rax,-0x18(%rbp)
0x000000000000039d <+29>:    xor    %eax,%eax
0x000000000000039f <+31>:    movzbl 0x2fc(%rdi),%eax <======
0x00000000000003a6 <+38>:    and    $0x1,%eax

(gdb) list  *typec_altmode_update_active+0x1f
0x39f is in typec_altmode_update_active (drivers/usb/typec/class.c:221).
216      */
217     void typec_altmode_update_active(struct typec_altmode *adev, bool active)
218     {
219             char dir[6];
220
221             if (adev->active == active)
222                     return;
223
224             if (!is_typec_port(adev->dev.parent) && adev->dev.driver) {
225                     if (!active)

(gdb) list *ucsi_altmode_update_active+0x83
0x12a3 is in ucsi_altmode_update_active (drivers/usb/typec/ucsi/ucsi.c:221).
216             }
217
218             if (cur < UCSI_MAX_ALTMODES)
219                     altmode = typec_altmode_get_partner(con->port_altmode[cur]);
220
221             for (i = 0; con->partner_altmode[i]; i++)
222                     typec_altmode_update_active(con->partner_altmode[i],
223                                                con->partner_altmode[i] == altmode);
224     }

This oops is for a similar array overrun in ucsi_unregister_altmodes

[ 4372.429633] usb 1-2.1.4: USB disconnect, device number 16
[ 4372.523235] usb 1-2.2: USB disconnect, device number 7
[ 4372.570537] usb 1-2.5: USB disconnect, device number 9
[ 4373.153246] BUG: kernel NULL pointer dereference, address: 00000000000002f2
[ 4373.153267] #PF: supervisor read access in kernel mode
[ 4373.153271] #PF: error_code(0x0000) - not-present page
[ 4373.153275] PGD 0 P4D 0 
[ 4373.153284] Oops: 0000 [#2] PREEMPT SMP NOPTI
[ 4373.153292] CPU: 0 PID: 13242 Comm: kworker/0:0 Tainted: G      D   
        5.8.0-rc6+ #1
[ 4373.153296] Hardware name: LENOVO 20RD002VUS/20RD002VUS, BIOS R16ET25W (1.11 )
 04/21/2020
[ 4373.153308] Workqueue: events ucsi_handle_connector_change [typec_ucsi]
[ 4373.153320] RIP: 0010:ucsi_unregister_altmodes+0x5f/0xa0 [typec_ucsi]
[ 4373.153326] Code: 54 48 8b 3b 41 83 c4 01 e8 9e f9 0c 00 49 63 c4 48 c7 
03 00 00 00 00 49 8d 5c c5 00 48 8b 3b 48 85 ff 74 31 41 80 fe 01 75 d7 
<0f> b7 87 f0 02 00 00 66 3d 01 ff 74 0f 66 3d 55 09 75 c4 83 bf f8
[ 4373.153332] RSP: 0018:ffffb2ef036b3dc8 EFLAGS: 00010246
[ 4373.153338] RAX: 000000000000001e RBX: ffff94268b006a60 RCX: 0000000080800067
[ 4373.153342] RDX: 0000000080800068 RSI: 0000000000000001 RDI: 0000000000000002
[ 4373.153347] RBP: ffffb2ef036b3de8 R08: 0000000000000000 R09: ffffffff8dc65400
[ 4373.153351] R10: ffff9426678d7200 R11: 0000000000000001 R12: 000000000000001e
[ 4373.153355] R13: ffff94268b006970 R14: 0000000000000001 R15: ffff94268b006800
[ 4373.153361] FS:  0000000000000000(0000) GS:ffff942691400000(0000)
knlGS:0000000000000000
[ 4373.153366] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4373.153371] CR2: 00000000000002f2 CR3: 00000004445a6005 CR4: 00000000003606f0
[ 4373.153375] Call Trace:
[ 4373.153389]  ucsi_unregister_partner.part.0+0x17/0x30 [typec_ucsi]
[ 4373.153400]  ucsi_handle_connector_change+0x25c/0x320 [typec_ucsi]
[ 4373.153418]  process_one_work+0x1df/0x3d0
[ 4373.153428]  worker_thread+0x4a/0x3d0
[ 4373.153436]  ? process_one_work+0x3d0/0x3d0
[ 4373.153444]  kthread+0x127/0x170
[ 4373.153451]  ? kthread_park+0x90/0x90
[ 4373.153461]  ret_from_fork+0x1f/0x30
[ 4373.153661] CR2: 00000000000002f2

