Messages in this thread Patch in this message | | | Date | Tue, 16 Nov 2010 11:46:03 +0100 | From | Marcus Meissner <> | Subject | [PATCH] kernel: make /proc/kallsyms mode 400 to reduce ease of attacking |
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Hi,
Making /proc/kallsyms readable only for root makes it harder for attackers to write generic kernel exploits by removing one source of knowledge where things are in the kernel.
This is the second submit, discussion happened on this on first submit and mostly concerned that this is just one hole of the sieve ... but one of the bigger ones.
Changing the permissions of at least System.map and vmlinux is also required to fix the same set, but a packaging issue.
Target of this starter patch and follow ups is removing any kind of kernel space address information leak from the kernel.
Ciao, Marcus
Signed-off-by: Marcus Meissner <meissner@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Eugene Teo <eugeneteo@kernel.org> Reviewed-by: Jesper Juhl <jj@chaosbits.net> --- kernel/kallsyms.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 6f6d091..a8db257 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -546,7 +546,7 @@ static const struct file_operations kallsyms_operations = { static int __init kallsyms_init(void) { - proc_create("kallsyms", 0444, NULL, &kallsyms_operations); + proc_create("kallsyms", 0400, NULL, &kallsyms_operations); return 0; } device_initcall(kallsyms_init); -- 1.7.1
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