From patchwork Thu Sep 26 13:34:38 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladislav Efanov X-Patchwork-Id: 13813372 X-Patchwork-Delegate: kuba@kernel.org Received: from mail.ispras.ru (mail.ispras.ru [83.149.199.84]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D749062171; Thu, 26 Sep 2024 13:38:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=83.149.199.84 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727357909; cv=none; b=LLggsRNKiWP/1crGIBE2H5G4IfXp1K7+Yx+lNjZR8RVxwri5unRHus0+xURg4nYnEnPualohY1tc0zKxrfoG1DqpVkTIxVC//GUXNKFOdtvu6MUtIIehuQIcEj0Tjc8gTGQxkXnsZu2KoOfLfQcQX4XEs18jQKdLCyGIoVvk3ko= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727357909; c=relaxed/simple; bh=HM8hWjCaGTIhZ+L0lEK+WDF+Dg03Qo7kEWliuN+AiEE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=kssgP2hxkGMgSSH364qSJbjKrnQYLBHHfzFuPc/EVd0s+pI623TzzK80CqXFwzSbQjL/0t2CReUFRvqSA+I7rDEsFM1WAjLmMDw42fwPqmZG5Cn7ZTqLOLv9732PPYpkGM4vVVFATmIoTyG+HjCKjrXJpC6O6JnKCj2YjXxNKmM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ispras.ru; spf=pass smtp.mailfrom=ispras.ru; dkim=pass (1024-bit key) header.d=ispras.ru header.i=@ispras.ru header.b=UHN9UHy4; arc=none smtp.client-ip=83.149.199.84 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ispras.ru Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ispras.ru Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ispras.ru header.i=@ispras.ru header.b="UHN9UHy4" Received: from vefanov-Precision-3650-Tower.intra.ispras.ru (unknown [10.10.2.69]) by mail.ispras.ru (Postfix) with ESMTPSA id 1A8C840769D4; Thu, 26 Sep 2024 13:38:25 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.ispras.ru 1A8C840769D4 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ispras.ru; s=default; t=1727357905; bh=U3C6gL58GGhS+NoBws1dkbyUPAYlkDpUF6lUMqgKoC8=; h=From:To:Cc:Subject:Date:From; b=UHN9UHy4+CdcrAOYtcOpWdmVsyzKGVFU+Jnbd0fQK8Hdy1xJ9dlZFWJQxJfe+V46j Wlu6q/ckIcKHCHwdzaBp8TbK6TrFEkywV8Nv361vXKDkWnw/kCwOTAvSnIgM0b1fIL QEPyGb/JLXOMb3QG9UviBeZmmvhf+mDVTNZ2WnhM= From: Vladislav Efanov To: Johannes Berg Cc: Vladislav Efanov , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , "John W. Linville" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, lvc-project@linuxtesting.org Subject: [PATCH] cfg80211: Convert WARN_ON() to warning message Date: Thu, 26 Sep 2024 16:34:38 +0300 Message-ID: <20240926133446.25445-1-VEfanov@ispras.ru> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org syzkaller got the following warning: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 9992 at net/wireless/ibss.c:36 __cfg80211_ibss This warning is the result of the race condition between the following events: event1 event2 event3 __ieee80211_sta_join_ibss() | | creates new cgf80211_bss | | structure. | | Calls cfg80211_ibss_joined() | | which will scheduled | | new event_work. | | ieee80211_ibss_disconnect() | is called due to connection | dropped/ibss leaves to | remove cfg80211_bss structure. | event_work starts. __cfg80211_ibss_joined() is called and WARNING is detected due to cfg80211_bss structure was removed by event2. It is a normal situation when connection is dropped during handshaking. So it looks reasonable to replace WARN_ON() with warning message to prevent false alarm. Found by Linux Verification Center (linuxtesting.org) with syzkaller. Fixes: 04a773ade068 ("cfg80211/nl80211: add IBSS API") Signed-off-by: Vladislav Efanov --- net/wireless/ibss.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/wireless/ibss.c b/net/wireless/ibss.c index e6fdb0b8187d..93c8bee12bdf 100644 --- a/net/wireless/ibss.c +++ b/net/wireless/ibss.c @@ -34,8 +34,10 @@ void __cfg80211_ibss_joined(struct net_device *dev, const u8 *bssid, bss = cfg80211_get_bss(wdev->wiphy, channel, bssid, NULL, 0, IEEE80211_BSS_TYPE_IBSS, IEEE80211_PRIVACY_ANY); - if (WARN_ON(!bss)) + if (!bss) { + pr_warn("cfg80211: cfg80211_bss with bssid %s not found.\n", bssid); return; + } if (wdev->u.ibss.current_bss) { cfg80211_unhold_bss(wdev->u.ibss.current_bss);