[071/117] kgdb: dont needlessly skip PAGE_USER test for Fsl booke

From: Greg KH
Date: Mon May 10 2010 - 18:53:54 EST


2.6.33-stable review patch. If anyone has any objections, please let us know.

------------------

From: Wufei <fei.wu@xxxxxxxxxxxxx>

commit 56151e753468e34aeb322af4b0309ab727c97d2e upstream.

The bypassing of this test is a leftover from 2.4 vintage
kernels, and is no longer appropriate, or even used by KGDB.
Currently KGDB uses probe_kernel_write() for all access to
memory via the KGDB core, so it can simply be deleted.

This fixes CVE-2010-1446.

CC: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
CC: Paul Mackerras <paulus@xxxxxxxxx>
CC: Kumar Gala <galak@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Wufei <fei.wu@xxxxxxxxxxxxx>
Signed-off-by: Jason Wessel <jason.wessel@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
arch/powerpc/mm/fsl_booke_mmu.c | 5 -----
1 file changed, 5 deletions(-)

--- a/arch/powerpc/mm/fsl_booke_mmu.c
+++ b/arch/powerpc/mm/fsl_booke_mmu.c
@@ -155,15 +155,10 @@ static void settlbcam(int index, unsigne
if (cur_cpu_spec->cpu_features & MMU_FTR_BIG_PHYS)
TLBCAM[index].MAS7 = (u64)phys >> 32;

-#ifndef CONFIG_KGDB /* want user access for breakpoints */
if (flags & _PAGE_USER) {
TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
}
-#else
- TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
- TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
-#endif

tlbcam_addrs[index].start = virt;
tlbcam_addrs[index].limit = virt + size - 1;


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