Messages in this thread | | | Date | Wed, 8 Jun 2022 09:40:24 +0200 | Subject | Re: [PATCH 16/36] tty/vt: consolemap: check put_user() in con_get_unimap() | From | Jiri Slaby <> |
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On 07. 06. 22, 16:19, Ilpo Järvinen wrote: > On Tue, 7 Jun 2022, Jiri Slaby wrote: > >> Only the return value of copy_to_user() is checked in con_get_unimap(). >> Do the same for put_user() of the count too. >> >> Signed-off-by: Jiri Slaby <jslaby@suse.cz> >> --- >> drivers/tty/vt/consolemap.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/tty/vt/consolemap.c b/drivers/tty/vt/consolemap.c >> index 831450f2bfd1..92b5dddb00d9 100644 >> --- a/drivers/tty/vt/consolemap.c >> +++ b/drivers/tty/vt/consolemap.c >> @@ -813,7 +813,8 @@ int con_get_unimap(struct vc_data *vc, ushort ct, ushort __user *uct, >> console_unlock(); >> if (copy_to_user(list, unilist, min(ect, ct) * sizeof(*unilist))) >> ret = -EFAULT; >> - put_user(ect, uct); >> + if (put_user(ect, uct)) >> + ret = -EFAULT; >> kvfree(unilist); >> return ret ? ret : (ect <= ct) ? 0 : -ENOMEM; >> } >> > > Doesn't this fix something?
If you mean a Fixes tag, this is pre-git.
If you mean a bug, well, likely yes, users now get informed. But I don't think anyone cares ;). But who knows, maybe we will start seeing userspace failures now (as they might not provide writable count field -- unlikely). That's one of the reasons why I did this as a separate commit. Let's see if are going to revert this or not...
thanks, -- js suse labs
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