7

CVE-2021-47479

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

staging: rtl8712: fix use-after-free in rtl8712_dl_fw

Syzbot reported use-after-free in rtl8712_dl_fw(). The problem was in
race condition between r871xu_dev_remove() ->ndo_open() callback.

It's easy to see from crash log, that driver accesses released firmware
in ->ndo_open() callback. It may happen, since driver was releasing
firmware _before_ unregistering netdev. Fix it by moving
unregister_netdev() before cleaning up resources.

Call Trace:
...
 rtl871x_open_fw drivers/staging/rtl8712/hal_init.c:83 [inline]
 rtl8712_dl_fw+0xd95/0xe10 drivers/staging/rtl8712/hal_init.c:170
 rtl8712_hal_init drivers/staging/rtl8712/hal_init.c:330 [inline]
 rtl871x_hal_init+0xae/0x180 drivers/staging/rtl8712/hal_init.c:394
 netdev_open+0xe6/0x6c0 drivers/staging/rtl8712/os_intfs.c:380
 __dev_open+0x2bc/0x4d0 net/core/dev.c:1484

Freed by task 1306:
...
 release_firmware+0x1b/0x30 drivers/base/firmware_loader/main.c:1053
 r871xu_dev_remove+0xcc/0x2c0 drivers/staging/rtl8712/usb_intf.c:599
 usb_unbind_interface+0x1d8/0x8d0 drivers/usb/core/driver.c:458

Verknüpft mit AI von unstrukturierten Daten zu bestehenden CPE der NVD
Diese Information steht angemeldeten Benutzern zur Verfügung.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Linux ≫ Linux Kernel Version >= 3.2.6 < 3.3
Linux ≫ Linux Kernel Version >= 3.3.1 < 5.10.79
Linux ≫ Linux Kernel Version >= 5.11 < 5.14.18
Linux ≫ Linux Kernel Version >= 5.15 < 5.15.2
Linux ≫ Linux Kernel Version3.3 Update-
Linux ≫ Linux Kernel Version3.3 Updaterc4
Linux ≫ Linux Kernel Version3.3 Updaterc5
Linux ≫ Linux Kernel Version3.3 Updaterc6
Linux ≫ Linux Kernel Version3.3 Updaterc7
Zu dieser CVE wurde keine CISA KEV oder CERT.AT-Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.02% 0.033
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 7 1 5.9
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE-416 Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.