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 C36F2217704; Sat, 30 May 2026 18:24:46 +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=1780165487; cv=none; b=op0+HIBugNU0zqHJ66M9CHE9rs9Dp41i5c1TvrxgnAyUUfElWga2pn0STXIBd6Vq8CepsMUqR9wtkoN6GCpT26yHPPGcOkSvFAbg6PR8dWfa9xCa2S9wW9nME2y1b72hJpljtmIQq8a8mw8pOCr0N335ZJW/N5oV/0qgu56vspk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780165487; c=relaxed/simple; bh=lPDsqjHIQDaYpFjRLcV//XgriDXR9TjVGJFfNkIeAzE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CvzOHwmS9sR84BdPFa+981aq7W6KpzwVC0Q78dJ6p6NWNzLDr9/Aqherd4PlBc/j0yeVzLsc4QkdUd3B1YwLnml8CLuIHFIWAVuJMRd/6VmjMWNBjruJ6QnWbNnXCx5dn/iERTRkHNWbuT1WrLfgOFVAPIuaVTXUxpLGU6KqY2g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=JjFVC3tV; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="JjFVC3tV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D12CB1F00893; Sat, 30 May 2026 18:24:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780165486; bh=PVlyd0cnB/eaz8W57/flYwFck+K+UV0eOptDrMVY2xU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=JjFVC3tVP+iQd9buF49TPsSaKfYiRddocmu35omi91NhK1hz6AZFu2ZpLF1b/BHTi lBxnW6sJGFJ0P2tvDMAPcysU45DDrSYGz0SEaaqE5QZfanB5IFBheROCy2NSFNpH/S vr/+yOD3O9+umAiWK2qdE9Tm9TBgHcv016nNAbOY= 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 5.10 091/589] wifi: mac80211: always free skb on ieee80211_tx_prepare_skb() failure Date: Sat, 30 May 2026 17:59:32 +0200 Message-ID: <20260530160227.081293628@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160224.570625122@linuxfoundation.org> References: <20260530160224.570625122@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-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/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 6cf0875221572..31b7921bf34f3 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/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c index 037358606a51a..865bbe0293436 100644 --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -2275,7 +2275,6 @@ 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 8f91609f928c1..70ee982f08d9d 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -6337,6 +6337,10 @@ 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 30ad46cfcad86..b923cd755a68c 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -1869,8 +1869,10 @@ 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