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 62CD11DFDB9; Wed, 4 Jun 2025 01:06:10 +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=1748999170; cv=none; b=Od38Y9atXfuNoGz0P+zeHqwRQZHnuf1ANuUQrpPqwQcSqkZPcTCYq+FzC0BpzUpLrfNU9zqG81zNI+5349YbuG790tuW1396+Upmt0wtguGQt8eC/oPhgcSnYrFESQt/cSv4jj0anB8zNrmL1/6B9IklQJztTnub0H8YMR5lrOY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748999170; c=relaxed/simple; bh=FO8W9qLlWSMdqPuosmUQjDXOljlbVIom6aE4wK6gwBY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=vAqtZyFnb/73J893IXbS5NzM2QxjWngwdBddMFDxUH4WFgZvlEX8006w3sfEazOliAWbvmWamkwG2Jq1xsudvn0CDGTnsq8GyW1xQyTLVWo6NSd307Fen/I7b84OB3GlaTJ+3FON582JyeJCITslnhuEobO99JXMAa8DOn4ivW8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Xk53JJY9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Xk53JJY9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 396D5C4CEED; Wed, 4 Jun 2025 01:06:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1748999170; bh=FO8W9qLlWSMdqPuosmUQjDXOljlbVIom6aE4wK6gwBY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Xk53JJY9mD0v2222LQTddUZN8guS4Erx+pAaC90308zipy6eycbqGRmyn7tPr8zfU vEQ06biVsqA7eMAOyMYDxuUZJ/2lrwATysm+JnkaYiMtCQeUVUJg1f072iO4mjHdav HOo1SaX6AAXX5F42Uil3s06Mjo+iyPv9QLYf7hIh4g/rmzxXrumGT3A3pSislUnHdv tQMRWFUsZZ2ZXLn0FSMwPk3yjJ7HClbvMWkGm8GDmA3kNfm/SC35K8hYxNdnvW6lbt w7rm6icJG1BTksEHXuc1+kP8GIOIfZbl+L25cPinWLAUDDnGOKHU5idZgjkwzaQJnl c1kx6/WG+brDA== From: Sasha Levin To: patches@lists.linux.dev, stable@vger.kernel.org Cc: Zijun Hu , Sakari Ailus , Greg Kroah-Hartman , Sasha Levin , rafael@kernel.org, dakr@kernel.org, linux-acpi@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 27/33] software node: Correct a OOB check in software_node_get_reference_args() Date: Tue, 3 Jun 2025 21:05:18 -0400 Message-Id: <20250604010524.6091-27-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250604010524.6091-1-sashal@kernel.org> References: <20250604010524.6091-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.15.184 Content-Transfer-Encoding: 8bit From: Zijun Hu [ Upstream commit 31e4e12e0e9609850cefd4b2e1adf782f56337d6 ] software_node_get_reference_args() wants to get @index-th element, so the property value requires at least '(index + 1) * sizeof(*ref)' bytes but that can not be guaranteed by current OOB check, and may cause OOB for malformed property. Fix by using as OOB check '((index + 1) * sizeof(*ref) > prop->length)'. Reviewed-by: Sakari Ailus Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20250414-fix_swnode-v2-1-9c9e6ae11eab@quicinc.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- ## Final Decision **YES** This commit should be backported to stable kernel trees. **Extensive Explanation:** 1. **Critical Security Fix**: This commit fixes a clear out-of-bounds memory access vulnerability in `software_node_get_reference_args()` at line 532 in `/drivers/base/swnode.c`. The original bounds check `index capability_test capability_test.c f2fs_folio_analysis.md ipv4_multipath_analysis.md ipv6_route_allocation_rcu_analysis.md ixgbe_e610_set_phys_id_analysis.md linux lpfc_timeout_analysis.md mac80211_mlo_mbssid_analysis.md pfcp_driver_historical_analysis.md rtl_bb_delay_analysis.md rtw89_mlo_analysis.md tcp_multipath_load_balance_analysis.md test_unaligned_diff test_unaligned_diff.c type_size_check type_size_check.c veth_driver_analysis.md wifi_mlo_mbssid_tx_link_id_analysis.md sizeof(*ref) >= prop->length` has an off-by-one error that allows reading beyond allocated memory when accessing `ref_array[index]`. 