On Fri, 2016-03-04 at 16:42 -0800, David Decotigny wrote:
> From: David Decotigny <de...@googlers.com>
>
> Tested:
> On qemu e1000:
> $ dd if=/dev/zero bs=2 count=5 | /mnt/ethtool -E eth0 length 9
> too much data from stdin
> $ dd if=/dev/zero bs=2 count=5 | /mnt/ethtool -E eth0 length 11
> not enough data from stdin
> $ dd if=/dev/zero bs=2 count=5 | /mnt/ethtool -E eth0 length 10
> Cannot set EEPROM data: Bad address
>
>
> Signed-off-by: David Decotigny <de...@googlers.com>
> ---
> ethtool.c | 24 ++++++++++++++++++++----
> 1 file changed, 20 insertions(+), 4 deletions(-)
>
> diff --git a/ethtool.c b/ethtool.c
> index c64b962..19f479c 100644
> --- a/ethtool.c
> +++ b/ethtool.c
> @@ -2828,8 +2828,14 @@ static int do_seeprom(struct cmd_context *ctx)
> if (seeprom_length == -1)
> seeprom_length = drvinfo.eedump_len;
>
> - if (drvinfo.eedump_len < seeprom_offset + seeprom_length)
> - seeprom_length = drvinfo.eedump_len - seeprom_offset;
> + if (drvinfo.eedump_len < seeprom_offset + seeprom_length) {
> + if (drvinfo.eedump_len > seeprom_offset)
> + seeprom_length = drvinfo.eedump_len - seeprom_offset;
Don't silently truncate - treat this as an error too.
> + else {
> + fprintf(stderr, "offset & length out of bounds\n");
> + return 75;
Use the default error code of 1 rather than making 75 even less
meaningful.
> + }
> + }
>
> eeprom = calloc(1, sizeof(*eeprom)+seeprom_length);
> if (!eeprom) {
> @@ -2844,8 +2850,18 @@ static int do_seeprom(struct cmd_context *ctx)
> eeprom->data[0] = seeprom_value;
>
> /* Multi-byte write: read input from stdin */
> - if (!seeprom_value_seen)
> - eeprom->len = fread(eeprom->data, 1, eeprom->len, stdin);
> + if (!seeprom_value_seen) {
> + if (1 != fread(eeprom->data, eeprom->len, 1, stdin)) {
> + fprintf(stderr, "not enough data from stdin\n");
> + free(eeprom);
> + return 75;
> + }
> + if ((EOF != fgetc(stdin)) || !feof(stdin)) {
Comparisons are the wrong way round.
Ben.
> + fprintf(stderr, "too much data from stdin\n");
> + free(eeprom);
> + return 75;
> + }
> + }
>
> err = send_ioctl(ctx, eeprom);
> if (err < 0) {
--
Ben Hutchings
The most exhausting thing in life is being insincere. - Anne Morrow Lindberg
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