diff options
| -rw-r--r-- | kernel.spec | 3 | ||||
| -rw-r--r-- | linux-2.6-32bit-mmap-exec-randomization.patch | 27 | ||||
| -rw-r--r-- | linux-2.6-i386-nx-emulation.patch | 22 |
3 files changed, 29 insertions, 23 deletions
diff --git a/kernel.spec b/kernel.spec index 044aaf043..0430ab674 100644 --- a/kernel.spec +++ b/kernel.spec @@ -2067,6 +2067,9 @@ fi # ||----w | # || || %changelog +* Mon Sep 19 2011 Dave Jones <davej@redhat.com> +- Merge some improvements to the 32bit mmap randomisation from Kees Cook. + * Wed Sep 14 2011 Josh Boyer <jwboyer@redhat.com> - Add patch to fix deadlock in ppc64 icswx (rhbz 737984) diff --git a/linux-2.6-32bit-mmap-exec-randomization.patch b/linux-2.6-32bit-mmap-exec-randomization.patch index 6008173b0..c25323323 100644 --- a/linux-2.6-32bit-mmap-exec-randomization.patch +++ b/linux-2.6-32bit-mmap-exec-randomization.patch @@ -152,7 +152,7 @@ Main executable randomisation (PIE) : 12 bits (guessed) struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c -@@ -124,13 +124,16 @@ static unsigned long mmap_legacy_base(void) +@@ -124,13 +124,19 @@ static unsigned long mmap_legacy_base(void) */ void arch_pick_mmap_layout(struct mm_struct *mm) { @@ -163,9 +163,12 @@ Main executable randomisation (PIE) : 12 bits (guessed) } else { mm->mmap_base = mmap_base(); mm->get_unmapped_area = arch_get_unmapped_area_topdown; ++#ifdef CONFIG_X86_32 + if (!(current->personality & READ_IMPLIES_EXEC) ++ && !(__supported_pte_mask & _PAGE_NX) + && mmap_is_ia32()) + mm->get_unmapped_exec_area = arch_get_unmapped_exec_area; ++#endif mm->unmap_area = arch_unmap_area_topdown; } } @@ -224,3 +227,25 @@ Main executable randomisation (PIE) : 12 bits (guessed) if (new_addr & ~PAGE_MASK) { ret = new_addr; goto out; +diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c +index 57d1868..29c0c35 100644 +--- a/arch/x86/kernel/process.c ++++ b/arch/x86/kernel/process.c +@@ -669,6 +669,16 @@ unsigned long arch_align_stack(unsigned long sp) + unsigned long arch_randomize_brk(struct mm_struct *mm) + { + unsigned long range_end = mm->brk + 0x02000000; +- return randomize_range(mm->brk, range_end, 0) ? : mm->brk; ++ unsigned long bump = 0; ++#ifdef CONFIG_X86_32 ++ /* in the case of NX emulation, shove the brk segment way out of the ++ way of the exec randomization area, since it can collide with ++ future allocations if not. */ ++ if ( (mm->get_unmapped_exec_area == arch_get_unmapped_exec_area) && ++ (mm->brk < 0x08000000) ) { ++ bump = (TASK_SIZE/6); ++ } ++#endif ++ return bump + (randomize_range(mm->brk, range_end, 0) ? : mm->brk); + } + diff --git a/linux-2.6-i386-nx-emulation.patch b/linux-2.6-i386-nx-emulation.patch index fb58c612e..07a0faec8 100644 --- a/linux-2.6-i386-nx-emulation.patch +++ b/linux-2.6-i386-nx-emulation.patch @@ -592,25 +592,3 @@ mmu_notifier_invalidate_range_start(mm, start, end); if (is_vm_hugetlb_page(vma)) hugetlb_change_protection(vma, start, end, vma->vm_page_prot); -diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c -index 57d1868..29c0c35 100644 ---- a/arch/x86/kernel/process.c -+++ b/arch/x86/kernel/process.c -@@ -669,6 +669,16 @@ unsigned long arch_align_stack(unsigned long sp) - unsigned long arch_randomize_brk(struct mm_struct *mm) - { - unsigned long range_end = mm->brk + 0x02000000; -- return randomize_range(mm->brk, range_end, 0) ? : mm->brk; -+ unsigned long bump = 0; -+#ifdef CONFIG_X86_32 -+ /* in the case of NX emulation, shove the brk segment way out of the -+ way of the exec randomization area, since it can collide with -+ future allocations if not. */ -+ if ( (mm->get_unmapped_exec_area == arch_get_unmapped_exec_area) && -+ (mm->brk < 0x08000000) ) { -+ bump = (TASK_SIZE/6); -+ } -+#endif -+ return bump + (randomize_range(mm->brk, range_end, 0) ? : mm->brk); - } - |