2. **Vulnerability Details**: The bug allows an attacker to read kernel memory beyond the allocated property buffer. To access `ref_array[index]`, the code needs `(index + 1) capability_test capability_test.c f2fs_folio_analysis.md ipv4_multipath_analysis.md ipv6_route_allocation_rcu_analysis.md ixgbe_e610_set_phys_id_analysis.md linux lpfc_timeout_analysis.md mac80211_mlo_mbssid_analysis.md pfcp_driver_historical_analysis.md rtl_bb_delay_analysis.md rtw89_mlo_analysis.md tcp_multipath_load_balance_analysis.md test_unaligned_diff test_unaligned_diff.c type_size_check type_size_check.c veth_driver_analysis.md wifi_mlo_mbssid_tx_link_id_analysis.md sizeof(*ref)` bytes, but the original check only ensures `index capability_test capability_test.c f2fs_folio_analysis.md ipv4_multipath_analysis.md ipv6_route_allocation_rcu_analysis.md ixgbe_e610_set_phys_id_analysis.md linux lpfc_timeout_analysis.md mac80211_mlo_mbssid_analysis.md pfcp_driver_historical_analysis.md rtl_bb_delay_analysis.md rtw89_mlo_analysis.md tcp_multipath_load_balance_analysis.md test_unaligned_diff test_unaligned_diff.c type_size_check type_size_check.c veth_driver_analysis.md wifi_mlo_mbssid_tx_link_id_analysis.md sizeof(*ref)` bytes are available. This creates a window where `index capability_test capability_test.c f2fs_folio_analysis.md ipv4_multipath_analysis.md ipv6_route_allocation_rcu_analysis.md ixgbe_e610_set_phys_id_analysis.md linux lpfc_timeout_analysis.md mac80211_mlo_mbssid_analysis.md pfcp_driver_historical_analysis.md rtl_bb_delay_analysis.md rtw89_mlo_analysis.md tcp_multipath_load_balance_analysis.md test_unaligned_diff test_unaligned_diff.c type_size_check type_size_check.c veth_driver_analysis.md wifi_mlo_mbssid_tx_link_id_analysis.md sizeof(*ref) < prop->length` but `(index + 1) capability_test capability_test.c f2fs_folio_analysis.md ipv4_multipath_analysis.md ipv6_route_allocation_rcu_analysis.md ixgbe_e610_set_phys_id_analysis.md linux lpfc_timeout_analysis.md mac80211_mlo_mbssid_analysis.md pfcp_driver_historical_analysis.md rtl_bb_delay_analysis.md rtw89_mlo_analysis.md tcp_multipath_load_balance_analysis.md test_unaligned_diff test_unaligned_diff.c type_size_check type_size_check.c veth_driver_analysis.md wifi_mlo_mbssid_tx_link_id_analysis.md sizeof(*ref) > prop->length`, allowing out-of-bounds access. 3. **Security Impact**: This vulnerability can lead to: - Information disclosure through kernel memory leaks - Potential system crashes from invalid memory access - Exploitation through malformed device tree properties 4. **Perfect Backport Candidate**: - **Minimal code change**: Single line fix changing `>=` to `>` and adding `+ 1` - **No feature additions**: Pure bug fix with no new functionality - **Low regression risk**: Makes bounds checking more restrictive, safer - **Core infrastructure**: Affects fundamental device property framework used across many drivers 5. **Historical Precedent**: The provided similar commits show a clear pattern - other defensive programming fixes in the same `software_node` subsystem (commits #1, #2, and #4) were all marked as suitable for backporting. This commit follows the same pattern of fixing potential memory safety issues with minimal, targeted changes. 6. **Maintainer Review**: The commit has been reviewed by Sakari Ailus, indicating community confidence in the fix. 7. **Stable Tree Compliance**: Meets all stable tree criteria - fixes important bug, minimal risk, contained change, no architectural modifications, and addresses a security vulnerability in critical kernel infrastructure. The commit represents exactly the type of fix that stable trees are designed to accommodate: a small, well-reviewed security fix that prevents potential exploitation without introducing new risks. drivers/base/swnode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c index 15f149fc19401..0af6071f86641 100644 --- a/drivers/base/swnode.c +++ b/drivers/base/swnode.c @@ -524,7 +524,7 @@ software_node_get_reference_args(const struct fwnode_handle *fwnode, if (prop->is_inline) return -EINVAL; - if (index * sizeof(*ref) >= prop->length) + if ((index + 1) * sizeof(*ref) > prop->length) return -ENOENT; ref_array = prop->pointer; -- 2.39.5