* [PATCH] platform/chrome: cros_ec_dev - Fix security issue
@ 2021-03-17 23:55 Gwendal Grignou
2021-03-18 5:51 ` Greg KH
2021-03-18 7:54 ` Lee Jones
0 siblings, 2 replies; 8+ messages in thread
From: Gwendal Grignou @ 2021-03-17 23:55 UTC (permalink / raw)
To: lee.jones; +Cc: stable, Gwendal Grignou, Olof Johansson
commit 5d749d0bbe811c10d9048cde6dfebc761713abfd upstream.
Prevent memory scribble by checking that ioctl buffer size parameters
are sane.
Without this check, on 32 bits system, if .insize = 0xffffffff - 20 and
.outsize the amount to scribble, we would overflow, allocate a small
amounts and be able to write outside of the malloc'ed area.
Adding a hard limit allows argument checking of the ioctl. With the
current EC, it is expected .insize and .outsize to be at around 512 bytes
or less.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
---
drivers/platform/chrome/cros_ec_dev.c | 4 ++++
drivers/platform/chrome/cros_ec_proto.c | 4 ++--
include/linux/mfd/cros_ec.h | 6 ++++--
3 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c
index 2b331d5b9e799..e16d82bb36a9d 100644
--- a/drivers/platform/chrome/cros_ec_dev.c
+++ b/drivers/platform/chrome/cros_ec_dev.c
@@ -137,6 +137,10 @@ static long ec_device_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg)
if (copy_from_user(&u_cmd, arg, sizeof(u_cmd)))
return -EFAULT;
+ if ((u_cmd.outsize > EC_MAX_MSG_BYTES) ||
+ (u_cmd.insize > EC_MAX_MSG_BYTES))
+ return -EINVAL;
+
s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize),
GFP_KERNEL);
if (!s_cmd)
diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index 5c285f2b3a650..d20190c8f0c06 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -311,8 +311,8 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
ec_dev->max_response = EC_PROTO2_MAX_PARAM_SIZE;
ec_dev->max_passthru = 0;
ec_dev->pkt_xfer = NULL;
- ec_dev->din_size = EC_MSG_BYTES;
- ec_dev->dout_size = EC_MSG_BYTES;
+ ec_dev->din_size = EC_PROTO2_MSG_BYTES;
+ ec_dev->dout_size = EC_PROTO2_MSG_BYTES;
} else {
/*
* It's possible for a test to occur too early when
diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index 3ab3cede28eac..93c14e9df6309 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -50,9 +50,11 @@ enum {
EC_MSG_TX_TRAILER_BYTES,
EC_MSG_RX_PROTO_BYTES = 3,
- /* Max length of messages */
- EC_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE +
+ /* Max length of messages for proto 2*/
+ EC_PROTO2_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE +
EC_MSG_TX_PROTO_BYTES,
+
+ EC_MAX_MSG_BYTES = 64 * 1024,
};
/*
--
2.31.0.rc2.261.g7f71774620-goog
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PATCH] platform/chrome: cros_ec_dev - Fix security issue
2021-03-17 23:55 [PATCH] platform/chrome: cros_ec_dev - Fix security issue Gwendal Grignou
@ 2021-03-18 5:51 ` Greg KH
2021-03-18 7:54 ` Lee Jones
1 sibling, 0 replies; 8+ messages in thread
From: Greg KH @ 2021-03-18 5:51 UTC (permalink / raw)
To: Gwendal Grignou; +Cc: lee.jones, stable, Olof Johansson
On Wed, Mar 17, 2021 at 04:55:22PM -0700, Gwendal Grignou wrote:
> commit 5d749d0bbe811c10d9048cde6dfebc761713abfd upstream.
>
> Prevent memory scribble by checking that ioctl buffer size parameters
> are sane.
> Without this check, on 32 bits system, if .insize = 0xffffffff - 20 and
> .outsize the amount to scribble, we would overflow, allocate a small
> amounts and be able to write outside of the malloc'ed area.
