wifi: brcmfmac: Check the count value of channel spec to prevent out-of-bounds reads
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · None · High
- Fix status
- Partial Red Hat: 3 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: wifi: brcmfmac: Check the count value of channel spec to prevent out-of-bounds reads This patch fixes slab-out-of-bounds reads in brcmfmac that occur in brcmf_construct_chaninfo() and brcmf_enable_bw40_2g() when the count value of channel specifications provided by the device is greater than the length of 'list->element[]', decided by the size of the 'list' allocated with kzalloc(). The patch adds checks that make the functions free the buffer and return -EINVAL if that is the case. Note that the negative return is handled by the caller, brcmf_setup_wiphybands() or brcmf_cfg80211_attach(). Found by a modified version of syzkaller. Crash Report from brcmf_construct_chaninfo(): ================================================================== BUG: KASAN: slab-out-of-bounds in brcmf_setup_wiphybands+0x1238/0x1430 Read of size 4 at addr ffff888115f24600 by task kworker/0:2/1896 CPU: 0 PID: 1896 Comm: kworker/0:2 Tainted: G W O 5.14.0+ #132 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 Workqueue: usb_hub_wq hub_event Call Trace: dump_stack_lvl+0x57/0x7d print_address_description.constprop.0.cold+0x93/0x334 kasan_report.cold+0x83/0xdf brcmf_setup_wiphybands+0x1238/0x1430 brcmf_cfg80211_attach+0x2118/0x3fd0 brcmf_attach+0x389/0xd40 brcmf_usb_probe+0x12de/0x1690 usb_probe_interface+0x25f/0x710 really_probe+0x1be/0xa90 __driver_probe_device+0x2ab/0x460 driver_probe_device+0x49/0x120 __device_attach_driver+0x18a/0x250 bus_for_each_drv+0x123/0x1a0 __device_attach+0x207/0x330 bus_probe_device+0x1a2/0x260 device_add+0xa61/0x1ce0 usb_set_configuration+0x984/0x1770 usb_generic_driver_probe+0x69/0x90 usb_probe_device+0x9c/0x220 really_probe+0x1be/0xa90 __driver_probe_device+0x2ab/0x460 driver_probe_device+0x49/0x120 __device_attach_driver+0x18a/0x250 bus_for_each_drv+0x123/0x1a0 __device_attach+0x207/0x330 bus_probe_device+0x1a2/0x260 device_add+0xa61/0x1ce0 usb_new_device.cold+0x463/0xf66 hub_event+0x10d5/0x3330 process_one_work+0x873/0x13e0 worker_thread+0x8b/0xd10 kthread+0x379/0x450 ret_from_fork+0x1f/0x30 Allocated by task 1896: kasan_save_stack+0x1b/0x40 __kasan_kmalloc+0x7c/0x90 kmem_cache_alloc_trace+0x19e/0x330 brcmf_setup_wiphybands+0x290/0x1430 brcmf_cfg80211_attach+0x2118/0x3fd0 brcmf_attach+0x389/0xd40 brcmf_usb_probe+0x12de/0x1690 usb_probe_interface+0x25f/0x710 really_probe+0x1be/0xa90 __driver_probe_device+0x2ab/0x460 driver_probe_device+0x49/0x120 __device_attach_driver+0x18a/0x250 bus_for_each_drv+0x123/0x1a0 __device_attach+0x207/0x330 bus_probe_device+0x1a2/0x260 device_add+0xa61/0x1ce0 usb_set_configuration+0x984/0x1770 usb_generic_driver_probe+0x69/0x90 usb_probe_device+0x9c/0x220 really_probe+0x1be/0xa90 __driver_probe_device+0x2ab/0x460 driver_probe_device+0x49/0x120 __device_attach_driver+0x18a/0x250 bus_for_each_drv+0x123/0x1a0 __device_attach+0x207/0x330 bus_probe_device+0x1a2/0x260 device_add+0xa61/0x1ce0 usb_new_device.cold+0x463/0xf66 hub_event+0x10d5/0x3330 process_one_work+0x873/0x13e0 worker_thread+0x8b/0xd10 kthread+0x379/0x450 ret_from_fork+0x1f/0x30 The buggy address belongs to the object at ffff888115f24000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1536 bytes inside of 2048-byte region [ffff888115f24000, ffff888115f24800) Memory state around the buggy address: ffff888115f24500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888115f24580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888115f24600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888115f24680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888115f24700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== Crash Report from brcmf_enable_bw40_2g(): ========== ---truncated---
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 3.10 and later | 5.4.232, 5.10.168, 5.15.93, 6.1.11, 6.2 | Patch available | CNA |
- Linux VendorLinux Affected 3.10 and later Fixed in 5.4.232, 5.10.168, 5.15.93, 6.1.11, 6.2 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | before 5.4.232; 5.5 to before 5.10.168; 5.11 to before 5.15.93; 5.16 to before 6.1.11 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 5.4.232; 5.5 to before 5.10.168; 5.11 to before 5.15.93; 5.16 to before 6.1.11 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.4.232, 5.10.168, 5.15.93, 6.1.11, 6.2
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 2 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-02 Threatist record created from CVE-2022-49740
- 2026-10-03 Alias added: GHSA-m76m-37m5-h9wj
References
Patch 5
- https://git.kernel.org/stable/c/9cf5e99c1ae1a85286a76c9a970202750538394c
- https://git.kernel.org/stable/c/b2e412879595821ff1b5545cbed5f108fba7f5b6
- https://git.kernel.org/stable/c/e4991910f15013db72f6ec0db7038ea67a57052e
- https://git.kernel.org/stable/c/f06de1bb6d61f0c18b0213bbc6298960037f9d42
- https://git.kernel.org/stable/c/4920ab131b2dbae7464b72bdcac465d070254209
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- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2022-49740 · CVE Program
- CVE-2022-49740 · NVD
- FIRST EPSS
- GHSA-m76m-37m5-h9wj · GitHub Advisory Database · CC BY 4.0
- CVE-2022-49740 · Red Hat security data · CC BY 4.0
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