From mboxrd@z Thu Jan 1 00:00:00 1970 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 78525C47088 for ; Mon, 5 Dec 2022 22:11:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233501AbiLEWLf (ORCPT ); Mon, 5 Dec 2022 17:11:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233303AbiLEWLd (ORCPT ); Mon, 5 Dec 2022 17:11:33 -0500 Received: from mail-wm1-x330.google.com (mail-wm1-x330.google.com [IPv6:2a00:1450:4864:20::330]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A434B17E33 for ; Mon, 5 Dec 2022 14:11:32 -0800 (PST) Received: by mail-wm1-x330.google.com with SMTP id ay27-20020a05600c1e1b00b003d070f4060bso11336919wmb.2 for ; Mon, 05 Dec 2022 14:11:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=vfJyjQH6Qly3zbvWfcSWgezdbGXYLhLITb4c4nyFl60=; b=ifbSTSU0il64gXhtN1KnceCqVNTmwaX82wuu/7Es9avtKxHhfh4UcP0NVIEmIP64d6 88Jp/f92NTJsMBYNY2TuQ+LgwdF4W/WOeKWKb7SZRCaDE6ML+yFXml5HS8dh/5Oc/nJg nO2S3mB948KOXFeax/8AaMWh8EFKVChm8dOmJaFFnzkUGEU6bcmMfDh4QeHN2VEO2oqo qwYfRTBOABeyuHXps8G1k4Gl3cIjghWRN5CIFhNXeRqinnTpHmlD72H9HEUoVJFmvsIe vxWngceU5/3L+nPe/7sjvw1MEGnwv/iFLChbUDPBwLgzjk4jmwDX08l7YzAnvAroWBvb by1w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=vfJyjQH6Qly3zbvWfcSWgezdbGXYLhLITb4c4nyFl60=; b=yJVlWPPfflK95/ymBAFCAJqt2oMqnQqzRLFw2lxpa9pcnhMQSG7CO4T59GZ9jiDatz j8+WVyMoRlDQYdCJGAlzijAl+y5fDcBXz+2IROovKta0omNpLe5IXfVUyCzWnrvQsIVp 5W3NmxvTgIZZs2Cg/DRV/IRt8zrc+QqbdjuwkeU4fq7QglK0xpL+MCeP0NA1LwkSHTel QOUIo9v3oSCZIFfsD4Amt3Y9u4RD4woJBO4HSsiIM+fIfWofgL9n8RKDiNEqBE2+0ULC 8DtVfKKj2Vg2GN5rsIunMTqVJ+yVIN2mHju26tLlOFR1KHXmSymgK64e2Evflp7BdFZa kquA== X-Gm-Message-State: ANoB5plOcPF+KvT9WvcU6KiMKQMtRW6+fD74ZIxjjzC6cA8HHQrcGrva LNngnnabe9R9IyixgwBBIqk= X-Google-Smtp-Source: AA0mqf6aOKCZRyrIESxo+gCvsknBMi6NDS671HQv20ByhKSu/P8U3PrrtHcueOmVwxehKL0eGLhsAQ== X-Received: by 2002:a7b:c00a:0:b0:3cf:e8f0:ad11 with SMTP id c10-20020a7bc00a000000b003cfe8f0ad11mr65765028wmb.65.1670278290950; Mon, 05 Dec 2022 14:11:30 -0800 (PST) Received: from niros.localdomain ([176.231.147.83]) by smtp.gmail.com with ESMTPSA id k4-20020adfd844000000b0023659925b2asm15390915wrl.51.2022.12.05.14.11.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 Dec 2022 14:11:30 -0800 (PST) From: Nir Levy To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, linux-atm-general@lists.sourceforge.net, netdev@vger.kernel.org, leon@kernel.org Cc: bhr166@gmail.com Subject: [PATCH net] net: atm: Fix use-after-free bug in atm_dev_register() Date: Tue, 6 Dec 2022 00:11:09 +0200 Message-Id: <20221205221109.435680-1-bhr166@gmail.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org When device_register() return failed in atm_register_sysfs, the program will return to atm_dev_register and will kfree the device. As the comment of device_register() says, put_device() needs to be used to give up the reference in the error path. Using kfree instead triggers a UAF, as shown by the following KASAN report, obtained by causing device_register() to fail. This patch calls put_device when atm_register_sysfs has failed, and call kfree only when atm_proc_dev_register has failed. KASAN report details