> Adding a hard limit allows argument checking of the ioctl. With the
> current EC, it is expected .insize and .outsize to be at around 512 bytes
> or less.
>
> Signed-off-by: Olof Johansson <olof@lixom.net>
> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> ---
> drivers/platform/chrome/cros_ec_dev.c | 4 ++++
> drivers/platform/chrome/cros_ec_proto.c | 4 ++--
> include/linux/mfd/cros_ec.h | 6 ++++--
> 3 files changed, 10 insertions(+), 4 deletions(-)
What stable tree(s) are you wanting this to be applied to?
Always give us a hint...
thanks,
greg k-h
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] platform/chrome: cros_ec_dev - Fix security issue
2021-03-17 23:55 [PATCH] platform/chrome: cros_ec_dev - Fix security issue Gwendal Grignou
2021-03-18 5:51 ` Greg KH
@ 2021-03-18 7:54 ` Lee Jones
2021-03-18 8:09 ` Greg KH
1 sibling, 1 reply; 8+ messages in thread
From: Lee Jones @ 2021-03-18 7:54 UTC (permalink / raw)
To: Gwendal Grignou; +Cc: stable, Olof Johansson
On Wed, 17 Mar 2021, Gwendal Grignou wrote:
> commit 5d749d0bbe811c10d9048cde6dfebc761713abfd upstream.
>
> Prevent memory scribble by checking that ioctl buffer size parameters
> are sane.
> Without this check, on 32 bits system, if .insize = 0xffffffff - 20 and
> .outsize the amount to scribble, we would overflow, allocate a small
> amounts and be able to write outside of the malloc'ed area.
> Adding a hard limit allows argument checking of the ioctl. With the
> current EC, it is expected .insize and .outsize to be at around 512 bytes
> or less.
>
> Signed-off-by: Olof Johansson <olof@lixom.net>
> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> ---
> drivers/platform/chrome/cros_ec_dev.c | 4 ++++
> drivers/platform/chrome/cros_ec_proto.c | 4 ++--
> include/linux/mfd/cros_ec.h | 6 ++++--
> 3 files changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c
> index 2b331d5b9e799..e16d82bb36a9d 100644
> --- a/drivers/platform/chrome/cros_ec_dev.c
> +++ b/drivers/platform/chrome/cros_ec_dev.c
> @@ -137,6 +137,10 @@ static long ec_device_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg)
> if (copy_from_user(&u_cmd, arg, sizeof(u_cmd)))
> return -EFAULT;
>
> + if ((u_cmd.outsize > EC_MAX_MSG_BYTES) ||
> + (u_cmd.insize > EC_MAX_MSG_BYTES))
> + return -EINVAL;
> +
> s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize),
> GFP_KERNEL);
> if (!s_cmd)
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> index 5c285f2b3a650..d20190c8f0c06 100644
> --- a/drivers/platform/chrome/cros_ec_proto.c
> +++ b/drivers/platform/chrome/cros_ec_proto.c
> @@ -311,8 +311,8 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
> ec_dev->max_response = EC_PROTO2_MAX_PARAM_SIZE;
> ec_dev->max_passthru = 0;
> ec_dev->pkt_xfer = NULL;
> - ec_dev->din_size = EC_MSG_BYTES;
> - ec_dev->dout_size = EC_MSG_BYTES;
> + ec_dev->din_size = EC_PROTO2_MSG_BYTES;
> + ec_dev->dout_size = EC_PROTO2_MSG_BYTES;
> } else {
> /*
> * It's possible for a test to occur too early when
> diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
> index 3ab3cede28eac..93c14e9df6309 100644
> --- a/include/linux/mfd/cros_ec.h
> +++ b/include/linux/mfd/cros_ec.h
> @@ -50,9 +50,11 @@ enum {
> EC_MSG_TX_TRAILER_BYTES,
> EC_MSG_RX_PROTO_BYTES = 3,
>
> - /* Max length of messages */
> - EC_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE +
> + /* Max length of messages for proto 2*/
> + EC_PROTO2_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE +
> EC_MSG_TX_PROTO_BYTES,
Nit: Better to not tab the '=' so far and place it all on one line.
