From: Ben Greear greearb@candelatech.com
[ Upstream commit 0473cbae2137b963bd0eaa74336131cb1d3bc6c3 ]
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: <TASK> 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 </TASK>
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 ==================================================================
Fixes: 08f7d8b69aaf ("iwlwifi: mvm: bring back mvm GSO code") Link: https://lore.kernel.org/linux-wireless/20220928193057.16132-1-greearb@candel... Tested-by: Amol Jawale amol.jawale@candelatech.com Signed-off-by: Ben Greear greearb@candelatech.com Link: https://lore.kernel.org/r/20221123225313.21b1ee31d666.I3b3ba184433dd2a544d91... Signed-off-by: Gregory Greenman gregory.greenman@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 b5368cb57ca8..e354918c2480 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c @@ -1150,6 +1150,7 @@ 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; @@ -1182,8 +1183,17 @@ 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; } }