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authorKees Cook <keescook@chromium.org>2019-12-04 16:52:40 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-12-04 19:44:14 -0800
commit6d13de1489b6bf539695f96d945de3860e6d5e17 (patch)
tree1d7f9e2f577347588bdc4335cc78340b7ea9947b
parent5bf8bec3f4ce044a223c40cbce92590d938f0e9c (diff)
downloadlinux-6d13de1489b6bf539695f96d945de3860e6d5e17.tar.bz2
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>
-rw-r--r--include/linux/thread_info.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index 659a4400517b..e93e249a4e9b 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -147,6 +147,8 @@ check_copy_size(const void *addr, size_t bytes, bool is_source)
__bad_copy_to();
return false;
}
+ if (WARN_ON_ONCE(bytes > INT_MAX))
+ return false;
check_object_size(addr, bytes, is_source);
return true;
}