Checkpatch now only complains about lines exceeding 100 chars.
Once fixed, feel free to apply my:
Acked-by: Lee Jones <lee.jones@linaro.org>
> +
> + EC_MAX_MSG_BYTES = 64 * 1024,
> };
>
> /*
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] platform/chrome: cros_ec_dev - Fix security issue
2021-03-18 7:54 ` Lee Jones
@ 2021-03-18 8:09 ` Greg KH
2021-03-18 8:20 ` Lee Jones
0 siblings, 1 reply; 8+ messages in thread
From: Greg KH @ 2021-03-18 8:09 UTC (permalink / raw)
To: Lee Jones; +Cc: Gwendal Grignou, stable, Olof Johansson
On Thu, Mar 18, 2021 at 07:54:43AM +0000, Lee Jones wrote:
> On Wed, 17 Mar 2021, Gwendal Grignou wrote:
>
> > commit 5d749d0bbe811c10d9048cde6dfebc761713abfd upstream.
> >
> > Prevent memory scribble by checking that ioctl buffer size parameters
> > are sane.
> > Without this check, on 32 bits system, if .insize = 0xffffffff - 20 and
> > .outsize the amount to scribble, we would overflow, allocate a small
> > amounts and be able to write outside of the malloc'ed area.
> > Adding a hard limit allows argument checking of the ioctl. With the
> > current EC, it is expected .insize and .outsize to be at around 512 bytes
> > or less.
> >
> > Signed-off-by: Olof Johansson <olof@lixom.net>
> > Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> > ---
> > drivers/platform/chrome/cros_ec_dev.c | 4 ++++
> > drivers/platform/chrome/cros_ec_proto.c | 4 ++--
> > include/linux/mfd/cros_ec.h | 6 ++++--
> > 3 files changed, 10 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c
> > index 2b331d5b9e799..e16d82bb36a9d 100644
> > --- a/drivers/platform/chrome/cros_ec_dev.c
> > +++ b/drivers/platform/chrome/cros_ec_dev.c
> > @@ -137,6 +137,10 @@ static long ec_device_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg)
> > if (copy_from_user(&u_cmd, arg, sizeof(u_cmd)))
> > return -EFAULT;
> >
> > + if ((u_cmd.outsize > EC_MAX_MSG_BYTES) ||
> > + (u_cmd.insize > EC_MAX_MSG_BYTES))
> > + return -EINVAL;
> > +
> > s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize),
> > GFP_KERNEL);
> > if (!s_cmd)
> > diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> > index 5c285f2b3a650..d20190c8f0c06 100644
> > --- a/drivers/platform/chrome/cros_ec_proto.c
> > +++ b/drivers/platform/chrome/cros_ec_proto.c
> > @@ -311,8 +311,8 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
> > ec_dev->max_response = EC_PROTO2_MAX_PARAM_SIZE;
> > ec_dev->max_passthru = 0;
> > ec_dev->pkt_xfer = NULL;
> > - ec_dev->din_size = EC_MSG_BYTES;
> > - ec_dev->dout_size = EC_MSG_BYTES;
> > + ec_dev->din_size = EC_PROTO2_MSG_BYTES;
> > + ec_dev->dout_size = EC_PROTO2_MSG_BYTES;
> > } else {
> > /*
> > * It's possible for a test to occur too early when
> > diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
> > index 3ab3cede28eac..93c14e9df6309 100644
> > --- a/include/linux/mfd/cros_ec.h
> > +++ b/include/linux/mfd/cros_ec.h
> > @@ -50,9 +50,11 @@ enum {
> > EC_MSG_TX_TRAILER_BYTES,
> > EC_MSG_RX_PROTO_BYTES = 3,
> >
> > - /* Max length of messages */
> > - EC_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE +
> > + /* Max length of messages for proto 2*/
> > + EC_PROTO2_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE +
> > EC_MSG_TX_PROTO_BYTES,
>
> Nit: Better to not tab the '=' so far and place it all on one line.
