CVE-2022-50248

In the Linux kernel, the following vulnerability has been resolved:

wifi: iwlwifi: mvm: fix double free on tx path.

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 R

---truncated---