lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20231017090815.1067790-4-jeffxu@chromium.org>
Date:   Tue, 17 Oct 2023 09:08:10 +0000
From:   jeffxu@...omium.org
To:     akpm@...ux-foundation.org, keescook@...omium.org, jannh@...gle.com,
        sroettger@...gle.com, willy@...radead.org,
        gregkh@...uxfoundation.org, torvalds@...ux-foundation.org
Cc:     jeffxu@...gle.com, jorgelo@...omium.org, groeck@...omium.org,
        linux-kernel@...r.kernel.org, linux-kselftest@...r.kernel.org,
        linux-mm@...ck.org, surenb@...gle.com, alex.sierra@....com,
        apopple@...dia.com, aneesh.kumar@...ux.ibm.com,
        axelrasmussen@...gle.com, ben@...adent.org.uk,
        catalin.marinas@....com, david@...hat.com, dwmw@...zon.co.uk,
        ying.huang@...el.com, hughd@...gle.com, joey.gouly@....com,
        corbet@....net, wangkefeng.wang@...wei.com,
        Liam.Howlett@...cle.com, lstoakes@...il.com, mawupeng1@...wei.com,
        linmiaohe@...wei.com, namit@...are.com, peterx@...hat.com,
        peterz@...radead.org, ryan.roberts@....com, shr@...kernel.io,
        vbabka@...e.cz, xiujianfeng@...wei.com, yu.ma@...el.com,
        zhangpeng362@...wei.com, dave.hansen@...el.com, luto@...nel.org,
        linux-hardening@...r.kernel.org
Subject: [RFC PATCH v2 3/8] mseal: add can_modify_mm and can_modify_vma

From: Jeff Xu <jeffxu@...gle.com>

can_modify_mm:
 checks sealing flags for given memory range.

can_modify_vma:
  checks sealing flags for given vma.

Signed-off-by: Jeff Xu <jeffxu@...gle.com>
---
 include/linux/mm.h | 26 ++++++++++++++++++++++++++
 mm/mseal.c         | 42 ++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index b511932df033..b09df8501987 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3299,6 +3299,32 @@ static inline void mm_populate(unsigned long addr, unsigned long len)
 static inline void mm_populate(unsigned long addr, unsigned long len) {}
 #endif
 
+#ifdef CONFIG_MSEAL
+extern bool can_modify_mm(struct mm_struct *mm, unsigned long start,
+			  unsigned long end, unsigned long checkSeals);
+
+extern bool can_modify_vma(struct vm_area_struct *vma,
+		    unsigned long checkSeals);
+
+static inline unsigned long vma_seals(struct vm_area_struct *vma)
+{
+	return (vma->vm_seals & MM_SEAL_ALL);
+}
+
+#else
+static inline bool can_modify_mm(struct mm_struct *mm, unsigned long start,
+			  unsigned long end, unsigned long checkSeals)
+{
+	return true;
+}
+
+static inline bool can_modify_vma(struct vm_area_struct *vma,
+		    unsigned long checkSeals)
+{
+	return true;
+}
+#endif
+
 /* These take the mm semaphore themselves */
 extern int __must_check vm_brk(unsigned long, unsigned long);
 extern int __must_check vm_brk_flags(unsigned long, unsigned long, unsigned long);
diff --git a/mm/mseal.c b/mm/mseal.c
index ffe4c4c3f1bc..3e9d1c732c38 100644
--- a/mm/mseal.c
+++ b/mm/mseal.c
@@ -26,6 +26,44 @@ static bool can_do_mseal(unsigned long types, unsigned long flags)
 	return true;
 }
 
+/*
+ * check if a vma is sealed for modification.
+ * return true, if modification is allowed.
+ */
+bool can_modify_vma(struct vm_area_struct *vma,
+		    unsigned long checkSeals)
+{
+	if (checkSeals & vma_seals(vma))
+		return false;
+
+	return true;
+}
+
+/*
+ * Check if the vmas of a memory range are allowed to be modified.
+ * the memory ranger can have a gap (unallocated memory).
+ * return true, if it is allowed.
+ */
+bool can_modify_mm(struct mm_struct *mm, unsigned long start, unsigned long end,
+		   unsigned long checkSeals)
+{
+	struct vm_area_struct *vma;
+
+	VMA_ITERATOR(vmi, mm, start);
+
+	if (!checkSeals)
+		return true;
+
+	/* going through each vma to check */
+	for_each_vma_range(vmi, vma, end) {
+		if (!can_modify_vma(vma, checkSeals))
+			return false;
+	}
+
+	/* Allow by default. */
+	return true;
+}
+
 /*
  * Check if a seal type can be added to VMA.
  */
@@ -33,7 +71,7 @@ static bool can_add_vma_seals(struct vm_area_struct *vma, unsigned long newSeals
 {
 	/* When SEAL_MSEAL is set, reject if a new type of seal is added */
 	if ((vma->vm_seals & MM_SEAL_MSEAL) &&
-	    (newSeals & ~(vma->vm_seals & MM_SEAL_ALL)))
+	    (newSeals & ~(vma_seals(vma))))
 		return false;
 
 	return true;
@@ -45,7 +83,7 @@ static int mseal_fixup(struct vma_iterator *vmi, struct vm_area_struct *vma,
 {
 	int ret = 0;
 
-	if (addtypes & ~(vma->vm_seals & MM_SEAL_ALL)) {
+	if (addtypes & ~(vma_seals(vma))) {
 		/*
 		 * Handle split at start and end.
 		 * Note: sealed VMA doesn't merge with other VMAs.
-- 
2.42.0.655.g421f12c284-goog

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