From: Helge Deller <deller@gmx.de>
Date: Sat, 31 May 2025 15:08:21 +0000 (+0200)
Subject: apparmor: Fix 8-byte alignment for initial dfa blob streams
X-Git-Tag: v6.17-rc1~50^2~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c567de2c4f5fe6e079672e074e1bc6122bf7e444;p=thirdparty%2Flinux.git

apparmor: Fix 8-byte alignment for initial dfa blob streams

The dfa blob stream for the aa_dfa_unpack() function is expected to be aligned
on a 8 byte boundary.

The static nulldfa_src[] and stacksplitdfa_src[] arrays store the initial
apparmor dfa blob streams, but since they are declared as an array-of-chars
the compiler and linker will only ensure a "char" (1-byte) alignment.

Add an __aligned(8) annotation to the arrays to tell the linker to always
align them on a 8-byte boundary. This avoids runtime warnings at startup on
alignment-sensitive platforms like parisc such as:

 Kernel: unaligned access to 0x7f2a584a in aa_dfa_unpack+0x124/0x788 (iir 0xca0109f)
 Kernel: unaligned access to 0x7f2a584e in aa_dfa_unpack+0x210/0x788 (iir 0xca8109c)
 Kernel: unaligned access to 0x7f2a586a in aa_dfa_unpack+0x278/0x788 (iir 0xcb01090)

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
Fixes: 98b824ff8984 ("apparmor: refcount the pdb")
Signed-off-by: John Johansen <john.johansen@canonical.com>
---

diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 0640a379a518b..d3da9db244b0c 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -2404,12 +2404,12 @@ static int __init apparmor_nf_ip_init(void)
 __initcall(apparmor_nf_ip_init);
 #endif
 
-static char nulldfa_src[] = {
+static char nulldfa_src[] __aligned(8) = {
 	#include "nulldfa.in"
 };
 static struct aa_dfa *nulldfa;
 
-static char stacksplitdfa_src[] = {
+static char stacksplitdfa_src[] __aligned(8) = {
 	#include "stacksplitdfa.in"
 };
 struct aa_dfa *stacksplitdfa;