CVE-2022-50258
HighIn the Linux kernel, the following vulnerability has been resolved: wifi: brcmfmac: Fix potential stack-out-of-bounds in brcmf_c_preinit_dcmds() This patch fixes a stack-out-of-bounds read in brcmfmac that occurs when 'buf' that is not null-terminated is passed as an argument of strsep() in brcmf_c_preinit_dcmds(). This buffer is filled with a firmware version string by memcpy() in brcmf_fil_iovar_data_get(). The patch ensures buf is null-terminated. Found by a modified version of syzkaller. [ 47.569679][ T1897] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43236b for chip BCM43236/3 [ 47.582839][ T1897] brcmfmac: brcmf_c_process_clm_blob: no clm_blob available (err=-2), device may have limited channels available [ 47.601565][ T1897] ================================================================== [ 47.602574][ T1897] BUG: KASAN: stack-out-of-bounds in strsep+0x1b2/0x1f0 [ 47.603447][ T1897] Read of size 1 at addr ffffc90001f6f000 by task kworker/0:2/1897 [ 47.604336][ T1897] [ 47.604621][ T1897] CPU: 0 PID: 1897 Comm: kworker/0:2 Tainted: G O 5.14.0+ #131 [ 47.605617][ T1897] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 [ 47.606907][ T1897] Workqueue: usb_hub_wq hub_event [ 47.607453][ T1897] Call Trace: [ 47.607801][ T1897] dump_stack_lvl+0x8e/0xd1 [ 47.608295][ T1897] print_address_description.constprop.0.cold+0xf/0x334 [ 47.609009][ T1897] ? strsep+0x1b2/0x1f0 [ 47.609434][ T1897] ? strsep+0x1b2/0x1f0 [ 47.609863][ T1897] kasan_report.cold+0x83/0xdf [ 47.610366][ T1897] ? strsep+0x1b2/0x1f0 [ 47.610882][ T1897] strsep+0x1b2/0x1f0 [ 47.611300][ T1897] ? brcmf_fil_iovar_data_get+0x3a/0xf0 [ 47.611883][ T1897] brcmf_c_preinit_dcmds+0x995/0xc40 [ 47.612434][ T1897] ? brcmf_c_set_joinpref_default+0x100/0x100 [ 47.613078][ T1897] ? rcu_read_lock_sched_held+0xa1/0xd0 [ 47.613662][ T1897] ? rcu_read_lock_bh_held+0xb0/0xb0 [ 47.614208][ T1897] ? lock_acquire+0x19d/0x4e0 [ 47.614704][ T1897] ? find_held_lock+0x2d/0x110 [ 47.615236][ T1897] ? brcmf_usb_deq+0x1a7/0x260 [ 47.615741][ T1897] ? brcmf_usb_rx_fill_all+0x5a/0xf0 [ 47.616288][ T1897] brcmf_attach+0x246/0xd40 [ 47.616758][ T1897] ? wiphy_new_nm+0x1703/0x1dd0 [ 47.617280][ T1897] ? kmemdup+0x43/0x50 [ 47.617720][ T1897] brcmf_usb_probe+0x12de/0x1690 [ 47.618244][ T1897] ? brcmf_usbdev_qinit.constprop.0+0x470/0x470 [ 47.618901][ T1897] usb_probe_interface+0x2aa/0x760 [ 47.619429][ T1897] ? usb_probe_device+0x250/0x250 [ 47.619950][ T1897] really_probe+0x205/0xb70 [ 47.620435][ T1897] ? driver_allows_async_probing+0x130/0x130 [ 47.621048][ T1897] __driver_probe_device+0x311/0x4b0 [ 47.621595][ T1897] ? driver_allows_async_probing+0x130/0x130 [ 47.622209][ T1897] driver_probe_device+0x4e/0x150 [ 47.622739][ T1897] __device_attach_driver+0x1cc/0x2a0 [ 47.623287][ T1897] bus_for_each_drv+0x156/0x1d0 [ 47.623796][ T1897] ? bus_rescan_devices+0x30/0x30 [ 47.624309][ T1897] ? lockdep_hardirqs_on_prepare+0x273/0x3e0 [ 47.624907][ T1897] ? trace_hardirqs_on+0x46/0x160 [ 47.625437][ T1897] __device_attach+0x23f/0x3a0 [ 47.625924][ T1897] ? device_bind_driver+0xd0/0xd0 [ 47.626433][ T1897] ? kobject_uevent_env+0x287/0x14b0 [ 47.627057][ T1897] bus_probe_device+0x1da/0x290 [ 47.627557][ T1897] device_add+0xb7b/0x1eb0 [ 47.628027][ T1897] ? wait_for_completion+0x290/0x290 [ 47.628593][ T1897] ? __fw_devlink_link_to_suppliers+0x5a0/0x5a0 [ 47.629249][ T1897] usb_set_configuration+0xf59/0x16f0 [ 47.629829][ T1897] usb_generic_driver_probe+0x82/0xa0 [ 47.630385][ T1897] usb_probe_device+0xbb/0x250 [ 47.630927][ T1897] ? usb_suspend+0x590/0x590 [ 47.631397][ T1897] really_probe+0x205/0xb70 [ 47.631855][ T1897] ? driver_allows_async_probing+0x130/0x130 [ 47.632469][ T1897] __driver_probe_device+0x311/0x4b0 [ 47.633002][ ---truncated---
CVSS 3.1 score
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness type
CWE-787CVE-2022-50258 is a Out-of-bounds Write vulnerability
What is Out-of-bounds Write?
The product writes data past the end or before the beginning of the intended buffer. Learn more on MITRE CWE
Affected versions
Linux kernel versions
3.8
and later are affected. Fixed in
4.14.308,
4.19.276,
5.4.235,
5.10.173,
5.15.99,
6.1.16,
6.2.3,
6.3
and their respective stable series.
References
The following references provide additional information about CVE-2022-50258 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/0a06cadcc2a0044e4a117cc0e61436fc3a0dad69
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PatchKernel patch commithttps://git.kernel.org/stable/c/17dbe90e13f52848c460d253f15b765038ec6dc0
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PatchKernel patch commithttps://git.kernel.org/stable/c/3a3a5e3f94068cd562d62a57da6983c8cd07d53c
Frequently asked questions
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What is CVE-2022-50258?
CVE-2022-50258 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Out-of-bounds Write flaw (CWE-787) . It affects Linux kernel versions from 3.8 onward and has been patched in 4.14.308, 4.19.276, 5.4.235 and others. CVE-2022-50258 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-2022-50258?
CVE-2022-50258 has a CVSS score of 7.8 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:H/A:H. -
Is there a patch available for CVE-2022-50258?
Yes — CVE-2022-50258 has been patched. Fixed versions include 4.14.308, 4.19.276, 5.4.235 and others. If you are running Linux kernel 3.8 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2022-50258 actively exploited?
No — CVE-2022-50258 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 Write (CWE-787)?
The product writes data past the end or before the beginning of the intended buffer. View CWE-787 on MITRE CWE →