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From 8125a64ff9e98d09c659dbd5adbca521d63a268b Mon Sep 17 00:00:00 2001
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From: Karel Zak <kzak@redhat.com>
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Date: Thu, 7 Jul 2016 14:22:41 +0200
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Subject: [PATCH 86/86] libblkid: avoid recursion in EBR
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Upstream: http://github.com/karelzak/util-linux/commit/7164a1c34d18831ac61c6744ad14ce916d389b3f
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Upstream: http://github.com/karelzak/util-linux/commit/50d1594c2e6142a3b51d2143c74027480df082e0
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Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=1349536
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Signed-off-by: Karel Zak <kzak@redhat.com>
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---
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 libblkid/src/partitions/dos.c        | 21 +++++++++++++++++++--
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 libblkid/src/partitions/partitions.c | 14 ++++++++++++++
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 libblkid/src/partitions/partitions.h |  2 ++
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 3 files changed, 35 insertions(+), 2 deletions(-)
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diff --git a/libblkid/src/partitions/dos.c b/libblkid/src/partitions/dos.c
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index 2d4a537..563fe9a 100644
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--- a/libblkid/src/partitions/dos.c
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+++ b/libblkid/src/partitions/dos.c
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@@ -48,6 +48,12 @@ static int parse_dos_extended(blkid_probe pr, blkid_parttable tab,
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 	int ct_nodata = 0;	/* count ext.partitions without data partitions */
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 	int i;
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+	DBG(LOWPROBE, blkid_debug("parse EBR [start=%d, size=%d]", ex_start/ssf, ex_size/ssf));
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+	if (ex_start == 0) {
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+		DBG(LOWPROBE, blkid_debug("Bad offset in primary extended partition -- ignore"));
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+		return 0;
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+	}
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+
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 	while (1) {
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 		struct dos_partition *p, *p0;
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 		uint32_t start, size;
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@@ -100,6 +106,13 @@ static int parse_dos_extended(blkid_probe pr, blkid_parttable tab,
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 					continue;
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 			}
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+			/* Avoid recursive non-empty links, see ct_nodata counter */
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+			if (blkid_partlist_get_partition_by_start(ls, abs_start)) {
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+				DBG(LOWPROBE, blkid_debug("#%d: EBR duplicate data partition [abs start=%u] -- ignore",
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+							i + 1, abs_start));
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+				continue;
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+			}
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+
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 			par = blkid_partlist_add_partition(ls, tab, abs_start, size);
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 			if (!par)
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 				return -ENOMEM;
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@@ -116,8 +129,12 @@ static int parse_dos_extended(blkid_probe pr, blkid_parttable tab,
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 			start = dos_partition_start(p) * ssf;
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 			size = dos_partition_size(p) * ssf;
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-			if (size && is_extended(p))
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-				break;
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+			if (size && is_extended(p)) {
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+				if (start == 0)
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+					DBG(LOWPROBE, blkid_debug("#%d: EBR link offset is zero -- ignore", i + 1));
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+				else
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+					break;
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+			}
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 		}
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 		if (i == 4)
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 			goto leave;
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diff --git a/libblkid/src/partitions/partitions.c b/libblkid/src/partitions/partitions.c
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index 752fc95..9d846ff 100644
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--- a/libblkid/src/partitions/partitions.c
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+++ b/libblkid/src/partitions/partitions.c
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@@ -928,6 +928,20 @@ blkid_partition blkid_partlist_get_partition(blkid_partlist ls, int n)
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 	return &ls->parts[n];
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 }
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+blkid_partition blkid_partlist_get_partition_by_start(blkid_partlist ls, uint64_t start)
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+{
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+	int i, nparts;
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+	blkid_partition par;
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+
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+	nparts = blkid_partlist_numof_partitions(ls);
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+	for (i = 0; i < nparts; i++) {
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+		par = blkid_partlist_get_partition(ls, i);
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+		if ((uint64_t) blkid_partition_get_start(par) == start)
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+			return par;
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+	}
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+	return NULL;
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+}
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+
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 /**
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  * blkid_partlist_devno_to_partition:
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  * @ls: partitions list
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diff --git a/libblkid/src/partitions/partitions.h b/libblkid/src/partitions/partitions.h
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index 61763bf..4e99e2a 100644
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--- a/libblkid/src/partitions/partitions.h
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+++ b/libblkid/src/partitions/partitions.h
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@@ -20,6 +20,8 @@ extern int blkid_partlist_increment_partno(blkid_partlist ls);
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 extern blkid_partition blkid_partlist_get_parent(blkid_partlist ls);
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+extern blkid_partition blkid_partlist_get_partition_by_start(blkid_partlist ls, uint64_t start);
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+
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 extern int blkid_partitions_do_subprobe(blkid_probe pr,
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 			blkid_partition parent, const struct blkid_idinfo *id);
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-- 
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2.7.4
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