mirror/freebsd
1
0
Fork 0
mirror of https://git.FreeBSD.org/src.git synced 2025-01-16 15:11:52 +00:00
Code Issues Releases Activity

mountmsdosfs: reject too high value of bytes per cluster

Browse Source 
Bytes per cluster are calcuated as bytes per sector times sectors per
cluster.  Too high value can overflow an internal variable with type
that can hold only values in valid range.  Trying to use a wider type
results in an attempt to read more than MAXBSIZE at once, a panic.
Unfortunately, it is FreeBSD newfs_msdos that  produces filesystems
with invalid parameters for certain types of media.

Reported by:	Fabian Keil <freebsd-listen@fabiankeil.de>,
		Paul B. Mahol <onemda@gmail.com>
Discussed with:	bde, kib
MFC after:	1 week
X-ToDo:		fix newfs_msdos
This commit is contained in:
Andriy Gapon 2010-04-02 15:22:23 +00:00
parent 1b4bc5f851
commit 423b0fb7ad
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=206098
1 changed files with 1 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
sys/fs/msdosfs/msdosfs_vfsops.c
View File

@ -580,6 +580,7 @@ mountmsdosfs(struct vnode *devvp, struct mount *mp)
|| (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1))
|| (pmp->pm_HugeSectors == 0)
|| (pmp->pm_FATsecs == 0)
|| (SecPerClust * pmp->pm_BlkPerSec > MAXBSIZE / DEV_BSIZE)
) {
error = EINVAL;
goto error_exit;