Security Vulnerabilities - CVEs Published In September 2024
In the Linux kernel, the following vulnerability has been resolved:
sched: sch_cake: fix bulk flow accounting logic for host fairness
In sch_cake, we keep track of the count of active bulk flows per host,
when running in dst/src host fairness mode, which is used as the
round-robin weight when iterating through flows. The count of active
bulk flows is updated whenever a flow changes state.
This has a peculiar interaction with the hash collision handling: when a
hash collision occurs (after the set-associative hashing), the state of
the hash bucket is simply updated to match the new packet that collided,
and if host fairness is enabled, that also means assigning new per-host
state to the flow. For this reason, the bulk flow counters of the
host(s) assigned to the flow are decremented, before new state is
assigned (and the counters, which may not belong to the same host
anymore, are incremented again).
Back when this code was introduced, the host fairness mode was always
enabled, so the decrement was unconditional. When the configuration
flags were introduced the *increment* was made conditional, but
the *decrement* was not. Which of course can lead to a spurious
decrement (and associated wrap-around to U16_MAX).
AFAICT, when host fairness is disabled, the decrement and wrap-around
happens as soon as a hash collision occurs (which is not that common in
itself, due to the set-associative hashing). However, in most cases this
is harmless, as the value is only used when host fairness mode is
enabled. So in order to trigger an array overflow, sch_cake has to first
be configured with host fairness disabled, and while running in this
mode, a hash collision has to occur to cause the overflow. Then, the
qdisc has to be reconfigured to enable host fairness, which leads to the
array out-of-bounds because the wrapped-around value is retained and
used as an array index. It seems that syzbot managed to trigger this,
which is quite impressive in its own right.
This patch fixes the issue by introducing the same conditional check on
decrement as is used on increment.
The original bug predates the upstreaming of cake, but the commit listed
in the Fixes tag touched that code, meaning that this patch won't apply
before that.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-09-27
In the Linux kernel, the following vulnerability has been resolved:
rtmutex: Drop rt_mutex::wait_lock before scheduling
rt_mutex_handle_deadlock() is called with rt_mutex::wait_lock held. In the
good case it returns with the lock held and in the deadlock case it emits a
warning and goes into an endless scheduling loop with the lock held, which
triggers the 'scheduling in atomic' warning.
Unlock rt_mutex::wait_lock in the dead lock case before issuing the warning
and dropping into the schedule for ever loop.
[ tglx: Moved unlock before the WARN(), removed the pointless comment,
massaged changelog, added Fixes tag ]
CVSS Score
5.5
EPSS Score
0.0
Published
2024-09-27
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Acquire kvm->srcu when handling KVM_SET_VCPU_EVENTS
Grab kvm->srcu when processing KVM_SET_VCPU_EVENTS, as KVM will forcibly
leave nested VMX/SVM if SMM mode is being toggled, and leaving nested VMX
reads guest memory.
Note, kvm_vcpu_ioctl_x86_set_vcpu_events() can also be called from KVM_RUN
via sync_regs(), which already holds SRCU. I.e. trying to precisely use
kvm_vcpu_srcu_read_lock() around the problematic SMM code would cause
problems. Acquiring SRCU isn't all that expensive, so for simplicity,
grab it unconditionally for KVM_SET_VCPU_EVENTS.
=============================
WARNING: suspicious RCU usage
6.10.0-rc7-332d2c1d713e-next-vm #552 Not tainted
-----------------------------
include/linux/kvm_host.h:1027 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by repro/1071:
#0: ffff88811e424430 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0x7d/0x970 [kvm]
stack backtrace:
CPU: 15 PID: 1071 Comm: repro Not tainted 6.10.0-rc7-332d2c1d713e-next-vm #552
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Call Trace:
<TASK>
dump_stack_lvl+0x7f/0x90
lockdep_rcu_suspicious+0x13f/0x1a0
kvm_vcpu_gfn_to_memslot+0x168/0x190 [kvm]
kvm_vcpu_read_guest+0x3e/0x90 [kvm]
nested_vmx_load_msr+0x6b/0x1d0 [kvm_intel]
load_vmcs12_host_state+0x432/0xb40 [kvm_intel]
vmx_leave_nested+0x30/0x40 [kvm_intel]
kvm_vcpu_ioctl_x86_set_vcpu_events+0x15d/0x2b0 [kvm]
kvm_arch_vcpu_ioctl+0x1107/0x1750 [kvm]
? mark_held_locks+0x49/0x70
? kvm_vcpu_ioctl+0x7d/0x970 [kvm]
? kvm_vcpu_ioctl+0x497/0x970 [kvm]
kvm_vcpu_ioctl+0x497/0x970 [kvm]
? lock_acquire+0xba/0x2d0
? find_held_lock+0x2b/0x80
? do_user_addr_fault+0x40c/0x6f0
? lock_release+0xb7/0x270
__x64_sys_ioctl+0x82/0xb0
do_syscall_64+0x6c/0x170
entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7ff11eb1b539
</TASK>
CVSS Score
7.8
EPSS Score
0.0
Published
2024-09-27
In the Linux kernel, the following vulnerability has been resolved:
net: microchip: vcap: Fix use-after-free error in kunit test
This is a clear use-after-free error. We remove it, and rely on checking
the return code of vcap_del_rule.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-09-27
In the Linux kernel, the following vulnerability has been resolved:
MIPS: cevt-r4k: Don't call get_c0_compare_int if timer irq is installed
This avoids warning:
[ 0.118053] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:283
Caused by get_c0_compare_int on secondary CPU.
We also skipped saving IRQ number to struct clock_event_device *cd as
it's never used by clockevent core, as per comments it's only meant
for "non CPU local devices".
CVSS Score
5.5
EPSS Score
0.0
Published
2024-09-27
In the Linux kernel, the following vulnerability has been resolved:
net: hns3: void array out of bound when loop tnl_num
When query reg inf of SSU, it loops tnl_num times. However, tnl_num comes
from hardware and the length of array is a fixed value. To void array out
of bound, make sure the loop time is not greater than the length of array
CVSS Score
7.8
EPSS Score
0.0
Published
2024-09-27
In the Linux kernel, the following vulnerability has been resolved:
ethtool: fail closed if we can't get max channel used in indirection tables
Commit 0d1b7d6c9274 ("bnxt: fix crashes when reducing ring count with
active RSS contexts") proves that allowing indirection table to contain
channels with out of bounds IDs may lead to crashes. Currently the
max channel check in the core gets skipped if driver can't fetch
the indirection table or when we can't allocate memory.
Both of those conditions should be extremely rare but if they do
happen we should try to be safe and fail the channel change.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-09-27
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: Fix smatch static checker warning
adev->gfx.imu.funcs could be NULL
CVSS Score
5.5
EPSS Score
0.0
Published
2024-09-27
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: aspeed_udc: validate endpoint index for ast udc
We should verify the bound of the array to assure that host
may not manipulate the index to point past endpoint array.
Found by static analysis.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-09-27
In the Linux kernel, the following vulnerability has been resolved:
drm/panthor: Restrict high priorities on group_create
We were allowing any users to create a high priority group without any
permission checks. As a result, this was allowing possible denial of
service.
We now only allow the DRM master or users with the CAP_SYS_NICE
capability to set higher priorities than PANTHOR_GROUP_PRIORITY_MEDIUM.
As the sole user of that uAPI lives in Mesa and hardcode a value of
MEDIUM [1], this should be safe to do.
Additionally, as those checks are performed at the ioctl level,
panthor_group_create now only check for priority level validity.
[1]https://gitlab.freedesktop.org/mesa/mesa/-/blob/f390835074bdf162a63deb0311d1a6de527f9f89/src/gallium/drivers/panfrost/pan_csf.c#L1038
CVSS Score
5.5
EPSS Score
0.0
Published
2024-09-27