Attachment 308773 Details for Bug 209968 – Prevent creating dos partitions > 2TB

[patch] Prevent creating dos partitions > 2TB

parted-1.6.19-2TB-limit.patch (text/plain), 2.86 KB, created by John Newbigin on 2008-06-10 05:57:12 UTC

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Creator: John Newbigin

Created: 2008-06-10 05:57:12 UTC

Size: 2.86 KB

patch

obsolete

>--- parted-1.6.19/libparted/disk.c.2tb	2004-11-19 14:37:34.000000000 -1000
>+++ parted-1.6.19/libparted/disk.c	2008-03-14 14:20:44.000000000 -1000
>@@ -32,6 +32,8 @@
> #endif /* ENABLE_NLS */
> 
> #include <string.h>
>+#include <stdint.h>
>+#include <limits.h>
> 
> /* UPDATE MODE functions */
> #ifdef DEBUG
>@@ -1385,6 +1387,34 @@
> 	return 1;
> }
> 
>+static PedSector
>+_partition_max_start (char const *label_type)
>+{
>+	/* List partition table names (a la disk->type->name) for which
>+	   the partition length, in sectors, must fit in 32 bytes. */
>+	static char const *const max_32[] = {"msdos", "dvh"};
>+	unsigned int i;
>+
>+	for (i = 0; i < sizeof max_32 / sizeof *max_32; i++)
>+		if (strcmp (label_type, max_32[i]) == 0)
>+			return UINT32_MAX;
>+
>+	if ((PedSector) (!(!((PedSector) 0 < (PedSector) -1))))
>+		return (PedSector) -1;
>+	else
>+		return ~(~(PedSector) 0 << (sizeof(PedSector) * CHAR_BIT-1));
>+}
>+
>+static PedSector
>+_partition_max_len (char const *label_type)
>+{
>+	/* NOTE: for now, they happen to be the same, so don't duplicate
>+	   needlessly.  Of course, if there's some format with different
>+	   length and starting sector limits, then these functions will
>+	   diverge. */
>+	return _partition_max_start (label_type);
>+}
>+
> static int
> _check_partition (PedDisk* disk, PedPartition* part)
> {
>@@ -1423,6 +1453,45 @@
> 		return 0;
> 	}
> 
>+	if (!(part->type & PED_PARTITION_METADATA)) {
>+		char const *label_type = disk->type->name;
>+		/* Enforce some restrictions inherent in the DOS partition
>+		   table format.  Without these, one would be able to create
>+		   a 2TB partition (or larger), and it would work, but only
>+		   until the next reboot.  This was insidious: the too-large
>+		   partition would work initially, because with Linux-2.4.x
>+		   and newer we set the partition start sector and length
>+		   (in sectors) accurately and directly via the BLKPG ioctl.
>+		   However, only the last 32 bits of each number would be
>+		   written to the partition table, and the next time the
>+		   system would read/use those corrupted numbers it would
>+		   usually complain about an invalid partition.
>+		   The same applies to the starting sector number. */
>+
>+		if (part->geom.length > _partition_max_len (label_type)) {
>+			ped_exception_throw (
>+				PED_EXCEPTION_ERROR, PED_EXCEPTION_CANCEL,
>+				_("partition length of %jd sectors exceeds the "
>+				  "%s-partition-table-imposed maximum of %jd"),
>+				part->geom.length,
>+				label_type,
>+				_partition_max_len (label_type));
>+			return 0;
>+		}
>+
>+		/* The starting sector number must fit in 32 bytes. */
>+		if (part->geom.start > _partition_max_start (label_type)) {
>+			ped_exception_throw (
>+				PED_EXCEPTION_ERROR, PED_EXCEPTION_CANCEL,
>+				_("starting sector number, %jd exceeds the"
>+				  " %s-partition-table-imposed maximum of %jd"),
>+				part->geom.start,
>+				label_type,
>+				_partition_max_start (label_type));
>+			return 0;
>+		}
>+	}
>+
> 	return 1;
> }
>

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