git: 45d4e82bf61f - main - msdosfs: fix cluster limit when mounting FAT-16 file systems

The branch main has been updated by se:

URL: https://cgit.FreeBSD.org/src/commit/?id=45d4e82bf61f91792142a2b9e2af657dab8500fd

commit 45d4e82bf61f91792142a2b9e2af657dab8500fd
Author:     Stefan Eßer <se@FreeBSD.org>
AuthorDate: 2024-08-09 17:26:27 +0000
Commit:     Stefan Eßer <se@FreeBSD.org>
CommitDate: 2024-08-09 17:26:27 +0000

    msdosfs: fix cluster limit when mounting FAT-16 file systems
    
    The maximum cluster number was calculated based on the number of data
    cluters that fit in the givem partition size and the size of the FAT
    area. This limit did not take into account that the highest 10 cluster
    numbers are reserved and must not be used for files.
    
    PR:             280347
    MFC after:      3 days
    Reported by:    pho@FreeBSD.org
---
 sys/fs/msdosfs/msdosfs_vfsops.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sys/fs/msdosfs/msdosfs_vfsops.c b/sys/fs/msdosfs/msdosfs_vfsops.c
index 258c701bd300..adcffe45df82 100644
--- a/sys/fs/msdosfs/msdosfs_vfsops.c
+++ b/sys/fs/msdosfs/msdosfs_vfsops.c
@@ -722,7 +722,9 @@ mountmsdosfs(struct vnode *odevvp, struct mount *mp)
 		}
 	}
 
-	clusters = (pmp->pm_fatsize / pmp->pm_fatmult) * pmp->pm_fatdiv ;
+	clusters = (pmp->pm_fatsize / pmp->pm_fatmult) * pmp->pm_fatdiv;
+	if (clusters >= (CLUST_RSRVD & pmp->pm_fatmask))
+		clusters = CLUST_RSRVD & pmp->pm_fatmask;
 	if (pmp->pm_maxcluster >= clusters) {
 #ifdef MSDOSFS_DEBUG
 		printf("Warning: number of clusters (%ld) exceeds FAT "