4c390211d8
CVE-2017-1000364 (rather bugfix for the original CVE fix): * mm/mmap.c: expand_downwards: don't require the gap if !vm_prev * mm/mmap.c: do not blow on PROT_NONE MAP_FIXED holes in the stack CVE-2017-1000365: fs/exec.c: account for argv/envp pointers CVE-2017-10810: drm/virtio: don't leak bo on drm_gem_object_init failure CVE-2017-7482: rxrpc: Fix several cases where a padded len isn't checked in ticket decode Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
99 lines
3.5 KiB
Diff
99 lines
3.5 KiB
Diff
From 6b44f156198491839655077fc7f3a469c67e1f8d Mon Sep 17 00:00:00 2001
|
|
From: Kees Cook <keescook@chromium.org>
|
|
Date: Wed, 12 Jul 2017 15:30:39 +0200
|
|
Subject: [PATCH 2/3] fs/exec.c: account for argv/envp pointers
|
|
|
|
When limiting the argv/envp strings during exec to 1/4 of the stack limit,
|
|
the storage of the pointers to the strings was not included. This means
|
|
that an exec with huge numbers of tiny strings could eat 1/4 of the stack
|
|
limit in strings and then additional space would be later used by the
|
|
pointers to the strings.
|
|
|
|
For example, on 32-bit with a 8MB stack rlimit, an exec with 1677721
|
|
single-byte strings would consume less than 2MB of stack, the max (8MB /
|
|
4) amount allowed, but the pointers to the strings would consume the
|
|
remaining additional stack space (1677721 * 4 == 6710884).
|
|
|
|
The result (1677721 + 6710884 == 8388605) would exhaust stack space
|
|
entirely. Controlling this stack exhaustion could result in
|
|
pathological behavior in setuid binaries (CVE-2017-1000365).
|
|
|
|
[akpm@linux-foundation.org: additional commenting from Kees]
|
|
Fixes: b6a2fea39318 ("mm: variable length argument support")
|
|
Link: http://lkml.kernel.org/r/20170622001720.GA32173@beast
|
|
Signed-off-by: Kees Cook <keescook@chromium.org>
|
|
Acked-by: Rik van Riel <riel@redhat.com>
|
|
Acked-by: Michal Hocko <mhocko@suse.com>
|
|
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
|
|
Cc: Qualys Security Advisory <qsa@qualys.com>
|
|
Cc: <stable@vger.kernel.org>
|
|
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
|
|
CVE-2017-1000365
|
|
|
|
(cherry-picked from commit 98da7d08850fb8bdeb395d6368ed15753304aa0c)
|
|
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
|
|
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
|
|
Acked-by: Seth Forshee <seth.forshee@canonical.com>
|
|
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
|
|
|
|
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
|
|
---
|
|
fs/exec.c | 28 ++++++++++++++++++++++++----
|
|
1 file changed, 24 insertions(+), 4 deletions(-)
|
|
|
|
diff --git a/fs/exec.c b/fs/exec.c
|
|
index 9fb90c37c37f..8cf76e2a0b83 100644
|
|
--- a/fs/exec.c
|
|
+++ b/fs/exec.c
|
|
@@ -225,8 +225,26 @@ static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
|
|
|
|
if (write) {
|
|
unsigned long size = bprm->vma->vm_end - bprm->vma->vm_start;
|
|
+ unsigned long ptr_size;
|
|
struct rlimit *rlim;
|
|
|
|
+ /*
|
|
+ * Since the stack will hold pointers to the strings, we
|
|
+ * must account for them as well.
|
|
+ *
|
|
+ * The size calculation is the entire vma while each arg page is
|
|
+ * built, so each time we get here it's calculating how far it
|
|
+ * is currently (rather than each call being just the newly
|
|
+ * added size from the arg page). As a result, we need to
|
|
+ * always add the entire size of the pointers, so that on the
|
|
+ * last call to get_arg_page() we'll actually have the entire
|
|
+ * correct size.
|
|
+ */
|
|
+ ptr_size = (bprm->argc + bprm->envc) * sizeof(void *);
|
|
+ if (ptr_size > ULONG_MAX - size)
|
|
+ goto fail;
|
|
+ size += ptr_size;
|
|
+
|
|
acct_arg_size(bprm, size / PAGE_SIZE);
|
|
|
|
/*
|
|
@@ -244,13 +262,15 @@ static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
|
|
* to work from.
|
|
*/
|
|
rlim = current->signal->rlim;
|
|
- if (size > ACCESS_ONCE(rlim[RLIMIT_STACK].rlim_cur) / 4) {
|
|
- put_page(page);
|
|
- return NULL;
|
|
- }
|
|
+ if (size > READ_ONCE(rlim[RLIMIT_STACK].rlim_cur) / 4)
|
|
+ goto fail;
|
|
}
|
|
|
|
return page;
|
|
+
|
|
+fail:
|
|
+ put_page(page);
|
|
+ return NULL;
|
|
}
|
|
|
|
static void put_arg_page(struct page *page)
|
|
--
|
|
2.11.0
|
|
|