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Fixed a serious off by 1 error. The cluster-in-use bitmap was overrun

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by 1 u_int if the number of clusters was 1 more than a multiple of
(8 * sizeof(u_int)).  The bitmap is malloced and large (often huge), so
fatal overrun probably only occurred if the number of clusters was 1
more than 1 multiple of PAGE_SIZE/8.
This commit is contained in:
Bruce Evans 2004-02-21 22:47:19 +00:00
parent b99c0fd2b4
commit 0ef0dd6f85
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=126086
1 changed files with 1 additions and 2 deletions
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3
sys/fs/msdosfs/msdosfs_vfsops.c
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@ -586,8 +586,7 @@ mountmsdosfs(devvp, mp, td, argp)
* Allocate memory for the bitmap of allocated clusters, and then
* fill it in.
*/
pmp->pm_inusemap = malloc(((pmp->pm_maxcluster + N_INUSEBITS - 1)
/ N_INUSEBITS)
pmp->pm_inusemap = malloc(howmany(pmp->pm_maxcluster + 1, N_INUSEBITS)
* sizeof(*pmp->pm_inusemap),
M_MSDOSFSFAT, M_WAITOK);