Re: [syzbot] [crypto?] general protection fault in xxh64_update

Eric Biggers
2025-09-08T18:47:21Z

On Mon, Sep 08, 2025 at 04:26:27AM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 4ac65880ebca Add linux-next specific files for 20250904
> git tree: linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=12951312580000
> kernel config: https://syzkaller.appspot.com/x/.config?x=fbc16d9faf3a88a4
> dashboard link: https://syzkaller.appspot.com/bug?extid=14c6a89d5f47cd26ea7a
> compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16951312580000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10b8e962580000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/36645a51612c/disk-4ac65880.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/bba80d634bef/vmlinux-4ac65880.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/e58dd70dfd0f/bzImage-4ac65880.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+14c6a89d5f47cd26ea7a@syzkaller.appspotmail.com
>
> Oops: general protection fault, probably for non-canonical address 0xe0009d1000000000: 0000 [#1] SMP KASAN PTI
> KASAN: maybe wild-memory-access in range [0x0005088000000000-0x0005088000000007]
> CPU: 0 UID: 0 PID: 6069 Comm: syz.0.32 Not tainted syzkaller #0 PREEMPT(full)
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
> RIP: 0010:get_unaligned_le64 include/linux/unaligned.h:28 [inline]
> RIP: 0010:xxh64_update+0x55b/0xcf0 lib/xxhash.c:312

Bug in mm/gup.c that reached linux-next but has already been fixed.

#syz dup: KASAN: null-ptr-deref Read in io_sqe_buffer_register

- Eric