Fix a couple of auto allocation corner cases.

Don't stop counting free partitions just because a spoofed
partition is encountered.

Always check for (end - start) underflow after rounding
start/end to cylinder boundaries.

diff --git a/sbin/disklabel/editor.c b/sbin/disklabel/editor.c
index 13fe749..6470e2c 100644 (file)
--- a/sbin/disklabel/editor.c
+++ b/sbin/disklabel/editor.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: editor.c,v 1.386 2023/01/05 00:19:53 krw Exp $        */
+/*     $OpenBSD: editor.c,v 1.387 2023/01/13 14:24:17 krw Exp $        */
 
 /*
  * Copyright (c) 1997-2000 Todd C. Miller <millert@openbsd.org>
@@ -179,7 +179,7 @@ int alignpartition(struct disklabel *, int, u_int64_t, u_int64_t, int);
 static u_int64_t starting_sector;
 static u_int64_t ending_sector;
 static int expert;
-static int overlap;
+static int resizeok;
 
 /*
  * Simple partition editor.
@@ -399,7 +399,7 @@ editor(int f)
                        break;
 
                case 'R':
-                       if (aflag && !overlap)
+                       if (aflag && resizeok)
                                editor_resize(&newlab, arg);
                        else
                                fputs("Resize only implemented for auto "
@@ -532,7 +532,7 @@ editor_allocspace(struct disklabel *lp_org)
        struct space_allocation *ap;
        struct partition *pp;
        const struct diskchunk *chunk;
-       u_int64_t chunkstart, chunkstop, chunksize;
+       u_int64_t chunkstart, chunksize, start, stop;
        u_int64_t cylsecs, secs, xtrasecs;
        char **partmp;
        int i, lastalloc, index, partno, freeparts;
@@ -541,23 +541,16 @@ editor_allocspace(struct disklabel *lp_org)
        /* How big is the OpenBSD portion of the disk?  */
        find_bounds(lp_org);
 
-       overlap = 0;
+       resizeok = 1;
        freeparts = 0;
        for (i = 0;  i < MAXPARTITIONS; i++) {
-               u_int64_t psz, pstart, pend;
-
+               if (i == RAW_PART)
+                       continue;
                pp = &lp_org->d_partitions[i];
-               psz = DL_GETPSIZE(pp);
-               if (psz == 0)
+               if (DL_GETPSIZE(pp) == 0 || pp->p_fstype == FS_UNUSED)
                        freeparts++;
-               pstart = DL_GETPOFFSET(pp);
-               pend = pstart + psz;
-               if (i != RAW_PART && psz != 0 &&
-                   ((pstart >= starting_sector && pstart < ending_sector) ||
-                   (pend > starting_sector && pend <= ending_sector))) {
-                       overlap = 1;
-                       break;
-               }
+               else
+                       resizeok = 0;
        }
 
        cylsecs = lp_org->d_secpercyl;
@@ -626,19 +619,21 @@ again:
                chunk = free_chunks(lp, -1);
                chunksize = 0;
                for (; chunk->start != 0 || chunk->stop != 0; chunk++) {
-                       if ((chunk->stop - chunk->start) > chunksize) {
-                               chunkstart = chunk->start;
-                               chunkstop = chunk->stop;
+                       start = chunk->start;
+                       stop = chunk->stop;
 #ifdef SUN_CYLCHECK
-                               if (lp->d_flags & D_VENDOR) {
-                                       /* Align to cylinder boundaries. */
-                                       chunkstart = ((chunkstart + cylsecs - 1)
-                                           / cylsecs) * cylsecs;
-                                       chunkstop = (chunkstop / cylsecs) *
-                                           cylsecs;
-                               }
+                       if (lp->d_flags & D_VENDOR) {
+                               /* Align to cylinder boundaries. */
+                               start = ((start + cylsecs - 1) / cylsecs) *
+                                   cylsecs;
+                               stop = (stop / cylsecs) * cylsecs;
+                               if (start > stop)
+                                       start = stop;
+                       }
 #endif
-                               chunksize = chunkstop - chunkstart;
+                       if (stop - start > chunksize) {
+                               chunkstart = start;
+                               chunksize = stop - start;
                        }
                }