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 0B41E4EC675; Tue, 13 Oct 2026 12:12:48 +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=1791893569; cv=none; b=nZBkHS0P9TFRG6Jvb6vz8UGWb7Ojc2dtxJBAOssabbDAfTGbPAd+KzRGbZy7Ttdz5ot05mMmGNlhFXmW8YowyuNX5ipfQUBfUkUEXMPX8gbiU6YGOl5htQWFYmSPCC3R9BKMt8g93LoEs60Z6cS7ljRHasM2nTbsW1bg2av8fUk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791893569; c=relaxed/simple; bh=HWGpManqlIaJbPG536rs3wTQJLsN/KwYdL2n6mPuheg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=f7usPzcMjmWM3RbXzeHyuTZQGqBl89hjAjZ9+gLMO/I2oXD+5cmb76qvdFGvXhqTHK9608tJe6879eTKH0Tl6m4ohKNcUPCAmJwvfWGG+dfBMAiV11W7i3ZLnUFRu55l2vNeYQSchdiIUiyx6uOpamAt3r9HdtOz31PxCcitgEg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=fERu1ogf; 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="fERu1ogf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 692C21F000FF; Tue, 13 Oct 2026 12:12:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791893567; bh=znQQS4gN+DtX6r1KFPlrWnZKor0W6HQU7aIMwbV8xUc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=fERu1ogfDBY/hMd6mReNqSQjEglUbRtX+8moylr1b10J0Y9kEJz/d7XDSzWiA0L5n k+TozoWSJvjcMHRi8JRQmAtPFzJhveQHHg+k075AT0SgdDTuzJn76u+9RWYX1ZML0J Y8uCEhhF37cNL6cR4ct9X943GICTwshJYSb+ZnXk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Matt Bobrowski , Daniel Borkmann , Kuniyuki Iwashima , Sasha Levin Subject: [PATCH 6.18 269/621] bpf: Fix UAF in sock clone early bailouts Date: Tue, 13 Oct 2026 13:34:24 +0200 Message-ID: <20261013112927.245170678@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261013112920.855194808@linuxfoundation.org> References: <20261013112920.855194808@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Matt Bobrowski [ Upstream commit 7cbd0c4cebe4c9f678d15e6b9ba975e1155a107f ] Similar to recent commit 9b51a6155d14 ("bpf,fork: wipe ->bpf_storage before bailouts that access it"), sk_clone() performs an initial shallow copy of the socket field ->sk_bpf_storage via sock_copy() for the cloned socket newsk. If sk_clone() bails out early (e.g. if sk_filter_charge() fails) prior to calling bpf_sk_storage_clone(), newsk->sk_bpf_storage still points to the parent socket's BPF local storage. When newsk is subsequently freed via sk_free(), the deallocation path (__sk_destruct() -> bpf_sk_storage_free()) destroys the parent socket's BPF local storage, leading to a use-after-free (UAF) on the parent socket. Fix this by resetting newsk->sk_bpf_storage to NULL immediately after sock_copy() in sk_clone(), and remove the now redundant initialization from bpf_sk_storage_clone(). Fixes: 6ac99e8f23d4 ("bpf: Introduce bpf sk local storage") Fixes: f12dd75959b0 ("bpf: net: Set sk_bpf_storage back to NULL for cloned sk") Signed-off-by: Matt Bobrowski Signed-off-by: Daniel Borkmann Reviewed-by: Kuniyuki Iwashima Acked-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20260709025316.999913-1-mattbobrowski@google.com Signed-off-by: Sasha Levin --- net/core/bpf_sk_storage.c | 2 -- net/core/sock.c | 3 +++ 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c index d3fbaf89a698d..eac5b710efcf9 100644 --- a/net/core/bpf_sk_storage.c +++ b/net/core/bpf_sk_storage.c @@ -157,8 +157,6 @@ int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk) struct bpf_local_storage_elem *selem; int ret = 0; - RCU_INIT_POINTER(newsk->sk_bpf_storage, NULL); - rcu_read_lock_dont_migrate(); sk_storage = rcu_dereference(sk->sk_bpf_storage); diff --git a/net/core/sock.c b/net/core/sock.c index 9031349d08c21..1f176ee02bd51 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2468,6 +2468,9 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority) sock_copy(newsk, sk); newsk->sk_prot_creator = prot; +#ifdef CONFIG_BPF_SYSCALL + RCU_INIT_POINTER(newsk->sk_bpf_storage, NULL); +#endif /* SANITY */ if (likely(newsk->sk_net_refcnt)) { -- 2.53.0