Re: [tip:x86/pti] x86/asm: Pad assembly functions with INT3 instructions

[Borislav Petkov]

On Sun, Jun 17, 2018 at 01:40:13PM +0200, Mike Galbraith wrote:
> On Mon, 2018-05-14 at 05:53 -0700, tip-bot for Alexey Dobriyan wrote:
> > Commit-ID:  51bad67ffbce0aaa44579f84ef5d05597054ec6a
> > Gitweb:     https://git.kernel.org/tip/51bad67ffbce0aaa44579f84ef5d05597054ec6a
> > Author:     Alexey Dobriyan <adobriyan@xxxxxxxxx>
> > AuthorDate: Tue, 8 May 2018 00:37:55 +0300
> > Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
> > CommitDate: Mon, 14 May 2018 11:43:03 +0200
> > 
> > x86/asm: Pad assembly functions with INT3 instructions
> > 
> > Use INT3 instead of NOP. All that padding between functions is
> > an illegal area, no legitimate code should jump into it.
> 
> Is dinky patchlet suggesting cryptomgr is being naughty?
> 
> (revert silences spew, but..)
> 
> ...
> [   21.041608] int3: 0000 [#1] SMP PTI
> [   21.041754] CPU: 3 PID: 935 Comm: cryptomgr_test Tainted: G            E     4.17.0.g075a1d3-tip-default #146
> [   21.041888] Hardware name: MEDION MS-7848/MS-7848, BIOS M7848W08.20C 09/23/2013
> [   21.042035] RIP: 0010:crypto_aegis128_aesni_enc_tail+0x74/0x80 [aegis128_aesni]
> [   21.042171] Code: 38 dc ca 66 0f 38 dc d3 66 0f 38 dc de 66 0f ef e5 f3 0f 7f 27 f3 0f 7f 47 10 f3 0f 7f 4f 20 f3 0f 7f 57 30 f3 0f 7f 5f 40 cc <cc> cc cc cc cc cc cc cc cc cc cc cc 48 83 fe 10 0f 82 c3 03 00 00

Looks like it misses a RET:

---