* [PATCH] ti-st: fix NULL dereference on protocol type check
@ 2013-07-23 14:29 Gustavo Padovan
2013-07-24 23:12 ` Andrew Morton
0 siblings, 1 reply; 4+ messages in thread
From: Gustavo Padovan @ 2013-07-23 14:29 UTC (permalink / raw)
To: linux-kernel
Cc: Gustavo Padovan, Greg Kroah-Hartman, Andrew Morton, channing,
Pavan Savoy
From: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
If the type we receive is greater than ST_MAX_CHANNELS we can't rely on
type as vector index since we would be accessing unknown memory when we use the type
as index.
Unable to handle kernel NULL pointer dereference at virtual address 0000001b
pgd = c0004000
[0000001b] *pgd=00000000
Internal error: Oops: 17 [#1] PREEMPT SMP ARM
Modules linked in: btwilink wl12xx wlcore mac80211 cfg80211 rfcomm bnep bluo
CPU: 0 Tainted: G W (3.4.0+ #15)
PC is at st_int_recv+0x278/0x344
LR is at get_parent_ip+0x14/0x30
pc : [<c03b01a8>] lr : [<c007273c>] psr: 200f0193
sp : dc631ed0 ip : e3e21c24 fp : dc631f04
r10: 00000000 r9 : 600f0113 r8 : 0000003f
r7 : e3e21b14 r6 : 00000067 r5 : e2e49c1c r4 : e3e21a80
r3 : 00000001 r2 : 00000001 r1 : 00000001 r0 : 600f0113
Flags: nzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel
Control: 10c5387d Table: 9c50004a DAC: 00000015
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
---
drivers/misc/ti-st/st_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/misc/ti-st/st_core.c b/drivers/misc/ti-st/st_core.c
index 0a14280..8e64eb1 100644
--- a/drivers/misc/ti-st/st_core.c
+++ b/drivers/misc/ti-st/st_core.c
@@ -343,7 +343,7 @@ void st_int_recv(void *disc_data,
/* Unknow packet? */
default:
type = *ptr;
- if (st_gdata->list[type] == NULL) {
+ if (type >= ST_MAX_CHANNELS || st_gdata->list[type] == NULL) {
pr_err("chip/interface misbehavior dropping"
" frame starting with 0x%02x", type);
goto done;
--
1.8.1.4
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] ti-st: fix NULL dereference on protocol type check
2013-07-23 14:29 [PATCH] ti-st: fix NULL dereference on protocol type check Gustavo Padovan
@ 2013-07-24 23:12 ` Andrew Morton
2013-07-25 18:16 ` Gustavo Padovan
0 siblings, 1 reply; 4+ messages in thread
From: Andrew Morton @ 2013-07-24 23:12 UTC (permalink / raw)
To: Gustavo Padovan
Cc: linux-kernel, Gustavo Padovan, Greg Kroah-Hartman, channing,
Pavan Savoy
On Tue, 23 Jul 2013 15:29:31 +0100 Gustavo Padovan <gustavo@padovan.org> wrote:
> From: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
>
> If the type we receive is greater than ST_MAX_CHANNELS we can't rely on
> type as vector index since we would be accessing unknown memory when we use the type
> as index.
>
> Unable to handle kernel NULL pointer dereference at virtual address 0000001b
> pgd = c0004000
> [0000001b] *pgd=00000000
> Internal error: Oops: 17 [#1] PREEMPT SMP ARM
> Modules linked in: btwilink wl12xx wlcore mac80211 cfg80211 rfcomm bnep bluo
> CPU: 0 Tainted: G W (3.4.0+ #15)
> PC is at st_int_recv+0x278/0x344
> LR is at get_parent_ip+0x14/0x30
> pc : [<c03b01a8>] lr : [<c007273c>] psr: 200f0193
> sp : dc631ed0 ip : e3e21c24 fp : dc631f04
> r10: 00000000 r9 : 600f0113 r8 : 0000003f
> r7 : e3e21b14 r6 : 00000067 r5 : e2e49c1c r4 : e3e21a80
> r3 : 00000001 r2 : 00000001 r1 : 00000001 r0 : 600f0113
> Flags: nzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel
> Control: 10c5387d Table: 9c50004a DAC: 00000015
>
> Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
> ---
> drivers/misc/ti-st/st_core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/misc/ti-st/st_core.c b/drivers/misc/ti-st/st_core.c
> index 0a14280..8e64eb1 100644
> --- a/drivers/misc/ti-st/st_core.c
> +++ b/drivers/misc/ti-st/st_core.c
> @@ -343,7 +343,7 @@ void st_int_recv(void *disc_data,
> /* Unknow packet? */
> default:
> type = *ptr;
> - if (st_gdata->list[type] == NULL) {
> + if (type >= ST_MAX_CHANNELS || st_gdata->list[type] == NULL) {
> pr_err("chip/interface misbehavior dropping"
> " frame starting with 0x%02x", type);
> goto done;
This would be a bug in the calling code, would it not?
How did this come about?
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] ti-st: fix NULL dereference on protocol type check
2013-07-24 23:12 ` Andrew Morton
@ 2013-07-25 18:16 ` Gustavo Padovan
2013-07-26 23:15 ` Greg Kroah-Hartman
0 siblings, 1 reply; 4+ messages in thread
From: Gustavo Padovan @ 2013-07-25 18:16 UTC (permalink / raw)
To: Andrew Morton; +Cc: linux-kernel, Greg Kroah-Hartman, channing, Pavan Savoy
* Andrew Morton <akpm@linux-foundation.org> [2013-07-24 16:12:22 -0700]:
> On Tue, 23 Jul 2013 15:29:31 +0100 Gustavo Padovan <gustavo@padovan.org> wrote:
>
> > From: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
> >
> > If the type we receive is greater than ST_MAX_CHANNELS we can't rely on
> > type as vector index since we would be accessing unknown memory when we use the type
> > as index.
