Re: [PATCH] x32: Mask away the x32 syscall bit in the ptrace codepath

2014-05-28 Thread H. Peter Anvin
On 05/28/2014 02:53 PM, Philipp Kern wrote: > On Wed, May 28, 2014 at 11:43 PM, Andy Lutomirski wrote: >> However: are you sure that entry_64.S handles this? It looks like >> tracesys has higher priority than badsys. And strace can certainly >> see out-of-range syscalls. […] > > Not only can it

Re: [PATCH] x32: Mask away the x32 syscall bit in the ptrace codepath

2014-05-28 Thread Andy Lutomirski
On Wed, May 28, 2014 at 2:53 PM, Philipp Kern wrote: > On Wed, May 28, 2014 at 11:43 PM, Andy Lutomirski wrote: >> However: are you sure that entry_64.S handles this? It looks like >> tracesys has higher priority than badsys. And strace can certainly >> see out-of-range syscalls. […] > > Not on

Re: [PATCH] x32: Mask away the x32 syscall bit in the ptrace codepath

2014-05-28 Thread Philipp Kern
On Wed, May 28, 2014 at 11:43 PM, Andy Lutomirski wrote: > However: are you sure that entry_64.S handles this? It looks like > tracesys has higher priority than badsys. And strace can certainly > see out-of-range syscalls. […] Not only can it see them: It must see that this bit is set as that's

Re: [PATCH] x32: Mask away the x32 syscall bit in the ptrace codepath

2014-05-28 Thread Andy Lutomirski
On Wed, May 28, 2014 at 2:19 PM, H. Peter Anvin wrote: > On 05/28/2014 02:15 PM, Andy Lutomirski wrote: >>> 3. The OOPS you're fixing doesn't seem like it's fixed. What if some other random high bits are set? >>> >>> There is a range check in entry_*.S for the system call. >> >> I can i

Re: [PATCH] x32: Mask away the x32 syscall bit in the ptrace codepath

2014-05-28 Thread H. Peter Anvin
On 05/28/2014 02:15 PM, Andy Lutomirski wrote: >> >>> 3. The OOPS you're fixing doesn't seem like it's fixed. What if some >>> other random high bits are set? >> >> There is a range check in entry_*.S for the system call. > > I can imagine that causing a certain amount of confusion to fancy > sec

Re: [PATCH] x32: Mask away the x32 syscall bit in the ptrace codepath

2014-05-28 Thread Andy Lutomirski
On Wed, May 28, 2014 at 2:01 PM, H. Peter Anvin wrote: > On 05/28/2014 01:47 PM, Andy Lutomirski wrote: >> On 05/28/2014 05:19 AM, Philipp Kern wrote: >>> audit_filter_syscall uses the syscall number to reference into a >>> bitmask (e->rule.mask[word]). Not removing the x32 bit before passing >>>

Re: [PATCH] x32: Mask away the x32 syscall bit in the ptrace codepath

2014-05-28 Thread H. Peter Anvin
On 05/28/2014 01:47 PM, Andy Lutomirski wrote: > On 05/28/2014 05:19 AM, Philipp Kern wrote: >> audit_filter_syscall uses the syscall number to reference into a >> bitmask (e->rule.mask[word]). Not removing the x32 bit before passing >> the number to this architecture independent codepath will fail

Re: [PATCH] x32: Mask away the x32 syscall bit in the ptrace codepath

2014-05-28 Thread Philipp Kern
On Wed, May 28, 2014 at 10:47 PM, Andy Lutomirski wrote: > On 05/28/2014 05:19 AM, Philipp Kern wrote: > > audit_filter_syscall uses the syscall number to reference into a > > bitmask (e->rule.mask[word]). Not removing the x32 bit before passing > > the number to this architecture independent code

Re: [PATCH] x32: Mask away the x32 syscall bit in the ptrace codepath

2014-05-28 Thread Andy Lutomirski
On 05/28/2014 05:19 AM, Philipp Kern wrote: > audit_filter_syscall uses the syscall number to reference into a > bitmask (e->rule.mask[word]). Not removing the x32 bit before passing > the number to this architecture independent codepath will fail to > lookup the proper audit bit. Furthermore it wi