From 305af34c35656960326b9f8b3c823231c8e478b2 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 10 Sep 2024 09:37:00 +0200 Subject: [PATCH] 6.1-stable patches added patches: x86-mm-fix-pti-for-i386-some-more.patch --- queue-6.1/series | 1 + .../x86-mm-fix-pti-for-i386-some-more.patch | 160 ++++++++++++++++++ 2 files changed, 161 insertions(+) create mode 100644 queue-6.1/x86-mm-fix-pti-for-i386-some-more.patch diff --git a/queue-6.1/series b/queue-6.1/series index 06951d5e9c9..a36cbf0ca7a 100644 --- a/queue-6.1/series +++ b/queue-6.1/series @@ -184,3 +184,4 @@ drm-i915-fence-mark-debug_fence_free-with-__maybe_un.patch gpio-rockchip-fix-of-node-leak-in-probe.patch gpio-modepin-enable-module-autoloading.patch ublk_drv-fix-null-pointer-dereference-in-ublk_ctrl_s.patch +x86-mm-fix-pti-for-i386-some-more.patch diff --git a/queue-6.1/x86-mm-fix-pti-for-i386-some-more.patch b/queue-6.1/x86-mm-fix-pti-for-i386-some-more.patch new file mode 100644 index 00000000000..8f14ca22380 --- /dev/null +++ b/queue-6.1/x86-mm-fix-pti-for-i386-some-more.patch @@ -0,0 +1,160 @@ +From c48b5a4cf3125adb679e28ef093f66ff81368d05 Mon Sep 17 00:00:00 2001 +From: Thomas Gleixner +Date: Tue, 6 Aug 2024 20:48:43 +0200 +Subject: x86/mm: Fix PTI for i386 some more + +From: Thomas Gleixner + +commit c48b5a4cf3125adb679e28ef093f66ff81368d05 upstream. + +So it turns out that we have to do two passes of +pti_clone_entry_text(), once before initcalls, such that device and +late initcalls can use user-mode-helper / modprobe and once after +free_initmem() / mark_readonly(). + +Now obviously mark_readonly() can cause PMD splits, and +pti_clone_pgtable() doesn't like that much. + +Allow the late clone to split PMDs so that pagetables stay in sync. + +[peterz: Changelog and comments] +Reported-by: Guenter Roeck +Signed-off-by: Thomas Gleixner +Signed-off-by: Peter Zijlstra (Intel) +Tested-by: Guenter Roeck +Link: https://lkml.kernel.org/r/20240806184843.GX37996@noisy.programming.kicks-ass.net +Signed-off-by: Greg Kroah-Hartman +--- + arch/x86/mm/pti.c | 45 +++++++++++++++++++++++++++++---------------- + 1 file changed, 29 insertions(+), 16 deletions(-) + +--- a/arch/x86/mm/pti.c ++++ b/arch/x86/mm/pti.c +@@ -241,7 +241,7 @@ static pmd_t *pti_user_pagetable_walk_pm + * + * Returns a pointer to a PTE on success, or NULL on failure. + */ +-static pte_t *pti_user_pagetable_walk_pte(unsigned long address) ++static pte_t *pti_user_pagetable_walk_pte(unsigned long address, bool late_text) + { + gfp_t gfp = (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO); + pmd_t *pmd; +@@ -251,10 +251,15 @@ static pte_t *pti_user_pagetable_walk_pt + if (!pmd) + return NULL; + +- /* We can't do anything sensible if we hit a large mapping. */ ++ /* Large PMD mapping found */ + if (pmd_large(*pmd)) { +- WARN_ON(1); +- return NULL; ++ /* Clear the PMD if we hit a large mapping from the first round */ ++ if (late_text) { ++ set_pmd(pmd, __pmd(0)); ++ } else { ++ WARN_ON_ONCE(1); ++ return NULL; ++ } + } + + if (pmd_none(*pmd)) { +@@ -283,7 +288,7 @@ static void __init pti_setup_vsyscall(vo + if (!pte || WARN_ON(level != PG_LEVEL_4K) || pte_none(*pte)) + return; + +- target_pte = pti_user_pagetable_walk_pte(VSYSCALL_ADDR); ++ target_pte = pti_user_pagetable_walk_pte(VSYSCALL_ADDR, false); + if (WARN_ON(!target_pte)) + return; + +@@ -301,7 +306,7 @@ enum pti_clone_level { + + static void + pti_clone_pgtable(unsigned long start, unsigned long end, +- enum pti_clone_level level) ++ enum pti_clone_level level, bool late_text) + { + unsigned long addr; + +@@ -390,7 +395,7 @@ pti_clone_pgtable(unsigned long start, u + return; + + /* Allocate PTE in the user page-table */ +- target_pte = pti_user_pagetable_walk_pte(addr); ++ target_pte = pti_user_pagetable_walk_pte(addr, late_text); + if (WARN_ON(!target_pte)) + return; + +@@ -452,7 +457,7 @@ static void __init pti_clone_user_shared + phys_addr_t pa = per_cpu_ptr_to_phys((void *)va); + pte_t *target_pte; + +- target_pte = pti_user_pagetable_walk_pte(va); ++ target_pte = pti_user_pagetable_walk_pte(va, false); + if (WARN_ON(!target_pte)) + return; + +@@ -475,7 +480,7 @@ static void __init pti_clone_user_shared + start = CPU_ENTRY_AREA_BASE; + end = start + (PAGE_SIZE * CPU_ENTRY_AREA_PAGES); + +- pti_clone_pgtable(start, end, PTI_CLONE_PMD); ++ pti_clone_pgtable(start, end, PTI_CLONE_PMD, false); + } + #endif /* CONFIG_X86_64 */ + +@@ -492,11 +497,11 @@ static void __init pti_setup_espfix64(vo + /* + * Clone the populated PMDs of the entry text and force it RO. + */ +-static void pti_clone_entry_text(void) ++static void pti_clone_entry_text(bool late) + { + pti_clone_pgtable((unsigned long) __entry_text_start, + (unsigned long) __entry_text_end, +- PTI_LEVEL_KERNEL_IMAGE); ++ PTI_LEVEL_KERNEL_IMAGE, late); + } + + /* +@@ -571,7 +576,7 @@ static void pti_clone_kernel_text(void) + * pti_set_kernel_image_nonglobal() did to clear the + * global bit. + */ +- pti_clone_pgtable(start, end_clone, PTI_LEVEL_KERNEL_IMAGE); ++ pti_clone_pgtable(start, end_clone, PTI_LEVEL_KERNEL_IMAGE, false); + + /* + * pti_clone_pgtable() will set the global bit in any PMDs +@@ -638,8 +643,15 @@ void __init pti_init(void) + + /* Undo all global bits from the init pagetables in head_64.S: */ + pti_set_kernel_image_nonglobal(); ++ + /* Replace some of the global bits just for shared entry text: */ +- pti_clone_entry_text(); ++ /* ++ * This is very early in boot. Device and Late initcalls can do ++ * modprobe before free_initmem() and mark_readonly(). This ++ * pti_clone_entry_text() allows those user-mode-helpers to function, ++ * but notably the text is still RW. ++ */ ++ pti_clone_entry_text(false); + pti_setup_espfix64(); + pti_setup_vsyscall(); + } +@@ -656,10 +668,11 @@ void pti_finalize(void) + if (!boot_cpu_has(X86_FEATURE_PTI)) + return; + /* +- * We need to clone everything (again) that maps parts of the +- * kernel image. ++ * This is after free_initmem() (all initcalls are done) and we've done ++ * mark_readonly(). Text is now NX which might've split some PMDs ++ * relative to the early clone. + */ +- pti_clone_entry_text(); ++ pti_clone_entry_text(true); + pti_clone_kernel_text(); + + debug_checkwx_user(); -- 2.47.3