From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 953B5143725 for ; Tue, 21 May 2024 15:06:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716303971; cv=none; b=lSNsbmrvFpvv/mDxukKY6EEqPt6ovxR7fIF42Se9TK6ddxZtTtUGRPy0Bav+mqNBmN+WBCTkT3f9Op4rAPMSCQ9hPNWPpLIWCbEE92D/bMxa0tq0e/h9dwbROEXaEIDVhit6hHTJ02lIYCVo7IM7zVGUd7MINf1/b4iMqEQWwQ8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716303971; c=relaxed/simple; bh=GFAYaekLIypI9zE+Bbmfzm/kfTiHySyjtpD2hb/7yKc=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=LnWXWnXarq0HCOB2oW7tWn/d+Rb8iNbnnspMx1XaV3VvQ6vFDa6aJ5OUkfbJuyTKwF2USBUcePsMImO9ECvOZykX9qPTKkVRMbUROkFjcY+5Fx1THOaONkKWeAvbJZhCxzSGaQc3CREasm7rNX8veJBY62yK8eyr5q1/M40ooB0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=DMFokTDy; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="DMFokTDy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E8FCC2BD11; Tue, 21 May 2024 15:06:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1716303971; bh=GFAYaekLIypI9zE+Bbmfzm/kfTiHySyjtpD2hb/7yKc=; h=From:To:Cc:Subject:Date:Reply-to:From; b=DMFokTDyLngM/EuM1ssq/97xdGvtf9lWLB/QUfQVYmMZlGO7K2fkFlHcxmYcc5pfa xY7uq5ciej3DhVYaLhPMNqy/kI1C5yHVOubxCg+aa2ufsLxcPFUBuD4A1F/QUUkgbl uAynMUQKYdj/ekQ0IF9PXTyunCv8O65KlV1KINTs= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2021-47402: net: sched: flower: protect fl_walk() with rcu Date: Tue, 21 May 2024 17:04:19 +0200 Message-ID: <2024052149-CVE-2021-47402-6c19@gregkh> X-Mailer: git-send-email 2.45.1 Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Reply-to: , X-Developer-Signature: v=1; a=openpgp-sha256; l=10370; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=GFAYaekLIypI9zE+Bbmfzm/kfTiHySyjtpD2hb/7yKc=; b=owGbwMvMwCRo6H6F97bub03G02pJDGk+2682qruu2BU3r2WmlPV7cT+bXdzR30MOS81f8bJBy 7F7YeL1jlgWBkEmBlkxRZYv23iO7q84pOhlaHsaZg4rE8gQBi5OAZjI906G+eVKP3/Kbf68chX7 A7kS5gfdVUvvX2aYZ/znmFpRq7r8Ou8bV6esuJBgrjJzCgA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit Description =========== In the Linux kernel, the following vulnerability has been resolved: net: sched: flower: protect fl_walk() with rcu Patch that refactored fl_walk() to use idr_for_each_entry_continue_ul() also removed rcu protection of individual filters which causes following use-after-free when filter is deleted concurrently. Fix fl_walk() to obtain rcu read lock while iterating and taking the filter reference and temporary release the lock while calling arg->fn() callback that can sleep. KASAN trace: [ 352.773640] ================================================================== [ 352.775041] BUG: KASAN: use-after-free in fl_walk+0x159/0x240 [cls_flower] [ 352.776304] Read of size 4 at addr ffff8881c8251480 by task tc/2987 [ 352.777862] CPU: 3 PID: 2987 Comm: tc Not tainted 5.15.0-rc2+ #2 [ 352.778980] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 352.781022] Call Trace: [ 352.781573] dump_stack_lvl+0x46/0x5a [ 352.782332] print_address_description.constprop.0+0x1f/0x140 [ 352.783400] ? fl_walk+0x159/0x240 [cls_flower] [ 352.784292] ? fl_walk+0x159/0x240 [cls_flower] [ 352.785138] kasan_report.cold+0x83/0xdf [ 352.785851] ? fl_walk+0x159/0x240 [cls_flower] [ 352.786587] kasan_check_range+0x145/0x1a0 [ 352.787337] fl_walk+0x159/0x240 [cls_flower] [ 352.788163] ? fl_put+0x10/0x10 [cls_flower] [ 352.789007] ? __mutex_unlock_slowpath.constprop.0+0x220/0x220 [ 352.790102] tcf_chain_dump+0x231/0x450 [ 352.790878] ? tcf_chain_tp_delete_empty+0x170/0x170 [ 352.791833] ? __might_sleep+0x2e/0xc0 [ 352.792594] ? tfilter_notify+0x170/0x170 [ 352.793400] ? __mutex_unlock_slowpath.constprop.0+0x220/0x220 [ 