Re: KASAN: use-after-free Read in crypto_chacha20_crypt

[Eric Biggers]

On Tue, Nov 28, 2017 at 07:23:01AM -0800, syzbot wrote:
> Hello,
> 
> syzkaller hit the following crash on
> 1ea8d039f9edcfefb20d8ddfe136930f6e551529
> git://git.cmpxchg.org/linux-mmots.git/master
> compiler: gcc (GCC) 7.1.1 20170620
> .config is attached
> Raw console output is attached.
> C reproducer is attached
> syzkaller reproducer is attached. See https://goo.gl/kgGztJ
> for information about syzkaller reproducers
> 
> 
> ==================================================================
> BUG: KASAN: use-after-free in __le32_to_cpup
> include/uapi/linux/byteorder/little_endian.h:58 [inline]
> BUG: KASAN: use-after-free in le32_to_cpuvp crypto/chacha20_generic.c:19
> [inline]
> BUG: KASAN: use-after-free in crypto_chacha20_init
> crypto/chacha20_generic.c:58 [inline]
> BUG: KASAN: use-after-free in crypto_chacha20_crypt+0xaf1/0xbd0
> crypto/chacha20_generic.c:91
> Read of size 4 at addr ffff880100000006 by task syzkaller030711/3690
> 

#syz dup: general protection fault in crypto_chacha20_crypt