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 0746E1A0BFD; Sun, 7 Sep 2025 20:34:19 +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=1757277259; cv=none; b=kUDYiAo0/Vp7JTz63ZuzzCpdbsBg1Gto4zBs/g7HQxKhhuQwjcbJnX0gVe6iriwAD6hb8Nsug7bA7gFo69Oq46jAOieYyXkWtKSP+SfbmG/7gStbr+TFX744OURuMeSB4cFMvFOEgTl0C+RoNZVfmZMoXlfYdFeuh8KpNMw2dnw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757277259; c=relaxed/simple; bh=H1qS7zzHG3B1IObzdsa3eFnB02IxkNx4mUIdlRVZAco=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WO37oMinjdD7DT98hGNs0JPBRS3zrX0w3kZ1KVSTTdWB14nP5znen376THPbd5FANQ6HM8FYp8MsvEzJz/ceSYubXEhqISMJkgS25mJ88dcRuEpNrRWXDKTZkA2/2IlgwQwPSN1csExBmihsCJgMRlSyQiUzw8aWhKLNIzysGlM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=XMPrzLag; 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="XMPrzLag" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 558AAC4CEF0; Sun, 7 Sep 2025 20:34:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1757277258; bh=H1qS7zzHG3B1IObzdsa3eFnB02IxkNx4mUIdlRVZAco=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XMPrzLago8kLYpYUjYmicHJbjNaWsoc1zWWCo559LJDINPp/30q8jdkFQmZQK/AU7 SNQbXsRp4ZTK+hf+ZFwhwNo5FAOOF0pceQwIyHMHYExj9TPoEJrpZ24yuc9ta01vfy uJmyrcLLDpEXf2LmTR2tAgTe413bttMG0N3bo10o= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Qingfang Deng , Eric Dumazet , Yue Haibing , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.12 088/175] ppp: fix memory leak in pad_compress_skb Date: Sun, 7 Sep 2025 21:58:03 +0200 Message-ID: <20250907195616.920181554@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250907195614.892725141@linuxfoundation.org> References: <20250907195614.892725141@linuxfoundation.org> User-Agent: quilt/0.68 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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Qingfang Deng [ Upstream commit 4844123fe0b853a4982c02666cb3fd863d701d50 ] If alloc_skb() fails in pad_compress_skb(), it returns NULL without releasing the old skb. The caller does: skb = pad_compress_skb(ppp, skb); if (!skb) goto drop; drop: kfree_skb(skb); When pad_compress_skb() returns NULL, the reference to the old skb is lost and kfree_skb(skb) ends up doing nothing, leading to a memory leak. Align pad_compress_skb() semantics with realloc(): only free the old skb if allocation and compression succeed. At the call site, use the new_skb variable so the original skb is not lost when pad_compress_skb() fails. Fixes: b3f9b92a6ec1 ("[PPP]: add PPP MPPE encryption module") Signed-off-by: Qingfang Deng Reviewed-by: Eric Dumazet Reviewed-by: Yue Haibing Link: https://patch.msgid.link/20250903100726.269839-1-dqfext@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ppp/ppp_generic.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c index 0553b0b356b30..afc1566488b32 100644 --- a/drivers/net/ppp/ppp_generic.c +++ b/drivers/net/ppp/ppp_generic.c @@ -1753,7 +1753,6 @@ pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) */ if (net_ratelimit()) netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); - kfree_skb(skb); consume_skb(new_skb); new_skb = NULL; } @@ -1855,9 +1854,10 @@ ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) "down - pkt dropped.\n"); goto drop; } - skb = pad_compress_skb(ppp, skb); - if (!skb) + new_skb = pad_compress_skb(ppp, skb); + if (!new_skb) goto drop; + skb = new_skb; } /* -- 2.50.1