From: Kees Cook <keescook@chromium.org>
To: linux-kernel@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
David Windsor <dave@nullcore.net>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>,
Christoph Hellwig <hch@infradead.org>,
Christoph Lameter <cl@linux.com>,
"David S. Miller" <davem@davemloft.net>,
Laura Abbott <labbott@redhat.com>,
Mark Rutland <mark.rutland@arm.com>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Christoffer Dall <christoffer.dall@linaro.org>,
Dave Kleikamp <dave.kleikamp@oracle.com>, Jan Kara <jack@suse.cz>,
Luis de Bethencourt <luisbg@kernel.org>,
Marc Zyngier <marc.zyngier@arm.com>,
Rik van Riel <riel@redhat.com>,
Matthew Garrett <mjg59@google.com>,
linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org,
netdev@vger.kernel.org, linux-mm@kvack.org,
kernel-hardening@lists.openwall.com
Subject: [kernel-hardening] [PATCH 36/36] lkdtm: Update usercopy tests for whitelisting
Date: Tue, 9 Jan 2018 12:56:05 -0800 [thread overview]
Message-ID: <1515531365-37423-37-git-send-email-keescook@chromium.org> (raw)
In-Reply-To: <1515531365-37423-1-git-send-email-keescook@chromium.org>
This updates the USERCOPY_HEAP_FLAG_* tests to USERCOPY_HEAP_WHITELIST_*,
since the final form of usercopy whitelisting ended up using an offset/size
window instead of the earlier proposed allocation flags.
Signed-off-by: Kees Cook <keescook@chromium.org>
---
drivers/misc/lkdtm.h | 4 +-
drivers/misc/lkdtm_core.c | 4 +-
drivers/misc/lkdtm_usercopy.c | 88 ++++++++++++++++++++++++-------------------
3 files changed, 53 insertions(+), 43 deletions(-)
diff --git a/drivers/misc/lkdtm.h b/drivers/misc/lkdtm.h
index 687a0dbbe199..9e513dcfd809 100644
--- a/drivers/misc/lkdtm.h
+++ b/drivers/misc/lkdtm.h
@@ -76,8 +76,8 @@ void __init lkdtm_usercopy_init(void);
void __exit lkdtm_usercopy_exit(void);
void lkdtm_USERCOPY_HEAP_SIZE_TO(void);
void lkdtm_USERCOPY_HEAP_SIZE_FROM(void);
-void lkdtm_USERCOPY_HEAP_FLAG_TO(void);
-void lkdtm_USERCOPY_HEAP_FLAG_FROM(void);
+void lkdtm_USERCOPY_HEAP_WHITELIST_TO(void);
+void lkdtm_USERCOPY_HEAP_WHITELIST_FROM(void);
void lkdtm_USERCOPY_STACK_FRAME_TO(void);
void lkdtm_USERCOPY_STACK_FRAME_FROM(void);
void lkdtm_USERCOPY_STACK_BEYOND(void);
diff --git a/drivers/misc/lkdtm_core.c b/drivers/misc/lkdtm_core.c
index ba92291508dc..e3f2bac4b245 100644
--- a/drivers/misc/lkdtm_core.c
+++ b/drivers/misc/lkdtm_core.c
@@ -177,8 +177,8 @@ static const struct crashtype crashtypes[] = {
CRASHTYPE(ATOMIC_TIMING),
CRASHTYPE(USERCOPY_HEAP_SIZE_TO),
CRASHTYPE(USERCOPY_HEAP_SIZE_FROM),
- CRASHTYPE(USERCOPY_HEAP_FLAG_TO),
- CRASHTYPE(USERCOPY_HEAP_FLAG_FROM),
+ CRASHTYPE(USERCOPY_HEAP_WHITELIST_TO),
+ CRASHTYPE(USERCOPY_HEAP_WHITELIST_FROM),
CRASHTYPE(USERCOPY_STACK_FRAME_TO),
CRASHTYPE(USERCOPY_STACK_FRAME_FROM),
CRASHTYPE(USERCOPY_STACK_BEYOND),
diff --git a/drivers/misc/lkdtm_usercopy.c b/drivers/misc/lkdtm_usercopy.c
index 9ebbb031e5e3..9725aed305bb 100644
--- a/drivers/misc/lkdtm_usercopy.c
+++ b/drivers/misc/lkdtm_usercopy.c
@@ -20,7 +20,7 @@
*/
static volatile size_t unconst = 0;
static volatile size_t cache_size = 1024;
-static struct kmem_cache *bad_cache;
+static struct kmem_cache *whitelist_cache;
static const unsigned char test_text[] = "This is a test.\n";
@@ -115,6 +115,10 @@ static noinline void do_usercopy_stack(bool to_user, bool bad_frame)
vm_munmap(user_addr, PAGE_SIZE);
}
+/*
+ * This checks for whole-object size validation with hardened usercopy,
+ * with or without usercopy whitelisting.
