From patchwork Wed Sep 28 19:30:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Greear X-Patchwork-Id: 610551 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 0ACCBC32771 for ; Wed, 28 Sep 2022 19:31:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234314AbiI1TbU (ORCPT ); Wed, 28 Sep 2022 15:31:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60756 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234402AbiI1TbP (ORCPT ); Wed, 28 Sep 2022 15:31:15 -0400 Received: from dispatch1-us1.ppe-hosted.com (dispatch1-us1.ppe-hosted.com [148.163.129.52]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B7D158C462 for ; Wed, 28 Sep 2022 12:31:13 -0700 (PDT) X-Virus-Scanned: Proofpoint Essentials engine Received: from mx1-us1.ppe-hosted.com (unknown [10.7.64.219]) by mx1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTPS id 07ABF2007B; Wed, 28 Sep 2022 19:31:12 +0000 (UTC) Received: from mail3.candelatech.com (mail2.candelatech.com [208.74.158.173]) by mx1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTP id BCCFA78007B; Wed, 28 Sep 2022 19:31:11 +0000 (UTC) Received: from ben-dt4.candelatech.com (50-251-239-81-static.hfc.comcastbusiness.net [50.251.239.81]) by mail3.candelatech.com (Postfix) with ESMTP id 4C03013C2B0; Wed, 28 Sep 2022 12:31:11 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 mail3.candelatech.com 4C03013C2B0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=candelatech.com; s=default; t=1664393471; bh=kx0HuXc6nCKxhhh7sAJvzMXAKl1QpxYorjYdkmAAkFg=; h=From:To:Cc:Subject:Date:From; b=A1BR6/zqVhlS+xANP2dM8KE9jnxU7F/B/NwQ2DUatogrteQ01Lih98MJ9UFM02SrT QQgGifV0AkePeJXtrsReNxzGCBpN7q9m6b2rloPxbFX+04CQhstSpUy5OZdjuFO9Lt M12kC3jK+FCgka8hS5YnEIbJdpkbJsBoa9YNoInM= From: greearb@candelatech.com To: linux-wireless@vger.kernel.org Cc: gregory.greenman@intel.com, Ben Greear , Amol Jawale Subject: [PATCH] wifi: iwlwifi: fix double free on tx path. Date: Wed, 28 Sep 2022 12:30:57 -0700 Message-Id: <20220928193057.16132-1-greearb@candelatech.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-MDID: 1664393472-ddbglkkFEgOA Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Ben Greear We see kernel crashes and lockups and KASAN errors related to ax210 firmware crashes. One of the KASAN dumps pointed at the tx path, and it appears there is indeed a way to double-free an skb. If iwl_mvm_tx_skb_sta returns non-zero, then the 'skb' sent into the method will be freed. But, in case where we build TSO skb buffer, the skb may also be freed in error case. So, return 0 in that particular error case and do cleanup manually. BUG: KASAN: use-after-free in __list_del_entry_valid+0x12/0x90 iwlwifi 0000:06:00.0: 0x00000000 | tsf hi Read of size 8 at addr ffff88813cfa4ba0 by task btserver/9650 CPU: 4 PID: 9650 Comm: btserver Tainted: G W 5.19.8+ #5 iwlwifi 0000:06:00.0: 0x00000000 | time gp1 Hardware name: Default string Default string/SKYBAY, BIOS 5.12 02/19/2019 Call Trace: dump_stack_lvl+0x55/0x6d print_report.cold.12+0xf2/0x684 iwlwifi 0000:06:00.0: 0x1D0915A8 | time gp2 ? __list_del_entry_valid+0x12/0x90 kasan_report+0x8b/0x180 iwlwifi 0000:06:00.0: 0x00000001 | uCode revision type ? __list_del_entry_valid+0x12/0x90 __list_del_entry_valid+0x12/0x90 iwlwifi 0000:06:00.0: 0x00000048 | uCode version major tcp_update_skb_after_send+0x5d/0x170 __tcp_transmit_skb+0xb61/0x15c0 iwlwifi 0000:06:00.0: 0xDAA05125 | uCode version minor ? __tcp_select_window+0x490/0x490 iwlwifi 0000:06:00.0: 0x00000420 | hw version ? trace_kmalloc_node+0x29/0xd0 ? __kmalloc_node_track_caller+0x12a/0x260 ? memset+0x1f/0x40 ? __build_skb_around+0x125/0x150 ? __alloc_skb+0x1d4/0x220 ? skb_zerocopy_clone+0x55/0x230 iwlwifi 0000:06:00.0: 0x00489002 | board version ? kmalloc_reserve+0x80/0x80 ? rcu_read_lock_bh_held+0x60/0xb0 tcp_write_xmit+0x3f1/0x24d0 iwlwifi 0000:06:00.0: 0x034E001C | hcmd ? __check_object_size+0x180/0x350 iwlwifi 0000:06:00.0: 0x24020000 | isr0 tcp_sendmsg_locked+0x8a9/0x1520 iwlwifi 0000:06:00.0: 0x01400000 | isr1 ? tcp_sendpage+0x50/0x50 iwlwifi 0000:06:00.0: 0x48F0000A | isr2 ? lock_release+0xb9/0x400 ? tcp_sendmsg+0x14/0x40 iwlwifi 0000:06:00.0: 0x00C3080C | isr3 ? lock_downgrade+0x390/0x390 ? do_raw_spin_lock+0x114/0x1d0 iwlwifi 0000:06:00.0: 0x00200000 | isr4 ? rwlock_bug.part.2+0x50/0x50 iwlwifi 0000:06:00.0: 0x034A001C | last cmd Id ? rwlock_bug.part.2+0x50/0x50 ? lockdep_hardirqs_on_prepare+0xe/0x200 iwlwifi 0000:06:00.0: 0x0000C2F0 | wait_event ? __local_bh_enable_ip+0x87/0xe0 ? inet_send_prepare+0x220/0x220 iwlwifi 0000:06:00.0: 0x000000C4 | l2p_control tcp_sendmsg+0x22/0x40 sock_sendmsg+0x5f/0x70 iwlwifi 0000:06:00.0: 0x00010034 | l2p_duration __sys_sendto+0x19d/0x250 iwlwifi 0000:06:00.0: 0x00000007 | l2p_mhvalid ? __ia32_sys_getpeername+0x40/0x40 iwlwifi 0000:06:00.0: 0x00000000 | l2p_addr_match ? rcu_read_lock_held_common+0x12/0x50 ? rcu_read_lock_sched_held+0x5a/0xd0 ? rcu_read_lock_bh_held+0xb0/0xb0 ? rcu_read_lock_sched_held+0x5a/0xd0 ? rcu_read_lock_sched_held+0x5a/0xd0 ? lock_release+0xb9/0x400 ? lock_downgrade+0x390/0x390 ? ktime_get+0x64/0x130 ? ktime_get+0x8d/0x130 ? rcu_read_lock_held_common+0x12/0x50 ? rcu_read_lock_sched_held+0x5a/0xd0 ? rcu_read_lock_held_common+0x12/0x50 ? rcu_read_lock_sched_held+0x5a/0xd0 ? rcu_read_lock_bh_held+0xb0/0xb0 ? rcu_read_lock_bh_held+0xb0/0xb0 __x64_sys_sendto+0x6f/0x80 do_syscall_64+0x34/0xb0 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f1d126e4531 Code: 00 00 00 00 0f 1f 44 00 00 f3 0f 1e fa 48 8d 05 35 80 0c 00 41 89 ca 8b 00 85 c0 75 1c 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 67 c3 66 0f 1f 44 00 00 55 48 83 ec 20 48 89 RSP: 002b:00007ffe21a679d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000000000000ffdc RCX: 00007f1d126e4531 RDX: 0000000000010000 RSI: 000000000374acf0 RDI: 0000000000000014 RBP: 00007ffe21a67ac0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000010 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 Allocated by task 9650: kasan_save_stack+0x1c/0x40 __kasan_slab_alloc+0x6d/0x90 kmem_cache_alloc_node+0xf3/0x2b0 __alloc_skb+0x191/0x220 tcp_stream_alloc_skb+0x3f/0x330 