[PATCH] usb: gadget: return the right length in ffs_epfile_io()
When the request length is aligned to maxpacketsize, sometimes
the return length ret > the user space requested len.
At that time, we will use min_t(size_t, ret, len) to limit the
size in case of user data buffer overflow.
But we need return the min_t(size_t, ret, len) to tell the user
space rightly also.
Signed-off-by: Chuansheng Liu
---
drivers/usb/gadget/f_fs.c | 10 ++
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
index 2b43343..31ee7af 100644
--- a/drivers/usb/gadget/f_fs.c
+++ b/drivers/usb/gadget/f_fs.c
@@ -687,10 +687,12 @@ static ssize_t ffs_epfile_io(struct file *file,
* space for.
*/
ret = ep->status;
- if (read && ret > 0 &&
- unlikely(copy_to_user(buf, data,
- min_t(size_t, ret, len
- ret = -EFAULT;
+ if (read && ret > 0) {
+ ret = min_t(size_t, ret, len);
+
+ if (unlikely(copy_to_user(buf, data, ret)))
+ ret = -EFAULT;
+ }
}
}
--
1.9.rc0
--
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Re: [PATCH] usb: gadget: return the right length in ffs_epfile_io()
On Thu, Feb 27 2014, Chuansheng Liu wrote:
> When the request length is aligned to maxpacketsize, sometimes
> the return length ret > the user space requested len.
>
> At that time, we will use min_t(size_t, ret, len) to limit the
> size in case of user data buffer overflow.
>
> But we need return the min_t(size_t, ret, len) to tell the user
> space rightly also.
>
> Signed-off-by: Chuansheng Liu
Acked-by: Michal Nazarewicz
> ---
> drivers/usb/gadget/f_fs.c | 10 ++
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
> index 2b43343..31ee7af 100644
> --- a/drivers/usb/gadget/f_fs.c
> +++ b/drivers/usb/gadget/f_fs.c
> @@ -687,10 +687,12 @@ static ssize_t ffs_epfile_io(struct file *file,
>* space for.
>*/
> ret = ep->status;
> - if (read && ret > 0 &&
> - unlikely(copy_to_user(buf, data,
> - min_t(size_t, ret, len
> - ret = -EFAULT;
> + if (read && ret > 0) {
> + ret = min_t(size_t, ret, len);
> +
> + if (unlikely(copy_to_user(buf, data, ret)))
> + ret = -EFAULT;
> + }
> }
> }
>
> --
> 1.9.rc0
>
--
Best regards, _ _
.o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o
..o | Computer Science, Michał “mina86” Nazarewicz(o o)
ooo +--ooO--(_)--Ooo--
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Re: [PATCH] usb: gadget: return the right length in ffs_epfile_io()
On Thu, Feb 27, 2014 at 01:15:25PM +0100, Michal Nazarewicz wrote: > On Thu, Feb 27 2014, Chuansheng Liu wrote: > > When the request length is aligned to maxpacketsize, sometimes > > the return length ret > the user space requested len. > > > > At that time, we will use min_t(size_t, ret, len) to limit the > > size in case of user data buffer overflow. > > > > But we need return the min_t(size_t, ret, len) to tell the user > > space rightly also. > > > > Signed-off-by: Chuansheng Liu > > Acked-by: Michal Nazarewicz Reviewed-by: David Cohen IMHO it makes sense to push this patch to 3.14-rc since it is an extension of usb gadget's quick_ep_out_aligned_size merged on 3.14-rc1 Br, David Cohen -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] usb: gadget: return the right length in ffs_epfile_io()
Hi,
On Thu, Feb 27, 2014 at 02:49:31PM +0800, Chuansheng Liu wrote:
> When the request length is aligned to maxpacketsize, sometimes
> the return length ret > the user space requested len.
>
> At that time, we will use min_t(size_t, ret, len) to limit the
> size in case of user data buffer overflow.
>
> But we need return the min_t(size_t, ret, len) to tell the user
> space rightly also.
>
> Signed-off-by: Chuansheng Liu
> ---
> drivers/usb/gadget/f_fs.c | 10 ++
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
> index 2b43343..31ee7af 100644
> --- a/drivers/usb/gadget/f_fs.c
> +++ b/drivers/usb/gadget/f_fs.c
> @@ -687,10 +687,12 @@ static ssize_t ffs_epfile_io(struct file *file,
>* space for.
>*/
> ret = ep->status;
> - if (read && ret > 0 &&
> - unlikely(copy_to_user(buf, data,
> - min_t(size_t, ret, len
> - ret = -EFAULT;
> + if (read && ret > 0) {
> + ret = min_t(size_t, ret, len);
> +
> + if (unlikely(copy_to_user(buf, data, ret)))
> + ret = -EFAULT;
> + }
please rebase on my "testing/next" branch
--
balbi
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RE: [PATCH] usb: gadget: return the right length in ffs_epfile_io()
Hello Balbi, > -Original Message- > From: Felipe Balbi [mailto:ba...@ti.com] > Sent: Tuesday, March 04, 2014 12:30 AM > To: Liu, Chuansheng > Cc: ba...@ti.com; gre...@linuxfoundation.org; min...@mina86.com; > linux-usb@vger.kernel.org; linux-ker...@vger.kernel.org; Cohen, David A; > Zhuang, Jin Can; Wang, Yu Y > Subject: Re: [PATCH] usb: gadget: return the right length in ffs_epfile_io() > > Hi, > > On Thu, Feb 27, 2014 at 02:49:31PM +0800, Chuansheng Liu wrote: > > When the request length is aligned to maxpacketsize, sometimes > > the return length ret > the user space requested len. > > > > At that time, we will use min_t(size_t, ret, len) to limit the > > size in case of user data buffer overflow. > > > > But we need return the min_t(size_t, ret, len) to tell the user > > space rightly also. > > > > Signed-off-by: Chuansheng Liu > please rebase on my "testing/next" branch Based on your branch "testing/next", I have sent patch v2 with some ack and reviewing, thanks. [PATCH v2] usb: gadget: return the right length in ffs_epfile_io() Best Regards Chuansheng -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
