CVE-2026-98406 is a vulnerability in Linux Kernel
Published on October 14, 2026
wifi: mac80211: avoid WARN in set_bitrate_mask when sdata not in driver
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]
Products Associated with CVE-2026-98406
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Affected Versions
Linux:- Version 554a43d5e77e8256aa9685ffd19ad555e6f77979 and below 4ba86c44b2fcb1c3175caa2456b6d58f483446ab is affected.
- Version 554a43d5e77e8256aa9685ffd19ad555e6f77979 and below 4095b66acae9893dd13deb39a4331651cb2f822b is affected.
- Version 554a43d5e77e8256aa9685ffd19ad555e6f77979 and below c2cd9c44777cf97be3e35c10b7c2d8f59ebb9306 is affected.
- Version 554a43d5e77e8256aa9685ffd19ad555e6f77979 and below 0d1700394e9f5d0bd9bebad8d5a50edf983f52fd is affected.
- Version 554a43d5e77e8256aa9685ffd19ad555e6f77979 and below 7978dda63d2b109ea9c3f7a096cd1aac6542cd54 is affected.
- Version 554a43d5e77e8256aa9685ffd19ad555e6f77979 and below 432c8532d5ccc2af77da43ed6ef1c80495a4efe8 is affected.
- Version 554a43d5e77e8256aa9685ffd19ad555e6f77979 and below c4ee5685af444024e6222ce29f6ed36adc44ffc3 is affected.
- Version 554a43d5e77e8256aa9685ffd19ad555e6f77979 and below da2ca406f45a6e21760243152ed8d2e8e72915c2 is affected.
- Version 3.5 is affected.
- Before 3.5 is unaffected.
- Version 5.10.271, <= 5.10.* is unaffected.
- Version 5.15.222, <= 5.15.* is unaffected.
- Version 6.1.189, <= 6.1.* is unaffected.
- Version 6.6.158, <= 6.6.* is unaffected.
- Version 6.12.112, <= 6.12.* is unaffected.
- Version 6.18.54, <= 6.18.* is unaffected.
- Version 7.2.8, <= 7.2.* is unaffected.
- Version 7.3-rc4, <= * is unaffected.