Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.4 144/191] uaccess: disallow > INT_MAX copy sizes | Date | Thu, 2 Jan 2020 23:07:06 +0100 |
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From: Kees Cook <keescook@chromium.org>
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@chromium.org> Suggested-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- 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; }
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