Re: [PATCH] net: ipv6: fix invalid alloclen in __ip6_append_data

[David Ahern]

On 3/8/22 12:46 PM, Tadeusz Struk wrote:
> That fails in the same way:
> 
> skbuff: skb_over_panic: text:ffffffff83e7b48b len:65575 put:65575
> head:ffff888101f8a000 data:ffff888101f8a088 tail:0x100af end:0x6c0
> dev:<NULL>
> ------------[ cut here ]------------
> kernel BUG at net/core/skbuff.c:113!
> invalid opcode: 0000 [#1] PREEMPT SMP KASAN
> CPU: 0 PID: 1852 Comm: repro Not tainted
> 5.17.0-rc7-00020-gea4424be1688-dirty #19
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1.fc35
> RIP: 0010:skb_panic+0x173/0x175
> 
> I'm not sure how it supposed to help since it doesn't change the
> alloclen at all.

alloclen is a function of fraglen and fraglen is a function of datalen.