Patchwork [3.5.y.z,extended,stable] Patch "libsas: fix handling vacant phy in sas_set_ex_phy()" has been added to staging queue

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Submitter Luis Henriques
Date April 17, 2013, 2:43 p.m.
Message ID <1366209818-15578-1-git-send-email-luis.henriques@canonical.com>
Download mbox | patch
Permalink /patch/237248/
State New
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Luis Henriques - April 17, 2013, 2:43 p.m.
This is a note to let you know that I have just added a patch titled

    libsas: fix handling vacant phy in sas_set_ex_phy()

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

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From 107df311e421a82260ace7dc5a25eb78103b6783 Mon Sep 17 00:00:00 2001
From: Lukasz Dorau <lukasz.dorau@intel.com>
Date: Wed, 3 Apr 2013 10:27:17 +0200
Subject: [PATCH] libsas: fix handling vacant phy in sas_set_ex_phy()

commit d4a2618fa77b5e58ec15342972bd3505a1c3f551 upstream.

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: [<ffffffff811c9002>] sysfs_find_dirent+0x12/0x90
Call Trace:
  [<ffffffff811c95f5>] sysfs_get_dirent+0x35/0x80
  [<ffffffff811cb55e>] sysfs_unmerge_group+0x1e/0xb0
  [<ffffffff813329f4>] dpm_sysfs_remove+0x24/0x90
  [<ffffffff8132b0f4>] device_del+0x44/0x1d0
  [<ffffffffa016fc59>] sas_rphy_delete+0x9/0x20 [scsi_transport_sas]
  [<ffffffffa01a16f6>] sas_destruct_devices+0xe6/0x110 [libsas]
  [<ffffffff8107ac7c>] process_one_work+0x16c/0x350
  [<ffffffff8107d84a>] worker_thread+0x17a/0x410
  [<ffffffff81081b76>] kthread+0x96/0xa0
  [<ffffffff81464944>] kernel_thread_helper+0x4/0x10

Signed-off-by: Lukasz Dorau <lukasz.dorau@intel.com>
Signed-off-by: Pawel Baldysiak <pawel.baldysiak@intel.com>
Reviewed-by: Maciej Patelczyk <maciej.patelczyk@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 drivers/scsi/libsas/sas_expander.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

--
1.8.1.2

Patch

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 101b28e..58e6183 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);