CVE-2022-49740 [High] | Out-of-bounds Read in Linux Kernel

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---

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2025-11-21	0.06%	0.03%	-0.03%
2	2025-11-18	0.02%	0.06%	+0.04%
3	2025-03-28	—	0.02%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2025-11-21

0.06%

0.03%

-0.03%

2025-11-18

0.02%

0.06%

+0.04%

2025-03-28

—

0.02%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.1	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	5.2	[email protected]
7.1	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	5.2	134c704f-9b21-4f2e-91b3-4a467353bcc0

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.1

3.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

5.2

[email protected]

7.1

3.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

5.2

134c704f-9b21-4f2e-91b3-4a467353bcc0

OS Trackers for CVE-2022-49740

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2022-49740 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2022-49740
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2022-49740
`suse`	medium	CVE-2022-49740 severity moderate: SUSE including 272 source package names (amazon/suse-sles-15-sp1-chost-byos-v20210304-hvm-ssd-x86_64, amazon/suse-sles-15-sp1-chost-byos-v20220127-hvm-ssd-x86_64, …), 532 product×package rows across 60 product lines (Image SLES12-SP5-Azure-BYOS, Image SLES12-SP5-Azure-HPC-BYOS, … (60 product lines)): Known Affected 231, Known Not Affected 228, Fixed 73.	https://www.suse.com/security/cve/CVE-2022-49740/
`ubuntu`	medium	CVE-2022-49740 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1551 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1145, ignored 150, released 138, not-affected 97, needed 20, needs-triage 1.	https://ubuntu.com/security/CVE-2022-49740

Affected software / configurations for CVE-2022-49740

Vendor	Product	Version	Raw CPE
linux	linux_kernel	< 5.4.232	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.5, < 5.10.168	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.11, < 5.15.93	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.16, < 6.1.11	cpe:2.3:o:linux:linux_kernel::::::::

References for CVE-2022-49740

URL	Tags
https://git.kernel.org/stable/c/4920ab131b2dbae7464b72bdcac465d070254209	Patch
https://git.kernel.org/stable/c/9cf5e99c1ae1a85286a76c9a970202750538394c	Patch
https://git.kernel.org/stable/c/b2e412879595821ff1b5545cbed5f108fba7f5b6	Patch
https://git.kernel.org/stable/c/e4991910f15013db72f6ec0db7038ea67a57052e	Patch
https://git.kernel.org/stable/c/f06de1bb6d61f0c18b0213bbc6298960037f9d42	Patch

URL

CVE-2022-49740 | wifi: brcmfmac: Check the count value of channel spec to prevent out-of-bounds reads

Exploit prediction scoring system (EPSS) score for CVE-2022-49740

Common vulnerability scoring system (CVSS) metrics for CVE-2022-49740

Weakness enumeration for CVE-2022-49740

OS Trackers for CVE-2022-49740

Affected software / configurations for CVE-2022-49740

References for CVE-2022-49740