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 6D8D23537DF; Fri, 24 Apr 2026 13:43:35 +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=1777038215; cv=none; b=K5Ovj9TGdSbREfKEjoQ9wk3/c2ab5kqAI9pcfsEzAuS382WvM7milo64OwIIwPBQh4t49P/mYZwoVkLE3vN+LzYpbVtmDC97PAmOUDPAI70W/hGjxwSsZGsf5R1SX1YElGbeDVVotgIFfBmmU6tgInsHMpSq9ADOBzxc8zbi5Z4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777038215; c=relaxed/simple; bh=Gw2PkFvtH8WXIw3/cPGGrFBAtZeZU+7KR6MwI2gbQ4E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FWweL1mMO37qP8AEAcC6V6XhyGnFRKuS8eqU9t7RfjpODFY9L0UD98Zf848K5wsTSZDMpZ4KLNBEwj5C37Z+jlotrdVxLdNzcwbia922cnucCIFF3hWHASQ3dSoEfkyIx/4T4Kq2YwFpwjhnW9As1xH4gaE52CFmw6GqGSxQJ2Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=TqrEA9Ck; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="TqrEA9Ck" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06252C19425; Fri, 24 Apr 2026 13:43:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1777038215; bh=Gw2PkFvtH8WXIw3/cPGGrFBAtZeZU+7KR6MwI2gbQ4E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TqrEA9CkXlxmtJhrx8wKrS7Pzmbb5ymKFazofqSd+tni8yCLi3uRP/mezgP/PgB9k P/0Mm7SzFB13WOdt+oJw1fsg8ATbMJcr1PDXLw69dFf579dG69ceomrLVREeGJh5sk o8Psamw0FPBgTRifVioPnofN4GGn9ey+U5uQOFis= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Felix Fietkau , Johannes Berg , Li hongliang <1468888505@139.com>, Sasha Levin Subject: [PATCH 6.12 05/35] wifi: mac80211: always free skb on ieee80211_tx_prepare_skb() failure Date: Fri, 24 Apr 2026 15:31:12 +0200 Message-ID: <20260424132412.686395810@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260424132411.427029259@linuxfoundation.org> References: <20260424132411.427029259@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Felix Fietkau [ Upstream commit d5ad6ab61cbd89afdb60881f6274f74328af3ee9 ] ieee80211_tx_prepare_skb() has three error paths, but only two of them free the skb. The first error path (ieee80211_tx_prepare() returning TX_DROP) does not free it, while invoke_tx_handlers() failure and the fragmentation check both do. Add kfree_skb() to the first error path so all three are consistent, and remove the now-redundant frees in callers (ath9k, mt76, mac80211_hwsim) to avoid double-free. Document the skb ownership guarantee in the function's kdoc. Signed-off-by: Felix Fietkau Link: https://patch.msgid.link/20260314065455.2462900-1-nbd@nbd.name Fixes: 06be6b149f7e ("mac80211: add ieee80211_tx_prepare_skb() helper function") Signed-off-by: Johannes Berg [ Exclude changes to drivers/net/wireless/mediatek/mt76/scan.c as this file is first introduced by commit 31083e38548f("wifi: mt76: add code for emulating hardware scanning") after linux-6.14.] Signed-off-by: Li hongliang <1468888505@139.com> Signed-off-by: Sasha Levin --- drivers/net/wireless/ath/ath9k/channel.c | 6 ++---- drivers/net/wireless/virtual/mac80211_hwsim.c | 1 - include/net/mac80211.h | 4 +++- net/mac80211/tx.c | 4 +++- 4 files changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/channel.c b/drivers/net/wireless/ath/ath9k/channel.c index 571062f2e82a7..ba8ec5112afe8 100644 --- a/drivers/net/wireless/ath/ath9k/channel.c +++ b/drivers/net/wireless/ath/ath9k/channel.c @@ -1011,7 +1011,7 @@ static void ath_scan_send_probe(struct ath_softc *sc, skb_set_queue_mapping(skb, IEEE80211_AC_VO); if (!ieee80211_tx_prepare_skb(sc->hw, vif, skb, band, NULL)) - goto error; + return; txctl.txq = sc->tx.txq_map[IEEE80211_AC_VO]; if (ath_tx_start(sc->hw, skb, &txctl)) @@ -1124,10 +1124,8 @@ ath_chanctx_send_vif_ps_frame(struct ath_softc *sc, struct ath_vif *avp, skb->priority = 7; skb_set_queue_mapping(skb, IEEE80211_AC_VO); - if (!ieee80211_tx_prepare_skb(sc->hw, vif, skb, band, &sta)) { - dev_kfree_skb_any(skb); + if (!ieee80211_tx_prepare_skb(sc->hw, vif, skb, band, &sta)) return false; - } break; default: return false; diff --git a/drivers/net/wireless/virtual/mac80211_hwsim.c b/drivers/net/wireless/virtual/mac80211_hwsim.c index 8b4fd5fd11b0e..e992e59b59189 100644 --- a/drivers/net/wireless/virtual/mac80211_hwsim.c +++ b/drivers/net/wireless/virtual/mac80211_hwsim.c @@ -2977,7 +2977,6 @@ static void hw_scan_work(struct work_struct *work) hwsim->tmp_chan->band, NULL)) { rcu_read_unlock(); - kfree_skb(probe); continue; } diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 80259a37e7247..7d71a4149cdf9 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -7208,7 +7208,9 @@ void ieee80211_report_wowlan_wakeup(struct ieee80211_vif *vif, * @band: the band to transmit on * @sta: optional pointer to get the station to send the frame to * - * Return: %true if the skb was prepared, %false otherwise + * Return: %true if the skb was prepared, %false otherwise. + * On failure, the skb is freed by this function; callers must not + * free it again. * * Note: must be called under RCU lock */ diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 9142d748a6a70..0458cbba232e2 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -1897,8 +1897,10 @@ bool ieee80211_tx_prepare_skb(struct ieee80211_hw *hw, struct ieee80211_tx_data tx; struct sk_buff *skb2; - if (ieee80211_tx_prepare(sdata, &tx, NULL, skb) == TX_DROP) + if (ieee80211_tx_prepare(sdata, &tx, NULL, skb) == TX_DROP) { + kfree_skb(skb); return false; + } info->band = band; info->control.vif = vif; -- 2.53.0