git: eefbecaab1b1 - stable/13 - Updates to UFS/FFS superblock integrity checks when reading a superblock.

The branch stable/13 has been updated by mckusick:

URL: https://cgit.FreeBSD.org/src/commit/?id=eefbecaab1b10c5a587bf1292e585ef480f81d71

commit eefbecaab1b10c5a587bf1292e585ef480f81d71
Author:     Kirk McKusick <mckusick@FreeBSD.org>
AuthorDate: 2023-04-29 18:52:27 +0000
Commit:     Kirk McKusick <mckusick@FreeBSD.org>
CommitDate: 2023-05-19 22:51:27 +0000

    Updates to UFS/FFS superblock integrity checks when reading a superblock.
    
    (cherry picked from commit a2d1957bbcc87b499526df8d99ec7e1ddd2193c0)
---
 sys/ufs/ffs/ffs_subr.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sys/ufs/ffs/ffs_subr.c b/sys/ufs/ffs/ffs_subr.c
index d847373a8cde..1bd298315dd9 100644
--- a/sys/ufs/ffs/ffs_subr.c
+++ b/sys/ufs/ffs/ffs_subr.c
@@ -432,6 +432,9 @@ validate_sblock(struct fs *fs, int isaltsblk)
 	    %jd);
 	CHK(fs->fs_sbsize, >, SBLOCKSIZE, %jd);
 	CHK(fs->fs_sbsize, <, (unsigned)sizeof(struct fs), %jd);
+	/* fix for misconfigured filesystems */
+	if (fs->fs_maxbsize == 0)
+		fs->fs_maxbsize = fs->fs_bsize;
 	CHK(fs->fs_maxbsize, <, fs->fs_bsize, %jd);
 	CHK(powerof2(fs->fs_maxbsize), ==, 0, %jd);
 	CHK(fs->fs_maxbsize, >, FS_MAXCONTIG * fs->fs_bsize, %jd);