>
> Checkpatch now only complains about lines exceeding 100 chars.
>
> Once fixed, feel free to apply my:
>
> Acked-by: Lee Jones <lee.jones@linaro.org>
This commit is already in 4.7, and is from 2016, so I don't know why you
are reviewing it :)
thanks,
greg k-h
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] platform/chrome: cros_ec_dev - Fix security issue
2021-03-18 8:09 ` Greg KH
@ 2021-03-18 8:20 ` Lee Jones
2021-03-18 18:08 ` Gwendal Grignou
0 siblings, 1 reply; 8+ messages in thread
From: Lee Jones @ 2021-03-18 8:20 UTC (permalink / raw)
To: Greg KH; +Cc: Gwendal Grignou, stable, Olof Johansson
On Thu, 18 Mar 2021, Greg KH wrote:
> On Thu, Mar 18, 2021 at 07:54:43AM +0000, Lee Jones wrote:
> > On Wed, 17 Mar 2021, Gwendal Grignou wrote:
> >
> > > commit 5d749d0bbe811c10d9048cde6dfebc761713abfd upstream.
> > >
> > > Prevent memory scribble by checking that ioctl buffer size parameters
> > > are sane.
> > > Without this check, on 32 bits system, if .insize = 0xffffffff - 20 and
> > > .outsize the amount to scribble, we would overflow, allocate a small
> > > amounts and be able to write outside of the malloc'ed area.
> > > Adding a hard limit allows argument checking of the ioctl. With the
> > > current EC, it is expected .insize and .outsize to be at around 512 bytes
> > > or less.
> > >
> > > Signed-off-by: Olof Johansson <olof@lixom.net>
> > > Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> > > ---
> > > drivers/platform/chrome/cros_ec_dev.c | 4 ++++
> > > drivers/platform/chrome/cros_ec_proto.c | 4 ++--
> > > include/linux/mfd/cros_ec.h | 6 ++++--
> > > 3 files changed, 10 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c
> > > index 2b331d5b9e799..e16d82bb36a9d 100644
> > > --- a/drivers/platform/chrome/cros_ec_dev.c
> > > +++ b/drivers/platform/chrome/cros_ec_dev.c
> > > @@ -137,6 +137,10 @@ static long ec_device_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg)
> > > if (copy_from_user(&u_cmd, arg, sizeof(u_cmd)))
> > > return -EFAULT;
> > >
> > > + if ((u_cmd.outsize > EC_MAX_MSG_BYTES) ||
> > > + (u_cmd.insize > EC_MAX_MSG_BYTES))
> > > + return -EINVAL;
> > > +
> > > s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize),
> > > GFP_KERNEL);
> > > if (!s_cmd)
> > > diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> > > index 5c285f2b3a650..d20190c8f0c06 100644
> > > --- a/drivers/platform/chrome/cros_ec_proto.c
> > > +++ b/drivers/platform/chrome/cros_ec_proto.c
> > > @@ -311,8 +311,8 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
> > > ec_dev->max_response = EC_PROTO2_MAX_PARAM_SIZE;
> > > ec_dev->max_passthru = 0;
> > > ec_dev->pkt_xfer = NULL;
> > > - ec_dev->din_size = EC_MSG_BYTES;
> > > - ec_dev->dout_size = EC_MSG_BYTES;
> > > + ec_dev->din_size = EC_PROTO2_MSG_BYTES;
> > > + ec_dev->dout_size = EC_PROTO2_MSG_BYTES;
> > > } else {
> > > /*
> > > * It's possible for a test to occur too early when
> > > diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
> > > index 3ab3cede28eac..93c14e9df6309 100644
> > > --- a/include/linux/mfd/cros_ec.h
> > > +++ b/include/linux/mfd/cros_ec.h
> > > @@ -50,9 +50,11 @@ enum {
> > > EC_MSG_TX_TRAILER_BYTES,
> > > EC_MSG_RX_PROTO_BYTES = 3,
> > >
> > > - /* Max length of messages */
> > > - EC_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE +
> > > + /* Max length of messages for proto 2*/
> > > + EC_PROTO2_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE +
> > > EC_MSG_TX_PROTO_BYTES,
> >
> > Nit: Better to not tab the '=' so far and place it all on one line.
