5.4-stable review patch. If anyone has any objections, please let me know.
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From: Vitaliy Shevtsov v.shevtsov@mt-integration.ru
commit 49f27f29446a5bfe633dd2cc0cfebd48a1a5e77f upstream.
It is possible to set both MONITOR_FLAG_COOK_FRAMES and MONITOR_FLAG_ACTIVE flags simultaneously on the same monitor interface from the userspace. This causes a sub-interface to be created with no IEEE80211_SDATA_IN_DRIVER bit set because the monitor interface is in the cooked state and it takes precedence over all other states. When the interface is then being deleted the kernel calls WARN_ONCE() from check_sdata_in_driver() because of missing that bit.
Fix this by rejecting MONITOR_FLAG_COOK_FRAMES if it is set along with other flags.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Fixes: 66f7ac50ed7c ("nl80211: Add monitor interface configuration flags") Cc: stable@vger.kernel.org Reported-by: syzbot+2e5c1e55b9e5c28a3da7@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=2e5c1e55b9e5c28a3da7 Signed-off-by: Vitaliy Shevtsov v.shevtsov@mt-integration.ru Link: https://patch.msgid.link/20250131152657.5606-1-v.shevtsov@mt-integration.ru Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/wireless/nl80211.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -3409,6 +3409,11 @@ static int parse_monitor_flags(struct nl if (flags[flag]) *mntrflags |= (1<<flag);
+ /* cooked monitor mode is incompatible with other modes */ + if (*mntrflags & MONITOR_FLAG_COOK_FRAMES && + *mntrflags != MONITOR_FLAG_COOK_FRAMES) + return -EOPNOTSUPP; + *mntrflags |= MONITOR_FLAG_CHANGED;
return 0;