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 1D41422CBC9; Thu, 12 Dec 2024 16:51:10 +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=1734022271; cv=none; b=atvTmjAsiFFJ/lRgucJKZA5yf2g+ap5dAhFwSttfzzEgbS1rpK+OMdFnqwJtkCQwMxOsjNSiBs/e9mk6/7F6+Dj+mAO5+DLGrI49Tp+SH77a0xBhoiCSYJp6OWf4DSqnlbnMYvzHAMMe635x2cp/lJn2/SSuzS7rJ23TBHQGidY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734022271; c=relaxed/simple; bh=bQKI6urU6wmcik/flpzq8LGmisR87l/sT/UUuodbhbs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oBjzNqrjOnNj5RwXsxQm3zK+//Lqk8Z3O7Q6adyf0ruXo1WuQSJ6v7PgtCngz9KyPtESdL1wRiKmfZfrtvQtafhwGmEqdzvNZ3ZyXFYNqF2GhcaxqjYGzFM/6Uy460sROuLgf/T8qO0z+GtnOzz9F4ig/SDoeCUoQTxT/5SWEVQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=StVjnA9p; 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="StVjnA9p" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3341AC4CECE; Thu, 12 Dec 2024 16:51:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1734022270; bh=bQKI6urU6wmcik/flpzq8LGmisR87l/sT/UUuodbhbs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=StVjnA9pg+XaIRnV8+NMSaxYaST3oPGsF3Azc9v6/CK9UgpWS3n+TefhCKMhcDN62 mvlIflCunSCgWO9JK4zqiGECNf0pMgbwW5Hop4cy1ks6F8CH1uTrLMkVHEntHyd0+L /a/eF1wlTKAup8dxwrqbTmd4VSLA8vfqonRBsQG8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zijian Zhang , John Fastabend , Martin KaFai Lau , Sasha Levin Subject: [PATCH 5.15 195/565] bpf, sockmap: Several fixes to bpf_msg_pop_data Date: Thu, 12 Dec 2024 15:56:30 +0100 Message-ID: <20241212144319.192295337@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241212144311.432886635@linuxfoundation.org> References: <20241212144311.432886635@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org 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: Zijian Zhang [ Upstream commit 5d609ba262475db450ba69b8e8a557bd768ac07a ] Several fixes to bpf_msg_pop_data, 1. In sk_msg_shift_left, we should put_page 2. if (len == 0), return early is better 3. pop the entire sk_msg (last == msg->sg.size) should be supported 4. Fix for the value of variable "a" 5. In sk_msg_shift_left, after shifting, i has already pointed to the next element. Addtional sk_msg_iter_var_next may result in BUG. Fixes: 7246d8ed4dcc ("bpf: helper to pop data from messages") Signed-off-by: Zijian Zhang Reviewed-by: John Fastabend Link: https://lore.kernel.org/r/20241106222520.527076-8-zijianzhang@bytedance.com Signed-off-by: Martin KaFai Lau Signed-off-by: Sasha Levin --- net/core/filter.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index c5d15fceee6da..8b51f57aaa251 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2883,8 +2883,10 @@ static const struct bpf_func_proto bpf_msg_push_data_proto = { static void sk_msg_shift_left(struct sk_msg *msg, int i) { + struct scatterlist *sge = sk_msg_elem(msg, i); int prev; + put_page(sg_page(sge)); do { prev = i; sk_msg_iter_var_next(i); @@ -2921,6 +2923,9 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start, if (unlikely(flags)) return -EINVAL; + if (unlikely(len == 0)) + return 0; + /* First find the starting scatterlist element */ i = msg->sg.start; do { @@ -2933,7 +2938,7 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start, } while (i != msg->sg.end); /* Bounds checks: start and pop must be inside message */ - if (start >= offset + l || last >= msg->sg.size) + if (start >= offset + l || last > msg->sg.size) return -EINVAL; space = MAX_MSG_FRAGS - sk_msg_elem_used(msg); @@ -2962,12 +2967,12 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start, */ if (start != offset) { struct scatterlist *nsge, *sge = sk_msg_elem(msg, i); - int a = start; + int a = start - offset; int b = sge->length - pop - a; sk_msg_iter_var_next(i); - if (pop < sge->length - a) { + if (b > 0) { if (space) { sge->length = a; sk_msg_shift_right(msg, i); @@ -2986,7 +2991,6 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start, if (unlikely(!page)) return -ENOMEM; - sge->length = a; orig = sg_page(sge); from = sg_virt(sge); to = page_address(page); @@ -2996,7 +3000,7 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start, put_page(orig); } pop = 0; - } else if (pop >= sge->length - a) { + } else { pop -= (sge->length - a); sge->length = a; } @@ -3030,7 +3034,6 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start, pop -= sge->length; sk_msg_shift_left(msg, i); } - sk_msg_iter_var_next(i); } sk_mem_uncharge(msg->sk, len - pop); -- 2.43.0