Signed-off-by: Zwane Mwaikambo <zwane@yosper.io>
---

Comments

Heikki Krogerus Aug. 24, 2020, 11:21 a.m. UTC | #1 
Hi,

The subject line should mention the subsystem:
https://www.kernel.org/doc/html/latest/process/submitting-patches.html#the-canonical-patch-format

On Thu, Aug 13, 2020 at 06:56:06PM -0700, Zwane Mwaikambo wrote:
> Plugging in a USB type C dock causes an Oops due to an array 
> overrun of ->partner_altmode[].
> 
> con->partner_altmode[i] ends up with the value 0x2 in the call and it's
> because the array has been accessed out of bounds resulting in random 
> contents of memory being checked. The patch was generated and tested 
> against 5.8.0-rc6.
> 
> 
> [  565.452023] BUG: kernel NULL pointer dereference, address: 00000000000002fe
> [  565.452025] #PF: supervisor read access in kernel mode
> [  565.452026] #PF: error_code(0x0000) - not-present page
> [  565.452026] PGD 0 P4D 0 
> [  565.452028] Oops: 0000 [#1] PREEMPT SMP NOPTI
> [  565.452030] CPU: 0 PID: 502 Comm: kworker/0:3 Not tainted 5.8.0-rc3+ #1
> [  565.452031] Hardware name: LENOVO 20RD002VUS/20RD002VUS, 
> BIOS R16ET25W (1.11 ) 04/21/2020
> [  565.452034] Workqueue: events ucsi_handle_connector_change [typec_ucsi]
> [  565.452039] RIP: 0010:typec_altmode_update_active+0x1f/0x100 [typec]
> [  565.452040] Code: 0f 1f 84 00 00 00 00 00 0f 1f 00 0f 1f 44 00 00 55 48 
> 89 e5 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 45 e8 31 c0 
> <0f> b6 87 fc 02 00 00 83 e0 01 40 38 f0 0f 84 95 00 00 00 48 8b 47
> [  565.452041] RSP: 0018:ffffb729c066bdb0 EFLAGS: 00010246
> [  565.452042] RAX: 0000000000000000 RBX: ffffa067c3e64a70 RCX: 0000000000000000
> [  565.452043] RDX: ffffb729c066bd20 RSI: 0000000000000000 RDI: 0000000000000002
> [  565.452044] RBP: ffffb729c066bdd0 R08: 00000083a7910a4f R09: 0000000000000000
> [  565.452044] R10: ffffffffa106a220 R11: 0000000000000000 R12: 0000000000000000
> [  565.452045] R13: ffffa067c3e64a98 R14: ffffa067c3e64810 R15: ffffa067c3e64800
> [  565.452046] FS:  0000000000000000(0000) GS:ffffa067d1400000(0000)
> knlGS:0000000000000000
> [  565.452047] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [  565.452048] CR2: 00000000000002fe CR3: 00000001b060a003 CR4: 00000000003606f0
> [  565.452048] Call Trace:
> [  565.452052]  ucsi_altmode_update_active+0x83/0xd0 [typec_ucsi]
> [  565.452054]  ucsi_handle_connector_change+0x1dc/0x320 [typec_ucsi]
> [  565.452057]  process_one_work+0x1df/0x3d0
> [  565.452059]  worker_thread+0x4d/0x3d0
> [  565.452060]  ? process_one_work+0x3d0/0x3d0
> [  565.452062]  kthread+0x127/0x170
> [  565.452063]  ? kthread_park+0x90/0x90
> [  565.452065]  ret_from_fork+0x1f/0x30
> 
> The failing instruction is;
> 
> 0x0000000000000380 <+0>:     callq  0x385 <typec_altmode_update_active+5>
> 0x0000000000000385 <+5>:     push   %rbp
> 0x0000000000000386 <+6>:     mov    %rsp,%rbp
> 0x0000000000000389 <+9>:     push   %r12
> 0x000000000000038b <+11>:    push   %rbx
> 0x000000000000038c <+12>:    sub    $0x10,%rsp
> 0x0000000000000390 <+16>:    mov    %gs:0x28,%rax
> 0x0000000000000399 <+25>:    mov    %rax,-0x18(%rbp)
> 0x000000000000039d <+29>:    xor    %eax,%eax
> 0x000000000000039f <+31>:    movzbl 0x2fc(%rdi),%eax <======
> 0x00000000000003a6 <+38>:    and    $0x1,%eax
> 
> (gdb) list  *typec_altmode_update_active+0x1f
> 0x39f is in typec_altmode_update_active (drivers/usb/typec/class.c:221).
> 216      */
> 217     void typec_altmode_update_active(struct typec_altmode *adev, bool active)
> 218     {
> 219             char dir[6];
> 220
> 221             if (adev->active == active)
> 222                     return;
> 223
> 224             if (!is_typec_port(adev->dev.parent) && adev->dev.driver) {
> 225                     if (!active)
> 
> (gdb) list *ucsi_altmode_update_active+0x83