> >
> > Checkpatch now only complains about lines exceeding 100 chars.
> >
> > Once fixed, feel free to apply my:
> >
> > Acked-by: Lee Jones <lee.jones@linaro.org>
>
> This commit is already in 4.7, and is from 2016, so I don't know why you
> are reviewing it :)
Heh! It looked like a standard patch at first glance.
Must have skipped over the "commit" line in the commit log.
I wonder why it doesn't have my Ack on it already then?
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] platform/chrome: cros_ec_dev - Fix security issue
2021-03-18 8:20 ` Lee Jones
@ 2021-03-18 18:08 ` Gwendal Grignou
0 siblings, 0 replies; 8+ messages in thread
From: Gwendal Grignou @ 2021-03-18 18:08 UTC (permalink / raw)
To: Lee Jones; +Cc: Greg KH, stable, Olof Johansson
On Thu, Mar 18, 2021 at 1:20 AM Lee Jones <lee.jones@linaro.org> wrote:
>
> On Thu, 18 Mar 2021, Greg KH wrote:
>
> > On Thu, Mar 18, 2021 at 07:54:43AM +0000, Lee Jones wrote:
> > > On Wed, 17 Mar 2021, Gwendal Grignou wrote:
> > >
> > > > commit 5d749d0bbe811c10d9048cde6dfebc761713abfd upstream.
> > > >
> > > > Prevent memory scribble by checking that ioctl buffer size parameters
> > > > are sane.
> > > > Without this check, on 32 bits system, if .insize = 0xffffffff - 20 and
> > > > .outsize the amount to scribble, we would overflow, allocate a small
> > > > amounts and be able to write outside of the malloc'ed area.
> > > > Adding a hard limit allows argument checking of the ioctl. With the
> > > > current EC, it is expected .insize and .outsize to be at around 512 bytes
> > > > or less.
> > > >
> > > > Signed-off-by: Olof Johansson <olof@lixom.net>
> > > > Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> > > > ---
> > > > drivers/platform/chrome/cros_ec_dev.c | 4 ++++
> > > > drivers/platform/chrome/cros_ec_proto.c | 4 ++--
> > > > include/linux/mfd/cros_ec.h | 6 ++++--
> > > > 3 files changed, 10 insertions(+), 4 deletions(-)
> > > >
> > > > diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c
> > > > index 2b331d5b9e799..e16d82bb36a9d 100644
> > > > --- a/drivers/platform/chrome/cros_ec_dev.c
> > > > +++ b/drivers/platform/chrome/cros_ec_dev.c
> > > > @@ -137,6 +137,10 @@ static long ec_device_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg)
> > > > if (copy_from_user(&u_cmd, arg, sizeof(u_cmd)))
> > > > return -EFAULT;
> > > >
> > > > + if ((u_cmd.outsize > EC_MAX_MSG_BYTES) ||
> > > > + (u_cmd.insize > EC_MAX_MSG_BYTES))
> > > > + return -EINVAL;
> > > > +
> > > > s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize),
> > > > GFP_KERNEL);
> > > > if (!s_cmd)
> > > > diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> > > > index 5c285f2b3a650..d20190c8f0c06 100644
> > > > --- a/drivers/platform/chrome/cros_ec_proto.c
> > > > +++ b/drivers/platform/chrome/cros_ec_proto.c
> > > > @@ -311,8 +311,8 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
> > > > ec_dev->max_response = EC_PROTO2_MAX_PARAM_SIZE;
> > > > ec_dev->max_passthru = 0;
> > > > ec_dev->pkt_xfer = NULL;
> > > > - ec_dev->din_size = EC_MSG_BYTES;
> > > > - ec_dev->dout_size = EC_MSG_BYTES;
> > > > + ec_dev->din_size = EC_PROTO2_MSG_BYTES;
> > > > + ec_dev->dout_size = EC_PROTO2_MSG_BYTES;
> > > > } else {
> > > > /*
> > > > * It's possible for a test to occur too early when
> > > > diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
> > > > index 3ab3cede28eac..93c14e9df6309 100644
> > > > --- a/include/linux/mfd/cros_ec.h
> > > > +++ b/include/linux/mfd/cros_ec.h
> > > > @@ -50,9 +50,11 @@ enum {
> > > > EC_MSG_TX_TRAILER_BYTES,
> > > > EC_MSG_RX_PROTO_BYTES = 3,
> > > >
> > > > - /* Max length of messages */
> > > > - EC_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE +
> > > > + /* Max length of messages for proto 2*/
> > > > + EC_PROTO2_MSG_BYTES = EC_PROTO2_MAX_PARAM_SIZE +
> > > > EC_MSG_TX_PROTO_BYTES,
> > >
> > > Nit: Better to not tab the '=' so far and place it all on one line.
