Re: 2.6.25-rc8-mm2: FIX kmalloc-2048 (was Re: 2.6.25-rc8-mm2: IP: [] __kmalloc+0x69/0x110)

Christoph Lameter
2008-04-14T20:05:37Z

On Mon, 14 Apr 2008, Alexey Dobriyan wrote:

> I can reproduce semi-reliably (by kernel standards) corruption in
> kmalloc-2048. No idea if this can explain all "struct file" related
> oopses I saw, or SLUB free pointer corruption Pekka and Christoph are
> looking into.

The slub free pointer corruption is usually a result of the overwrites.

> Bytes b4 0xffff81017ff9d2c0: 62 ea ff ff 00 00 00 00 5a 5a 5a 5a 5a 5a 5a 5a
> Object 0xffff81017ff9d2d0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
> Object 0xffff81017ff9d2e0: 6b 6b 00 18 f3 a2 9f 90 00 1b 38 af 22 49 08 00
> Object 0xffff81017ff9d2f0: 45 10 00 4c ff 59 40 00 40 11 86 ac c0 a8 00 2a
> Object 0xffff81017ff9d300: 50 fa a2 be 91 43 00 7b 00 38 54 d4 23 00 00 00
> Object 0xffff81017ff9d310: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> Object 0xffff81017ff9d320: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> Object 0xffff81017ff9d330: 00 00 00 00 4c ff 10 44 74 7f 6f 9d e4 c8 a2 4f
> Object 0xffff81017ff9d340: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> Redzone 0xffff81017ff9dad0: bb bb bb bb bb bb bb bb
> Padding 0xffff81017ff9db10: 5a 5a 5a 5a 5a 5a 5a 5a
>
> FIX kmalloc-2048: Restoring 0xffff81017ff9d2e2-0xffff81017ff9d8d9=0x6b

Looks like skb corruption. Would be helpful to have the complete output
though. Does the data in the restored range trigger any memories?