CVE-2022-50099

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

video: fbdev: arkfb: Check the size of screen before memset_io()

In the function arkfb_set_par(), the value of screen_size is calculated by the user input. If the user provides the improper value, the value of screen_size may larger than info->screen_size, which may cause the following bug:

[ 659.399066] BUG: unable to handle page fault for address: ffffc90003000000 [ 659.399077] #PF: supervisor write access in kernel mode [ 659.399079] #PF: error_code(0x0002) - not-present page [ 659.399094] RIP: 0010:memset_orig+0x33/0xb0 [ 659.399116] Call Trace: [ 659.399122] arkfb_set_par+0x143f/0x24c0 [ 659.399130] fb_set_var+0x604/0xeb0 [ 659.399161] do_fb_ioctl+0x234/0x670 [ 659.399189] fb_ioctl+0xdd/0x130

Fix the this by checking the value of screen_size before memset_io().

Affected Software

References

• https://git.kernel.org/stable/c/0701df594bc1d7ae55fed407fb65dd90a93f8a9c
• https://git.kernel.org/stable/c/09e733d6ac948e6fda4b16252e44ea46f98fc8b4
• https://git.kernel.org/stable/c/2ce61c39c2a0b8ec82f48e0f7136f0dac105ae75
• https://git.kernel.org/stable/c/352305ea50d682b8e081d826da53caf9e744d7d0
• https://git.kernel.org/stable/c/4a20c5510aa2c031a096a58deb356e91609781c9
• https://git.kernel.org/stable/c/53198b81930e567ad6b879812d88052a1e8ac79e
• https://git.kernel.org/stable/c/8bcb1a06e3091716b7cbebe0e91d1de9895068cd
• https://git.kernel.org/stable/c/96b550971c65d54d64728d8ba973487878a06454