The branch main has been updated by mckusick:
URL:
https://cgit.FreeBSD.org/src/commit/?id=f030f1102c62d3de498cf2b5f0ce8d3582182923
commit f030f1102c62d3de498cf2b5f0ce8d3582182923
Author: Kirk McKusick <mckus...@freebsd.org>
AuthorDate: 2022-07-21 05:45:18 +0000
Commit: Kirk McKusick <mckus...@freebsd.org>
CommitDate: 2022-07-21 05:52:10 +0000
Delete UFS2 backup superblock recovery info when building a UFS1 filesystem.
Only the UFS2 filesystem has support for storing information needed
to find alternate superblocks. If that information is inadvertently
left in place when building a UFS1 filesystem, fsck_ffs may stumble
across it and attempt to use it to recover the UFS1 filesystem
which can only end poorly.
---
sbin/newfs/mkfs.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
diff --git a/sbin/newfs/mkfs.c b/sbin/newfs/mkfs.c
index a6c4ee60c2d5..48091d7882d0 100644
--- a/sbin/newfs/mkfs.c
+++ b/sbin/newfs/mkfs.c
@@ -636,23 +636,26 @@ restart:
* Read the last sector of the boot block, replace the last
* 20 bytes with the recovery information, then write it back.
* The recovery information only works for UFS2 filesystems.
+ * For UFS1, zero out the area to ensure that an old UFS2
+ * recovery block is not accidentally found.
*/
- if (sblock.fs_magic == FS_UFS2_MAGIC) {
- if ((fsrbuf = malloc(realsectorsize)) == NULL || bread(&disk,
- part_ofs + (SBLOCK_UFS2 - realsectorsize) / disk.d_bsize,
- fsrbuf, realsectorsize) == -1)
- err(1, "can't read recovery area: %s", disk.d_error);
- fsr =
- (struct fsrecovery *)&fsrbuf[realsectorsize - sizeof *fsr];
+ if ((fsrbuf = malloc(realsectorsize)) == NULL || bread(&disk,
+ part_ofs + (SBLOCK_UFS2 - realsectorsize) / disk.d_bsize,
+ fsrbuf, realsectorsize) == -1)
+ err(1, "can't read recovery area: %s", disk.d_error);
+ fsr = (struct fsrecovery *)&fsrbuf[realsectorsize - sizeof *fsr];
+ if (sblock.fs_magic != FS_UFS2_MAGIC) {
+ memset(fsr, 0, sizeof *fsr);
+ } else {
fsr->fsr_magic = sblock.fs_magic;
fsr->fsr_fpg = sblock.fs_fpg;
fsr->fsr_fsbtodb = sblock.fs_fsbtodb;
fsr->fsr_sblkno = sblock.fs_sblkno;
fsr->fsr_ncg = sblock.fs_ncg;
- wtfs((SBLOCK_UFS2 - realsectorsize) / disk.d_bsize,
- realsectorsize, fsrbuf);
- free(fsrbuf);
}
+ wtfs((SBLOCK_UFS2 - realsectorsize) / disk.d_bsize,
+ realsectorsize, fsrbuf);
+ free(fsrbuf);
/*
* Update information about this partition in pack
* label, to that it may be updated on disk.
