On Sat, May 26, 2018 at 9:22 AM, Eric Biggers <ebiggers3@xxxxxxxxx> wrote: > On Sat, May 12, 2018 at 10:43:08AM +0200, Dmitry Vyukov wrote: >> On Fri, Feb 2, 2018 at 11:18 PM, Eric Biggers <ebiggers3@xxxxxxxxx> wrote: >> > On Fri, Feb 02, 2018 at 02:57:32PM +0100, Dmitry Vyukov wrote: >> >> On Fri, Feb 2, 2018 at 2:48 PM, syzbot >> >> <syzbot+ffa3a158337bbc01ff09@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: >> >> > Hello, >> >> > >> >> > syzbot hit the following crash on upstream commit >> >> > 7109a04eae81c41ed529da9f3c48c3655ccea741 (Thu Feb 1 17:37:30 2018 +0000) >> >> > Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide >> >> > >> >> > So far this crash happened 4 times on net-next, upstream. >> >> > C reproducer is attached. >> >> > syzkaller reproducer is attached. >> >> > Raw console output is attached. >> >> > compiler: gcc (GCC) 7.1.1 20170620 >> >> > .config is attached. >> >> >> >> >> >> From suspicious frames I see salsa20_asm_crypt there, so +crypto maintainers. >> >> >> > >> > Looks like the x86 implementations of Salsa20 (both i586 and x86_64) need to be >> > updated to not use %ebp/%rbp. >> >> Ard, >> >> This was bisected as introduced by: >> >> commit 83dee2ce1ae791c3dc0c9d4d3a8d42cb109613f6 >> Author: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> >> Date: Fri Jan 19 12:04:34 2018 +0000 >> >> crypto: sha3-generic - rewrite KECCAK transform to help the >> compiler optimize >> >> https://gist.githubusercontent.com/dvyukov/47f93f5a0679170dddf93bc019b42f6d/raw/65beac8ddd30003bbd4e9729236dc8572094abf7/gistfile1.txt > > Note that syzbot's original C reproducer (from Feb 1) for this actually > triggered the warning through salsa20-asm, which I've just proposed to "fix" by > https://patchwork.kernel.org/patch/10428863/. sha3-generic is apparently > another instance of the same bug, where the %rbp register is used for data. Mailed "crypto: don't optimize keccakf()" to fix this. Amusingly __optimize("O3") always lead to degraded performance as gcc does not inline across different optimizations levels, so keccakf() wasn't inlined into its callers and keccakf_round() wasn't inlined into keccakf().
