Messages in this thread Patch in this message | | | Date | Wed, 16 Sep 2009 15:36:55 -0700 | From | Greg KH <> | Subject | [patch 42/45] libata: fix off-by-one error in ata_tf_read_block() |
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2.6.31-stable review patch. If anyone has any objections, please let us know.
------------------ 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;
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