> 0x12a3 is in ucsi_altmode_update_active (drivers/usb/typec/ucsi/ucsi.c:221).
> 216             }
> 217
> 218             if (cur < UCSI_MAX_ALTMODES)
> 219                     altmode = typec_altmode_get_partner(con->port_altmode[cur]);
> 220
> 221             for (i = 0; con->partner_altmode[i]; i++)
> 222                     typec_altmode_update_active(con->partner_altmode[i],
> 223                                                con->partner_altmode[i] == altmode);
> 224     }
> 
> This oops is for a similar array overrun in ucsi_unregister_altmodes
> 
> [ 4372.429633] usb 1-2.1.4: USB disconnect, device number 16
> [ 4372.523235] usb 1-2.2: USB disconnect, device number 7
> [ 4372.570537] usb 1-2.5: USB disconnect, device number 9
> [ 4373.153246] BUG: kernel NULL pointer dereference, address: 00000000000002f2
> [ 4373.153267] #PF: supervisor read access in kernel mode
> [ 4373.153271] #PF: error_code(0x0000) - not-present page
> [ 4373.153275] PGD 0 P4D 0 
> [ 4373.153284] Oops: 0000 [#2] PREEMPT SMP NOPTI
> [ 4373.153292] CPU: 0 PID: 13242 Comm: kworker/0:0 Tainted: G      D   
>         5.8.0-rc6+ #1
> [ 4373.153296] Hardware name: LENOVO 20RD002VUS/20RD002VUS, BIOS R16ET25W (1.11 )
>  04/21/2020
> [ 4373.153308] Workqueue: events ucsi_handle_connector_change [typec_ucsi]
> [ 4373.153320] RIP: 0010:ucsi_unregister_altmodes+0x5f/0xa0 [typec_ucsi]
> [ 4373.153326] Code: 54 48 8b 3b 41 83 c4 01 e8 9e f9 0c 00 49 63 c4 48 c7 
> 03 00 00 00 00 49 8d 5c c5 00 48 8b 3b 48 85 ff 74 31 41 80 fe 01 75 d7 
> <0f> b7 87 f0 02 00 00 66 3d 01 ff 74 0f 66 3d 55 09 75 c4 83 bf f8
> [ 4373.153332] RSP: 0018:ffffb2ef036b3dc8 EFLAGS: 00010246
> [ 4373.153338] RAX: 000000000000001e RBX: ffff94268b006a60 RCX: 0000000080800067
> [ 4373.153342] RDX: 0000000080800068 RSI: 0000000000000001 RDI: 0000000000000002
> [ 4373.153347] RBP: ffffb2ef036b3de8 R08: 0000000000000000 R09: ffffffff8dc65400
> [ 4373.153351] R10: ffff9426678d7200 R11: 0000000000000001 R12: 000000000000001e
> [ 4373.153355] R13: ffff94268b006970 R14: 0000000000000001 R15: ffff94268b006800
> [ 4373.153361] FS:  0000000000000000(0000) GS:ffff942691400000(0000)
> knlGS:0000000000000000
> [ 4373.153366] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 4373.153371] CR2: 00000000000002f2 CR3: 00000004445a6005 CR4: 00000000003606f0
> [ 4373.153375] Call Trace:
> [ 4373.153389]  ucsi_unregister_partner.part.0+0x17/0x30 [typec_ucsi]
> [ 4373.153400]  ucsi_handle_connector_change+0x25c/0x320 [typec_ucsi]
> [ 4373.153418]  process_one_work+0x1df/0x3d0
> [ 4373.153428]  worker_thread+0x4a/0x3d0
> [ 4373.153436]  ? process_one_work+0x3d0/0x3d0
> [ 4373.153444]  kthread+0x127/0x170
> [ 4373.153451]  ? kthread_park+0x90/0x90
> [ 4373.153461]  ret_from_fork+0x1f/0x30
> [ 4373.153661] CR2: 00000000000002f2
> 
> Signed-off-by: Zwane Mwaikambo <zwane@yosper.io>
> ---
> 
> diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> index d0c63afaf..79061705e 100644
> --- a/drivers/usb/typec/ucsi/ucsi.c
> +++ b/drivers/usb/typec/ucsi/ucsi.c
> @@ -218,9 +218,10 @@ void ucsi_altmode_update_active(struct ucsi_connector *con)
>  	if (cur < UCSI_MAX_ALTMODES)
>  		altmode = typec_altmode_get_partner(con->port_altmode[cur]);
>  
> -	for (i = 0; con->partner_altmode[i]; i++)
> -		typec_altmode_update_active(con->partner_altmode[i],
> -					    con->partner_altmode[i] == altmode);
> +	for (i = 0; i < UCSI_MAX_ALTMODES; i++)
> +		if (con->partner_altmode[i])
> +			typec_altmode_update_active(con->partner_altmode[i],
> +										con->partner_altmode[i] == altmode);
>  }
>  
>  static u8 ucsi_altmode_next_mode(struct typec_altmode **alt, u16 svid)
> @@ -479,7 +480,10 @@ static void ucsi_unregister_altmodes(struct ucsi_connector *con, u8 recipient)
>  		return;
>  	}
>  
> -	while (adev[i]) {
> +	for (i = 0; i < UCSI_MAX_ALTMODES; i++) {
> +		if (!adev[i])
> +			break;
> +

