Module Name: src
Committed By: mlelstv
Date: Tue May 3 18:17:29 UTC 2016
Modified Files:
src/sys/fs/msdosfs: msdosfs_fat.c
Log Message:
Validate FAT entries to avoid some panics caused by a corrupted FAT.
Also print FAT write errors when mount is synchronous (-o sync). This
reveals problems caused by a write protected disklabel on sector 1.
To generate a diff of this commit:
cvs rdiff -u -r1.29 -r1.30 src/sys/fs/msdosfs/msdosfs_fat.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/fs/msdosfs/msdosfs_fat.c
diff -u src/sys/fs/msdosfs/msdosfs_fat.c:1.29 src/sys/fs/msdosfs/msdosfs_fat.c:1.30
--- src/sys/fs/msdosfs/msdosfs_fat.c:1.29 Sat Mar 28 19:24:05 2015
+++ src/sys/fs/msdosfs/msdosfs_fat.c Tue May 3 18:17:28 2016
@@ -1,4 +1,4 @@
-/* $NetBSD: msdosfs_fat.c,v 1.29 2015/03/28 19:24:05 maxv Exp $ */
+/* $NetBSD: msdosfs_fat.c,v 1.30 2016/05/03 18:17:28 mlelstv Exp $ */
/*-
* Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
@@ -52,7 +52,7 @@
#endif
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: msdosfs_fat.c,v 1.29 2015/03/28 19:24:05 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: msdosfs_fat.c,v 1.30 2016/05/03 18:17:28 mlelstv Exp $");
/*
* kernel include files.
@@ -273,6 +273,18 @@ pcbmap(struct denode *dep, u_long findcn
*/
if (cn >= (CLUST_RSRVD & pmp->pm_fatmask))
goto hiteof;
+
+ /*
+ * Also stop when cluster is not in the filesystem
+ */
+ if (cn < CLUST_FIRST || cn > pmp->pm_maxcluster) {
+ DPRINTF(("%s(cn, %lu not in %lu..%lu)\n", __func__,
+ cn, CLUST_FIRST, pmp->pm_maxcluster));
+ if (bp)
+ brelse(bp, 0);
+ return (EINVAL);
+ }
+
byteoffset = FATOFS(pmp, cn);
fatblock(pmp, byteoffset, &bn, &bsize, &bo);
if (bn != bp_bn) {
@@ -383,7 +395,7 @@ fc_purge(struct denode *dep, u_int frcn)
void
updatefats(struct msdosfsmount *pmp, struct buf *bp, u_long fatbn)
{
- int i;
+ int i, error;
struct buf *bpn;
DPRINTF(("%s(pmp %p, bp %p, fatbn %lu)\n", __func__, pmp, bp, fatbn));
@@ -448,9 +460,12 @@ updatefats(struct msdosfsmount *pmp, str
bpn = getblk(pmp->pm_devvp, de_bn2kb(pmp, fatbn),
bp->b_bcount, 0, 0);
memcpy(bpn->b_data, bp->b_data, bp->b_bcount);
- if (pmp->pm_flags & MSDOSFSMNT_WAITONFAT)
- bwrite(bpn);
- else
+ if (pmp->pm_flags & MSDOSFSMNT_WAITONFAT) {
+ error = bwrite(bpn);
+ if (error)
+ printf("%s: copy FAT %d (error=%d)\n",
+ __func__, i, error);
+ } else
bdwrite(bpn);
}
}
@@ -458,9 +473,12 @@ updatefats(struct msdosfsmount *pmp, str
/*
* Write out the first (or current) FAT last.
*/
- if (pmp->pm_flags & MSDOSFSMNT_WAITONFAT)
- bwrite(bp);
- else
+ if (pmp->pm_flags & MSDOSFSMNT_WAITONFAT) {
+ error = bwrite(bp);
+ if (error)
+ printf("%s: write FAT (error=%d)\n",
+ __func__, error);
+ } else
bdwrite(bp);
/*
* Maybe update fsinfo sector here?