> > >
> > > Checkpatch now only complains about lines exceeding 100 chars.
> > >
> > > Once fixed, feel free to apply my:
> > >
> > > Acked-by: Lee Jones <lee.jones@linaro.org>
> >
> > This commit is already in 4.7, and is from 2016, so I don't know why you
> > are reviewing it :)
My mistake, I overlooked the branch information is removed when
formatting a patch: it is for branch linux-4.4.y in linux stable git
tree.
>
> Heh! It looked like a standard patch at first glance.
>
> Must have skipped over the "commit" line in the commit log.
>
> I wonder why it doesn't have my Ack on it already then?
You were not in the loop on the original thread:
https://lkml.org/lkml/2016/3/8/628
Sorry about that,
Gwendal.
>
> --
> Lee Jones [李琼斯]
> Senior Technical Lead - Developer Services
> Linaro.org │ Open source software for Arm SoCs
> Follow Linaro: Facebook | Twitter | Blog
^ permalink raw reply [flat|nested] 8+ messages in thread
* Security hole in cros_ec_dev.c on 32bit chrome hosts
@ 2016-03-01 20:33 Alan Cox
2016-03-03 5:58 ` [PATCH] platform/chrome: cros_ec_dev - Fix security issue Gwendal Grignou
0 siblings, 1 reply; 8+ messages in thread
From: Alan Cox @ 2016-03-01 20:33 UTC (permalink / raw)
To: linux-kernel, gwendal, javier.martinez
This was reported to Google on Feb 2nd with no action but an
acknowledgement.
Making public since so as we are close to release
/* Ioctls */
static long ec_device_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg)
{
long ret;
struct cros_ec_command u_cmd;
struct cros_ec_command *s_cmd;
if (copy_from_user(&u_cmd, arg, sizeof(u_cmd)))
return -EFAULT;
s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize),
GFP_KERNEL);
Pass u_cmd.insize as a very large value so that it overflows with the
sizeof to a small number which we kmalloc
if (!s_cmd)
return -ENOMEM;
and copy u_cmd.outsize bytes into it.
if (copy_from_user(s_cmd, arg, sizeof(*s_cmd) + u_cmd.outsize)) {
ret = -EFAULT;
goto exit;
}
Alan
^ permalink raw reply [flat|nested] 8+ messages in thread* [PATCH] platform/chrome: cros_ec_dev - Fix security issue
2016-03-01 20:33 Security hole in cros_ec_dev.c on 32bit chrome hosts Alan Cox
@ 2016-03-03 5:58 ` Gwendal Grignou
2016-03-03 18:35 ` Randy Dunlap
0 siblings, 1 reply; 8+ messages in thread
From: Gwendal Grignou @ 2016-03-03 5:58 UTC (permalink / raw)
To: olofj, alan, javier.martinez; +Cc: linux-kernel
Add a check to prevent memory scribbe when sending an ioctl with .insize
set so large that memory allocation argument overflows.
