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| author | Natanael Copa <ncopa@alpinelinux.org> | 2015-10-29 13:50:28 +0000 |
|---|---|---|
| committer | Natanael Copa <ncopa@alpinelinux.org> | 2015-10-29 15:18:02 +0000 |
| commit | 1e0864dfc2222c7a623cf8eefa098700e17f304a (patch) | |
| tree | 7dcb90c07506d5fd05bb677372277ad1e2791d70 /main/xen/xsa148.patch | |
| parent | f3da078305d1ccc488e6948a1c1e9136edc21529 (diff) | |
| download | aports-1e0864dfc2222c7a623cf8eefa098700e17f304a.tar.bz2 aports-1e0864dfc2222c7a623cf8eefa098700e17f304a.tar.xz | |
main/xen: upgrade to 4.6.0 and fix sec issues
Diffstat (limited to 'main/xen/xsa148.patch')
| -rw-r--r-- | main/xen/xsa148.patch | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/main/xen/xsa148.patch b/main/xen/xsa148.patch new file mode 100644 index 0000000000..3b6843a8e2 --- /dev/null +++ b/main/xen/xsa148.patch @@ -0,0 +1,39 @@ +x86: guard against undue super page PTE creation + +When optional super page support got added (commit bd1cd81d64 "x86: PV +support for hugepages"), two adjustments were missed: mod_l2_entry() +needs to consider the PSE and RW bits when deciding whether to use the +fast path, and the PSE bit must not be removed from L2_DISALLOW_MASK +unconditionally. + +This is XSA-148. + +Signed-off-by: Jan Beulich <jbeulich@suse.com> +Reviewed-by: Tim Deegan <tim@xen.org> + +--- a/xen/arch/x86/mm.c ++++ b/xen/arch/x86/mm.c +@@ -160,7 +160,10 @@ static void put_superpage(unsigned long + static uint32_t base_disallow_mask; + /* Global bit is allowed to be set on L1 PTEs. Intended for user mappings. */ + #define L1_DISALLOW_MASK ((base_disallow_mask | _PAGE_GNTTAB) & ~_PAGE_GLOBAL) +-#define L2_DISALLOW_MASK (base_disallow_mask & ~_PAGE_PSE) ++ ++#define L2_DISALLOW_MASK (unlikely(opt_allow_superpage) \ ++ ? base_disallow_mask & ~_PAGE_PSE \ ++ : base_disallow_mask) + + #define l3_disallow_mask(d) (!is_pv_32bit_domain(d) ? \ + base_disallow_mask : 0xFFFFF198U) +@@ -1841,7 +1844,10 @@ static int mod_l2_entry(l2_pgentry_t *pl + } + + /* Fast path for identical mapping and presence. */ +- if ( !l2e_has_changed(ol2e, nl2e, _PAGE_PRESENT) ) ++ if ( !l2e_has_changed(ol2e, nl2e, ++ unlikely(opt_allow_superpage) ++ ? _PAGE_PSE | _PAGE_RW | _PAGE_PRESENT ++ : _PAGE_PRESENT) ) + { + adjust_guest_l2e(nl2e, d); + if ( UPDATE_ENTRY(l2, pl2e, ol2e, nl2e, pfn, vcpu, preserve_ad) ) |