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Re: [Qemu-devel] [PATCHv3] qdev: Validate hex properties
From: |
Andreas Färber |
Subject: |
Re: [Qemu-devel] [PATCHv3] qdev: Validate hex properties |
Date: |
Thu, 28 Nov 2013 15:09:42 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 |
Am 28.11.2013 09:39, schrieb Hannes Reinecke:
> strtoul(l) might overflow, in which case it'll return '-1' and set
> the appropriate error code. So update the calls to strtoul(l) when
> parsing hex properties to avoid silent overflows.
>
> Signed-off-by: Hannes Reinecke <address@hidden>
> ---
> hw/core/qdev-properties.c | 20 ++++++++++++++++++--
> 1 file changed, 18 insertions(+), 2 deletions(-)
>
> diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
> index dc8ae69..4891a01 100644
> --- a/hw/core/qdev-properties.c
> +++ b/hw/core/qdev-properties.c
> @@ -191,6 +191,7 @@ PropertyInfo qdev_prop_uint8 = {
>
> static int parse_hex8(DeviceState *dev, Property *prop, const char *str)
> {
> + unsigned long val;
> uint8_t *ptr = qdev_get_prop_ptr(dev, prop);
> char *end;
>
> @@ -198,11 +199,18 @@ static int parse_hex8(DeviceState *dev, Property *prop,
> const char *str)
> return -EINVAL;
> }
>
> - *ptr = strtoul(str, &end, 16);
> + errno = 0;
> + val = strtoul(str, &end, 16);
> + if (errno) {
> + return -errno;
> + }
> + if (val > 255) {
> + return -ERANGE;
> + }
> if ((*end != '\0') || (end == str)) {
> return -EINVAL;
> }
> -
> + *ptr = val;
> return 0;
> }
>
This part looks okay to me.
> @@ -329,7 +337,11 @@ static int parse_hex32(DeviceState *dev, Property *prop,
> const char *str)
> return -EINVAL;
> }
>
> + errno = 0;
> *ptr = strtoul(str, &end, 16);
> + if (errno) {
> + return -errno;
> + }
I can image that on a 64-bit system long can be larger than 32 bits, so
we'll need an equivalent val > UINT32_MAX check here, I guess?
> if ((*end != '\0') || (end == str)) {
> return -EINVAL;
> }
> @@ -396,7 +408,11 @@ static int parse_hex64(DeviceState *dev, Property *prop,
> const char *str)
> return -EINVAL;
> }
>
> + errno = 0;
> *ptr = strtoull(str, &end, 16);
> + if (errno) {
> + return -errno;
> + }
> if ((*end != '\0') || (end == str)) {
> return -EINVAL;
> }
Eric, do we have any size guarantee for long long or do we also need a
symmetric if (... > UINT64_MAX) { return -ERANGE; } for the unlikely
128-bit case?
Andreas
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