From: Kees Cook <keescook@chromium.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>,
kernel test robot <lkp@intel.com>,
Matt Porter <mporter@kernel.crashing.org>,
Alexandre Bounine <alex.bou9@gmail.com>,
Jing Xiangfeng <jingxiangfeng@huawei.com>,
Ira Weiny <ira.weiny@intel.com>,
Souptick Joarder <jrdr.linux@gmail.com>,
"Gustavo A . R . Silva" <gustavoars@kernel.org>,
John Hubbard <jhubbard@nvidia.com>, Joe Perches <joe@perches.com>,
Miguel Ojeda <ojeda@kernel.org>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Andy Whitcroft <apw@canonical.com>,
Dwaipayan Ray <dwaipayanray1@gmail.com>,
Lukas Bulwahn <lukas.bulwahn@gmail.com>,
Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Vlastimil Babka <vbabka@suse.cz>,
Daniel Micay <danielmicay@gmail.com>,
Dennis Zhou <dennis@kernel.org>, Tejun Heo <tj@kernel.org>,
Masahiro Yamada <masahiroy@kernel.org>,
Michal Marek <michal.lkml@markovi.net>,
clang-built-linux@googlegroups.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org,
linux-hardening@vger.kernel.org
Subject: [PATCH v3 1/8] rapidio: Avoid bogus __alloc_size warning
Date: Thu, 30 Sep 2021 15:26:57 -0700 [thread overview]
Message-ID: <20210930222704.2631604-2-keescook@chromium.org> (raw)
In-Reply-To: <20210930222704.2631604-1-keescook@chromium.org>
After adding __alloc_size attributes to the allocators, GCC 9.3 (but not
later) may incorrectly evaluate the arguments to check_copy_size(),
getting seemingly confused by the size being returned from array_size().
Instead, perform the calculation once, which both makes the code more
readable and avoids the bug in GCC.
In file included from arch/x86/include/asm/preempt.h:7,
from include/linux/preempt.h:78,
from include/linux/spinlock.h:55,
from include/linux/mm_types.h:9,
from include/linux/buildid.h:5,
from include/linux/module.h:14,
from drivers/rapidio/devices/rio_mport_cdev.c:13:
In function 'check_copy_size',
inlined from 'copy_from_user' at include/linux/uaccess.h:191:6,
inlined from 'rio_mport_transfer_ioctl' at drivers/rapidio/devices/rio_mport_cdev.c:983:6:
include/linux/thread_info.h:213:4: error: call to '__bad_copy_to' declared with attribute error: copy destination size is too small
213 | __bad_copy_to();
| ^~~~~~~~~~~~~~~
But the allocation size and the copy size are identical:
transfer = vmalloc(array_size(sizeof(*transfer), transaction.count));
if (!transfer)
return -ENOMEM;
if (unlikely(copy_from_user(transfer,
(void __user *)(uintptr_t)transaction.block,
array_size(sizeof(*transfer), transaction.count)))) {
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/linux-mm/202109091134.FHnRmRxu-lkp@intel.com/
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Jing Xiangfeng <jingxiangfeng@huawei.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
---
drivers/rapidio/devices/rio_mport_cdev.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/rapidio/devices/rio_mport_cdev.c b/drivers/rapidio/devices/rio_mport_cdev.c
index 94331d999d27..7df466e22282 100644
--- a/drivers/rapidio/devices/rio_mport_cdev.c
+++ b/drivers/rapidio/devices/rio_mport_cdev.c
@@ -965,6 +965,7 @@ static int rio_mport_transfer_ioctl(struct file *filp, void __user *arg)
struct rio_transfer_io *transfer;
enum dma_data_direction dir;
int i, ret = 0;
+ size_t size;
if (unlikely(copy_from_user(&transaction, arg, sizeof(transaction))))
return -EFAULT;
@@ -976,13 +977,14 @@ static int rio_mport_transfer_ioctl(struct file *filp, void __user *arg)
priv->md->properties.transfer_mode) == 0)
return -ENODEV;
- transfer = vmalloc(array_size(sizeof(*transfer), transaction.count));
+ size = array_size(sizeof(*transfer), transaction.count);
+ transfer = vmalloc(size);
if (!transfer)
return -ENOMEM;
if (unlikely(copy_from_user(transfer,
(void __user *)(uintptr_t)transaction.block,
- array_size(sizeof(*transfer), transaction.count)))) {
+ size))) {
ret = -EFAULT;
goto out_free;
}
@@ -994,8 +996,7 @@ static int rio_mport_transfer_ioctl(struct file *filp, void __user *arg)
transaction.sync, dir, &transfer[i]);
if (unlikely(copy_to_user((void __user *)(uintptr_t)transaction.block,
- transfer,
- array_size(sizeof(*transfer), transaction.count))))
+ transfer, size)))
ret = -EFAULT;
out_free:
--
2.30.2
next prev parent reply other threads:[~2021-09-30 22:27 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-30 22:26 [PATCH v3 0/8] Add __alloc_size() Kees Cook
2021-09-30 22:26 ` Kees Cook [this message]
2021-09-30 22:46 ` [PATCH v3 1/8] rapidio: Avoid bogus __alloc_size warning Gustavo A. R. Silva
2021-09-30 22:26 ` [PATCH v3 2/8] Compiler Attributes: add __alloc_size() for better bounds checking Kees Cook
2021-09-30 22:48 ` Miguel Ojeda
2021-09-30 22:26 ` [PATCH v3 3/8] slab: Clean up function prototypes Kees Cook
2021-09-30 22:27 ` [PATCH v3 4/8] slab: Add __alloc_size attributes for better bounds checking Kees Cook
2021-10-06 1:47 ` Andrew Morton
2021-10-06 3:06 ` Kees Cook
2021-10-06 3:22 ` Jann Horn
2021-10-06 3:56 ` Kees Cook
2021-10-06 4:52 ` Jann Horn
2021-09-30 22:27 ` [PATCH v3 5/8] mm/kvmalloc: " Kees Cook
2021-09-30 22:27 ` [PATCH v3 6/8] mm/vmalloc: " Kees Cook
2021-09-30 22:27 ` [PATCH v3 7/8] mm/page_alloc: " Kees Cook
2021-09-30 22:27 ` [PATCH v3 8/8] percpu: " Kees Cook
2021-10-01 14:15 ` Dennis Zhou
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210930222704.2631604-2-keescook@chromium.org \
--to=keescook@chromium.org \
--cc=akpm@linux-foundation.org \
--cc=alex.bou9@gmail.com \
--cc=apw@canonical.com \
--cc=cl@linux.com \
--cc=clang-built-linux@googlegroups.com \
--cc=danielmicay@gmail.com \
--cc=dennis@kernel.org \
--cc=dwaipayanray1@gmail.com \
--cc=gustavoars@kernel.org \
--cc=iamjoonsoo.kim@lge.com \
--cc=ira.weiny@intel.com \
--cc=jhubbard@nvidia.com \
--cc=jingxiangfeng@huawei.com \
--cc=joe@perches.com \
--cc=jrdr.linux@gmail.com \
--cc=linux-hardening@vger.kernel.org \
--cc=linux-kbuild@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=lkp@intel.com \
--cc=lukas.bulwahn@gmail.com \
--cc=masahiroy@kernel.org \
--cc=michal.lkml@markovi.net \
--cc=mporter@kernel.crashing.org \
--cc=nathan@kernel.org \
--cc=ndesaulniers@google.com \
--cc=ojeda@kernel.org \
--cc=penberg@kernel.org \
--cc=rientjes@google.com \
--cc=tj@kernel.org \
--cc=vbabka@suse.cz \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).