as below: [ 94.341664] BUG: KASAN: use-after-free in sysfs_kf_seq_show+0x306/0x440 [ 94.341674] Read of size 8 at addr ffff88819a8a30e8 by task systemd-udevd/484 [ 94.341680] CPU: 3 PID: 484 Comm: systemd-udevd Tainted: G E 6.1.0-rc1+ #1 [ 94.341684] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 02/27/2020 [ 94.341703] Call Trace: [ 94.341705] [ 94.341707] dump_stack_lvl+0x49/0x63 [ 94.341713] print_report+0x177/0x46e [ 94.341717] ? kasan_complete_mode_report_info+0x7c/0x210 [ 94.341720] ? sysfs_kf_seq_show+0x306/0x440 [ 94.341753] kasan_report+0xb0/0x140 [ 94.341757] ? sysfs_kf_seq_show+0x306/0x440 [ 94.341760] __asan_report_load8_noabort+0x14/0x20 [ 94.341763] sysfs_kf_seq_show+0x306/0x440 [ 94.341766] kernfs_seq_show+0x145/0x1b0 [ 94.341769] seq_read_iter+0x408/0x1080 [ 94.341774] kernfs_fop_read_iter+0x3d5/0x540 [ 94.341794] vfs_read+0x542/0x800 [ 94.341797] ? kernel_read+0x130/0x130 [ 94.341800] ? __kasan_check_read+0x11/0x20 [ 94.341824] ? get_nth_filter.part.0+0x200/0x200 [ 94.341828] ksys_read+0x116/0x220 [ 94.341831] ? __ia32_sys_pwrite64+0x1f0/0x1f0 [ 94.341849] ? __secure_computing+0x17c/0x2d0 [ 94.341852] __x64_sys_read+0x72/0xb0 [ 94.341875] do_syscall_64+0x59/0x90 [ 94.341878] ? exc_page_fault+0x72/0xf0 [ 94.341881] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 94.341885] RIP: 0033:0x7fc391f14992 [ 94.341888] Code: c0 e9 b2 fe ff ff 50 48 8d 3d fa b2 0c 00 e8 c5 1d 02 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24 [ 94.341891] RSP: 002b:00007ffe33fed818 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 94.341896] RAX: ffffffffffffffda RBX: 0000000000001018 RCX: 00007fc391f14992 [ 94.341898] RDX: 0000000000001018 RSI: 0000558a696b0880 RDI: 000000000000000e [ 94.341900] RBP: 0000558a696b0880 R08: 0000000000000000 R09: 0000558a696b0880 [ 94.341902] R10: 00007fc39201a300 R11: 0000000000000246 R12: 000000000000000e [ 94.341904] R13: 0000000000001017 R14: 0000000000000002 R15: 00007ffe33fed840 [ 94.341908] [ 94.341911] Allocated by task 2613: [ 94.341914] kasan_save_stack+0x26/0x50 [ 94.341932] kasan_set_track+0x25/0x40 [ 94.341934] kasan_save_alloc_info+0x1e/0x30 [ 94.341936] __kasan_kmalloc+0xb4/0xc0 [ 94.341938] kmalloc_trace+0x4a/0xb0 [ 94.341941] atm_dev_register+0x5d/0x700 [atm] [ 94.341949] atmtcp_create+0x77/0x1f0 [atmtcp] [ 94.341953] atmtcp_ioctl+0x12d/0xb9f [atmtcp] [ 94.341957] do_vcc_ioctl+0xfe/0x640 [atm] [ 94.341962] vcc_ioctl+0x10/0x20 [atm] [ 94.341968] svc_ioctl+0x587/0x6c0 [atm] [ 94.341973] sock_do_ioctl+0xd7/0x1e0 [ 94.341977] sock_ioctl+0x1b5/0x560 [ 94.341979] __x64_sys_ioctl+0x132/0x1b0 [ 94.341981] do_syscall_64+0x59/0x90 [ 94.341983] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 94.341986] Freed by task 2613: [ 94.341988] kasan_save_stack+0x26/0x50 [ 94.341991] kasan_set_track+0x25/0x40 [ 94.341993] kasan_save_free_info+0x2e/0x50 [ 94.341995] ____kasan_slab_free+0x174/0x1e0 [ 94.341997] __kasan_slab_free+0x12/0x20 [ 94.342000] slab_free_freelist_hook+0xd0/0x1a0 [ 94.342002] __kmem_cache_free+0x193/0x2c0 [ 94.342005] kfree+0x79/0x120 [ 94.342007] atm_dev_register.cold+0x46/0x64 [atm] [ 94.342013] atmtcp_create+0x77/0x1f0 [atmtcp] [ 94.342016] atmtcp_ioctl+0x12d/0xb9f [atmtcp] [ 94.342020] do_vcc_ioctl+0xfe/0x640 [atm] [ 94.342077] vcc_ioctl+0x10/0x20 [atm] [ 94.342083] svc_ioctl+0x587/0x6c0 [atm] [ 94.342088] sock_do_ioctl+0xd7/0x1e0 [ 94.342091] sock_ioctl+0x1b5/0x560 [ 94.342093] __x64_sys_ioctl+0x132/0x1b0 [ 94.342095] do_syscall_64+0x59/0x90 [ 94.342098] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 94.342102] The buggy address belongs to the object at ffff88819a8a3000 which belongs to the cache kmalloc-1k of size 1024 [ 94.342105] The buggy address is located 232 bytes inside of 1024-byte region [ffff88819a8a3000, ffff88819a8a3400) [ 94.342109] The buggy address belongs to the physical page: [ 94.342111] page:0000000099993f0a refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x19a8a0 [ 94.342114] head:0000000099993f0a order:3 compound_mapcount:0 compound_pincount:0 [ 94.342116] flags: 0x17ffffc0010200(slab|head|node=0|zone=2|lastcpupid=0x1fffff) [ 94.342136] raw: 0017ffffc0010200 dead000000000100 dead000000000122 ffff888100042dc0 [ 94.342138] raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 [ 94.342139] page dumped because: kasan: bad access detected [ 94.342141] Memory state around the buggy address: [ 94.342143] ffff88819a8a2f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 94.342145] ffff88819a8a3000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 94.342147] >ffff88819a8a3080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 94.342148] ^ [ 94.342150] ffff88819a8a3100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 94.342152] ffff88819a8a3180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Fixes: 656d98b09d57 ([ATM]: basic sysfs support for ATM devices) Signed-off-by: Nir Levy --- net/atm/atm_sysfs.c | 5 ++++- net/atm/resources.c | 2 +- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/net/atm/atm_sysfs.c b/net/atm/atm_sysfs.c index 0fdbdfd19474..df881d70ba86 100644 --- a/net/atm/atm_sysfs.c +++ b/net/atm/atm_sysfs.c @@ -150,7 +150,10 @@ int atm_register_sysfs(struct atm_dev *adev, struct device *parent) dev_set_name(cdev, "%s%d", adev->type, adev->number); err = device_register(cdev); if (err < 0) + { + put_device(cdev); return err; + } for (i = 0; atm_attrs[i]; i++) { err = device_create_file(cdev, atm_attrs[i]); @@ -163,7 +166,7 @@ int atm_register_sysfs(struct atm_dev *adev, struct device *parent) err_out: for (j = 0; j < i; j++) device_remove_file(cdev, atm_attrs[j]); - device_del(cdev); + device_unregister(cdev); return err; } diff --git a/net/atm/resources.c b/net/atm/resources.c index 2b2d33eeaf20..485ad9a571e1 100644 --- a/net/atm/resources.c +++ b/net/atm/resources.c @@ -112,6 +112,7 @@ struct atm_dev *atm_dev_register(const char *type, struct device *parent, if (atm_proc_dev_register(dev) < 0) { pr_err("atm_proc_dev_register failed for dev %s\n", type); + kfree(dev); goto out_fail; } @@ -128,7 +129,6 @@ struct atm_dev *atm_dev_register(const char *type, struct device *parent, return dev; out_fail: - kfree(dev); dev = NULL; goto out; } -- 2.34.1