CVE-2022-50701 wifi: mt76: mt7921s: fix slab-out-of-bounds access in sdio host
A slab-out-of-bounds access in the mt7921s WiFi driver can cause a kernel crash, requiring a patch to prevent denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-50701?
CVE-2022-50701 is a high-severity memory corruption vulnerability in Linux, published on 24 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7921s: fix slab-out-of-bounds access in sdio host
SDIO may need addtional 511 bytes to align bus operation. If the tailroom of this skb is not big enough, we would access invalid memory region. For low level operation, increase skb size to keep valid memory access in SDIO host.
Error message: [69.951] BUG: KASAN: slab-out-of-bounds in sg_copy_buffer+0xe9/0x1a0 [69.951] Read of size 64 at addr ffff88811c9cf000 by task kworker/u16:7/451 [69.951] CPU: 4 PID: 451 Comm: kworker/u16:7 Tainted: G W OE 6.1.0-rc5 #1 [69.951] Workqueue: kvub300c vub300_cmndwork_thread [vub300] [69.951] Call Trace: [69.951] <TASK> [69.952] dump_stack_lvl+0x49/0x63 [69.952] print_report+0x171/0x4a8 [69.952] kasan_report+0xb4/0x130 [69.952] kasan_check_range+0x149/0x1e0 [69.952] memcpy+0x24/0x70 [69.952] sg_copy_buffer+0xe9/0x1a0 [69.952] sg_copy_to_buffer+0x12/0x20 [69.952] __command_write_data.isra.0+0x23c/0xbf0 [vub300] [69.952] vub300_cmndwork_thread+0x17f3/0x58b0 [vub300] [69.952] process_one_work+0x7ee/0x1320 [69.952] worker_thread+0x53c/0x1240 [69.952] kthread+0x2b8/0x370 [69.952] ret_from_fork+0x1f/0x30 [69.952] </TASK>
[69.952] Allocated by task 854: [69.952] kasan_save_stack+0x26/0x50 [69.952] kasan_set_track+0x25/0x30 [69.952] kasan_save_alloc_info+0x1b/0x30 [69.952] __kasan_kmalloc+0x87/0xa0 [69.952] __kmalloc_node_track_caller+0x63/0x150 [69.952] kmalloc_reserve+0x31/0xd0 [69.952] __alloc_skb+0xfc/0x2b0 [69.952] __mt76_mcu_msg_alloc+0xbf/0x230 [mt76] [69.952] mt76_mcu_send_and_get_msg+0xab/0x110 [mt76] [69.952] __mt76_mcu_send_firmware.cold+0x94/0x15d [mt76] [69.952] mt76_connac_mcu_send_ram_firmware+0x415/0x54d [mt76_connac_lib] [69.952] mt76_connac2_load_ram.cold+0x118/0x4bc [mt76_connac_lib] [69.952] mt7921_run_firmware.cold+0x2e9/0x405 [mt7921_common] [69.952] mt7921s_mcu_init+0x45/0x80 [mt7921s] [69.953] mt7921_init_work+0xe1/0x2a0 [mt7921_common] [69.953] process_one_work+0x7ee/0x1320 [69.953] worker_thread+0x53c/0x1240 [69.953] kthread+0x2b8/0x370 [69.953] ret_from_fork+0x1f/0x30 [69.953] The buggy address belongs to the object at ffff88811c9ce800 which belongs to the cache kmalloc-2k of size 2048 [69.953] The buggy address is located 0 bytes to the right of 2048-byte region [ffff88811c9ce800, ffff88811c9cf000)
[69.953] Memory state around the buggy address: [69.953] ffff88811c9cef00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [69.953] ffff88811c9cef80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [69.953] >ffff88811c9cf000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [69.953] ^ [69.953] ffff88811c9cf080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [69.953] ffff88811c9cf100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
Which versions are affected by CVE-2022-50701?
How do I fix CVE-2022-50701?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2022-50701 being exploited?
There is no known exploitation of CVE-2022-50701 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2022-50701, GHSA-9vm9-fqq4-5wqv, UBUNTU-CVE-2022-50701.