CVE-2022-49740
HighIn 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---
CVSS 3.1 score
7.1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Weakness type
CWE-125CVE-2022-49740 is a Out-of-bounds Read vulnerability
What is Out-of-bounds Read?
The product reads data past the end or before the beginning of the intended buffer. Learn more on MITRE CWE
Affected versions
Linux kernel versions
3.10
and later are affected. Fixed in
5.4.232,
5.10.168,
5.15.93,
6.1.11,
6.2
and their respective stable series.
References
The following references provide additional information about CVE-2022-49740 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/4920ab131b2dbae7464b72bdcac465d070254209
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PatchKernel patch commithttps://git.kernel.org/stable/c/9cf5e99c1ae1a85286a76c9a970202750538394c
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PatchKernel patch commithttps://git.kernel.org/stable/c/b2e412879595821ff1b5545cbed5f108fba7f5b6
Frequently asked questions
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What is CVE-2022-49740?
CVE-2022-49740 is a High severity Linux kernel vulnerability with a CVSS score of 7.1 out of 10 , classified as an Out-of-bounds Read flaw (CWE-125) . It affects Linux kernel versions from 3.10 onward and has been patched in 5.4.232, 5.10.168, 5.15.93 and others. CVE-2022-49740 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2022-49740?
CVE-2022-49740 has a CVSS score of 7.1 out of 10, rated High severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H. -
Is there a patch available for CVE-2022-49740?
Yes — CVE-2022-49740 has been patched. Fixed versions include 5.4.232, 5.10.168, 5.15.93 and others. If you are running Linux kernel 3.10 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2022-49740 actively exploited?
No — CVE-2022-49740 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is Out-of-bounds Read (CWE-125)?
The product reads data past the end or before the beginning of the intended buffer. View CWE-125 on MITRE CWE →