for (i = 0; adev[i]; i++)

>  		if (recipient == UCSI_RECIPIENT_SOP &&
>  		    (adev[i]->svid == USB_TYPEC_DP_SID ||
>  			(adev[i]->svid == USB_TYPEC_NVIDIA_VLINK_SID &&
> @@ -488,7 +492,7 @@ static void ucsi_unregister_altmodes(struct ucsi_connector *con, u8 recipient)
>  			ucsi_displayport_remove_partner((void *)pdev);
>  		}
>  		typec_unregister_altmode(adev[i]);
> -		adev[i++] = NULL;
> +		adev[i] = NULL;
>  	}
>  }

So are the two fixes here? If so, then please supply one patch per
fix.


thanks,
Zwane Mwaikambo Aug. 25, 2020, 8:33 a.m. UTC | #2 
Hi,

On Mon, Aug 24, 2020 at 4:21 AM Heikki Krogerus
<heikki.krogerus@linux.intel.com> wrote:
>
> Hi,
>
> The subject line should mention the subsystem:
> https://www.kernel.org/doc/html/latest/process/submitting-patches.html#the-canonical-patch-format

Thanks i'll update and resubmit

> On Thu, Aug 13, 2020 at 06:56:06PM -0700, Zwane Mwaikambo wrote:
> > Plugging in a USB type C dock causes an Oops due to an array
> > overrun of ->partner_altmode[].
> >
> > con->partner_altmode[i] ends up with the value 0x2 in the call and it's
> > because the array has been accessed out of bounds resulting in random
> > contents of memory being checked. The patch was generated and tested
> > against 5.8.0-rc6.
> >
> >
> > [  565.452023] BUG: kernel NULL pointer dereference, address: 00000000000002fe
> > [  565.452025] #PF: supervisor read access in kernel mode
> > [  565.452026] #PF: error_code(0x0000) - not-present page
> > [  565.452026] PGD 0 P4D 0
> > [  565.452028] Oops: 0000 [#1] PREEMPT SMP NOPTI
> > [  565.452030] CPU: 0 PID: 502 Comm: kworker/0:3 Not tainted 5.8.0-rc3+ #1
> > [  565.452031] Hardware name: LENOVO 20RD002VUS/20RD002VUS,
> > BIOS R16ET25W (1.11 ) 04/21/2020
> > [  565.452034] Workqueue: events ucsi_handle_connector_change [typec_ucsi]
> > [  565.452039] RIP: 0010:typec_altmode_update_active+0x1f/0x100 [typec]
> > [  565.452040] Code: 0f 1f 84 00 00 00 00 00 0f 1f 00 0f 1f 44 00 00 55 48
> > 89 e5 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 45 e8 31 c0
> > <0f> b6 87 fc 02 00 00 83 e0 01 40 38 f0 0f 84 95 00 00 00 48 8b 47
> > [  565.452041] RSP: 0018:ffffb729c066bdb0 EFLAGS: 00010246
> > [  565.452042] RAX: 0000000000000000 RBX: ffffa067c3e64a70 RCX: 0000000000000000
> > [  565.452043] RDX: ffffb729c066bd20 RSI: 0000000000000000 RDI: 0000000000000002
> > [  565.452044] RBP: ffffb729c066bdd0 R08: 00000083a7910a4f R09: 0000000000000000
> > [  565.452044] R10: ffffffffa106a220 R11: 0000000000000000 R12: 0000000000000000
> > [  565.452045] R13: ffffa067c3e64a98 R14: ffffa067c3e64810 R15: ffffa067c3e64800
> > [  565.452046] FS:  0000000000000000(0000) GS:ffffa067d1400000(0000)
> > knlGS:0000000000000000
> > [  565.452047] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [  565.452048] CR2: 00000000000002fe CR3: 00000001b060a003 CR4: 00000000003606f0
> > [  565.452048] Call Trace:
