Re: [PATCH v2] tty: vt: keyboard: initialize "kbs" so that kfree(kbs) runs fine even if kbs is not kmalloced.

On 11/6/21 15:16, Ajay Garg wrote:

Hi Pavel,

Thanks for the review.

quoted

Please, don't put change log into commit message. It should go under ---

Ok, many thanks Pavel.
Will take care in all my future patches.

quoted

These is only one caller of vt_do_kdgkb_ioctl, which simple does:


        case KDGKBSENT:
        case KDSKBSENT:
                return vt_do_kdgkb_ioctl(cmd, up, perm);

It means, that cmd can not be different from KDGKBSENT and KDSKBSENT.

I guess, you found this "issue" via static analysis tool like smatch or
smth similar, but this bug is impossible right now.

Yes, following was reported by smatch (amongst others) :
vt_do_kdgkb_ioctl() error: uninitialized symbol 'kbs'.


Regarding the current state, "vt_do_kdgkb_ioctl" should ideally behave
correctly independently, without bothering whether a cmd is a valid
one. From that perspective, it makes sense to ensure that kfree never
crashes.

However, I don't have any strong opinions on what is right or what is
wrong, as long as things work fine.

So, if there is a general consensus that the change should not be made
currently, I would be ok.
In case the change should be made, kindly let me know, I will post the
v3 patch (making change as per the review-comment of moving changelog
below ---).

I can't say if it needed or not, since I am not the maintainer. I've 
just said my thoughts on this change. It looks like you missed all 
maintainers emails in your CC list :)

└──$ ./scripts/get_maintainer.pl -f drivers/tty/vt/keyboard.c
Greg Kroah-Hartman [off-list ref] (supporter:TTY 
LAYER,commit_signer:10/10=100%,authored:2/10=20%,added_lines:31/66=47%,removed_lines:31/59=53%)
Jiri Slaby [off-list ref] (supporter:TTY 
LAYER,commit_signer:6/10=60%,authored:3/10=30%,added_lines:14/66=21%,removed_lines:4/59=7%)
Andy Shevchenko [off-list ref] 
(commit_signer:4/10=40%,authored:4/10=40%,added_lines:18/66=27%,removed_lines:21/59=36%)
Emil Renner Berthing [off-list ref] 
(commit_signer:1/10=10%,authored:1/10=10%,removed_lines:3/59=5%)
linux-kernel@vger.kernel.org (open list)


This is the list of people you need to send patches to. Please, use this 
script next time to not miss people related to your change :)


The same for your other patch.



With regards,
Pavel Skripkin