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 C33F526B971; Mon, 13 Apr 2026 16:36:16 +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=1776098176; cv=none; b=qQ8d0rgRHZhFBZ3HN92zEws4lW/biJEqmqzFzl7UURT2En4ojwZUhQjpRRgeYzW0nKSZ4vv0+9yDmNKGV/dNqBKm1H6XkfDB1tfEWYt9Zjiwk03trd+xhvnFTgmfaU4GcKt+FHeDetl7iZxydKYcV7OIQFdCv8kGimE+CaAgaKg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776098176; c=relaxed/simple; bh=SvwiTfKKVaRFxhvOf6i7gLhmHIn3r/c4iBPopjVLSRs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lNmqSfGbB/wZ4+bvHD0hXY7yHA82lCTElwxpgPkg0SUrcCFMpqJx0tEZVA7K9mGHE/gquXFUWVsJY3DLsKh233p9TEz8NVvvtIFb8ao+NoZzs7Bmwiug8hHTuu/lRx3coCp1U9Sylcj70yV6T4KksQI9R9IC/qlprMumi7d4Q80= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ycPr2vB8; 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="ycPr2vB8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5AA6FC2BCAF; Mon, 13 Apr 2026 16:36:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1776098176; bh=SvwiTfKKVaRFxhvOf6i7gLhmHIn3r/c4iBPopjVLSRs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ycPr2vB8K6/CEbmP8+tFChssPRwG3kSSjmSHpKwDP0EmCI7dYcGkmke9xUnLRc1t0 aaZQnsb1to1jgzwUyOQScuSr/fYCGJQoXg1hrmVfW5iY8K8YmenkZPF09NsEB6hLeq 2l8TSw9pQYF1BhqCT+a/XPIMDHTzDKyox8+1kbOg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Qi Tang , Phil Sutter , Pablo Neira Ayuso , Sasha Levin Subject: [PATCH 5.15 423/570] netfilter: nf_conntrack_helper: pass helper to expect cleanup Date: Mon, 13 Apr 2026 17:59:14 +0200 Message-ID: <20260413155846.317911019@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260413155830.386096114@linuxfoundation.org> References: <20260413155830.386096114@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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Qi Tang [ Upstream commit a242a9ae58aa46ff7dae51ce64150a93957abe65 ] nf_conntrack_helper_unregister() calls nf_ct_expect_iterate_destroy() to remove expectations belonging to the helper being unregistered. However, it passes NULL instead of the helper pointer as the data argument, so expect_iter_me() never matches any expectation and all of them survive the cleanup. After unregister returns, nfnl_cthelper_del() frees the helper object immediately. Subsequent expectation dumps or packet-driven init_conntrack() calls then dereference the freed exp->helper, causing a use-after-free. Pass the actual helper pointer so expectations referencing it are properly destroyed before the helper object is freed. BUG: KASAN: slab-use-after-free in string+0x38f/0x430 Read of size 1 at addr ffff888003b14d20 by task poc/103 Call Trace: string+0x38f/0x430 vsnprintf+0x3cc/0x1170 seq_printf+0x17a/0x240 exp_seq_show+0x2e5/0x560 seq_read_iter+0x419/0x1280 proc_reg_read+0x1ac/0x270 vfs_read+0x179/0x930 ksys_read+0xef/0x1c0 Freed by task 103: The buggy address is located 32 bytes inside of freed 192-byte region [ffff888003b14d00, ffff888003b14dc0) Fixes: ac7b84839003 ("netfilter: expect: add and use nf_ct_expect_iterate helpers") Signed-off-by: Qi Tang Reviewed-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/netfilter/nf_conntrack_helper.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c index de5ac9f431031..b5f4bfc60f897 100644 --- a/net/netfilter/nf_conntrack_helper.c +++ b/net/netfilter/nf_conntrack_helper.c @@ -469,7 +469,7 @@ void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me) */ synchronize_rcu(); - nf_ct_expect_iterate_destroy(expect_iter_me, NULL); + nf_ct_expect_iterate_destroy(expect_iter_me, me); nf_ct_iterate_destroy(unhelp, me); /* Maybe someone has gotten the helper already when unhelp above. -- 2.53.0