> >
> > Unable to handle kernel NULL pointer dereference at virtual address 0000001b
> > pgd = c0004000
> > [0000001b] *pgd=00000000
> > Internal error: Oops: 17 [#1] PREEMPT SMP ARM
> > Modules linked in: btwilink wl12xx wlcore mac80211 cfg80211 rfcomm bnep bluo
> > CPU: 0 Tainted: G W (3.4.0+ #15)
> > PC is at st_int_recv+0x278/0x344
> > LR is at get_parent_ip+0x14/0x30
> > pc : [<c03b01a8>] lr : [<c007273c>] psr: 200f0193
> > sp : dc631ed0 ip : e3e21c24 fp : dc631f04
> > r10: 00000000 r9 : 600f0113 r8 : 0000003f
> > r7 : e3e21b14 r6 : 00000067 r5 : e2e49c1c r4 : e3e21a80
> > r3 : 00000001 r2 : 00000001 r1 : 00000001 r0 : 600f0113
> > Flags: nzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel
> > Control: 10c5387d Table: 9c50004a DAC: 00000015
> >
> > Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
> > ---
> > drivers/misc/ti-st/st_core.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/misc/ti-st/st_core.c b/drivers/misc/ti-st/st_core.c
> > index 0a14280..8e64eb1 100644
> > --- a/drivers/misc/ti-st/st_core.c
> > +++ b/drivers/misc/ti-st/st_core.c
> > @@ -343,7 +343,7 @@ void st_int_recv(void *disc_data,
> > /* Unknow packet? */
> > default:
> > type = *ptr;
> > - if (st_gdata->list[type] == NULL) {
> > + if (type >= ST_MAX_CHANNELS || st_gdata->list[type] == NULL) {
> > pr_err("chip/interface misbehavior dropping"
> > " frame starting with 0x%02x", type);
> > goto done;
>
> This would be a bug in the calling code, would it not?
It is possible and it seems 39f610e40 could be a fix for this. I would need to
test. I was testing it on old kernel without this patch. In any case my patch
is still needed.
Gustavo
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] ti-st: fix NULL dereference on protocol type check
2013-07-25 18:16 ` Gustavo Padovan
@ 2013-07-26 23:15 ` Greg Kroah-Hartman
0 siblings, 0 replies; 4+ messages in thread
From: Greg Kroah-Hartman @ 2013-07-26 23:15 UTC (permalink / raw)
To: Gustavo Padovan, Andrew Morton, linux-kernel, channing,
Pavan Savoy
On Thu, Jul 25, 2013 at 07:16:28PM +0100, Gustavo Padovan wrote:
> * Andrew Morton <akpm@linux-foundation.org> [2013-07-24 16:12:22 -0700]:
>
> > On Tue, 23 Jul 2013 15:29:31 +0100 Gustavo Padovan <gustavo@padovan.org> wrote:
> >
> > > From: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
> > >
> > > If the type we receive is greater than ST_MAX_CHANNELS we can't rely on
> > > type as vector index since we would be accessing unknown memory when we use the type
> > > as index.
> > >
> > > Unable to handle kernel NULL pointer dereference at virtual address 0000001b
> > > pgd = c0004000
> > > [0000001b] *pgd=00000000
> > > Internal error: Oops: 17 [#1] PREEMPT SMP ARM
> > > Modules linked in: btwilink wl12xx wlcore mac80211 cfg80211 rfcomm bnep bluo
> > > CPU: 0 Tainted: G W (3.4.0+ #15)
> > > PC is at st_int_recv+0x278/0x344
> > > LR is at get_parent_ip+0x14/0x30
> > > pc : [<c03b01a8>] lr : [<c007273c>] psr: 200f0193
> > > sp : dc631ed0 ip : e3e21c24 fp : dc631f04
> > > r10: 00000000 r9 : 600f0113 r8 : 0000003f
> > > r7 : e3e21b14 r6 : 00000067 r5 : e2e49c1c r4 : e3e21a80
> > > r3 : 00000001 r2 : 00000001 r1 : 00000001 r0 : 600f0113
> > > Flags: nzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel
> > > Control: 10c5387d Table: 9c50004a DAC: 00000015
> > >
> > > Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
> > > ---
> > > drivers/misc/ti-st/st_core.c | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/misc/ti-st/st_core.c b/drivers/misc/ti-st/st_core.c
> > > index 0a14280..8e64eb1 100644
> > > --- a/drivers/misc/ti-st/st_core.c
> > > +++ b/drivers/misc/ti-st/st_core.c
> > > @@ -343,7 +343,7 @@ void st_int_recv(void *disc_data,
> > > /* Unknow packet? */
> > > default:
> > > type = *ptr;
> > > - if (st_gdata->list[type] == NULL) {
> > > + if (type >= ST_MAX_CHANNELS || st_gdata->list[type] == NULL) {
> > > pr_err("chip/interface misbehavior dropping"
> > > " frame starting with 0x%02x", type);
> > > goto done;
> >
> > This would be a bug in the calling code, would it not?
>
> It is possible and it seems 39f610e40 could be a fix for this. I would need to
> test. I was testing it on old kernel without this patch. In any case my patch
> is still needed.
Why? Shouldn't you just prevent this from ever happening in the first
place?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-07-26 23:16 UTC | newest]
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2013-07-23 14:29 [PATCH] ti-st: fix NULL dereference on protocol type check Gustavo Padovan
2013-07-24 23:12 ` Andrew Morton
2013-07-25 18:16 ` Gustavo Padovan
2013-07-26 23:15 ` Greg Kroah-Hartman
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