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| author | Kees Cook <keescook@chromium.org> | 2019-12-04 16:52:40 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-12-04 19:44:14 -0800 |
| commit | 6d13de1489b6bf539695f96d945de3860e6d5e17 (patch) | |
| tree | 1d7f9e2f577347588bdc4335cc78340b7ea9947b | |
| parent | 5bf8bec3f4ce044a223c40cbce92590d938f0e9c (diff) | |
| download | linux-6d13de1489b6bf539695f96d945de3860e6d5e17.tar.gz linux-6d13de1489b6bf539695f96d945de3860e6d5e17.tar.bz2 linux-6d13de1489b6bf539695f96d945de3860e6d5e17.zip | |
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.h | 2 |
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; } |