352.794477] tc_dump_tfilter+0x385/0x4b0 [ 352.795262] ? tc_new_tfilter+0x1180/0x1180 [ 352.796103] ? __mod_node_page_state+0x1f/0xc0 [ 352.796974] ? __build_skb_around+0x10e/0x130 [ 352.797826] netlink_dump+0x2c0/0x560 [ 352.798563] ? netlink_getsockopt+0x430/0x430 [ 352.799433] ? __mutex_unlock_slowpath.constprop.0+0x220/0x220 [ 352.800542] __netlink_dump_start+0x356/0x440 [ 352.801397] rtnetlink_rcv_msg+0x3ff/0x550 [ 352.802190] ? tc_new_tfilter+0x1180/0x1180 [ 352.802872] ? rtnl_calcit.isra.0+0x1f0/0x1f0 [ 352.803668] ? tc_new_tfilter+0x1180/0x1180 [ 352.804344] ? _copy_from_iter_nocache+0x800/0x800 [ 352.805202] ? kasan_set_track+0x1c/0x30 [ 352.805900] netlink_rcv_skb+0xc6/0x1f0 [ 352.806587] ? rht_deferred_worker+0x6b0/0x6b0 [ 352.807455] ? rtnl_calcit.isra.0+0x1f0/0x1f0 [ 352.808324] ? netlink_ack+0x4d0/0x4d0 [ 352.809086] ? netlink_deliver_tap+0x62/0x3d0 [ 352.809951] netlink_unicast+0x353/0x480 [ 352.810744] ? netlink_attachskb+0x430/0x430 [ 352.811586] ? __alloc_skb+0xd7/0x200 [ 352.812349] netlink_sendmsg+0x396/0x680 [ 352.813132] ? netlink_unicast+0x480/0x480 [ 352.813952] ? __import_iovec+0x192/0x210 [ 352.814759] ? netlink_unicast+0x480/0x480 [ 352.815580] sock_sendmsg+0x6c/0x80 [ 352.816299] ____sys_sendmsg+0x3a5/0x3c0 [ 352.817096] ? kernel_sendmsg+0x30/0x30 [ 352.817873] ? __ia32_sys_recvmmsg+0x150/0x150 [ 352.818753] ___sys_sendmsg+0xd8/0x140 [ 352.819518] ? sendmsg_copy_msghdr+0x110/0x110 [ 352.820402] ? ___sys_recvmsg+0xf4/0x1a0 [ 352.821110] ? __copy_msghdr_from_user+0x260/0x260 [ 352.821934] ? _raw_spin_lock+0x81/0xd0 [ 352.822680] ? __handle_mm_fault+0xef3/0x1b20 [ 352.823549] ? rb_insert_color+0x2a/0x270 [ 352.824373] ? copy_page_range+0x16b0/0x16b0 [ 352.825209] ? perf_event_update_userpage+0x2d0/0x2d0 [ 352.826190] ? __fget_light+0xd9/0xf0 [ 352.826941] __sys_sendmsg+0xb3/0x130 [ 352.827613] ? __sys_sendmsg_sock+0x20/0x20 [ 352.828377] ? do_user_addr_fault+0x2c5/0x8a0 [ 352.829184] ? fpregs_assert_state_consistent+0x52/0x60 [ 352.830001] ? exit_to_user_mode_prepare+0x32/0x160 [ 352.830845] do_syscall_64+0x35/0x80 [ 352.831445] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 352.832331] RIP: 0033:0x7f7bee973c17 [ 352.833078] Code: 0c 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10 [ 352.836202] RSP: 002b:00007ffcbb368e28 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 352.837524] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7bee973c17 [ 352.838715] RDX: 0000000000000000 RSI: 00007ffcbb368e50 RDI: 0000000000000003 [ 352.839838] RBP: 00007ffcbb36d090 R08: 00000000cea96d79 R09: 00007f7beea34a40 [ 352.841021] R10: 00000000004059bb R11: 0000000000000246 R12: 000000000046563f [ 352.842208] R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffcbb36d088 [ 352.843784] Allocated by task 2960: [ 352.844451] kasan_save_stack+0x1b/0x40 [ 352.845173] __kasan_kmalloc+0x7c/0x90 [ 352.845873] fl_change+0x282/0x22db [cls_flower] [ 352.846696] tc_new_tfilter+0x6cf/0x1180 [ 352.847493] rtnetlink_rcv_msg+0x471/0x550 [ 352.848323] netlink_rcv_skb+0xc6/0x1f0 [ 352.849097] netlink_unicast+0x353/0x480 [ 352.849886] netlink_sendmsg+0x396/0x680 [ 352.850678] sock_sendmsg+0x6c/0x80 [ 352.851398] ____sys_sendmsg+0x3a5/0x3c0 [ 352.852202] ___sys_sendmsg+0xd8/0x140 [ 352.852967] __sys_sendmsg+0xb3/0x130 [ 352.853718] do_syscall_64+0x35/0x80 [ 352.854457] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 352.855830] Freed by task 7: [ 352.856421] kasan_save_stack+0x1b/0x40 [ 352.857139] kasan_set_track+0x1c/0x30 [ 352.857854] kasan_set_free_info+0x20/0x30 [ 352.858609] __kasan_slab_free+0xed/0x130 [ 