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 A47A143FD0D; Tue, 21 Jul 2026 22:10:59 +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=1784671860; cv=none; b=DjSEjQB0JsOuUNRrcOyKrkbUR8xM3vw1Tul7i8SZtVVHvNSIiKalcv5S80if5y+q73Dbk2a3LgmF37Vx0edqlcKHb20z3mlpvAX2ES3Vz5aUsoju3AYbieEEkrm/3ZDajAA+tUwLxakG2SBfs6ihZmoy9GqBW7GbfDhUou/8gIY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784671860; c=relaxed/simple; bh=7OldnQYQHE4J6f94JmjVdjZ+AXnGT+iYTEMLGw2TG0I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TpA/g0o0sSeFRaywER8EHqeFsluGQ8RLUEfRVm3jh91EiXNbcbPTORPSp3P1UeaE6nZyTtq/BY+ygj1YcByl26EPA/NkGOCcjFV6efw+wL27rXCHHqusR+osoeS2UX3+JleTfCS3f0qkSJtLFzmGoUUKzyNfliQ3mIrcvoDlIlY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=T1w1iuCh; 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="T1w1iuCh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 15C641F00A3A; Tue, 21 Jul 2026 22:10:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784671859; bh=VWFbMWhGYK2nscmpI3BCMEaDWXZu5Bz5akIMEC5pMkI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=T1w1iuChMPpwRZ+mn2rS4D0iHxVJ1i/4Xqz0xxLgs48TeGdxg4nbpeLP8Q0Qci6uJ zS2luD/ke0VXZviX16I9AnY6onrQ9wgROcLOeiJchiXmBq1ScPSBV43FwBxLJkGXQH l8+PzHn2dZndgRCxIjzMxG6dzKohnakmEhAnJTwM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yadan Fan , Thomas Bogendoerfer , Sasha Levin Subject: [PATCH 5.15 363/843] MIPS: mm: Fix out-of-bounds write in maar_res_walk() Date: Tue, 21 Jul 2026 17:19:58 +0200 Message-ID: <20260721152414.194848852@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152405.946368001@linuxfoundation.org> References: <20260721152405.946368001@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: Yadan Fan [ Upstream commit 1b001b16bc88f3f7817e228acfd91ee01bdcfcce ] maar_res_walk() uses wi->num_cfg as the index into the fixed-size wi->cfg array, but checks whether the array is full only after it has filled the selected entry. If walk_system_ram_range() reports more than 16 memory ranges, the overflow call writes one struct maar_config past the end of the array before WARN_ON() prevents num_cfg from advancing. Move the full-array check before taking the array slot and return non-zero when the scratch array is full, so walk_system_ram_range() terminates the walk instead of invoking the callback for further ranges. Fixes: a5718fe8f70f ("MIPS: mm: Drop boot_mem_map") Signed-off-by: Yadan Fan Signed-off-by: Thomas Bogendoerfer Signed-off-by: Sasha Levin --- arch/mips/mm/init.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c index 81fda8c583ae16..bf9037b662ac4f 100644 --- a/arch/mips/mm/init.c +++ b/arch/mips/mm/init.c @@ -276,9 +276,15 @@ static int maar_res_walk(unsigned long start_pfn, unsigned long nr_pages, void *data) { struct maar_walk_info *wi = data; - struct maar_config *cfg = &wi->cfg[wi->num_cfg]; + struct maar_config *cfg; unsigned int maar_align; + /* Ensure we don't overflow the cfg array */ + if (WARN_ON(wi->num_cfg >= ARRAY_SIZE(wi->cfg))) + return -1; + + cfg = &wi->cfg[wi->num_cfg]; + /* MAAR registers hold physical addresses right shifted by 4 bits */ maar_align = BIT(MIPS_MAAR_ADDR_SHIFT + 4); @@ -287,9 +293,7 @@ static int maar_res_walk(unsigned long start_pfn, unsigned long nr_pages, cfg->upper = ALIGN_DOWN(PFN_PHYS(start_pfn + nr_pages), maar_align) - 1; cfg->attrs = MIPS_MAAR_S; - /* Ensure we don't overflow the cfg array */ - if (!WARN_ON(wi->num_cfg >= ARRAY_SIZE(wi->cfg))) - wi->num_cfg++; + wi->num_cfg++; return 0; } -- 2.53.0