> > [  565.452052]  ucsi_altmode_update_active+0x83/0xd0 [typec_ucsi]
> > [  565.452054]  ucsi_handle_connector_change+0x1dc/0x320 [typec_ucsi]
> > [  565.452057]  process_one_work+0x1df/0x3d0
> > [  565.452059]  worker_thread+0x4d/0x3d0
> > [  565.452060]  ? process_one_work+0x3d0/0x3d0
> > [  565.452062]  kthread+0x127/0x170
> > [  565.452063]  ? kthread_park+0x90/0x90
> > [  565.452065]  ret_from_fork+0x1f/0x30
> >
> > The failing instruction is;
> >
> > 0x0000000000000380 <+0>:     callq  0x385 <typec_altmode_update_active+5>
> > 0x0000000000000385 <+5>:     push   %rbp
> > 0x0000000000000386 <+6>:     mov    %rsp,%rbp
> > 0x0000000000000389 <+9>:     push   %r12
> > 0x000000000000038b <+11>:    push   %rbx
> > 0x000000000000038c <+12>:    sub    $0x10,%rsp
> > 0x0000000000000390 <+16>:    mov    %gs:0x28,%rax
> > 0x0000000000000399 <+25>:    mov    %rax,-0x18(%rbp)
> > 0x000000000000039d <+29>:    xor    %eax,%eax
> > 0x000000000000039f <+31>:    movzbl 0x2fc(%rdi),%eax <======
> > 0x00000000000003a6 <+38>:    and    $0x1,%eax
> >
> > (gdb) list  *typec_altmode_update_active+0x1f
> > 0x39f is in typec_altmode_update_active (drivers/usb/typec/class.c:221).
> > 216      */
> > 217     void typec_altmode_update_active(struct typec_altmode *adev, bool active)
> > 218     {
> > 219             char dir[6];
> > 220
> > 221             if (adev->active == active)
> > 222                     return;
> > 223
> > 224             if (!is_typec_port(adev->dev.parent) && adev->dev.driver) {
> > 225                     if (!active)
> >
> > (gdb) list *ucsi_altmode_update_active+0x83
> > 0x12a3 is in ucsi_altmode_update_active (drivers/usb/typec/ucsi/ucsi.c:221).
> > 216             }
> > 217
> > 218             if (cur < UCSI_MAX_ALTMODES)
> > 219                     altmode = typec_altmode_get_partner(con->port_altmode[cur]);
> > 220
> > 221             for (i = 0; con->partner_altmode[i]; i++)
> > 222                     typec_altmode_update_active(con->partner_altmode[i],
> > 223                                                con->partner_altmode[i] == altmode);
> > 224     }
> >
> > This oops is for a similar array overrun in ucsi_unregister_altmodes
> >
> > [ 4372.429633] usb 1-2.1.4: USB disconnect, device number 16
> > [ 4372.523235] usb 1-2.2: USB disconnect, device number 7
> > [ 4372.570537] usb 1-2.5: USB disconnect, device number 9
> > [ 4373.153246] BUG: kernel NULL pointer dereference, address: 00000000000002f2
> > [ 4373.153267] #PF: supervisor read access in kernel mode
> > [ 4373.153271] #PF: error_code(0x0000) - not-present page
> > [ 4373.153275] PGD 0 P4D 0
> > [ 4373.153284] Oops: 0000 [#2] PREEMPT SMP NOPTI
> > [ 4373.153292] CPU: 0 PID: 13242 Comm: kworker/0:0 Tainted: G      D
> >         5.8.0-rc6+ #1
> > [ 4373.153296] Hardware name: LENOVO 20RD002VUS/20RD002VUS, BIOS R16ET25W (1.11 )
> >  04/21/2020
> > [ 4373.153308] Workqueue: events ucsi_handle_connector_change [typec_ucsi]
