From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2BDF523ED5B for ; Wed, 1 Jul 2026 09:52:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782899533; cv=none; b=okfameS4JcdgPOrhD46vO8XEyHYsXch1nff6orpiV3ZJGIzTJHfe1KiUTcxCnTYEnrs5dclmKoW2qLyyrkfrl3CZs2LpxeTAY3ty3o2egoV8rrFNbQoROy/apztU/FQHIiuISesOPZ87FR+Cs/TQTr8PxBpnLEZXGx4l4TDvUxI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782899533; c=relaxed/simple; bh=EOzx00JTYIu3gmSwGnGKP3TSMrjktZU3nS4txAJ2z6U=; h=From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type:Date; b=gRykyLMMgf0bU4CGDj+UVLyDUyRAhhGhusXCw72bPmx4ThONCqsjuXpcxdTZPAE1Rd7Uv6tNclbHY6NOZyqWFgYO7yg2PNdS798qLy1pYNxkTvp8J+WAf8+nwGUsAJdIMQHXP+2ouuegdOcY2Uzs5jLzsCg/7imX6sxEVyRbnjM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=V4HnGObR; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="V4HnGObR" Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id A2FA11F00A3A; Wed, 1 Jul 2026 09:52:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782899531; bh=JaR8wk7xPEDKyaG0THZqAauhC9KNThOd1wbHa0mLJds=; h=From:To:Cc:Subject:Date; b=V4HnGObRg3NxzzmneExwn0gr9MxkDg/9bk1dJ+vGp86G5dSdg14Bs3nzRFruaFkSB ITdqO4AqP9bXnYHsWyYRGyAEFtVDMDGIk08HDWnPJ0Ec1AgbBLfsjG8I8M196fsJzG FTTquVdVyAvaFecZ4PNM7vPTIpJnBQPf/vXgsousQf5e8onfQqFw8Uk6cSzGpjolZr g/IcLEmtXrXPqmSIWlRfXmZ5uf1eUxxPKJkIt719oNWx6U/jEZViqZfo3K9NKTpUEj KKbKFZiEAtP/NyskUSLI2CTXX+RoUATbJ4hoDZDsH4J1fasWT4dIXLR67Qknm8cU6g dMGMOYJrOW/zg== From: "syzbot" To: syzkaller-upstream-moderation@googlegroups.com Cc: syzbot@lists.linux.dev Subject: [PATCH RFC] wifi: mac80211: reject station association if AP is not started Message-ID: <8e8a5122-a09e-43b2-b42f-4c73b021b173@mail.kernel.org> Precedence: bulk X-Mailing-List: syzbot@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Date: Wed, 1 Jul 2026 09:52:11 +0000 (UTC) If an interface is changed to AP mode but not started, its channel context configuration (chanctx_conf) remains NULL. If a station is then added to this interface, the kernel may automatically set the NL80211_STA_FLAG_ASSOCIATED flag for compatibility with older userspace applications. When this flag is set, sta_apply_auth_flags() attempts to initialize rate control for the station by calling rate_control_rate_init_all_links(). This eventually leads to rate_control_rate_init(), which dereferences the NULL chanctx_conf, triggering a WARN_ON: WARNING: net/mac80211/rate.c:51 at rate_control_rate_init+0x5a6/0x630 ... Call Trace: rate_control_rate_init_all_links+0xf4/0x190 net/mac80211/rate.c:84 sta_apply_auth_flags+0x1bc/0x430 net/mac80211/cfg.c:2152 sta_apply_parameters+0x126d/0x1b10 net/mac80211/cfg.c:2618 ieee80211_add_station+0x3de/0x700 net/mac80211/cfg.c:2684 rdev_add_station+0xfc/0x290 net/wireless/rdev-ops.h:201 nl80211_new_station+0x1b4e/0x1fd0 net/wireless/nl80211.c:9505 Fix this by rejecting the addition or modification of a station to the associated state if the AP has not been started (chanctx_conf is NULL). Exempt Multi-Link Operation (MLO) interfaces from this check, as they handle chanctx_conf per-link rather than globally on the VIF, and rate_control_rate_init() already handles them correctly. Fixes: 55de908ab292 ("mac80211: use channel contexts") Assisted-by: Gemini:gemini-3.1-pro-preview best-expensive syzbot Reported-by: syzbot+9bdc0c5998ab45b05030@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=9bdc0c5998ab45b05030 Link: https://syzkaller.appspot.com/ai_job?id=86851195-2aa0-410f-9fc9-952d95ae035d To: "Johannes Berg" To: Cc: --- diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index 3b58af59f..b45d7923c 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -2143,6 +2143,10 @@ static int sta_apply_auth_flags(struct ieee80211_local *local, if (mask & BIT(NL80211_STA_FLAG_ASSOCIATED) && set & BIT(NL80211_STA_FLAG_ASSOCIATED) && !test_sta_flag(sta, WLAN_STA_ASSOC)) { + if (!ieee80211_vif_is_mld(&sta->sdata->vif) && + !rcu_access_pointer(sta->sdata->vif.bss_conf.chanctx_conf)) + return -EINVAL; + /* * When peer becomes associated, init rate control as * well. Some drivers require rate control initialized base-commit: dc59e4fea9d83f03bad6bddf3fa2e52491777482 -- This is an AI-generated patch subject to moderation. Reply with '#syz upstream' to Sign-off the patch as a human author and send it to the upstream kernel mailing lists. Reply with '#syz reject' to reject it ('#syz unreject' to undo). See https://goo.gle/syzbot-ai-patches for information about AI-generated patches. You can comment on the patch as usual, syzbot will try to address the comments and send a new version of the patch if necessary. syzbot engineers can be reached at syzkaller@googlegroups.com.