+ */
static void do_usercopy_heap_size(bool to_user)
{
unsigned long user_addr;
@@ -177,77 +181,79 @@ static void do_usercopy_heap_size(bool to_user)
kfree(two);
}
-static void do_usercopy_heap_flag(bool to_user)
+/*
+ * This checks for the specific whitelist window within an object. If this
+ * test passes, then do_usercopy_heap_size() tests will pass too.
+ */
+static void do_usercopy_heap_whitelist(bool to_user)
{
- unsigned long user_addr;
- unsigned char *good_buf = NULL;
- unsigned char *bad_buf = NULL;
+ unsigned long user_alloc;
+ unsigned char *buf = NULL;
+ unsigned char __user *user_addr;
+ size_t offset, size;
/* Make sure cache was prepared. */
- if (!bad_cache) {
+ if (!whitelist_cache) {
pr_warn("Failed to allocate kernel cache\n");
return;
}
/*
- * Allocate one buffer from each cache (kmalloc will have the
- * SLAB_USERCOPY flag already, but "bad_cache" won't).
+ * Allocate a buffer with a whitelisted window in the buffer.
*/
- good_buf = kmalloc(cache_size, GFP_KERNEL);
- bad_buf = kmem_cache_alloc(bad_cache, GFP_KERNEL);
- if (!good_buf || !bad_buf) {
- pr_warn("Failed to allocate buffers from caches\n");
+ buf = kmem_cache_alloc(whitelist_cache, GFP_KERNEL);
+ if (!buf) {
+ pr_warn("Failed to allocate buffer from whitelist cache\n");
goto free_alloc;
}
/* Allocate user memory we'll poke at. */
- user_addr = vm_mmap(NULL, 0, PAGE_SIZE,
+ user_alloc = vm_mmap(NULL, 0, PAGE_SIZE,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_ANONYMOUS | MAP_PRIVATE, 0);
- if (user_addr >= TASK_SIZE) {
+ if (user_alloc >= TASK_SIZE) {
pr_warn("Failed to allocate user memory\n");
goto free_alloc;
}
+ user_addr = (void __user *)user_alloc;
- memset(good_buf, 'A', cache_size);
- memset(bad_buf, 'B', cache_size);
+ memset(buf, 'B', cache_size);
+
+ /* Whitelisted window in buffer, from kmem_cache_create_usercopy. */
+ offset = (cache_size / 4) + unconst;
+ size = (cache_size / 16) + unconst;
if (to_user) {
- pr_info("attempting good copy_to_user with SLAB_USERCOPY\n");
- if (copy_to_user((void __user *)user_addr, good_buf,
- cache_size)) {
+ pr_info("attempting good copy_to_user inside whitelist\n");
+ if (copy_to_user(user_addr, buf + offset, size)) {
pr_warn("copy_to_user failed unexpectedly?!\n");
goto free_user;
}
- pr_info("attempting bad copy_to_user w/o SLAB_USERCOPY\n");
- if (copy_to_user((void __user *)user_addr, bad_buf,
- cache_size)) {
+ pr_info("attempting bad copy_to_user outside whitelist\n");
+ if (copy_to_user(user_addr, buf + offset - 1, size)) {
pr_warn("copy_to_user failed, but lacked Oops\n");
goto free_user;
}
} else {
- pr_info("attempting good copy_from_user with SLAB_USERCOPY\n");
- if (copy_from_user(good_buf, (void __user *)user_addr,
- cache_size)) {
+ pr_info("attempting good copy_from_user inside whitelist\n");
+ if (copy_from_user(buf + offset, user_addr, size)) {
pr_warn("copy_from_user failed unexpectedly?!\n");
goto free_user;
}
- pr_info("attempting bad copy_from_user w/o SLAB_USERCOPY\n");
- if (copy_from_user(bad_buf, (void __user *)user_addr,
- cache_size)) {
+ pr_info("attempting bad copy_from_user outside whitelist\n");
+ if (copy_from_user(buf + offset - 1, user_addr, size)) {
