From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 A82A912C7F8; Fri, 2 Feb 2024 18:40:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706899218; cv=none; b=IQOKV/6CuCy1YGIwOtjc0iPqav80PYYrKhoidl7zL8aYVQnXN2u9A0gb7drwNdioRatrosso1mZ4hENeEeVg8L39uWUHuIQ0IuW7/Pfnf91iw2Dc54QPfvaQiqfg1Nzs+965/XrWibn0ng+Tt6IWWu6vVyTAhuDOOawklpQJ2Rs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706899218; c=relaxed/simple; bh=4t8DjpdB+QHR7yIJIaxXvdAMCr78XlKCpw7mUAnf1z4=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=mBJTMByAHTUlI0dn83a4hXDIIudGQpbAdKcMghzP3NbUPZzS5uEIjiSVsnpD+GWjjTyjTf9XSUf49g317spazgS2NT7E5YWR8pw8FklTVznWovsjfy4cYhgbr5HEEEWWes2Jof1XBWtOY/VK0c9x0o8eoIqTjmGOXE6w0NbpbJw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LZIGAeI9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LZIGAeI9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EFC47C433F1; Fri, 2 Feb 2024 18:40:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706899218; bh=4t8DjpdB+QHR7yIJIaxXvdAMCr78XlKCpw7mUAnf1z4=; h=From:To:Cc:Subject:Date:From; b=LZIGAeI9kqwQT97o9fF85FR0NRmaN+xHiWxGQeyK+QSZ2guvAuvvRpJnyCFMG0fIG bSuG05yLxuTKd/jyK2HJJLgvqw/hNn4AGPjs/J64t3d1g3emfFD/p48vvmyHMomJo8 APLS3nqAJ1Rk2F3ovUI/Xf0fW8MjGAT9hAAaxn1h/OQbG5KlOMkMKk3nCW+EUr0h3/ 1LYq7nVOf5odDAcTpuFmVk2iqN5oYmaJQ7zcY+3ymaVBRrxQLu4HWVM7s36ThG1g/s EecahU/EFX92/9Oy1XrtWMmVCtVO7nfbZkkrSbAlL8gyXTNSnXl7ydbHY5p7yO0XrS m6L8XrYUIR4hQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Michal Kazior , Johannes Berg , Sasha Levin , johannes@sipsolutions.net, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, linux-wireless@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 6.6 01/21] wifi: cfg80211: fix missing interfaces when dumping Date: Fri, 2 Feb 2024 13:39:48 -0500 Message-ID: <20240202184015.540966-1-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.6.15 Content-Transfer-Encoding: 8bit From: Michal Kazior [ Upstream commit a6e4f85d3820d00694ed10f581f4c650445dbcda ] The nl80211_dump_interface() supports resumption in case nl80211_send_iface() doesn't have the resources to complete its work. The logic would store the progress as iteration offsets for rdev and wdev loops. However the logic did not properly handle resumption for non-last rdev. Assuming a system with 2 rdevs, with 2 wdevs each, this could happen: dump(cb=[0, 0]): if_start=cb[1] (=0) send rdev0.wdev0 -> ok send rdev0.wdev1 -> yield cb[1] = 1 dump(cb=[0, 1]): if_start=cb[1] (=1) send rdev0.wdev1 -> ok // since if_start=1 the rdev0.wdev0 got skipped // through if_idx < if_start send rdev1.wdev1 -> ok The if_start needs to be reset back to 0 upon wdev loop end. The problem is actually hard to hit on a desktop, and even on most routers. The prerequisites for this manifesting was: - more than 1 wiphy - a few handful of interfaces - dump without rdev or wdev filter I was seeing this with 4 wiphys 9 interfaces each. It'd miss 6 interfaces from the last wiphy reported to userspace. Signed-off-by: Michal Kazior Link: https://msgid.link/20240116142340.89678-1-kazikcz@gmail.com Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- net/wireless/nl80211.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 0b0dfecedc50..c8bfacd5c8f3 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -4012,6 +4012,7 @@ static int nl80211_dump_interface(struct sk_buff *skb, struct netlink_callback * if_idx++; } + if_start = 0; wp_idx++; } out: -- 2.43.0