From d4a2618fa77b5e58ec15342972bd3505a1c3f551 Mon Sep 17 00:00:00 2001 From: Lukasz Dorau Date: Wed, 3 Apr 2013 10:27:17 +0200 Subject: [PATCH] [SCSI] libsas: fix handling vacant phy in sas_set_ex_phy() If a result of the SMP discover function is PHY VACANT, the content of discover response structure (dr) is not valid. It sometimes happens that dr->attached_sas_addr can contain even SAS address of other phy. In such case an invalid phy is created, what causes NULL pointer dereference during destruction of expander's phys. So if a result of SMP function is PHY VACANT, the content of discover response structure (dr) must not be copied to phy structure. This patch fixes the following bug: BUG: unable to handle kernel NULL pointer dereference at 0000000000000030 IP: [] sysfs_find_dirent+0x12/0x90 Call Trace: [] sysfs_get_dirent+0x35/0x80 [] sysfs_unmerge_group+0x1e/0xb0 [] dpm_sysfs_remove+0x24/0x90 [] device_del+0x44/0x1d0 [] sas_rphy_delete+0x9/0x20 [scsi_transport_sas] [] sas_destruct_devices+0xe6/0x110 [libsas] [] process_one_work+0x16c/0x350 [] worker_thread+0x17a/0x410 [] kthread+0x96/0xa0 [] kernel_thread_helper+0x4/0x10 Signed-off-by: Lukasz Dorau Signed-off-by: Pawel Baldysiak Reviewed-by: Maciej Patelczyk Cc: Signed-off-by: James Bottomley --- drivers/scsi/libsas/sas_expander.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c index 588affd6fde7..55cbd0180159 100644 --- a/drivers/scsi/libsas/sas_expander.c +++ b/drivers/scsi/libsas/sas_expander.c @@ -235,6 +235,17 @@ static void sas_set_ex_phy(struct domain_device *dev, int phy_id, void *rsp) linkrate = phy->linkrate; memcpy(sas_addr, phy->attached_sas_addr, SAS_ADDR_SIZE); + /* Handle vacant phy - rest of dr data is not valid so skip it */ + if (phy->phy_state == PHY_VACANT) { + memset(phy->attached_sas_addr, 0, SAS_ADDR_SIZE); + phy->attached_dev_type = NO_DEVICE; + if (!test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) { + phy->phy_id = phy_id; + goto skip; + } else + goto out; + } + phy->attached_dev_type = to_dev_type(dr); if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) goto out; @@ -272,6 +283,7 @@ static void sas_set_ex_phy(struct domain_device *dev, int phy_id, void *rsp) phy->phy->maximum_linkrate = dr->pmax_linkrate; phy->phy->negotiated_linkrate = phy->linkrate; + skip: if (new_phy) if (sas_phy_add(phy->phy)) { sas_phy_free(phy->phy); -- GitLab