tcp_sendmsg_locked+0x67c/0x1520 tcp_sendmsg+0x22/0x40 sock_sendmsg+0x5f/0x70 __sys_sendto+0x19d/0x250 __x64_sys_sendto+0x6f/0x80 do_syscall_64+0x34/0xb0 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Freed by task 9650: kasan_save_stack+0x1c/0x40 kasan_set_track+0x21/0x30 kasan_set_free_info+0x20/0x30 __kasan_slab_free+0x102/0x170 kmem_cache_free+0xc8/0x3e0 iwl_mvm_mac_itxq_xmit+0x124/0x270 [iwlmvm] ieee80211_queue_skb+0x874/0xd10 [mac80211] ieee80211_xmit_fast+0xf80/0x1180 [mac80211] __ieee80211_subif_start_xmit+0x287/0x680 [mac80211] ieee80211_subif_start_xmit+0xcd/0x730 [mac80211] dev_hard_start_xmit+0xf6/0x420 __dev_queue_xmit+0x165b/0x1b50 ip_finish_output2+0x66e/0xfb0 __ip_finish_output+0x487/0x6d0 ip_output+0x11c/0x350 __ip_queue_xmit+0x36b/0x9d0 __tcp_transmit_skb+0xb35/0x15c0 tcp_write_xmit+0x3f1/0x24d0 tcp_sendmsg_locked+0x8a9/0x1520 tcp_sendmsg+0x22/0x40 sock_sendmsg+0x5f/0x70 __sys_sendto+0x19d/0x250 __x64_sys_sendto+0x6f/0x80 do_syscall_64+0x34/0xb0 entry_SYSCALL_64_after_hwframe+0x46/0xb0 The buggy address belongs to the object at ffff88813cfa4b40 which belongs to the cache skbuff_fclone_cache of size 472 The buggy address is located 96 bytes inside of 472-byte region [ffff88813cfa4b40, ffff88813cfa4d18) The buggy address belongs to the physical page: page:ffffea0004f3e900 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88813cfa6c40 pfn:0x13cfa4 head:ffffea0004f3e900 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x5fff8000010200(slab|head|node=0|zone=2|lastcpupid=0x3fff) raw: 005fff8000010200 ffffea0004656b08 ffffea0008e8cf08 ffff8881081a5240 raw: ffff88813cfa6c40 0000000000170015 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88813cfa4a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88813cfa4b00: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff88813cfa4b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88813cfa4c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88813cfa4c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Tested-by: Amol Jawale Signed-off-by: Ben Greear --- drivers/net/wireless/intel/iwlwifi/mvm/tx.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c index f9e08b339e0c..72bba83b4603 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c @@ -1206,6 +1206,7 @@ int iwl_mvm_tx_skb_sta(struct iwl_mvm *mvm, struct sk_buff *skb, struct sk_buff_head mpdus_skbs; unsigned int payload_len; int ret; + struct sk_buff *orig_skb = skb; if (WARN_ON_ONCE(!mvmsta)) return -1; @@ -1238,8 +1239,17 @@ int iwl_mvm_tx_skb_sta(struct iwl_mvm *mvm, struct sk_buff *skb, ret = iwl_mvm_tx_mpdu(mvm, skb, &info, sta); if (ret) { + /* Free skbs created as part of TSO logic that have not yet been dequeued */ __skb_queue_purge(&mpdus_skbs); - return ret; + /* skb here is not necessarily same as skb that entered this method, + * so free it explicitly. + */ + if (skb == orig_skb) + ieee80211_free_txskb(mvm->hw, skb); + else + kfree_skb(skb); + /* there was error, but we consumed skb one way or another, so return 0 */ + return 0; } }