p71924506
/
linux_old1
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

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@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>
This commit is contained in:
Kees Cook 2019-12-04 16:52:40 -08:00 committed by Linus Torvalds
parent 5bf8bec3f4
commit 6d13de1489
1 changed files with 2 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/linux/thread_info.h
View File

@ -147,6 +147,8 @@ check_copy_size(const void *addr, size_t bytes, bool is_source)
__bad_copy_to(); __bad_copy_to();
return false; return false;
} }
if (WARN_ON_ONCE(bytes > INT_MAX))
return false;
check_object_size(addr, bytes, is_source); check_object_size(addr, bytes, is_source);
return true; return true;
} }