> > [ 4373.153320] RIP: 0010:ucsi_unregister_altmodes+0x5f/0xa0 [typec_ucsi]
> > [ 4373.153326] Code: 54 48 8b 3b 41 83 c4 01 e8 9e f9 0c 00 49 63 c4 48 c7
> > 03 00 00 00 00 49 8d 5c c5 00 48 8b 3b 48 85 ff 74 31 41 80 fe 01 75 d7
> > <0f> b7 87 f0 02 00 00 66 3d 01 ff 74 0f 66 3d 55 09 75 c4 83 bf f8
> > [ 4373.153332] RSP: 0018:ffffb2ef036b3dc8 EFLAGS: 00010246
> > [ 4373.153338] RAX: 000000000000001e RBX: ffff94268b006a60 RCX: 0000000080800067
> > [ 4373.153342] RDX: 0000000080800068 RSI: 0000000000000001 RDI: 0000000000000002
> > [ 4373.153347] RBP: ffffb2ef036b3de8 R08: 0000000000000000 R09: ffffffff8dc65400
> > [ 4373.153351] R10: ffff9426678d7200 R11: 0000000000000001 R12: 000000000000001e
> > [ 4373.153355] R13: ffff94268b006970 R14: 0000000000000001 R15: ffff94268b006800
> > [ 4373.153361] FS:  0000000000000000(0000) GS:ffff942691400000(0000)
> > knlGS:0000000000000000
> > [ 4373.153366] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [ 4373.153371] CR2: 00000000000002f2 CR3: 00000004445a6005 CR4: 00000000003606f0
> > [ 4373.153375] Call Trace:
> > [ 4373.153389]  ucsi_unregister_partner.part.0+0x17/0x30 [typec_ucsi]
> > [ 4373.153400]  ucsi_handle_connector_change+0x25c/0x320 [typec_ucsi]
> > [ 4373.153418]  process_one_work+0x1df/0x3d0
> > [ 4373.153428]  worker_thread+0x4a/0x3d0
> > [ 4373.153436]  ? process_one_work+0x3d0/0x3d0
> > [ 4373.153444]  kthread+0x127/0x170
> > [ 4373.153451]  ? kthread_park+0x90/0x90
> > [ 4373.153461]  ret_from_fork+0x1f/0x30
> > [ 4373.153661] CR2: 00000000000002f2
> >
> > Signed-off-by: Zwane Mwaikambo <zwane@yosper.io>
> > ---
> >
> > diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> > index d0c63afaf..79061705e 100644
> > --- a/drivers/usb/typec/ucsi/ucsi.c
> > +++ b/drivers/usb/typec/ucsi/ucsi.c
> > @@ -218,9 +218,10 @@ void ucsi_altmode_update_active(struct ucsi_connector *con)
> >       if (cur < UCSI_MAX_ALTMODES)
> >               altmode = typec_altmode_get_partner(con->port_altmode[cur]);
> >
> > -     for (i = 0; con->partner_altmode[i]; i++)
> > -             typec_altmode_update_active(con->partner_altmode[i],
> > -                                         con->partner_altmode[i] == altmode);
> > +     for (i = 0; i < UCSI_MAX_ALTMODES; i++)
> > +             if (con->partner_altmode[i])
> > +                     typec_altmode_update_active(con->partner_altmode[i],
> > +                                                                             con->partner_altmode[i] == altmode);
> >  }
> >
> >  static u8 ucsi_altmode_next_mode(struct typec_altmode **alt, u16 svid)
> > @@ -479,7 +480,10 @@ static void ucsi_unregister_altmodes(struct ucsi_connector *con, u8 recipient)
> >               return;
> >       }
> >
> > -     while (adev[i]) {
> > +     for (i = 0; i < UCSI_MAX_ALTMODES; i++) {
> > +             if (!adev[i])
> > +                     break;
> > +
>
> for (i = 0; adev[i]; i++)

