From a7f6c1b63b863d29f126d9b163ad5b40008544b2 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Mon, 14 Nov 2016 20:11:52 +0900 Subject: [PATCH] AppArmor: Use GFP_KERNEL for __aa_kvmalloc(). Calling kmalloc(GFP_NOIO) with order == PAGE_ALLOC_COSTLY_ORDER is not recommended because it might fall into infinite retry loop without invoking the OOM killer. Since aa_dfa_unpack() is the only caller of kvzalloc() and aa_dfa_unpack() which is calling kvzalloc() via unpack_table() is doing kzalloc(GFP_KERNEL), it is safe to use GFP_KERNEL from __aa_kvmalloc(). Since aa_simple_write_to_buffer() is the only caller of kvmalloc() and aa_simple_write_to_buffer() is calling copy_from_user() which is GFP_KERNEL context (see memdup_user_nul()), it is safe to use GFP_KERNEL from __aa_kvmalloc(). Therefore, replace GFP_NOIO with GFP_KERNEL. Also, since we have vmalloc() fallback, add __GFP_NORETRY so that we don't invoke the OOM killer by kmalloc(GFP_KERNEL) with order == PAGE_ALLOC_COSTLY_ORDER. Signed-off-by: Tetsuo Handa Signed-off-by: John Johansen --- security/apparmor/lib.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/security/apparmor/lib.c b/security/apparmor/lib.c index c1827e068454..2ef422a25474 100644 --- a/security/apparmor/lib.c +++ b/security/apparmor/lib.c @@ -95,7 +95,8 @@ void *__aa_kvmalloc(size_t size, gfp_t flags) /* do not attempt kmalloc if we need more than 16 pages at once */ if (size <= (16*PAGE_SIZE)) - buffer = kmalloc(size, flags | GFP_NOIO | __GFP_NOWARN); + buffer = kmalloc(size, flags | GFP_KERNEL | __GFP_NORETRY | + __GFP_NOWARN); if (!buffer) { if (flags & __GFP_ZERO) buffer = vzalloc(size); -- 2.20.1