Re: [syzbot] [bcachefs] KASAN: slab-out-of-bounds Read in poly1305_update_arch

Subject: Re: [syzbot] [bcachefs] KASAN: slab-out-of-bounds Read in poly1305_update_arch
From: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Date: Sat, 19 Jul 2025 17:57:20 -0400
Cc: bp@xxxxxxxxx, dave.hansen@xxxxxxxxxxxxxxx, davem@xxxxxxxxxxxxx, herbert@xxxxxxxxxxxxxxxxxxx, hpa@xxxxxxxxx, linux-bcachefs@xxxxxxxxxxxxxxx, linux-crypto@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, mingo@xxxxxxxxxx, mmpgouride@xxxxxxxxx, syzkaller-bugs@xxxxxxxxxxxxxxxx, tglx@xxxxxxxxxxxxx, x86@xxxxxxxxxx
In-reply-to: <686415f3.a70a0220.3b7e22.1ec0.GAE@google.com>
References: <000000000000d62d530617ca4c33@google.com> <686415f3.a70a0220.3b7e22.1ec0.GAE@google.com>

#syz fix: bcachefs: Move bset size check before csum check

References:
- [syzbot] [crypto?] KASAN: slab-out-of-bounds Read in poly1305_update_arch
  - From: syzbot
- Re: [syzbot] [bcachefs] KASAN: slab-out-of-bounds Read in poly1305_update_arch
  - From: syzbot