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 82D3053A7; Fri, 6 Dec 2024 15:00:53 +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=1733497253; cv=none; b=jk8MH975s4dAEGatg3qSCU6mHXP/8bAl9LgcdEv6EKUjqdanQOkGn111pZFVEFTEDSjNMOi1IL5TO9C1oXEOFQrfK38XihKO5VPeOsIJxRfD0I6TfJhYbXSr/VksjZBSGpZT6eupW81cGEBHJIC9RtrIdU8gy/yrIgDDdH1SPXk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733497253; c=relaxed/simple; bh=4qXHvHM8LMwjACXZwxUJS8noYWJi3sF4d9ZUETxRT5w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IEheYwVg7iKua8c/Nz6QvO3+CZqOyFCgb28p1X84MYfE3zG5zVz1pEJ5M/7yXNlsQ1bDJNzw2G0E+/BecRAAivy6Ufspm1rWsdEPRg8LAb3FJofoke17j0Hi+5OmWSy/2p9757DGjAbQPw/n/XPOdr4HQsqamAEM/Zmx0SAvA/w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=rOdwpq/h; 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="rOdwpq/h" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DEDE1C4CED1; Fri, 6 Dec 2024 15:00:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1733497253; bh=4qXHvHM8LMwjACXZwxUJS8noYWJi3sF4d9ZUETxRT5w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rOdwpq/hbcDTb5pHz/DJzADeac5X+gV7pN4DGVEMcU24NZtfie5hh+UakSBDKkFnJ 3NtPmakSETnPDURgcJEJr0uR5EI1rcxPCXe/H2N4aIAYEn2txcrtc93IfIzD9+joZM dOAcI3TlFpqLJWmOz3X+J7A9AuatEBu7Oe02lTag= 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 6.6 238/676] bpf, sockmap: Several fixes to bpf_msg_pop_data Date: Fri, 6 Dec 2024 15:30:57 +0100 Message-ID: <20241206143702.627526560@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241206143653.344873888@linuxfoundation.org> References: <20241206143653.344873888@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 6.6-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 62092948b390f..c223e072b35e9 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2902,8 +2902,10 @@ 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); @@ -2940,6 +2942,9 @@ 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 { @@ -2952,7 +2957,7 @@ 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); @@ -2981,12 +2986,12 @@ 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); @@ -3005,7 +3010,6 @@ 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); @@ -3015,7 +3019,7 @@ 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; } @@ -3049,7 +3053,6 @@ 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