Date: Sat, 11 Aug 2007 11:52:08 +0200 (CEST) From: Stefan Richter Subject: ieee1394: sbp2: fix unsafe iteration over list of devices sbp2_host_reset and sbp2_handle_status_write are not serialized against sbp2_alloc_device and sbp2_remove_device. Signed-off-by: Stefan Richter --- drivers/ieee1394/sbp2.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) Index: linux/drivers/ieee1394/sbp2.c =================================================================== --- linux.orig/drivers/ieee1394/sbp2.c +++ linux/drivers/ieee1394/sbp2.c @@ -242,6 +242,8 @@ static int sbp2_max_speed_and_size(struc static const u8 sbp2_speedto_max_payload[] = { 0x7, 0x8, 0x9, 0xA, 0xB, 0xC }; +static DEFINE_RWLOCK(sbp2_hi_logical_units_lock); + static struct hpsb_highlevel sbp2_highlevel = { .name = SBP2_DEVICE_NAME, .host_reset = sbp2_host_reset, @@ -732,6 +734,7 @@ static struct sbp2_lu *sbp2_alloc_device struct sbp2_fwhost_info *hi; struct Scsi_Host *shost = NULL; struct sbp2_lu *lu = NULL; + unsigned long flags; lu = kzalloc(sizeof(*lu), GFP_KERNEL); if (!lu) { @@ -784,7 +787,9 @@ static struct sbp2_lu *sbp2_alloc_device lu->hi = hi; + write_lock_irqsave(&sbp2_hi_logical_units_lock, flags); list_add_tail(&lu->lu_list, &hi->logical_units); + write_unlock_irqrestore(&sbp2_hi_logical_units_lock, flags); /* Register the status FIFO address range. We could use the same FIFO * for targets at different nodes. However we need different FIFOs per @@ -828,16 +833,20 @@ static void sbp2_host_reset(struct hpsb_ { struct sbp2_fwhost_info *hi; struct sbp2_lu *lu; + unsigned long flags; hi = hpsb_get_hostinfo(&sbp2_highlevel, host); if (!hi) return; + + read_lock_irqsave(&sbp2_hi_logical_units_lock, flags); list_for_each_entry(lu, &hi->logical_units, lu_list) if (likely(atomic_read(&lu->state) != SBP2LU_STATE_IN_SHUTDOWN)) { atomic_set(&lu->state, SBP2LU_STATE_IN_RESET); scsi_block_requests(lu->shost); } + read_unlock_irqrestore(&sbp2_hi_logical_units_lock, flags); } static int sbp2_start_device(struct sbp2_lu *lu) @@ -919,6 +928,7 @@ alloc_fail: static void sbp2_remove_device(struct sbp2_lu *lu) { struct sbp2_fwhost_info *hi; + unsigned long flags; if (!lu) return; @@ -933,7 +943,9 @@ static void sbp2_remove_device(struct sb flush_scheduled_work(); sbp2util_remove_command_orb_pool(lu, hi->host); + write_lock_irqsave(&sbp2_hi_logical_units_lock, flags); list_del(&lu->lu_list); + write_unlock_irqrestore(&sbp2_hi_logical_units_lock, flags); if (lu->login_response) dma_free_coherent(hi->host->device.parent, @@ -1707,6 +1719,7 @@ static int sbp2_handle_status_write(stru } /* Find the unit which wrote the status. */ + read_lock_irqsave(&sbp2_hi_logical_units_lock, flags); list_for_each_entry(lu_tmp, &hi->logical_units, lu_list) { if (lu_tmp->ne->nodeid == nodeid && lu_tmp->status_fifo_addr == addr) { @@ -1714,6 +1727,8 @@ static int sbp2_handle_status_write(stru break; } } + read_unlock_irqrestore(&sbp2_hi_logical_units_lock, flags); + if (unlikely(!lu)) { SBP2_ERR("lu is NULL - device is gone?"); return RCODE_ADDRESS_ERROR;