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authorbp <bp@FreeBSD.org>2000-01-02 03:30:42 +0000
committerbp <bp@FreeBSD.org>2000-01-02 03:30:42 +0000
commit11b5b4872ea97ba1acf882fc84bf885c607b0980 (patch)
treed1a17b02550eeb8d138561c88cf1746ba2cab8d2 /sys/fs
parent034f4c18839b7e3aba2de93e8676d439a367f35e (diff)
downloadFreeBSD-src-11b5b4872ea97ba1acf882fc84bf885c607b0980.zip
FreeBSD-src-11b5b4872ea97ba1acf882fc84bf885c607b0980.tar.gz
Fix the mess with signed/unsigned longs and ints (inspired by bde).
Fix potential bug with directory reading. Explicitly limit file size to 4GB (msdos can't handle larger files). Slightly reorganize msdosfs_read() to reduce number of 'if's.
Diffstat (limited to 'sys/fs')
-rw-r--r--sys/fs/msdosfs/msdosfs_vnops.c44
1 files changed, 26 insertions, 18 deletions
diff --git a/sys/fs/msdosfs/msdosfs_vnops.c b/sys/fs/msdosfs/msdosfs_vnops.c
index d72a4cd..15e8578 100644
--- a/sys/fs/msdosfs/msdosfs_vnops.c
+++ b/sys/fs/msdosfs/msdosfs_vnops.c
@@ -74,6 +74,8 @@
#include <msdosfs/msdosfsmount.h>
#include <msdosfs/fat.h>
+#define DOS_FILESIZE_MAX 0xffffffff
+
/*
* Prototypes for MSDOSFS vnode operations
*/
@@ -545,12 +547,12 @@ msdosfs_read(ap)
} */ *ap;
{
int error = 0;
- off_t diff;
int blsize;
int isadir;
int orig_resid;
- long n;
- long on;
+ u_int n;
+ u_long diff;
+ u_long on;
daddr_t lbn;
daddr_t rablock;
int rasize;
@@ -564,6 +566,8 @@ msdosfs_read(ap)
if (uio->uio_offset < 0)
return (EINVAL);
+ if (uio->uio_offset > DOS_FILESIZE_MAX)
+ return (EFBIG);
/*
* If they didn't ask for any data, then we are done.
*/
@@ -578,41 +582,42 @@ msdosfs_read(ap)
if (uio->uio_offset >= dep->de_FileSize)
break;
lbn = de_cluster(pmp, uio->uio_offset);
- on = uio->uio_offset & pmp->pm_crbomask;
- n = min((u_long) (pmp->pm_bpcluster - on), uio->uio_resid);
- diff = dep->de_FileSize - uio->uio_offset;
- if (diff < n)
- n = diff;
- /* convert cluster # to block # if a directory */
- if (isadir) {
- error = pcbmap(dep, lbn, &lbn, 0, &blsize);
- if (error)
- break;
- }
/*
* If we are operating on a directory file then be sure to
* do i/o with the vnode for the filesystem instead of the
* vnode for the directory.
*/
if (isadir) {
+ /* convert cluster # to block # */
+ error = pcbmap(dep, lbn, &lbn, 0, &blsize);
+ if (error)
+ break;
error = bread(pmp->pm_devvp, lbn, blsize, NOCRED, &bp);
} else {
+ blsize = pmp->pm_bpcluster;
rablock = lbn + 1;
if (seqcount > 1 &&
de_cn2off(pmp, rablock) < dep->de_FileSize) {
rasize = pmp->pm_bpcluster;
- error = breadn(vp, lbn, pmp->pm_bpcluster,
+ error = breadn(vp, lbn, blsize,
&rablock, &rasize, 1, NOCRED, &bp);
} else {
- error = bread(vp, lbn, pmp->pm_bpcluster,
- NOCRED, &bp);
+ error = bread(vp, lbn, blsize, NOCRED, &bp);
}
}
- n = min(n, pmp->pm_bpcluster - bp->b_resid);
if (error) {
brelse(bp);
break;
}
+ on = uio->uio_offset & pmp->pm_crbomask;
+ diff = pmp->pm_bpcluster - on;
+ n = diff > uio->uio_resid ? uio->uio_resid : diff;
+ diff = dep->de_FileSize - uio->uio_offset;
+ if (diff < n)
+ n = diff;
+ diff = blsize - bp->b_resid;
+ if (diff < n)
+ n = diff;
error = uiomove(bp->b_data + on, (int) n, uio);
brelse(bp);
} while (error == 0 && uio->uio_resid > 0 && n != 0);
@@ -676,6 +681,9 @@ msdosfs_write(ap)
if (uio->uio_resid == 0)
return (0);
+ if (uio->uio_offset + uio->uio_resid > DOS_FILESIZE_MAX)
+ return (EFBIG);
+
/*
* If they've exceeded their filesize limit, tell them about it.
*/
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