pr_warn("copy_from_user failed, but lacked Oops\n");
goto free_user;
}
}
free_user:
- vm_munmap(user_addr, PAGE_SIZE);
+ vm_munmap(user_alloc, PAGE_SIZE);
free_alloc:
- if (bad_buf)
- kmem_cache_free(bad_cache, bad_buf);
- kfree(good_buf);
+ if (buf)
+ kmem_cache_free(whitelist_cache, buf);
}
/* Callable tests. */
@@ -261,14 +267,14 @@ void lkdtm_USERCOPY_HEAP_SIZE_FROM(void)
do_usercopy_heap_size(false);
}
-void lkdtm_USERCOPY_HEAP_FLAG_TO(void)
+void lkdtm_USERCOPY_HEAP_WHITELIST_TO(void)
{
- do_usercopy_heap_flag(true);
+ do_usercopy_heap_whitelist(true);
}
-void lkdtm_USERCOPY_HEAP_FLAG_FROM(void)
+void lkdtm_USERCOPY_HEAP_WHITELIST_FROM(void)
{
- do_usercopy_heap_flag(false);
+ do_usercopy_heap_whitelist(false);
}
void lkdtm_USERCOPY_STACK_FRAME_TO(void)
@@ -319,11 +325,15 @@ void lkdtm_USERCOPY_KERNEL(void)
void __init lkdtm_usercopy_init(void)
{
/* Prepare cache that lacks SLAB_USERCOPY flag. */
- bad_cache = kmem_cache_create("lkdtm-no-usercopy", cache_size, 0,
- 0, NULL);
+ whitelist_cache =
+ kmem_cache_create_usercopy("lkdtm-usercopy", cache_size,
+ 0, 0,
+ cache_size / 4,
+ cache_size / 16,
+ NULL);
}
void __exit lkdtm_usercopy_exit(void)
{
- kmem_cache_destroy(bad_cache);
+ kmem_cache_destroy(whitelist_cache);
}
--
2.7.4
prev parent reply other threads:[~2018-01-09 20:56 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-09 20:55 [kernel-hardening] [PATCH v4 00/36] Hardened usercopy whitelisting Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 01/36] usercopy: Remove pointer from overflow report Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 02/36] usercopy: Include offset in " Kees Cook
2018-01-10 15:25 ` [kernel-hardening] " Christopher Lameter
2018-01-10 21:15 ` Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 03/36] lkdtm/usercopy: Adjust test to include an offset to check reporting Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 04/36] usercopy: Prepare for usercopy whitelisting Kees Cook
2018-01-10 18:28 ` [kernel-hardening] " Christopher Lameter
2018-01-10 21:06 ` Kees Cook
2018-01-12 15:10 ` [kernel-hardening] " David Laight
2018-01-12 15:56 ` Christopher Lameter
2018-01-14 23:07 ` [kernel-hardening] " Matthew Wilcox
2018-01-16 15:21 ` [kernel-hardening] kmem_cache_attr (was Re: [PATCH 04/36] usercopy: Prepare for usercopy whitelisting) Christopher Lameter
2018-01-16 16:05 ` [kernel-hardening] " Matthew Wilcox
2018-01-16 16:54 ` Christopher Lameter
2018-01-16 17:43 ` Matthew Wilcox
2018-01-16 18:07 ` Christopher Lameter
2018-01-16 18:17 ` Christopher Lameter
2018-01-16 21:03 ` Matthew Wilcox
2018-01-17 14:46 ` Christopher Lameter
2018-01-17 17:42 ` Christopher Lameter
2018-01-17 19:31 ` Matthew Wilcox
2018-01-20 1:58 ` Christopher Lameter
2018-01-09 20:55 ` [kernel-hardening] [PATCH 05/36] usercopy: WARN() on slab cache usercopy region violations Kees Cook
2018-01-10 18:31 ` [kernel-hardening] " Christopher Lameter
