CVE-2026-98406
Received
Received - Intake
Kernel WARN in mac80211 set_bitrate_mask without driver presence
Vulnerability report for CVE-2026-98406, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-14
Last updated on: 2026-10-14
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: avoid WARN in set_bitrate_mask when sdata not in driver
ieee80211_set_bitrate_mask() checks if the interface is running via
ieee80211_sdata_running(), but it does not check if the interface is
still present in the driver.
When sdata is running but IEEE80211_SDATA_IN_DRIVER is not set, the
call reaches drv_set_bitrate_mask() in driver-ops.h which hits
wlan1: Failed check-sdata-in-driver check, flags: 0x0
WARNING: net/mac80211/driver-ops.h:884 at drv_set_bitrate_mask
Syzkaller triggers this via wext SIOCSIWRATE ioctl. The Call Trace shows
wext_ioctl_dispatch() in wext-core.c dispatching the ioctl, calling
ioctl_standard_call() for SIOCSIWRATE, which calls cfg80211_wext_siwrate()
in wext-compat.c. That builds a bitrate mask and calls
rdev_set_bitrate_mask() which ends up in ieee80211_set_bitrate_mask() in
cfg.c. The interface is marked running via SDATA_STATE_RUNNING but
flags is 0, so check_sdata_in_driver() fails.
When the interface is being torn down, or when wext ioctl is issued
during interface bringup before drv_add_interface() sets IN_DRIVER, the
running check passes while IN_DRIVER is clear.
Check IEEE80211_SDATA_IN_DRIVER in ieee80211_set_bitrate_mask() before
calling the driver, returning -ENETDOWN. This avoids the WARN_ONCE in
driver-ops.h and matches other cfg.c operations that bail early when not
in driver.
This change should be safe because wiphy mutex is held in
cfg80211_wext_siwrate() via guard(wiphy), and IN_DRIVER is set/cleared
under RTNL and wiphy paths in drv_add_interface() and
drv_remove_interface() in driver-ops.c, so the check is race-free
against driver add/remove. Returning -ENETDOWN is the same error other
not-running paths use and does not introduce new locking.
[also add second syzbot report]
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| Linux | Linux | 554a43d5e77e8256aa9685ffd19ad555e6f77979 |
| Linux | Linux | 554a43d5e77e8256aa9685ffd19ad555e6f77979 |
| Linux | Linux | 554a43d5e77e8256aa9685ffd19ad555e6f77979 |
| Linux | Linux | 554a43d5e77e8256aa9685ffd19ad555e6f77979 |
| Linux | Linux | 554a43d5e77e8256aa9685ffd19ad555e6f77979 |
| Linux | Linux | 554a43d5e77e8256aa9685ffd19ad555e6f77979 |
| Linux | Linux | 554a43d5e77e8256aa9685ffd19ad555e6f77979 |
| Linux | Linux | 554a43d5e77e8256aa9685ffd19ad555e6f77979 |
| Linux | Linux | 3.5 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
