Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

wifi: brcmfmac: ensure CLM version is null-terminated to prevent stack-out-of-bounds

Fix a stack-out-of-bounds read in brcmfmac that occurs when 'buf' that is not null-terminated is passed as an argument of strreplace() in brcmf_c_preinit_dcmds(). This buffer is filled with a CLM version string by memcpy() in brcmf_fil_iovar_data_get(). Ensure buf is null-terminated.

Found by a modified version of syzkaller.

[ 33.004414][ T1896] brcmfmac: brcmf_c_process_clm_blob: no clm_blob available (err=-2), device may have limited channels available [ 33.013486][ T1896] brcmfmac: brcmf_c_preinit_dcmds: Firmware: BCM43236/3 wl0: Nov 30 2011 17:33:42 version 5.90.188.22 [ 33.021554][ T1896] ================================================================== [ 33.022379][ T1896] BUG: KASAN: stack-out-of-bounds in strreplace+0xf2/0x110 [ 33.023122][ T1896] Read of size 1 at addr ffffc90001d6efc8 by task kworker/0:2/1896 [ 33.023852][ T1896] [ 33.024096][ T1896] CPU: 0 PID: 1896 Comm: kworker/0:2 Tainted: G O 5.14.0+ #132 [ 33.024927][ T1896] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 [ 33.026065][ T1896] Workqueue: usb_hub_wq hub_event [ 33.026581][ T1896] Call Trace: [ 33.026896][ T1896] dump_stack_lvl+0x57/0x7d [ 33.027372][ T1896] print_address_description.constprop.0.cold+0xf/0x334 [ 33.028037][ T1896]…