This is a note to let you know that I've just added the patch titled
kheaders: Use array declaration instead of char
to the 6.1-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:
kheaders-use-array-declaration-instead-of-char.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b69edab47f1da8edd8e7bfdf8c70f51a2a5d89fb Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@xxxxxxxxxxxx>
Date: Thu, 2 Mar 2023 14:49:50 -0800
Subject: kheaders: Use array declaration instead of char
From: Kees Cook <keescook@xxxxxxxxxxxx>
commit b69edab47f1da8edd8e7bfdf8c70f51a2a5d89fb upstream.
Under CONFIG_FORTIFY_SOURCE, memcpy() will check the size of destination
and source buffers. Defining kernel_headers_data as "char" would trip
this check. Since these addresses are treated as byte arrays, define
them as arrays (as done everywhere else).
This was seen with:
$ cat /sys/kernel/kheaders.tar.xz >> /dev/null
detected buffer overflow in memcpy
kernel BUG at lib/string_helpers.c:1027!
...
RIP: 0010:fortify_panic+0xf/0x20
[...]
Call Trace:
<TASK>
ikheaders_read+0x45/0x50 [kheaders]
kernfs_fop_read_iter+0x1a4/0x2f0
...
Reported-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Link: https://lore.kernel.org/bpf/20230302112130.6e402a98@xxxxxxxxxx/
Acked-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@xxxxxxxxx>
Tested-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Fixes: 43d8ce9d65a5 ("Provide in-kernel headers to make extending kernel easier")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230302224946.never.243-kees@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/kheaders.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
--- a/kernel/kheaders.c
+++ b/kernel/kheaders.c
@@ -26,15 +26,15 @@ asm (
" .popsection \n"
);
-extern char kernel_headers_data;
-extern char kernel_headers_data_end;
+extern char kernel_headers_data[];
+extern char kernel_headers_data_end[];
static ssize_t
ikheaders_read(struct file *file, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t len)
{
- memcpy(buf, &kernel_headers_data + off, len);
+ memcpy(buf, &kernel_headers_data[off], len);
return len;
}
@@ -48,8 +48,8 @@ static struct bin_attribute kheaders_att
static int __init ikheaders_init(void)
{
- kheaders_attr.size = (&kernel_headers_data_end -
- &kernel_headers_data);
+ kheaders_attr.size = (kernel_headers_data_end -
+ kernel_headers_data);
return sysfs_create_bin_file(kernel_kobj, &kheaders_attr);
}
Patches currently in stable-queue which might be from keescook@xxxxxxxxxxxx are
queue-6.1/arm64-always-load-shadow-stack-pointer-directly-from-the-task-struct.patch
queue-6.1/arm64-stash-shadow-stack-pointer-in-the-task-struct-on-interrupt.patch
queue-6.1/kheaders-use-array-declaration-instead-of-char.patch