2018-01-10 20:14 ` Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 06/36] usercopy: Mark kmalloc caches as usercopy caches Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 07/36] dcache: Define usercopy region in dentry_cache slab cache Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 08/36] vfs: Define usercopy region in names_cache slab caches Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 09/36] vfs: Copy struct mount.mnt_id to userspace using put_user() Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 10/36] ext4: Define usercopy region in ext4_inode_cache slab cache Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 11/36] ext2: Define usercopy region in ext2_inode_cache " Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 12/36] jfs: Define usercopy region in jfs_ip " Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 13/36] befs: Define usercopy region in befs_inode_cache " Kees Cook
2018-01-10 10:53 ` [kernel-hardening] " Luis de Bethencourt
2018-01-09 20:55 ` [kernel-hardening] [PATCH 14/36] exofs: Define usercopy region in exofs_inode_cache " Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 15/36] orangefs: Define usercopy region in orangefs_inode_cache " Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 16/36] ufs: Define usercopy region in ufs_inode_cache " Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 17/36] vxfs: Define usercopy region in vxfs_inode " Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 18/36] cifs: Define usercopy region in cifs_request " Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 19/36] scsi: Define usercopy region in scsi_sense_cache " Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 20/36] net: Define usercopy region in struct proto " Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 21/36] ip: Define usercopy region in IP " Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 22/36] caif: Define usercopy region in caif " Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 23/36] sctp: Define usercopy region in SCTP " Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 24/36] sctp: Copy struct sctp_sock.autoclose to userspace using put_user() Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 25/36] net: Restrict unwhitelisted proto caches to size 0 Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 26/36] fork: Define usercopy region in mm_struct slab caches Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 27/36] fork: Define usercopy region in thread_stack " Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 28/36] fork: Provide usercopy whitelisting for task_struct Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 29/36] x86: Implement thread_struct whitelist for hardened usercopy Kees Cook
2018-01-09 20:55 ` [kernel-hardening] [PATCH 30/36] arm64: " Kees Cook
2018-01-09 20:56 ` [kernel-hardening] [PATCH 31/36] arm: " Kees Cook
2018-01-09 20:56 ` [kernel-hardening] [PATCH 32/36] kvm: whitelist struct kvm_vcpu_arch Kees Cook
2018-01-09 20:56 ` [kernel-hardening] [PATCH 33/36] kvm: x86: fix KVM_XEN_HVM_CONFIG ioctl Kees Cook
2018-01-09 20:56 ` [kernel-hardening] [PATCH 34/36] usercopy: Allow strict enforcement of whitelists Kees Cook
2018-01-09 20:56 ` [kernel-hardening] [PATCH 35/36] usercopy: Restrict non-usercopy caches to size 0 Kees Cook
2018-01-09 20:56 ` Kees Cook [this message]
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