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 637BD33E347; Fri, 24 Apr 2026 13:39:02 +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=1777037942; cv=none; b=BLtrY7TBwW2KR0CsTgYW5ELKT22WlBsaWKZmZ8HBo+FQwsBxGt/r5Cv/0xL7WHJ4Yp/7EBa/2Dw3nG9G/2JVBjQQQJP/8HSnW7NcKB+ZzNxO7IpoCkMJegH5ikoeurpzJjbVoQE+O+ONFHKbZbML7UnaQe+vxTDxAh7HlgW7vj0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777037942; c=relaxed/simple; bh=g4hi8mzWjRaiI84Gma+5B5Rb0F1ckTsMdl9iV2frB8M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=W70lHlCxWVOPBigcEaYQ772+Uk9lsW7GsC4aPCwLQPeIPKn/WQfTXSk5eJQ+fgoKIYDuvOFxu3lTTY0+SZvk5CVAbtde+q2oZWODsvwKB1w790JUO/QsyQ4eqUnQiBfYisfPqwCYwxqLMiP4wN8ynVFmkxDwAwPMQYiGeDg2eKI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=xuTkK689; 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="xuTkK689" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EEB16C19425; Fri, 24 Apr 2026 13:39:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1777037942; bh=g4hi8mzWjRaiI84Gma+5B5Rb0F1ckTsMdl9iV2frB8M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xuTkK689F0GLWXwrVaoV7fZ1Q8kstWHZwk+7Jx5sinGJTbJHEuTnV3MYEL9mKZgOY 3zQnRtuB1sVwwG75BnWTvBXguDuZm2OzVYQWtvxJf5cCh7ggPFrpuuKeBNvZnFJIEp bNSIGsLgSyW+HWSU0gMhquFM4yOqUcj6Jn/tIrwg= 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 6.6 130/166] wifi: mac80211: always free skb on ieee80211_tx_prepare_skb() failure Date: Fri, 24 Apr 2026 15:30:44 +0200 Message-ID: <20260424132600.130441339@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260424132532.812258529@linuxfoundation.org> References: <20260424132532.812258529@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 6.6-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, 9 insertions(+), 6 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 1214e7dcc8124..bf12ff0ab06ab 100644 --- a/drivers/net/wireless/virtual/mac80211_hwsim.c +++ b/drivers/net/wireless/virtual/mac80211_hwsim.c @@ -2892,7 +2892,6 @@ 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 adaa1b2323d2c..85d785060e761 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -7032,6 +7032,10 @@ 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. + * On failure, the skb is freed by this function; callers must not + * free it again. + * * Note: must be called under RCU lock */ bool ieee80211_tx_prepare_skb(struct ieee80211_hw *hw, diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 7eddcb6f96455..2a708132320c4 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -1911,8 +1911,10 @@ 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