From: Karel Zak <kzak@redhat.com>
Date: Wed, 29 Apr 2020 09:10:54 +0000 (+0200)
Subject: libfdisk: fix alignment logic for tiny partitions
X-Git-Tag: v2.36-rc1~125
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=89c0297bcc313b69347ee110c422e84857bd3265;p=thirdparty%2Futil-linux.git

libfdisk: fix alignment logic for tiny partitions

Addresses: https://github.com/karelzak/util-linux/issues/1018 (second case)
Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/libfdisk/src/alignment.c b/libfdisk/src/alignment.c
index 4ae5ff08f9..cf79180563 100644
--- a/libfdisk/src/alignment.c
+++ b/libfdisk/src/alignment.c
@@ -140,12 +140,14 @@ fdisk_sector_t fdisk_align_lba_in_range(struct fdisk_context *cxt,
 {
 	fdisk_sector_t res;
 
-	start = fdisk_align_lba(cxt, start, FDISK_ALIGN_UP);
-	stop = fdisk_align_lba(cxt, stop, FDISK_ALIGN_DOWN);
+	DBG(CXT, ul_debugobj(cxt, "LBA: align in range <%ju..%ju>", (uintmax_t) start, (uintmax_t) stop));
 
-	if (lba > start && lba < stop
-	    && (lba - start) < (cxt->grain / cxt->sector_size)) {
+	if (start + (cxt->grain / cxt->sector_size) <= stop) {
+		start = fdisk_align_lba(cxt, start, FDISK_ALIGN_UP);
+		stop = fdisk_align_lba(cxt, stop, FDISK_ALIGN_DOWN);
+	}
 
+	if (start + (cxt->grain / cxt->sector_size) > stop) {
 		DBG(CXT, ul_debugobj(cxt, "LBA: area smaller than grain, don't align"));
 		res = lba;
 		goto done;
diff --git a/libfdisk/src/dos.c b/libfdisk/src/dos.c
index 79a55528df..6268d2f3af 100644
--- a/libfdisk/src/dos.c
+++ b/libfdisk/src/dos.c
@@ -1236,7 +1236,11 @@ static int add_partition(struct fdisk_context *cxt, size_t n,
 		struct pte *pe = self_pte(cxt, n);
 
 		assert(pe);
+		assert(start >= cxt->first_lba);
+
 		pe->offset = start - cxt->first_lba;
+		DBG(LABEL, ul_debug("DOS: setting EBR offset to %ju [start=%ju]", pe->offset, start));
+
 		if (pe->offset == l->ext_offset) { /* must be corrected */
 			pe->offset++;
 			if (cxt->first_lba == 1)
@@ -1337,7 +1341,6 @@ static int add_partition(struct fdisk_context *cxt, size_t n,
 	set_partition(cxt, n, 0, start, stop, sys, fdisk_partition_is_bootable(pa));
 	if (n > 4) {
 		struct pte *pe = self_pte(cxt, n);
-
 		assert(pe);
 		set_partition(cxt, n - 1, 1, pe->offset, stop,
 					MBR_DOS_EXTENDED_PARTITION, 0);