Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.1.7. Affected by this issue is some unknown functionality of the component mac80211. The manipulation leads to null pointer dereference. This vulnerability is handled as CVE-2022-48876. There is no exploit available. It is recommended to upgrade the affected component. Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.1.7. Affected by this vulnerability is some unknown processing of the component mac80211. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: fix initialization of rx->link and rx->link_sta There are some codepaths that do not initialize rx->link_sta properly. This causes a crash in places which assume that rx->link_sta is valid if rx->sta is valid. One known instance is triggered by __ieee80211_rx_h_amsdu being called from fast-rx. It results in a crash like this one: BUG: kernel NULL pointer dereference, address: 00000000000000a8 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] PREEMPT SMP PTI CPU: 1 PID: 506 Comm: mt76-usb-rx phy Tainted: G E 6.1.0-debian64x+1.7 #3 Hardware name: ZOTAC ZBOX-ID92/ZBOX-IQ01/ZBOX-ID92/ZBOX-IQ01, BIOS B220P007 05/21/2014 RIP: 0010:ieee80211_deliver_skb+0x62/0x1f0 [mac80211] Code: 00 48 89 04 24 e8 9e a7 c3 df 89 c0 48 03 1c c5 a0 ea 39 a1 4c 01 6b 08 48 ff 03 48 83 7d 28 00 74 11 48 8b 45 30 48 63 55 44 83 84 d0 a8 00 00 00 01 41 8b 86 c0 11 00 00 8d 50 fd 83 fa 01 RSP: 0018:ffff999040803b10 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffffb9903f496480 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff999040803ce0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8d21828ac900 R13: 000000000000004a R14: ffff8d2198ed89c0 R15: ffff8d2198ed8000 FS: 0000000000000000(0000) GS:ffff8d24afe80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000a8 CR3: 0000000429810002 CR4: 00000000001706e0 Call Trace: __ieee80211_rx_h_amsdu+0x1b5/0x240 [mac80211] ? ieee80211_prepare_and_rx_handle+0xcdd/0x1320 [mac80211] ? __local_bh_enable_ip+0x3b/0xa0 ieee80211_prepare_and_rx_handle+0xcdd/0x1320 [mac80211] ? prepare_transfer+0x109/0x1a0 [xhci_hcd] ieee80211_rx_list+0xa80/0xda0 [mac80211] mt76_rx_complete+0x207/0x2e0 [mt76] mt76_rx_poll_complete+0x357/0x5a0 [mt76] mt76u_rx_worker+0x4f5/0x600 [mt76_usb] ? mt76_get_min_avg_rssi+0x140/0x140 [mt76] __mt76_worker_fn+0x50/0x80 [mt76] kthread+0xed/0x120 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x22/0x30 Since the initialization of rx->link and rx->link_sta is rather convoluted and duplicated in many places, clean it up by using a helper function to set it. [remove unnecessary rx->sta->sta.mlo check]

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2022-48876 since 07/16/2024. The exploitation appears to be difficult. Neither technical details nor an exploit are publicly available.

Upgrading to version 6.1.8 eliminates this vulnerability. Applying the patch a57c981d9f24/e66b7920aa5a is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.1.0
• 6.1.1
• 6.1.2
• 6.1.3
• 6.1.4
• 6.1.5
• 6.1.6
• 6.1.7

License

• open-source

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Discussion