auxv stuff (Re: [PATCH] prctl: fix PR_SET_MM_AUXV kernel stack leak)

[Alexey Dobriyan]

On Sun, Mar 14, 2021 at 02:40:05PM -0700, Linus Torvalds wrote:
> [mm->saved_auxv]
> 
> That's a separate issue, and I can't find it in myself to care (and
> nobody has ever complained), but I thought I'd mention it.

There is another (non-security) one. Compat 32-bit process will report
2 longs too many:

00000000  20 00 00 00 40 85 f5 f7  21 00 00 00 00 80 f5 f7  | ...@...!.......|
00000010  10 00 00 00 ff fb 8b 0f  06 00 00 00 00 10 00 00  |................|
00000020  11 00 00 00 64 00 00 00  03 00 00 00 34 80 04 08  |....d.......4...|
00000030  04 00 00 00 20 00 00 00  05 00 00 00 08 00 00 00  |.... ...........|
00000040  07 00 00 00 00 90 f5 f7  08 00 00 00 00 00 00 00  |................|
00000050  09 00 00 00 25 83 04 08  0b 00 00 00 00 00 00 00  |....%...........|
00000060  0c 00 00 00 00 00 00 00  0d 00 00 00 00 00 00 00  |................|
00000070  0e 00 00 00 00 00 00 00  17 00 00 00 00 00 00 00  |................|
00000080  19 00 00 00 8b 27 99 ff  1a 00 00 00 02 00 00 00  |.....'..........|
00000090  1f 00 00 00 f0 2f 99 ff  0f 00 00 00 9b 27 99 ff  |...../.......'..|
000000a0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
	  AT_NULL     AT_NULL	   ^^^^^^^^^^^^^^^^^^^^^^^
000000b0