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 D93D444DB64; Tue, 16 Jun 2026 16:20:03 +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=1781626805; cv=none; b=AI3XrRXdvoNFZ+VwXtMocf+tRzRDFGw9+3dr/x4/cvx9HMfY6E+vRyi+Hbt1wkVWHZuQ5wZcjCxXJiIcf/gHhEez08tf+YyYDiXq8CMV0GnGAyHlwWmeCFTC069wjVva8y27R6GLBriC47nqbHTIMM+V1XEZ+Yu9TLmJd6qGtAI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781626805; c=relaxed/simple; bh=+1AgAVoH1zsMQFw2fZRRFYlnG9wfsbrGO6GqzAqRM/E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cVFCDosZO/gOdrlKAOYGQ2XgLpXzgWetvywokIj839lKyBRU5BKYwPxvtZGLB7Vaiiv6e1bE7hXHuROxfzaUmX7Nr2A16nOsp9YFjIU2vjErKJFKgt7Mr4dxlX9NDOmsW/4Xa5xd4jsUu1C4bmTpAGstInA8MA3eTsC4yxIeBWM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=bTe0kllk; 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="bTe0kllk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E923B1F00A3A; Tue, 16 Jun 2026 16:20:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781626803; bh=Q+Ky/aV3F0O2kuWwLp+kkjFux8UItrAT5UKDU9nCYpM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=bTe0kllkpuN9wjEMfE+zlVWKZ+f+AdfGXb52G5NCpLxoi+ZTirT6AilovtUJQomzM OUWPSrTQcPT/2u2NPI4HbJo42a/W0iz339XEyNXC0r18H5sNrmePjwvOZgPUTk3ROp CupMqQm/Y9BMDsWaDVRAahhSG6yvTnyY0kblwUIA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sanghyun Park , Steffen Klassert , Sasha Levin Subject: [PATCH 6.12 074/261] xfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx() Date: Tue, 16 Jun 2026 20:28:32 +0530 Message-ID: <20260616145048.537913955@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145044.869532709@linuxfoundation.org> References: <20260616145044.869532709@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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sanghyun Park [ Upstream commit 7f2d76c9c03257c0782afef9d95321fa04096f60 ] Fix the race by pruning the bin while still holding xfrm_policy_lock, before dropping it. Use __xfrm_policy_inexact_prune_bin() directly since the lock is already held. The wrapper xfrm_policy_inexact_prune_bin() becomes unused and is removed. Race: CPU0 (XFRM_MSG_DELPOLICY) CPU1 (XFRM_MSG_NEWSPDINFO) ========================== ========================== xfrm_policy_bysel_ctx(): spin_lock_bh(xfrm_policy_lock) bin = xfrm_policy_inexact_lookup() __xfrm_policy_unlink(pol) spin_unlock_bh(xfrm_policy_lock) xfrm_policy_kill(ret) // wide window, lock not held xfrm_hash_rebuild(): spin_lock_bh(xfrm_policy_lock) __xfrm_policy_inexact_flush(): kfree_rcu(bin) // bin freed spin_unlock_bh(xfrm_policy_lock) xfrm_policy_inexact_prune_bin(bin) // UAF: bin is freed Fixes: 6be3b0db6db8 ("xfrm: policy: add inexact policy search tree infrastructure") Signed-off-by: Sanghyun Park Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin --- net/xfrm/xfrm_policy.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index dab782dcc829de..5a7ec72e17b0e5 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -1156,15 +1156,6 @@ static void __xfrm_policy_inexact_prune_bin(struct xfrm_pol_inexact_bin *b, bool } } -static void xfrm_policy_inexact_prune_bin(struct xfrm_pol_inexact_bin *b) -{ - struct net *net = read_pnet(&b->k.net); - - spin_lock_bh(&net->xfrm.xfrm_policy_lock); - __xfrm_policy_inexact_prune_bin(b, false); - spin_unlock_bh(&net->xfrm.xfrm_policy_lock); -} - static void __xfrm_policy_inexact_flush(struct net *net) { struct xfrm_pol_inexact_bin *bin, *t; @@ -1707,12 +1698,12 @@ xfrm_policy_bysel_ctx(struct net *net, const struct xfrm_mark *mark, u32 if_id, } ret = pol; } + if (bin && delete) + __xfrm_policy_inexact_prune_bin(bin, false); spin_unlock_bh(&net->xfrm.xfrm_policy_lock); if (ret && delete) xfrm_policy_kill(ret); - if (bin && delete) - xfrm_policy_inexact_prune_bin(bin); return ret; } EXPORT_SYMBOL(xfrm_policy_bysel_ctx); -- 2.53.0