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
---
drivers/platform/chrome/cros_ec_dev.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c
index d45cd25..86d6373 100644
--- a/drivers/platform/chrome/cros_ec_dev.c
+++ b/drivers/platform/chrome/cros_ec_dev.c
@@ -131,13 +131,23 @@ static ssize_t ec_device_read(struct file *filp, char __user *buffer,
static long ec_device_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg)
{
long ret;
+ size_t data_size;
struct cros_ec_command u_cmd;
struct cros_ec_command *s_cmd;
if (copy_from_user(&u_cmd, arg, sizeof(u_cmd)))
return -EFAULT;
- s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize),
+ /*
+ * Prevent mallicious attack where .inside is so big that amount
+ * kmalloc'ed rollover, allowing memcpy to write beyond the allocated
+ * space.
+ */
+ data_size = max(u_cmd.outsize, u_cmd.insize);
+ if (data_size + sizeof(*s_cmd) < data_size)
+ return -EINVAL;
+
+ s_cmd = kmalloc(sizeof(*s_cmd) + data_size,
GFP_KERNEL);
if (!s_cmd)
return -ENOMEM;
--
2.7.0.rc3.207.g0ac5344
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PATCH] platform/chrome: cros_ec_dev - Fix security issue
2016-03-03 5:58 ` [PATCH] platform/chrome: cros_ec_dev - Fix security issue Gwendal Grignou
@ 2016-03-03 18:35 ` Randy Dunlap
0 siblings, 0 replies; 8+ messages in thread
From: Randy Dunlap @ 2016-03-03 18:35 UTC (permalink / raw)
To: Gwendal Grignou, olofj, alan, javier.martinez; +Cc: linux-kernel
On 03/02/16 21:58, Gwendal Grignou wrote:
> Add a check to prevent memory scribbe when sending an ioctl with .insize
scribble
> set so large that memory allocation argument overflows.
>
> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> ---
> drivers/platform/chrome/cros_ec_dev.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c
> index d45cd25..86d6373 100644
> --- a/drivers/platform/chrome/cros_ec_dev.c
> +++ b/drivers/platform/chrome/cros_ec_dev.c
> @@ -131,13 +131,23 @@ static ssize_t ec_device_read(struct file *filp, char __user *buffer,
> static long ec_device_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg)
> {
> long ret;
> + size_t data_size;
> struct cros_ec_command u_cmd;
> struct cros_ec_command *s_cmd;
>
> if (copy_from_user(&u_cmd, arg, sizeof(u_cmd)))
> return -EFAULT;
>
> - s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize),
> + /*
> + * Prevent mallicious attack where .inside is so big that amount
malicious .insize
> + * kmalloc'ed rollover, allowing memcpy to write beyond the allocated
> + * space.
> + */
> + data_size = max(u_cmd.outsize, u_cmd.insize);
> + if (data_size + sizeof(*s_cmd) < data_size)
> + return -EINVAL;
> +
> + s_cmd = kmalloc(sizeof(*s_cmd) + data_size,
> GFP_KERNEL);
> if (!s_cmd)
> return -ENOMEM;
>
--
~Randy
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2021-03-18 18:09 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2021-03-17 23:55 [PATCH] platform/chrome: cros_ec_dev - Fix security issue Gwendal Grignou
2021-03-18 5:51 ` Greg KH
2021-03-18 7:54 ` Lee Jones
2021-03-18 8:09 ` Greg KH
2021-03-18 8:20 ` Lee Jones
2021-03-18 18:08 ` Gwendal Grignou
-- strict thread matches above, loose matches on Subject: below --
2016-03-01 20:33 Security hole in cros_ec_dev.c on 32bit chrome hosts Alan Cox
2016-03-03 5:58 ` [PATCH] platform/chrome: cros_ec_dev - Fix security issue Gwendal Grignou
2016-03-03 18:35 ` Randy Dunlap
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