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authorJens Axboe <jens.axboe@oracle.com>2008-07-24 22:53:35 +0200
committerBartlomiej Zolnierkiewicz <bzolnier@gmail.com>2008-07-24 22:53:35 +0200
commite8e7b9eb11c34ee18bde8b7011af41938d1ad667 (patch)
tree07e97088cee787f02e9e8de1105829775bc41b5c /drivers/ide/ide-cd.c
parent96cc112c09b3c6674da01ef8b377f7a916883ea2 (diff)
downloadlinux-e8e7b9eb11c34ee18bde8b7011af41938d1ad667.tar.bz2
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>
Diffstat (limited to 'drivers/ide/ide-cd.c')
-rw-r--r--drivers/ide/ide-cd.c27
1 files changed, 22 insertions, 5 deletions
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 8f253e5f26a8..e617cf08aef6 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -1311,13 +1311,30 @@ static int cdrom_read_capacity(ide_drive_t *drive, unsigned long *capacity,
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,