352.859348] kfree+0xa7/0x3c0 [ 352.859951] process_one_work+0x44d/0x780 [ 352.860685] worker_thread+0x2e2/0x7e0 [ 352.861390] kthread+0x1f4/0x220 [ 352.862022] ret_from_fork+0x1f/0x30 [ 352.862955] Last potentially related work creation: [ 352.863758] kasan_save_stack+0x1b/0x40 [ 352.864378] kasan_record_aux_stack+0xab/0xc0 [ 352.865028] insert_work+0x30/0x160 [ 352.865617] __queue_work+0x351/0x670 [ 352.866261] rcu_work_rcufn+0x30/0x40 [ 352.866917] rcu_core+0x3b2/0xdb0 [ 352.867561] __do_softirq+0xf6/0x386 [ 352.868708] Second to last potentially related work creation: [ 352.869779] kasan_save_stack+0x1b/0x40 [ 352.870560] kasan_record_aux_stack+0xab/0xc0 [ 352.871426] call_rcu+0x5f/0x5c0 [ 352.872108] queue_rcu_work+0x44/0x50 [ 352.872855] __fl_put+0x17c/0x240 [cls_flower] [ 352.873733] fl_delete+0xc7/0x100 [cls_flower] [ 352.874607] tc_del_tfilter+0x510/0xb30 [ 352.886085] rtnetlink_rcv_msg+0x471/0x550 [ 352.886875] netlink_rcv_skb+0xc6/0x1f0 [ 352.887636] netlink_unicast+0x353/0x480 [ 352.888285] netlink_sendmsg+0x396/0x680 [ 352.888942] sock_sendmsg+0x6c/0x80 [ 352.889583] ____sys_sendmsg+0x3a5/0x3c0 [ 352.890311] ___sys_sendmsg+0xd8/0x140 [ 352.891019] __sys_sendmsg+0xb3/0x130 [ 352.891716] do_syscall_64+0x35/0x80 [ 352.892395] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 352.893666] The buggy address belongs to the object at ffff8881c8251000 which belongs to the cache kmalloc-2k of size 2048 [ 352.895696] The buggy address is located 1152 bytes inside of 2048-byte region [ffff8881c8251000, ffff8881c8251800) [ 352.897640] The buggy address belongs to the page: [ 352.898492] page:00000000213bac35 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1c8250 [ 352.900110] head:00000000213bac35 order:3 compound_mapcount:0 compound_pincount:0 [ 352.901541] flags: 0x2ffff800010200(slab|head|node=0|zone=2|lastcpupid=0x1ffff) [ 352.902908] raw: 002ffff800010200 0000000000000000 dead000000000122 ffff888100042f00 [ 352.904391] raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000 [ 352.905861] page dumped because: kasan: bad access detected [ 352.907323] Memory state around the buggy address: [ 352.908218] ffff8881c8251380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 352.909471] ffff8881c8251400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 352.910735] >ffff8881c8251480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 352.912012] ^ [ 352.912642] ffff8881c8251500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 352.913919] ffff8881c8251580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 352.915185] ================================================================== The Linux kernel CVE team has assigned CVE-2021-47402 to this issue. Affected and fixed versions =========================== Issue introduced in 5.3 with commit d39d714969cd and fixed in 5.4.151 with commit 694b0cee7f85 Issue introduced in 5.3 with commit d39d714969cd and fixed in 5.10.71 with commit d0d520c19e7e Issue introduced in 5.3 with commit d39d714969cd and fixed in 5.14.10 with commit dab4677bdbff Issue introduced in 5.3 with commit d39d714969cd and fixed in 5.15 with commit d5ef190693a7 Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2021-47402 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: net/sched/cls_flower.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/694b0cee7f8546b69a80996a29cb3cf4149c0453 https://git.kernel.org/stable/c/d0d520c19e7ea19ed38dc5797b12397b6ccf9f88 https://git.kernel.org/stable/c/dab4677bdbffa5c8270e79e34e51c89efa0728a0 https://git.kernel.org/stable/c/d5ef190693a7d76c5c192d108e8dec48307b46ee