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