Re: [PATCH] new setprocuid syscall

[Petr Vandrovec]

On 20 Feb 01 at 7:11, Peter Samuelson wrote:
> [Alan Cox]
> > There is an assumption in the kernel that only the task changes its
> > own uid and other related data.
> 
> Fair enough but could you explain the potential problems?  And how is
> it different from sys_setpriority?

Look at what fs/open.c:sys_access does, at least. It switches
fsuid/fsgid/capabilities during its execution.

sys_setpriority is completely different, no piece of kernel changes that
and nothing except schedule() touches that. But {,fs,e}[ug]id are used
here and there through whole kernel. Also, changing priority does not
remove some access rights from your process, while changing uid/gid does...
                                        Petr Vandrovec
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