CVE-2021-47479
Assigner: Linux
Published: 2024-05-22T08:19:32.174Z
State: PUBLISHED
descriptions: value: 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
affected: product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions: version: 8c213fa59199
lessThan: c430094541a8
status: affected
versionType: git
version: 8c213fa59199
lessThan: befd23bd3b17
status: affected
versionType: git
version: 8c213fa59199
lessThan: a65c9afe9f2f
status: affected
versionType: git
version: 8c213fa59199
lessThan: c052cc1a069c
status: affected
versionType: git
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions: version: 3.3
status: affected
version: 0
lessThan: 3.3
status: unaffected
versionType: custom
version: 5.10.79
lessThanOrEqual: 5.10.*
status: unaffected
versionType: custom
version: 5.14.18
lessThanOrEqual: 5.14.*
status: unaffected
versionType: custom
version: 5.15.2
lessThanOrEqual: 5.15.*
status: unaffected
versionType: custom
version: 5.16
lessThanOrEqual: *
status: unaffected
versionType: original_commit_for_fix
title: staging: rtl8712: fix use-after-free in rtl8712_dl_fw
x_generator: engine: bippy-d175d3acf727