This is a note to let you know that I've just added the patch titled
uaccess: disallow > INT_MAX copy sizes
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
uaccess-disallow-int_max-copy-sizes.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 6d13de1489b6bf539695f96d945de3860e6d5e17 Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@xxxxxxxxxxxx>
Date: Wed, 4 Dec 2019 16:52:40 -0800
Subject: uaccess: disallow > INT_MAX copy sizes
From: Kees Cook <keescook@xxxxxxxxxxxx>
commit 6d13de1489b6bf539695f96d945de3860e6d5e17 upstream.
As we've done with VFS, string operations, etc, reject usercopy sizes
larger than INT_MAX, which would be nice to have for catching bugs
related to size calculation overflows[1].
This adds 10 bytes to x86_64 defconfig text and 1980 bytes to the data
section:
text data bss dec hex filename
19691167 5134320 1646664 26472151 193eed7 vmlinux.before
19691177 5136300 1646664 26474141 193f69d vmlinux.after
[1] https://marc.info/?l=linux-s390&m=156631939010493&w=2
Link: http://lkml.kernel.org/r/201908251612.F9902D7A@keescook
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Suggested-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/thread_info.h | 2 ++
1 file changed, 2 insertions(+)
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -147,6 +147,8 @@ check_copy_size(const void *addr, size_t
__bad_copy_to();
return false;
}
+ if (WARN_ON_ONCE(bytes > INT_MAX))
+ return false;
check_object_size(addr, bytes, is_source);
return true;
}
Patches currently in stable-queue which might be from keescook@xxxxxxxxxxxx are
queue-5.4/drm-limit-to-int_max-in-create_blob-ioctl.patch
queue-5.4/dma-mapping-add-vmap-checks-to-dma_map_single.patch
queue-5.4/uaccess-disallow-int_max-copy-sizes.patch
