[PATCH AUTOSEL 4.9 08/22] cpufreq/pasemi: fix use-after-free in pas_cpufreq_cpu_init()

[PATCH AUTOSEL 4.9 08/22] cpufreq/pasemi: fix use-after-free in pas_cpufreq_cpu_init()

[Sasha Levin]

From: Wen Yang <wen.yang99@zte.com.cn>

[ Upstream commit e0a12445d1cb186d875410d093a00d215bec6a89 ]

The cpu variable is still being used in the of_get_property() call
after the of_node_put() call, which may result in use-after-free.

Fixes: a9acc26b75f6 ("cpufreq/pasemi: fix possible object reference leak")
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/cpufreq/pasemi-cpufreq.c | 23 +++++++++--------------
 1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/drivers/cpufreq/pasemi-cpufreq.c b/drivers/cpufreq/pasemi-cpufreq.c
index 58c933f483004..991b6a3062c4f 100644
--- a/drivers/cpufreq/pasemi-cpufreq.c
+++ b/drivers/cpufreq/pasemi-cpufreq.c
@@ -145,10 +145,18 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
 	int err = -ENODEV;
 
 	cpu = of_get_cpu_node(policy->cpu, NULL);
+	if (!cpu)
+		goto out;
 
+	max_freqp = of_get_property(cpu, "clock-frequency", NULL);
 	of_node_put(cpu);
-	if (!cpu)
+	if (!max_freqp) {
+		err = -EINVAL;
 		goto out;
+	}
+
+	/* we need the freq in kHz */
+	max_freq = *max_freqp / 1000;
 
 	dn = of_find_compatible_node(NULL, NULL, "1682m-sdc");
 	if (!dn)
@@ -185,16 +193,6 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
 	}
 
 	pr_debug("init cpufreq on CPU %d\n", policy->cpu);
-
-	max_freqp = of_get_property(cpu, "clock-frequency", NULL);
-	if (!max_freqp) {
-		err = -EINVAL;
-		goto out_unmap_sdcpwr;
-	}
-
-	/* we need the freq in kHz */
-	max_freq = *max_freqp / 1000;
-
 	pr_debug("max clock-frequency is at %u kHz\n", max_freq);
 	pr_debug("initializing frequency table\n");
 
@@ -212,9 +210,6 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
 
 	return cpufreq_generic_init(policy, pas_freqs, get_gizmo_latency());
 
-out_unmap_sdcpwr:
-	iounmap(sdcpwr_mapbase);
-
 out_unmap_sdcasr:
 	iounmap(sdcasr_mapbase);
 out:
-- 
2.20.1

[PATCH AUTOSEL 4.9 19/22] scsi: ibmvfc: fix WARN_ON during event pool release

[Sasha Levin]

From: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>

[ Upstream commit 5578257ca0e21056821e6481bd534ba267b84e58 ]

While removing an ibmvfc client adapter a WARN_ON like the following
WARN_ON is seen in the kernel log:

WARNING: CPU: 6 PID: 5421 at ./include/linux/dma-mapping.h:541
ibmvfc_free_event_pool+0x12c/0x1f0 [ibmvfc]
CPU: 6 PID: 5421 Comm: rmmod Tainted: G            E     4.17.0-rc1-next-20180419-autotest #1
NIP:  d00000000290328c LR: d00000000290325c CTR: c00000000036ee20
REGS: c000000288d1b7e0 TRAP: 0700   Tainted: G            E      (4.17.0-rc1-next-20180419-autotest)
MSR:  800000010282b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE,TM[E]>  CR: 44008828  XER: 20000000
CFAR: c00000000036e408 SOFTE: 1
GPR00: d00000000290325c c000000288d1ba60 d000000002917900 c000000289d75448
GPR04: 0000000000000071 c0000000ff870000 0000000018040000 0000000000000001
GPR08: 0000000000000000 c00000000156e838 0000000000000001 d00000000290c640
GPR12: c00000000036ee20 c00000001ec4dc00 0000000000000000 0000000000000000
GPR16: 0000000000000000 0000000000000000 00000100276901e0 0000000010020598
GPR20: 0000000010020550 0000000010020538 0000000010020578 00000000100205b0
GPR24: 0000000000000000 0000000000000000 0000000010020590 5deadbeef0000100
GPR28: 5deadbeef0000200 d000000002910b00 0000000000000071 c0000002822f87d8
NIP [d00000000290328c] ibmvfc_free_event_pool+0x12c/0x1f0 [ibmvfc]
LR [d00000000290325c] ibmvfc_free_event_pool+0xfc/0x1f0 [ibmvfc]
Call Trace:
[c000000288d1ba60] [d00000000290325c] ibmvfc_free_event_pool+0xfc/0x1f0 [ibmvfc] (unreliable)
[c000000288d1baf0] [d000000002909390] ibmvfc_abort_task_set+0x7b0/0x8b0 [ibmvfc]
[c000000288d1bb70] [c0000000000d8c68] vio_bus_remove+0x68/0x100
[c000000288d1bbb0] [c0000000007da7c4] device_release_driver_internal+0x1f4/0x2d0
[c000000288d1bc00] [c0000000007da95c] driver_detach+0x7c/0x100
[c000000288d1bc40] [c0000000007d8af4] bus_remove_driver+0x84/0x140
[c000000288d1bcb0] [c0000000007db6ac] driver_unregister+0x4c/0xa0
[c000000288d1bd20] [c0000000000d6e7c] vio_unregister_driver+0x2c/0x50
[c000000288d1bd50] [d00000000290ba0c] cleanup_module+0x24/0x15e0 [ibmvfc]
[c000000288d1bd70] [c0000000001dadb0] sys_delete_module+0x220/0x2d0
[c000000288d1be30] [c00000000000b284] system_call+0x58/0x6c
Instruction dump:
e8410018 e87f0068 809f0078 e8bf0080 e8df0088 2fa30000 419e008c e9230200
2fa90000 419e0080 894d098a 794a07e0 <0b0a0000> e9290008 2fa90000 419e0028

This is tripped as a result of irqs being disabled during the call to
dma_free_coherent() by ibmvfc_free_event_pool(). At this point in the code path
we have quiesced the adapter and its overly paranoid anyways to be holding the
host lock.

Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/ibmvscsi/ibmvfc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index 7e487c78279cb..54dea767dfde9 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -4883,8 +4883,8 @@ static int ibmvfc_remove(struct vio_dev *vdev)
 
 	spin_lock_irqsave(vhost->host->host_lock, flags);
 	ibmvfc_purge_requests(vhost, DID_ERROR);
-	ibmvfc_free_event_pool(vhost);
 	spin_unlock_irqrestore(vhost->host->host_lock, flags);
+	ibmvfc_free_event_pool(vhost);
 
 	ibmvfc_free_mem(vhost);
 	spin_lock(&ibmvfc_driver_lock);
-- 
2.20.1