Re: Linux-2.4.30-hf3

[Willy Tarreau <willy@w.ods.org>]

Hi again,

Julien corrected me on the points below :

>   - a NULL dereference in serial.c found by Julien Tinnes which could lead
>     to an oops.

Could possibly be exploited by mapping the first page of a program and
watching the kernel eat the data instead of oopsing.

>   - an off-by-one in mtrr.c found by Brad Spengler and reported by J.Tinnes
>     which could lead to a panic.

This is inexact. I've checked several other archs :
 - sparc, sparc64, x86_64, alpha, mips all assume that (n) is unsigned and
   will overflow, possibly executing user-controlled code.
 - ppc and ppc64 explicitly check that (n) is < TASK_SIZE and should be safe.
 - x86 will BUG_ON((long)n < 0) (=> oops/panic).
 - others not checked.

>   - a few unchecked strcpy() in ipvs fixed in PaX which I'm not absolutely
>     sure are exploitable, but are definitely dirty and risky.

They are exploitable by anyone with enough privilege to manipulate IPVS.
Think of a user front-end for example.

Thanks,
Willy