| From ac8672ea922bde59acf50eaa1eaa1640a6395fd2 Mon Sep 17 00:00:00 2001 |
| From: Tejun Heo <htejun@gmail.com> |
| Date: Sun, 16 Aug 2009 21:21:21 +0900 |
| Subject: libata: fix off-by-one error in ata_tf_read_block() |
| |
| From: Tejun Heo <htejun@gmail.com> |
| |
| commit ac8672ea922bde59acf50eaa1eaa1640a6395fd2 upstream. |
| |
| ata_tf_read_block() has off-by-one error when converting CHS address |
| to LBA. The bug isn't very visible because ata_tf_read_block() is |
| used only when generating sense data for a failed RW command and CHS |
| addressing isn't used too often these days. |
| |
| This problem was spotted by Atsushi Nemoto. |
| |
| Signed-off-by: Tejun Heo <tj@kernel.org> |
| Reported-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> |
| Signed-off-by: Jeff Garzik <jgarzik@redhat.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| drivers/ata/libata-core.c | 8 +++++++- |
| 1 file changed, 7 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/ata/libata-core.c |
| +++ b/drivers/ata/libata-core.c |
| @@ -709,7 +709,13 @@ u64 ata_tf_read_block(struct ata_taskfil |
| head = tf->device & 0xf; |
| sect = tf->lbal; |
| |
| - block = (cyl * dev->heads + head) * dev->sectors + sect; |
| + if (!sect) { |
| + ata_dev_printk(dev, KERN_WARNING, "device reported " |
| + "invalid CHS sector 0\n"); |
| + sect = 1; /* oh well */ |
| + } |
| + |
| + block = (cyl * dev->heads + head) * dev->sectors + sect - 1; |
| } |
| |
| return block; |