Using a for loop with conditional 'adev[i]' for termination of the
loop will result in the same overrun as the original code.

> >               if (recipient == UCSI_RECIPIENT_SOP &&
> >                   (adev[i]->svid == USB_TYPEC_DP_SID ||
> >                       (adev[i]->svid == USB_TYPEC_NVIDIA_VLINK_SID &&
> > @@ -488,7 +492,7 @@ static void ucsi_unregister_altmodes(struct ucsi_connector *con, u8 recipient)
> >                       ucsi_displayport_remove_partner((void *)pdev);
> >               }
> >               typec_unregister_altmode(adev[i]);
> > -             adev[i++] = NULL;
> > +             adev[i] = NULL;
> >       }
> >  }
>
> So are the two fixes here? If so, then please supply one patch per
> fix.

Both fixes were in that patch, i had kept them together since they
were effectively fixing the same array issue, but i'll break them up
into two patches.

Thanks,
   Zwane
diff mbox series

Patch

diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index d0c63afaf..79061705e 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -218,9 +218,10 @@  void ucsi_altmode_update_active(struct ucsi_connector *con)
 	if (cur < UCSI_MAX_ALTMODES)
 		altmode = typec_altmode_get_partner(con->port_altmode[cur]);
 
-	for (i = 0; con->partner_altmode[i]; i++)
-		typec_altmode_update_active(con->partner_altmode[i],
-					    con->partner_altmode[i] == altmode);
+	for (i = 0; i < UCSI_MAX_ALTMODES; i++)
+		if (con->partner_altmode[i])
+			typec_altmode_update_active(con->partner_altmode[i],
+										con->partner_altmode[i] == altmode);
 }
 
 static u8 ucsi_altmode_next_mode(struct typec_altmode **alt, u16 svid)
@@ -479,7 +480,10 @@  static void ucsi_unregister_altmodes(struct ucsi_connector *con, u8 recipient)
 		return;
 	}
 
-	while (adev[i]) {
+	for (i = 0; i < UCSI_MAX_ALTMODES; i++) {
+		if (!adev[i])
+			break;
+
 		if (recipient == UCSI_RECIPIENT_SOP &&
 		    (adev[i]->svid == USB_TYPEC_DP_SID ||
 			(adev[i]->svid == USB_TYPEC_NVIDIA_VLINK_SID &&
@@ -488,7 +492,7 @@  static void ucsi_unregister_altmodes(struct ucsi_connector *con, u8 recipient)
 			ucsi_displayport_remove_partner((void *)pdev);
 		}
 		typec_unregister_altmode(adev[i]);
-		adev[i++] = NULL;
+		adev[i] = NULL;
 	}
 }