Revert "fsck.cramfs: Fix bus error on broken file system."

This reverts commit 7cb962c77015e9383b53eeb22ce732cb5216bbc3.

It can't be right that we mmap (start + super.size) bytes from a file
which is usually only super.size bytes large. The patch "fixed" a
problem when super.size is bad but now it fails for the correct case:

$ mkdir -p root/subdir
$ ./mkfs.cramfs -p root cramfs
$ ./fsck.cramfs cramfs
Bus error (core dumped)

We will fix the original problem later.

CC: Tobias Stoeckmann <tobias@stoeckmann.org>
Signed-off-by: Ruediger Meier <ruediger.meier@ga-group.nl>

diff --git a/disk-utils/fsck.cramfs.c b/disk-utils/fsck.cramfs.c
index b2a3cc15366f02d9aef2665c095240bc957b11d2..50c7d33b9e0d8a30da2e130124307e2eb75cbf97 100644 (file)
--- a/disk-utils/fsck.cramfs.c
+++ b/disk-utils/fsck.cramfs.c
@@ -220,24 +220,23 @@ static void test_crc(int start)
        crc = crc32(0L, NULL, 0);
 
        buf =
-           mmap(NULL, start + super.size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+           mmap(NULL, super.size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
        if (buf == MAP_FAILED) {
                buf =
-                   mmap(NULL, start + super.size, PROT_READ | PROT_WRITE,
+                   mmap(NULL, super.size, PROT_READ | PROT_WRITE,
                         MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
                if (buf != MAP_FAILED) {
-                       if (lseek(fd, start, SEEK_SET) == (off_t) -1)
+                       if (lseek(fd, 0, SEEK_SET) == (off_t) -1)
                                err(FSCK_EX_ERROR, _("seek on %s failed"), filename);
-                       if (read(fd, (unsigned char *) buf + start, super.size) !=
-                           (ssize_t) super.size)
+                       if (read(fd, buf, super.size) != (ssize_t) super.size)
                                err(FSCK_EX_ERROR, _("cannot read %s"), filename);
                }
        }
        if (buf != MAP_FAILED) {
                ((struct cramfs_super *)((unsigned char *) buf + start))->fsid.crc =
                    crc32(0L, NULL, 0);
-               crc = crc32(crc, (unsigned char *) buf + start, super.size);
-               munmap(buf, start + super.size);
+               crc = crc32(crc, (unsigned char *) buf + start, super.size - start);
+               munmap(buf, super.size);
        } else {
                int retval;
                size_t length = 0;