From: Ming Lei ming.lei@redhat.com

[ Upstream commit 66a834d092930cf41d809c0e989b13cd6f9ca006 ]

After device is initialized via device_initialize(), or its name is set via dev_set_name(), the device has to be freed via put_device(). Otherwise device name will be leaked because it is allocated dynamically in dev_set_name().

Fix the leak by replacing kfree() with put_device(). Since scsi_host_dev_release() properly handles IDA and kthread removal, remove special-casing these from the error handling as well.

Link: https://lore.kernel.org/r/20210602133029.2864069-2-ming.lei@redhat.com Cc: Bart Van Assche bvanassche@acm.org Cc: John Garry john.garry@huawei.com Cc: Hannes Reinecke hare@suse.de Tested-by: John Garry john.garry@huawei.com Reviewed-by: Bart Van Assche bvanassche@acm.org Reviewed-by: John Garry john.garry@huawei.com Reviewed-by: Hannes Reinecke hare@suse.de Signed-off-by: Ming Lei ming.lei@redhat.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/hosts.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index ef22b275d050..7f99f02aef1c 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -404,8 +404,10 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) mutex_init(&shost->scan_mutex);

index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL); - if (index < 0) - goto fail_kfree; + if (index < 0) { + kfree(shost); + return NULL; + } shost->host_no = index;

shost->dma_channel = 0xff; @@ -493,7 +495,7 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) shost_printk(KERN_WARNING, shost, "error handler thread failed to spawn, error = %ld\n", PTR_ERR(shost->ehandler)); - goto fail_index_remove; + goto fail; }

shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d", @@ -502,17 +504,18 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) if (!shost->tmf_work_q) { shost_printk(KERN_WARNING, shost, "failed to create tmf workq\n"); - goto fail_kthread; + goto fail; } scsi_proc_hostdir_add(shost->hostt); return shost; + fail: + /* + * Host state is still SHOST_CREATED and that is enough to release + * ->shost_gendev. scsi_host_dev_release() will free + * dev_name(&shost->shost_dev). + */ + put_device(&shost->shost_gendev);

- fail_kthread: - kthread_stop(shost->ehandler); - fail_index_remove: - ida_simple_remove(&host_index_ida, shost->host_no); - fail_kfree: - kfree(shost); return NULL; } EXPORT_SYMBOL(scsi_host_alloc);

From: Ming Lei ming.lei@redhat.com

[ Upstream commit 1e0d4e6225996f05271de1ebcb1a7c9381af0b27 ]

get_device(shost->shost_gendev.parent) is called after host state has switched to SHOST_RUNNING. scsi_host_dev_release() shouldn't release the parent device if host state is still SHOST_CREATED.

Link: https://lore.kernel.org/r/20210602133029.2864069-5-ming.lei@redhat.com Cc: Bart Van Assche bvanassche@acm.org Cc: John Garry john.garry@huawei.com Cc: Hannes Reinecke hare@suse.de Tested-by: John Garry john.garry@huawei.com Reviewed-by: John Garry john.garry@huawei.com Signed-off-by: Ming Lei ming.lei@redhat.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/hosts.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index ff92df3fe401..5788a2ce3571 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -355,7 +355,7 @@ static void scsi_host_dev_release(struct device *dev)

ida_simple_remove(&host_index_ida, shost->host_no);

- if (parent) + if (shost->shost_state != SHOST_CREATED) put_device(parent); kfree(shost); }

From: Paolo Bonzini pbonzini@redhat.com

[ Upstream commit da27a83fd6cc7780fea190e1f5c19e87019da65c ]

KVM's mechanism for accessing guest memory translates a guest physical address (gpa) to a host virtual address using the right-shifted gpa (also known as gfn) and a struct kvm_memory_slot. The translation is performed in __gfn_to_hva_memslot using the following formula:

hva = slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE

It is expected that gfn falls within the boundaries of the guest's physical memory. However, a guest can access invalid physical addresses in such a way that the gfn is invalid.

