On 2023-09-07 10:25, Will Deacon wrote:
On Tue, Sep 05, 2023 at 04:02:19PM +0100, Robin Murphy wrote:
On 05/09/2023 3:37 pm, Will Deacon wrote:
On Mon, Aug 28, 2023 at 03:04:44AM -0700, syzbot wrote:
HEAD commit: 908f31f2a05b Merge branch 'for-next/core', remote-tracking..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=155e0463280000
kernel config: https://syzkaller.appspot.com/x/.config?x=c1058fe68f4b7b2c
dashboard link: https://syzkaller.appspot.com/bug?extid=4a9f9820bd8d302e22f7
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16bc548d280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=135bba3b280000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/87d095820229/disk-908f31f2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a1bf67af9675/vmlinux-908f31f2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7784a88b37e8/Image-908f31f2.gz.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4a9f9820bd8d302e22f7@xxxxxxxxxxxxxxxxxxxxxxxxx
netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
==================================================================
BUG: KASAN: slab-out-of-bounds in do_csum+0x44/0x254 arch/arm64/lib/csum.c:39
Read of size 4294966928 at addr ffff0000d7ac0170 by task syz-executor412/5975
Yup, that looks suspiciously "-368"-shaped...
Judging by the UBSAN errors:
| shift exponent 3008 is too large for 64-bit type 'u64' (aka 'unsigned long long')
We're probably being passed a negative 'len' argument. It looks like the
generic version in lib/checksum.c rejects that early, so maybe we should
do the same in the arch code?
Hmm, indeed I can offer no explanation as to why I put "if (len == 0)" there
rather than "if (len <= 0)" like literally every other C implementation* :/
I've made that change:
https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/commit/?h=for-next/fixes&id=8bd795fedb8450ecbef18eeadbd23ed8fc7630f5
If you want it,
Acked-by: Robin Murphy <robin.murphy@xxxxxxx>
Cheers,
Will
