On Mon, Jan 6, 2014 at 9:25 PM, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: > On Mon, 2014-01-06 at 21:02 +0530, Krishna Chaitanya wrote: >> On Mon, Jan 6, 2014 at 8:45 PM, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: >> > On Mon, 2014-01-06 at 20:35 +0530, Krishna Chaitanya wrote: >> >> On Mon, Jan 6, 2014 at 8:18 PM, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: >> >> > On Sun, 2014-01-05 at 02:36 +0530, Chaitanya T K wrote: >> >> >> This was blocking sending SMPS action frames >> >> >> through debugfs. >> >> > >> >> > I don't see any issue here, explain. >> >> > >> >> > johannes >> >> > >> >> buflen includes the new line character as well, hence the comparison >> >> strncmp fails for all combiantions. >> >> >> >> echo "static" > ieee80211/phyX/netdev\:wlanX/smps >> >> Then >> >> >> >> buf=static\n >> >> buflen=7 >> >> >> >> But the comparison is with "static" which doesn't include "\n" >> >> hence the comparison fails. >> > >> > Err, ok, so you can just do "echo -n static", right? >> > >> > And then your patch breaks the way it currently works, which is about >> > the worst you can do. >> > >> Ok, if one works other fails. >> >> So instead why cant we use strlen(local_string) >> instead of using buflen(remote). That way we can make sure we only >> compare the characters we need and leave out the extra ones. > > It wouldn't fix the problem and would introduce a buffer overflow bug. > We can add some checks to make sure it doesn't overflow, but its not worth it. My intention is as most of the users are familiar with "echo" and not "echo -n", its better to have a solution which works with "echo". Also if we use buflen-1 and give "echo -n" it still works but problem is it compares 1 less character. Anyways either one is fine with me. Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
