Messages in this thread | | | Date | Sat, 6 Nov 2021 23:48:30 +0300 | Subject | Re: [PATCH] tty: vt: keyboard: do not copy an extra-byte in copy_to_user | From | Pavel Skripkin <> |
| |
On 11/6/21 23:44, Ajay Garg wrote: >> > >> > That's the whole point of the discussion :) >> > >> > The method "vt_do_kdgkb_ioctl" does not manage "func_table[kb_func]". >> > Thus, the method does not know whether or not >> > strlen(func_table[kb_func]) < sizeof(user_kdgkb->kb_string). >> > >> >> It manages. The code under `case KDSKBSENT:` sets func_table[] entries >> via vt_kdskbsent(). >> >> kbs = strndup_user(..., sizeof(user_kdgkb->kb_string)); >> >> is used to allocate buffer for the func_table[] entry. That's my main >> point :) > > func_table is set in vt_kdskbent, which itself is external. > > More importantly, vt_kdskbent is handled in case KDSKBSENT:, while the > strlcpy issue we are dealing with is in case KDGKBSENT: > In case KDGKBSENT, following are managed : > > ssize_t len = sizeof(user_kdgkb->kb_string); > kbs = kmalloc(len, GFP_KERNEL); > > while func_table[kb_func] is external entity here, so no assumption > ought to be made for it, just my 2 cents though :) > > Anyhow, really, it is the maintainers' choice now :), since there > isn't a burning (compilation/runtime) issue. >
I fully agree here, it's maintainer's choice. Let's sit down and wait what experienced people thing about this :)
I've just wanted to explain my idea better to exclude possible misunderstanding.
Thanks
With regards, Pavel Skripkin
| |