Date: Thu, 21 Jul 2022 05:52:41 GMT From: Kirk McKusick <mckusick@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: f030f1102c62 - main - Delete UFS2 backup superblock recovery info when building a UFS1 filesystem. Message-ID: <202207210552.26L5qfan065930@gitrepo.freebsd.org>
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The branch main has been updated by mckusick: URL: https://cgit.FreeBSD.org/src/commit/?id=f030f1102c62d3de498cf2b5f0ce8d3582182923 commit f030f1102c62d3de498cf2b5f0ce8d3582182923 Author: Kirk McKusick <mckusick@FreeBSD.org> AuthorDate: 2022-07-21 05:45:18 +0000 Commit: Kirk McKusick <mckusick@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.
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