__gfn_to_hva_memslot is called from kvm_vcpu_gfn_to_hva_prot, which first retrieves a memslot through __gfn_to_memslot. While __gfn_to_memslot does check that the gfn falls within the boundaries of the guest's physical memory or not, a CPU can speculate the result of the check and continue execution speculatively using an illegal gfn. The speculation can result in calculating an out-of-bounds hva. If the resulting host virtual address is used to load another guest physical address, this is effectively a Spectre gadget consisting of two consecutive reads, the second of which is data dependent on the first.

Right now it's not clear if there are any cases in which this is exploitable. One interesting case was reported by the original author of this patch, and involves visiting guest page tables on x86. Right now these are not vulnerable because the hva read goes through get_user(), which contains an LFENCE speculation barrier. However, there are patches in progress for x86 uaccess.h to mask kernel addresses instead of using LFENCE; once these land, a guest could use speculation to read from the VMM's ring 3 address space. Other architectures such as ARM already use the address masking method, and would be susceptible to this same kind of data-dependent access gadgets. Therefore, this patch proactively protects from these attacks by masking out-of-bounds gfns in __gfn_to_hva_memslot, which blocks speculation of invalid hvas.

Sean Christopherson noted that this patch does not cover kvm_read_guest_offset_cached. This however is limited to a few bytes past the end of the cache, and therefore it is unlikely to be useful in the context of building a chain of data dependent accesses.

Reported-by: Artemiy Margaritov artemiy.margaritov@gmail.com Co-developed-by: Artemiy Margaritov artemiy.margaritov@gmail.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/kvm_host.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 2e06ca46f07c..a28a5c80f117 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -963,7 +963,15 @@ __gfn_to_memslot(struct kvm_memslots *slots, gfn_t gfn) static inline unsigned long __gfn_to_hva_memslot(struct kvm_memory_slot *slot, gfn_t gfn) { - return slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE; + /* + * The index was checked originally in search_memslots. To avoid + * that a malicious guest builds a Spectre gadget out of e.g. page + * table walks, do not let the processor speculate loads outside + * the guest's registered memslots. + */ + unsigned long offset = array_index_nospec(gfn - slot->base_gfn, + slot->npages); + return slot->userspace_addr + offset * PAGE_SIZE; }

static inline int memslot_id(struct kvm *kvm, gfn_t gfn)

From: Riwen Lu luriwen@kylinos.cn

[ Upstream commit 78d13552346289bad4a9bf8eabb5eec5e5a321a5 ]

The scpi hwmon shows the sub-zero temperature in an unsigned integer, which would confuse the users when the machine works in low temperature environment. This shows the sub-zero temperature in an signed value and users can get it properly from sensors.

Signed-off-by: Riwen Lu luriwen@kylinos.cn Tested-by: Xin Chen chenxin@kylinos.cn Link: https://lore.kernel.org/r/20210604030959.736379-1-luriwen@kylinos.cn Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hwmon/scpi-hwmon.c | 9 +++++++++ 1 file changed, 9 insertions(+)

diff --git a/drivers/hwmon/scpi-hwmon.c b/drivers/hwmon/scpi-hwmon.c index 7e49da50bc69..562f3e287297 100644 --- a/drivers/hwmon/scpi-hwmon.c +++ b/drivers/hwmon/scpi-hwmon.c @@ -107,6 +107,15 @@ scpi_show_sensor(struct device *dev, struct device_attribute *attr, char *buf)

scpi_scale_reading(&value, sensor);

+ /* + * Temperature sensor values are treated as signed values based on + * observation even though that is not explicitly specified, and + * because an unsigned u64 temperature does not really make practical + * sense especially when the temperature is below zero degrees Celsius. + */ + if (sensor->info.class == TEMPERATURE) + return sprintf(buf, "%lld\n", (s64)value); + return sprintf(buf, "%llu\n", value); }