From nobody Thu Feb 12 08:03:01 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 97F53EE6457 for ; Fri, 15 Sep 2023 12:37:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234991AbjIOMhR (ORCPT ); Fri, 15 Sep 2023 08:37:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49950 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232706AbjIOMhI (ORCPT ); Fri, 15 Sep 2023 08:37:08 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BA62C1A5 for ; Fri, 15 Sep 2023 05:36:58 -0700 (PDT) Received: from kwepemi500008.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4RnD9W4BswztS29; Fri, 15 Sep 2023 20:32:47 +0800 (CST) Received: from huawei.com (10.90.53.73) by kwepemi500008.china.huawei.com (7.221.188.139) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Fri, 15 Sep 2023 20:36:56 +0800 From: Jinjie Ruan To: , , , , , , CC: Subject: [PATCH v2 2/2] static_call: Fix a wild-memory-access bug when static_call_key_sites(key) is true Date: Fri, 15 Sep 2023 20:36:05 +0800 Message-ID: <20230915123605.3732345-3-ruanjinjie@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230915123605.3732345-1-ruanjinjie@huawei.com> References: <20230915123605.3732345-1-ruanjinjie@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.90.53.73] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemi500008.china.huawei.com (7.221.188.139) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Inject fault while probing btrfs.ko, when static_call_key_sites(key) is true, if the first kzalloc() succeeds but the second kzalloc() fails in __static_call_init() in the for loop, the key->mods will not be initialized in the subsequent sites. And then in static_call_del_module() the site_mod->mod will cause wild-memory-access as below. So assign key->mods to NULL in __static_call_init() if it fails and break if key->mods is NULL in exit func to fix the issue. Free the just allocated site_mod in key->mods because site_mod->mod will be NULL without a site_mod->mod =3D mod head node, so it will not be found in static_call_del_module(). general protection fault, probably for non-canonical address 0xfec001628a9= f8a82: 0000 [#1] PREEMPT SMP KASAN KASAN: maybe wild-memory-access in range [0xf6002b1454fc5410-0xf6002b1454f= c5417] CPU: 2 PID: 1812 Comm: modprobe Tainted: G W N 6.6.0-rc1+ #96 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu= 1.1 04/01/2014 RIP: 0010:static_call_del_module+0x11a/0x2a0 Code: 00 00 49 8b 6e 08 48 85 ed 75 14 e9 8c 00 00 00 48 85 db 0f 84 83 00= 00 00 49 89 ef 48 89 dd 48 8d 7d 08 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 = 0f 85 87 00 00 00 48 89 e8 4c 8b 6d 08 48 c1 e8 03 RSP: 0018:ffff888101e97860 EFLAGS: 00010a06 RAX: 1ec005628a9f8a82 RBX: f6002b1454fc540b RCX: ffffffffa05b1880 RDX: ffffffffa05acd84 RSI: 0000000000000000 RDI: f6002b1454fc5413 RBP: f6002b1454fc540b R08: ffffffffa05adb3c R09: ffffed10203d2eda R10: ffffed10203d2ed9 R11: ffff888101e976cf R12: dffffc0000000000 R13: 68002b144cfe8871 R14: ffffffff851958a0 R15: ffffffff84ee4449 FS: 00007f20cb75f540(0000) GS:ffff888119f00000(0000) knlGS:00000000000000= 00 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe945e1bb8 CR3: 000000010c3d6003 CR4: 0000000000170ee0 DR0: ffffffff8faefce8 DR1: ffffffff8faefce9 DR2: ffffffff8faefcea DR3: ffffffff8faefceb DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: ? __die_body+0x1b/0x60 ? die_addr+0x43/0x70 ? exc_general_protection+0x121/0x210 ? asm_exc_general_protection+0x22/0x30 ? static_call_del_module+0x11a/0x2a0 ? __SCT__cond_resched+0x8/0x8 static_call_module_notify+0x2a6/0x3c0 notifier_call_chain+0xbf/0x280 ? stack_trace_save+0x91/0xc0 notifier_call_chain_robust+0x7f/0xe0 ? notifier_call_chain+0x280/0x280 ? alloc_covered_add+0x30/0x60 blocking_notifier_call_chain_robust+0x5b/0x80 load_module+0x4d1d/0x69f0 ? module_frob_arch_sections+0x20/0x20 ? uprobe_apply+0x100/0x100 ? rwsem_down_write_slowpath+0x11c0/0x11c0 ? kernel_read_file+0x3ca/0x510 ? __x64_sys_fsconfig+0x650/0x650 ? init_module_from_file+0xd2/0x130 init_module_from_file+0xd2/0x130 ? __ia32_sys_init_module+0xa0/0xa0 ? userfaultfd_unmap_prep+0x3d0/0x3d0 ? _raw_spin_lock_irqsave+0xe0/0xe0 idempotent_init_module+0x32d/0x6a0 ? init_module_from_file+0x130/0x130 ? __fget_light+0x57/0x500 __x64_sys_finit_module+0xbb/0x130 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Fixes: a945c8345ec0 ("static_call: Allow early init") Signed-off-by: Jinjie Ruan --- kernel/static_call_inline.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/static_call_inline.c b/kernel/static_call_inline.c index e7aa70d33530..a8ade6208237 100644 --- a/kernel/static_call_inline.c +++ b/kernel/static_call_inline.c @@ -274,8 +274,11 @@ static int __static_call_init(struct module *mod, key->mods =3D site_mod; =20 site_mod =3D kzalloc(sizeof(*site_mod), GFP_KERNEL); - if (!site_mod) + if (!site_mod) { + kfree(key->mods); + key->mods =3D NULL; return -ENOMEM; + } } =20 site_mod->mod =3D mod; --=20 2.34.1