5.5

CVE-2022-49978

fbdev: fb_pm2fb: Avoid potential divide by zero error

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

fbdev: fb_pm2fb: Avoid potential divide by zero error

In `do_fb_ioctl()` of fbmem.c, if cmd is FBIOPUT_VSCREENINFO, var will be
copied from user, then go through `fb_set_var()` and
`info->fbops->fb_check_var()` which could may be `pm2fb_check_var()`.
Along the path, `var->pixclock` won't be modified. This function checks
whether reciprocal of `var->pixclock` is too high. If `var->pixclock` is
zero, there will be a divide by zero error. So, it is necessary to check
whether denominator is zero to avoid crash. As this bug is found by
Syzkaller, logs are listed below.

divide error in pm2fb_check_var
Call Trace:
 <TASK>
 fb_set_var+0x367/0xeb0 drivers/video/fbdev/core/fbmem.c:1015
 do_fb_ioctl+0x234/0x670 drivers/video/fbdev/core/fbmem.c:1110
 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1189
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Linux ≫ Linux Kernel Version < 4.9.327
Linux ≫ Linux Kernel Version >= 4.10 < 4.14.292
Linux ≫ Linux Kernel Version >= 4.15 < 4.19.257
Linux ≫ Linux Kernel Version >= 4.20 < 5.4.212
Linux ≫ Linux Kernel Version >= 5.5 < 5.10.141
Linux ≫ Linux Kernel Version >= 5.11 < 5.15.65
Linux ≫ Linux Kernel Version >= 5.16 < 5.19.7
Linux ≫ Linux Kernel Version6.0 Updaterc1
Linux ≫ Linux Kernel Version6.0 Updaterc2
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.21% 0.11
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 5.5 1.8 3.6
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-369 Divide By Zero

The product divides a value by zero.

https://git.kernel.org/stable/c/0f1174f4972ea9fad6becf8881d71adca8e9ca91
Patch
https://git.kernel.org/stable/c/3ec326a6a0d4667585ca595f438c7293e5ced7c4
Patch
https://git.kernel.org/stable/c/7f88cdfea8d7f4dbaf423d808241403b2bb945e4
Patch
https://git.kernel.org/stable/c/7d9591b32a9092fc6391a316b56e8016c6181c3d
Patch
https://git.kernel.org/stable/c/8fc778ee2fb2853f7a3531fa7273349640d8e4e9
Patch
https://git.kernel.org/stable/c/34c3dea1189525cd533071ed5c176fc4ea8d982b
Patch
https://git.kernel.org/stable/c/cb4bb011a683532841344ca7f281b5e04389b4f8
Patch
https://git.kernel.org/stable/c/19f953e7435644b81332dd632ba1b2d80b1e37af
Patch