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

Alexey Dobriyan
2021-03-15T06:00:55Z

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