From 5d7a2a78b85226aee632103e9c0b373abdad9e70 Mon Sep 17 00:00:00 2001
From: Mounir IDRASSI <mounir.idrassi@amcrypto.jp>
Date: Mon, 25 May 2026 22:31:20 +0900
Subject: [PATCH] OpenBSD: fix device-hosted volume sizing

OpenBSD device length detection was returning the raw disk sector count from DIOCGPDINFO directly. That value is not bytes and it describes the physical/default disk label, which caused VeraCrypt to expose an incorrectly sized FUSE backing image through vnd for device-hosted volumes.

Use the current disklabel from DIOCGDINFO, derive the opened partition from the device minor number, and return the selected partition size in bytes. Keep the raw c partition on the whole-disk path by using DL_GETDSIZE there.

Also reject sector-misaligned device-hosted sizes during volume creation so new malformed OpenBSD device-hosted volumes are not created. Do not reject existing malformed headers at mount time, so users can still mount old OpenBSD-created volumes for recovery.

Refs #1589.

Refs #1593.
---
 src/Core/VolumeCreator.cpp |  3 +++
 src/Platform/Unix/File.cpp | 33 ++++++++++++++++++++++++++++++---
 2 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/src/Core/VolumeCreator.cpp b/src/Core/VolumeCreator.cpp
index e9bf92e6..2f18be1d 100644
--- a/src/Core/VolumeCreator.cpp
+++ b/src/Core/VolumeCreator.cpp
@@ -282,6 +282,9 @@ namespace VeraCrypt
 				{
 					throw UnsupportedSectorSize (SRC_POS);
 				}
+
+				if (HostSize % options->SectorSize != 0)
+					throw ParameterIncorrect (SRC_POS);
 			}
 			else
 				options->SectorSize = TC_SECTOR_SIZE_FILE_HOSTED_VOLUME;
diff --git a/src/Platform/Unix/File.cpp b/src/Platform/Unix/File.cpp
index f8e62316..cacd4fc1 100644
--- a/src/Platform/Unix/File.cpp
+++ b/src/Platform/Unix/File.cpp
@@ -125,7 +125,11 @@ namespace VeraCrypt
 
 #elif defined (TC_OPENBSD)
 			struct disklabel dl;
-			throw_sys_sub_if (ioctl (FileHandle, DIOCGPDINFO, &dl) == -1, wstring (Path));
+			throw_sys_sub_if (ioctl (FileHandle, DIOCGDINFO, &dl) == -1, wstring (Path));
+
+			if (dl.d_secsize == 0)
+				throw ParameterIncorrect (SRC_POS);
+
 			return (uint32) dl.d_secsize;
 
 #elif defined (TC_SOLARIS)
@@ -213,8 +217,31 @@ namespace VeraCrypt
 			return blockCount * blockSize;
 #	elif TC_OPENBSD
 			struct disklabel dl;
-			throw_sys_sub_if (ioctl (FileHandle, DIOCGPDINFO, &dl) == -1, wstring (Path));
-			return DL_GETDSIZE(&dl);
+			struct stat statData;
+			throw_sys_sub_if (ioctl (FileHandle, DIOCGDINFO, &dl) == -1, wstring (Path));
+			throw_sys_sub_if (fstat (FileHandle, &statData) == -1, wstring (Path));
+
+			if (dl.d_secsize == 0)
+				throw ParameterIncorrect (SRC_POS);
+
+			uint64 sectors;
+			int partition = DISKPART (statData.st_rdev);
+			if (partition == RAW_PART)
+			{
+				sectors = DL_GETDSIZE (&dl);
+			}
+			else
+			{
+				if (partition < 0 || partition >= dl.d_npartitions)
+					throw ParameterIncorrect (SRC_POS);
+
+				sectors = DL_GETPSIZE (&dl.d_partitions[partition]);
+			}
+
+			if (sectors > ((uint64) -1) / dl.d_secsize)
+				throw ParameterIncorrect (SRC_POS);
+
+			return sectors * dl.d_secsize;
 #	else
 			uint64 mediaSize;
 			throw_sys_sub_if (ioctl (FileHandle, DIOCGMEDIASIZE, &mediaSize) == -1, wstring (Path));