[PATCH AUTOSEL 4.19 078/237] usbip: tools: fix atoi() on non-null terminated string

Sasha Levin
2019-11-16T15:42:52Z

From: Colin Ian King <colin.king@canonical.com>

[ Upstream commit e325808c0051b16729ffd472ff887c6cae5c6317 ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 dc93fadbee963..d79c7581b175f 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;
}
--
2.20.1