Re: Compat 32-bit syscall entry from 64-bit task!? [was: Re: [RFC,PATCH 1/2] seccomp_filters: system call filtering using BPF]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Andi Kleen wrote:
> > Not everybody. There are programs which try hard to distinguish between
> > int80 and syscall. One such example is a sandbox for programming contests
> > I wrote several years ago. It analyses the instruction before EIP and as
> > it does not allow threads nor executing writeable memory, it should be
> > correct.
> 
> There are other ways to break it, like using the syscall itself to change
> input arguments or using ptrace from another process and other ways.
> 
> Generally there are so many races with ptrace that if you want to do
> things like that it's better to use a LSM. That's what they are for.

I could see the LSM approach working *if* there was an LSM module to
make it available to unpriviledged userspace.  I.e. a replacement for
ptrace() for this purpose.

It would be nice to be able to trace and check syscall strings properly.

-- Jamie
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux