Linux: >> Linux Kernel >> 2.0.14 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
watchdog: Fix possible use-after-free in wdt_startup()
This module's remove path calls del_timer(). However, that function
does not wait until the timer handler finishes. This means that the
timer handler may still be running after the driver's remove function
has finished, which would result in a use-after-free.
Fix by calling del_timer_sync(), which makes sure the timer handler
has finished, and unable to re-schedule itself.
CVSS Score
8.8
EPSS Score
0.001
Published
2024-05-21
In the Linux kernel, the following vulnerability has been resolved:
iommu/arm-smmu: Fix arm_smmu_device refcount leak in address translation
The reference counting issue happens in several exception handling paths
of arm_smmu_iova_to_phys_hard(). When those error scenarios occur, the
function forgets to decrease the refcount of "smmu" increased by
arm_smmu_rpm_get(), causing a refcount leak.
Fix this issue by jumping to "out" label when those error scenarios
occur.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-05-21
In the Linux kernel, the following vulnerability has been resolved:
iommu/arm-smmu: Fix arm_smmu_device refcount leak when arm_smmu_rpm_get fails
arm_smmu_rpm_get() invokes pm_runtime_get_sync(), which increases the
refcount of the "smmu" even though the return value is less than 0.
The reference counting issue happens in some error handling paths of
arm_smmu_rpm_get() in its caller functions. When arm_smmu_rpm_get()
fails, the caller functions forget to decrease the refcount of "smmu"
increased by arm_smmu_rpm_get(), causing a refcount leak.
Fix this issue by calling pm_runtime_resume_and_get() instead of
pm_runtime_get_sync() in arm_smmu_rpm_get(), which can keep the refcount
balanced in case of failure.
CVSS Score
7.1
EPSS Score
0.0
Published
2024-05-21
In the Linux kernel, the following vulnerability has been resolved:
scsi: iscsi: Fix conn use after free during resets
If we haven't done a unbind target call we can race where
iscsi_conn_teardown wakes up the EH thread and then frees the conn while
those threads are still accessing the conn ehwait.
We can only do one TMF per session so this just moves the TMF fields from
the conn to the session. We can then rely on the
iscsi_session_teardown->iscsi_remove_session->__iscsi_unbind_session call
to remove the target and it's devices, and know after that point there is
no device or scsi-ml callout trying to access the session.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-05-21
In the Linux kernel, the following vulnerability has been resolved:
scsi: megaraid_sas: Fix resource leak in case of probe failure
The driver doesn't clean up all the allocated resources properly when
scsi_add_host(), megasas_start_aen() function fails during the PCI device
probe.
Clean up all those resources.
CVSS Score
6.2
EPSS Score
0.0
Published
2024-05-21
In the Linux kernel, the following vulnerability has been resolved:
tty: serial: 8250: serial_cs: Fix a memory leak in error handling path
In the probe function, if the final 'serial_config()' fails, 'info' is
leaking.
Add a resource handling path to free this memory.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-05-21
In the Linux kernel, the following vulnerability has been resolved:
cifs: prevent NULL deref in cifs_compose_mount_options()
The optional @ref parameter might contain an NULL node_name, so
prevent dereferencing it in cifs_compose_mount_options().
Addresses-Coverity: 1476408 ("Explicit null dereferenced")
CVSS Score
5.5
EPSS Score
0.001
Published
2024-05-21
In the Linux kernel, the following vulnerability has been resolved:
scsi: libfc: Fix array index out of bound exception
Fix array index out of bound exception in fc_rport_prli_resp().
CVSS Score
6.5
EPSS Score
0.0
Published
2024-05-21
In the Linux kernel, the following vulnerability has been resolved:
kvm: avoid speculation-based attacks from out-of-range memslot accesses
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.
CVSS Score
7.1
EPSS Score
0.0
Published
2024-05-21
In the Linux kernel, the following vulnerability has been resolved:
drm: Fix use-after-free read in drm_getunique()
There is a time-of-check-to-time-of-use error in drm_getunique() due
to retrieving file_priv->master prior to locking the device's master
mutex.
An example can be seen in the crash report of the use-after-free error
found by Syzbot:
https://syzkaller.appspot.com/bug?id=148d2f1dfac64af52ffd27b661981a540724f803
In the report, the master pointer was used after being freed. This is
because another process had acquired the device's master mutex in
drm_setmaster_ioctl(), then overwrote fpriv->master in
drm_new_set_master(). The old value of fpriv->master was subsequently
freed before the mutex was unlocked.
To fix this, we lock the device's master mutex before retrieving the
pointer from from fpriv->master. This patch passes the Syzbot
reproducer test.
CVSS Score
7.0
EPSS Score
0.0
Published
2024-05-21