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From: Kees Cook <keescook@chromium.org>
To: kernel-hardening@lists.openwall.com
Cc: Kees Cook <keescook@chromium.org>,
	Laura Abbott <labbott@redhat.com>,
	x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2 01/20] NFS: Avoid cross-structure casting
Date: Fri, 26 May 2017 13:17:05 -0700	[thread overview]
Message-ID: <1495829844-69341-2-git-send-email-keescook@chromium.org> (raw)
In-Reply-To: <1495829844-69341-1-git-send-email-keescook@chromium.org>

When the call to nfs_devname() fails, the error path attempts to retain
the error via the mnt variable, but this requires a cast across very
different types (char * to struct vfsmount *), which the upcoming
structure layout randomization plugin flags as being potentially
dangerous in the face of randomization. This is a false positive, but
what this code actually wants to do is retain the error value, so this
patch explicitly sets it, instead of using what seems to be an
unexpected cast.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
---
 fs/nfs/namespace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index 1a224a33a6c2..e5686be67be8 100644
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -246,7 +246,7 @@ struct vfsmount *nfs_do_submount(struct dentry *dentry, struct nfs_fh *fh,
 
 	devname = nfs_devname(dentry, page, PAGE_SIZE);
 	if (IS_ERR(devname))
-		mnt = (struct vfsmount *)devname;
+		mnt = ERR_CAST(devname);
 	else
 		mnt = nfs_do_clone_mount(NFS_SB(dentry->d_sb), devname, &mountdata);
 
-- 
2.7.4

  reply	other threads:[~2017-05-27  1:10 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-26 20:17 [PATCH v2 00/20] Introduce struct layout randomization plugin Kees Cook
2017-05-26 20:17 ` Kees Cook [this message]
2017-05-28  7:53   ` [PATCH v2 01/20] NFS: Avoid cross-structure casting Christoph Hellwig
2017-05-28 16:55     ` Kees Cook
2017-05-26 20:17 ` [PATCH v2 02/20] gcc-plugins: Detail c-common.h location for GCC 4.6 Kees Cook
2017-05-26 20:17 ` [PATCH v2 03/20] compiler: Add __designated_init annotation Kees Cook
2017-05-26 20:17 ` [PATCH v2 04/20] gcc-plugins: Add the randstruct plugin Kees Cook
2017-06-29 22:08   ` Arnd Bergmann
2017-06-29 22:53     ` Kees Cook
2017-06-30  0:04       ` Kees Cook
2017-06-30  7:35       ` Arnd Bergmann
2017-06-30  7:55         ` Ard Biesheuvel
2017-06-30  8:27           ` Arnd Bergmann
2017-06-30 14:41             ` Kees Cook
2017-06-30 15:22               ` Arnd Bergmann
2017-05-26 20:17 ` [PATCH v2 05/20] randstruct: Whitelist struct security_hook_heads cast Kees Cook
2017-05-27  8:41   ` Christoph Hellwig
2017-05-27 20:09     ` Kees Cook
2017-05-27 22:04       ` Tetsuo Handa
2017-05-28  0:43         ` [kernel-hardening] " Kees Cook
2017-05-30 10:34       ` James Morris
2017-05-26 20:17 ` [PATCH v2 06/20] randstruct: Whitelist UNIXCB cast Kees Cook
2017-05-26 20:20   ` Kees Cook
2017-05-28  7:56   ` Christoph Hellwig
2017-05-26 20:17 ` [PATCH v2 07/20] randstruct: Whitelist big_key path struct overloading Kees Cook
2017-05-28  8:12   ` Christoph Hellwig
2017-05-28 16:59     ` Kees Cook
2017-06-19 19:24       ` Kees Cook
2017-09-07  7:20         ` Christoph Hellwig
2017-09-07 22:55           ` Kees Cook
2017-05-26 20:17 ` [PATCH v2 08/20] randstruct: Whitelist NIU struct page overloading Kees Cook
2017-05-28  8:15   ` Christoph Hellwig
2017-05-28 17:35     ` Kees Cook
2017-05-28 17:37     ` Kees Cook
2017-05-26 20:17 ` [PATCH v2 09/20] randstruct: Mark various structs for randomization Kees Cook
2017-05-26 20:17 ` [PATCH v2 10/20] randstruct: opt-out externally exposed function pointer structs Kees Cook
2017-05-26 20:17 ` [PATCH v2 11/20] randstruct: Disable randomization of ACPICA structs Kees Cook
2017-05-27  8:42   ` Christoph Hellwig
2017-05-27 20:03     ` Kees Cook
2017-05-28  4:55       ` Christoph Hellwig
2017-05-26 20:17 ` [PATCH v2 12/20] sgi-xp: Use designated initializers Kees Cook
2017-05-27  8:44   ` Christoph Hellwig
2017-05-26 20:17 ` [PATCH v2 13/20] drm/amdgpu: " Kees Cook
2017-05-26 20:17 ` [PATCH v2 14/20] drm/amd/powerplay: " Kees Cook
2017-05-27  8:47   ` Christoph Hellwig
2017-05-27 20:10     ` Kees Cook
2017-05-26 20:17 ` [PATCH v2 15/20] mtk-vcodec: " Kees Cook
2017-05-26 20:17 ` [PATCH v2 16/20] ntfs: Use ERR_CAST() to avoid cross-structure cast Kees Cook
2017-05-26 20:17 ` [PATCH v2 17/20] ocfs2: " Kees Cook
2017-05-26 20:17 ` [PATCH v2 18/20] randstruct: Enable function pointer struct detection Kees Cook
2017-05-26 20:17 ` [PATCH v2 19/20] [RFC] task_struct: Allow randomized layout Kees Cook
2017-05-26 20:23   ` Linus Torvalds
2017-05-26 20:32     ` Kees Cook
2017-05-26 20:17 ` [PATCH v2 20/20] ACPICA: Use designated initializers Kees Cook
2017-05-28  7:45   ` Christoph Hellwig

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