* [PATCH] usbip: tools: fix atoi() on non-null terminated string
@ 2018-10-16 18:03 Colin King
2018-10-25 18:49 ` Shuah Khan
0 siblings, 1 reply; 2+ messages in thread
From: Colin King @ 2018-10-16 18:03 UTC (permalink / raw)
To: Valentina Manea, Shuah Khan, Greg Kroah-Hartman, linux-usb
Cc: kernel-janitors, linux-kernel
From: Colin Ian King <colin.king@canonical.com>
Currently the call to atoi is being passed a single char string
that is not null terminated, so there is a potential read overrun
along the stack when parsing for an integer value. Fix this by
instead using a 2 char string that is initialized to all zeros
to ensure that a 1 char read into the string is always terminated
with a \0.
Detected by cppcheck:
"Invalid atoi() argument nr 1. A nul-terminated string is required."
Fixes: 3391ba0e2792 ("usbip: tools: Extract generic code to be shared with vudc backend")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
tools/usb/usbip/libsrc/usbip_host_common.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/tools/usb/usbip/libsrc/usbip_host_common.c b/tools/usb/usbip/libsrc/usbip_host_common.c
index dc93fadbee96..d79c7581b175 100644
--- a/tools/usb/usbip/libsrc/usbip_host_common.c
+++ b/tools/usb/usbip/libsrc/usbip_host_common.c
@@ -43,7 +43,7 @@ static int32_t read_attr_usbip_status(struct usbip_usb_device *udev)
int size;
int fd;
int length;
- char status;
+ char status[2] = { 0 };
int value = 0;
size = snprintf(status_attr_path, sizeof(status_attr_path),
@@ -61,14 +61,14 @@ static int32_t read_attr_usbip_status(struct usbip_usb_device *udev)
return -1;
}
- length = read(fd, &status, 1);
+ length = read(fd, status, 1);
if (length < 0) {
err("error reading attribute %s", status_attr_path);
close(fd);
return -1;
}
- value = atoi(&status);
+ value = atoi(status);
return value;
}
--
2.19.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] usbip: tools: fix atoi() on non-null terminated string
2018-10-16 18:03 [PATCH] usbip: tools: fix atoi() on non-null terminated string Colin King
@ 2018-10-25 18:49 ` Shuah Khan
0 siblings, 0 replies; 2+ messages in thread
From: Shuah Khan @ 2018-10-25 18:49 UTC (permalink / raw)
To: Colin King, Valentina Manea, Greg Kroah-Hartman, linux-usb
Cc: kernel-janitors, linux-kernel
Hi Colin,
On 10/16/2018 12:03 PM, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> Currently the call to atoi is being passed a single char string
> that is not null terminated, so there is a potential read overrun
> along the stack when parsing for an integer value. Fix this by
> instead using a 2 char string that is initialized to all zeros
> to ensure that a 1 char read into the string is always terminated
> with a \0.
>
> Detected by cppcheck:
> "Invalid atoi() argument nr 1. A nul-terminated string is required."
>
> Fixes: 3391ba0e2792 ("usbip: tools: Extract generic code to be shared with vudc backend")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
> tools/usb/usbip/libsrc/usbip_host_common.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/tools/usb/usbip/libsrc/usbip_host_common.c b/tools/usb/usbip/libsrc/usbip_host_common.c
> index dc93fadbee96..d79c7581b175 100644
> --- a/tools/usb/usbip/libsrc/usbip_host_common.c
> +++ b/tools/usb/usbip/libsrc/usbip_host_common.c
> @@ -43,7 +43,7 @@ static int32_t read_attr_usbip_status(struct usbip_usb_device *udev)
> int size;
> int fd;
> int length;
> - char status;
> + char status[2] = { 0 }> int value = 0;
>
> size = snprintf(status_attr_path, sizeof(status_attr_path),
> @@ -61,14 +61,14 @@ static int32_t read_attr_usbip_status(struct usbip_usb_device *udev)
> return -1;
> }
>
> - length = read(fd, &status, 1);
> + length = read(fd, status, 1);
> if (length < 0) {
> err("error reading attribute %s", status_attr_path);
> close(fd);
> return -1;
> }
>
> - value = atoi(&status);
> + value = atoi(status);
>
> return value;
> }
>
Thanks for the patch. Looks good to me.
Acked-by: Shuah Khan <shuah@kernel.org>
thanks,
-- Shuah
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