On 02/25, Stephen Smalley wrote: > > On Mon, 2008-02-25 at 20:42 +0300, Oleg Nesterov wrote: > > kill_pid_info_as_uid() is solely used by drivers/usb/core/. The original > > "[PATCH] Fix signal sending in usbdevio on async URB completion" commit > > 46113830a18847cff8da73005e57bc49c2f95a56 was right, but nowadays we use > > struct pid and this solves most of the addressed problems. > > > > It would be nice to use kill_pid_info() instead, but we can't because USB > > uses .si_code = SI_ASYNCIO which fools SI_FROMUSER() and thus security > > checks. > > > > I think we should omit the permission checks completely, the task which does > > ioctl(USBDEVFS_SUBMITURB) explicitly asks to send the signal to it, we > > should > > not deny the signal even if the task changes its credentials in any way. > > If we are applying checks based on uid/gid to protect suid/sgid > programs, then we ought to also invoke the LSM hook to allow protection > of other credential-changing transformations, like SELinux context > transitions. You either remove all checking or none, please.
Yes, you are right. I'd like to remove all uid/euid checks. This patch doesn't do this because - perhaps it will be possible to kill this helper - if we remove these checks, we should do some subsequent cleanups in drivers/usb/core/, while this series is all about LSM hooks. I am going to do this later. > And if all, what's the rationale? I think it is not good that LSM has some special (and unneeded!) hacks for USB. Please also look at the next patch. Do you agree? Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/