diff options
Diffstat (limited to 'meta-rcar-gen2/recipes-kernel/linux/linux-renesas')
| -rw-r--r-- | meta-rcar-gen2/recipes-kernel/linux/linux-renesas/9999-Backport-fix-for-CVE-2016-5195.patch | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/meta-rcar-gen2/recipes-kernel/linux/linux-renesas/9999-Backport-fix-for-CVE-2016-5195.patch b/meta-rcar-gen2/recipes-kernel/linux/linux-renesas/9999-Backport-fix-for-CVE-2016-5195.patch new file mode 100644 index 0000000..e7a143f --- /dev/null +++ b/meta-rcar-gen2/recipes-kernel/linux/linux-renesas/9999-Backport-fix-for-CVE-2016-5195.patch @@ -0,0 +1,68 @@ +From 8003e1524789537680204d44d5bf7a82561f8ba3 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Jan-Simon=20M=C3=B6ller?= <jsmoeller@linuxfoundation.org> +Date: Fri, 4 Nov 2016 20:58:46 +0100 +Subject: [PATCH] Backport fix for CVE-2016-5195 +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +Signed-off-by: Jan-Simon Möller <jsmoeller@linuxfoundation.org> +--- + include/linux/mm.h | 1 + + mm/memory.c | 14 ++++++++++++-- + 2 files changed, 13 insertions(+), 2 deletions(-) + +diff --git a/include/linux/mm.h b/include/linux/mm.h +index 3bf21c3..263b405 100644 +--- a/include/linux/mm.h ++++ b/include/linux/mm.h +@@ -1702,6 +1702,7 @@ static inline struct page *follow_page(struct vm_area_struct *vma, + #define FOLL_HWPOISON 0x100 /* check page is hwpoisoned */ + #define FOLL_NUMA 0x200 /* force NUMA hinting page fault */ + #define FOLL_MIGRATION 0x400 /* wait for page to replace migration entry */ ++#define FOLL_COW 0x4000 /* internal GUP flag */ + + typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr, + void *data); +diff --git a/mm/memory.c b/mm/memory.c +index 48aa275..3a3f316 100644 +--- a/mm/memory.c ++++ b/mm/memory.c +@@ -1462,6 +1462,16 @@ int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address, + } + EXPORT_SYMBOL_GPL(zap_vma_ptes); + ++/* ++ * FOLL_FORCE can write to even unwritable pte's, but only ++ * after we've gone through a COW cycle and they are dirty. ++ */ ++static inline bool can_follow_write_pte(pte_t pte, unsigned int flags) ++{ ++ return pte_write(pte) || ++ ((flags & FOLL_FORCE) && (flags & FOLL_COW) && pte_dirty(pte)); ++} ++ + /** + * follow_page_mask - look up a page descriptor from a user-virtual address + * @vma: vm_area_struct mapping @address +@@ -1569,7 +1579,7 @@ split_fallthrough: + } + if ((flags & FOLL_NUMA) && pte_numa(pte)) + goto no_page; +- if ((flags & FOLL_WRITE) && !pte_write(pte)) ++ if ((flags & FOLL_WRITE) && !can_follow_write_pte(pte, flags)) + goto unlock; + + page = vm_normal_page(vma, address, pte); +@@ -1876,7 +1886,7 @@ long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, + */ + if ((ret & VM_FAULT_WRITE) && + !(vma->vm_flags & VM_WRITE)) +- foll_flags &= ~FOLL_WRITE; ++ foll_flags |= FOLL_COW; + + cond_resched(); + } +-- +2.1.4 + |