The patch titled
Subject: uaccess: disallow > INT_MAX copy sizes
has been added to the -mm tree. Its filename is
uaccess-disallow-int_max-copy-sizes.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/uaccess-disallow-int_max-copy-sizes.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/uaccess-disallow-int_max-copy-sizes.patch
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------------------------------------------------------
From: Kees Cook <keescook@xxxxxxxxxxxx>
Subject: uaccess: disallow > INT_MAX copy sizes
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>
---
include/linux/thread_info.h | 2 ++
1 file changed, 2 insertions(+)
--- a/include/linux/thread_info.h~uaccess-disallow-int_max-copy-sizes
+++ a/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 -mm which might be from keescook@xxxxxxxxxxxx are
uaccess-disallow-int_max-copy-sizes.patch
