ide-cd: fix oops when using growisofs
cdrom_read_capacity() will blindly return the capacity from the device
without sanity-checking it. This later causes code in fs/buffer.c to
oops.
Fix this by checking that the device is telling us sensible things.
From: Jens Axboe <jens.axboe@oracle.com>
Cc: Michael Buesch <mb@bu3sch.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: <stable@kernel.org>
Cc: Borislav Petkov <petkovbb@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[bart: print device name instead of driver name]
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
[harvey: blocklen is a big-endian value]
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 8f253e5..e617cf0 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -1311,13 +1311,30 @@
stat = ide_cd_queue_pc(drive, cmd, 0, &capbuf, &len, sense, 0,
REQ_QUIET);
- if (stat == 0) {
- *capacity = 1 + be32_to_cpu(capbuf.lba);
- *sectors_per_frame =
- be32_to_cpu(capbuf.blocklen) >> SECTOR_BITS;
+ if (stat)
+ return stat;
+
+ /*
+ * Sanity check the given block size
+ */
+ switch (capbuf.blocklen) {
+ case __constant_cpu_to_be32(512):
+ case __constant_cpu_to_be32(1024):
+ case __constant_cpu_to_be32(2048):
+ case __constant_cpu_to_be32(4096):
+ break;
+ default:
+ printk(KERN_ERR "%s: weird block size %u\n",
+ drive->name, capbuf.blocklen);
+ printk(KERN_ERR "%s: default to 2kb block size\n",
+ drive->name);
+ capbuf.blocklen = __constant_cpu_to_be32(2048);
+ break;
}
- return stat;
+ *capacity = 1 + be32_to_cpu(capbuf.lba);
+ *sectors_per_frame = be32_to_cpu(capbuf.blocklen) >> SECTOR_BITS;
+ return 0;
}
static int cdrom_read_tocentry(ide_drive_t *drive, int trackno, int msf_flag,
