[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20180628131621.GA21189@openwall.com>
Date: Thu, 28 Jun 2018 15:16:21 +0200
From: Solar Designer <solar@...nwall.com>
To: Vasily Averin <vvs@...tuozzo.com>
Cc: owl-dev@...ts.openwall.com
Subject: Re: 32-bit syscall breakage in -431 kernel with KAISER
On Thu, Jun 28, 2018 at 04:08:29PM +0300, Vasily Averin wrote:
> On 06/26/2018 10:13 PM, Solar Designer wrote:
> > per my review of the full struct tss_struct, the stack[] field
> > offset is:
> >
> > 4+8*5+4*2+2*2+1025*8+8 = 8264
>
> Alexander,
> seems you're wrong
>
> in my version of rhel5-based -123.1 kernel
>
> crash> tss_struct -o
> struct tss_struct {
> [0x0] u32 reserved1;
> [0x4] u64 rsp0;
> [0xc] u64 rsp1;
> [0x14] u64 rsp2;
> [0x1c] u64 reserved2;
> [0x24] u64 ist[7];
> [0x5c] u32 reserved3;
> [0x60] u32 reserved4;
> [0x64] u16 reserved5;
> [0x66] u16 io_bitmap_base;
> [0x68] unsigned long io_bitmap[1025];
> [0x2070] unsigned long stack_canary;
> [0x2078] unsigned long stack[64];
> }
> SIZE: 0x3000
> crash> tss_struct -od
> struct tss_struct {
> [0] u32 reserved1;
> [4] u64 rsp0;
> [12] u64 rsp1;
> [20] u64 rsp2;
> [28] u64 reserved2;
> [36] u64 ist[7];
> [92] u32 reserved3;
> [96] u32 reserved4;
> [100] u16 reserved5;
> [102] u16 io_bitmap_base;
> [104] unsigned long io_bitmap[1025];
> [8304] unsigned long stack_canary;
> [8312] unsigned long stack[64];
> }
> SIZE: 12288
>
> Seems you missed that 'ist' filed is an array
Ah, yes, indeed. But since it has an odd number of elements, this
leaves stack[] just as unaligned.
Can you check your RHEL6-based kernels as well?
Thanks!
Alexander
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
