In the Linux kernel, the following vulnerability has been resolved:
hwmon: (coretemp) Check for null before removing sysfs attrs
If coretemp_add_core() gets an error then pdata->core_data[indx]
is already NULL and has been kfreed. Don't pass that to
sysfs_remove_group() as that will crash in sysfs_remove_group().
[Shortened for readability]
[91854.020159] sysfs: cannot create duplicate filename '/devices/platform/coretemp.0/hwmon/hwmon2/temp20_label'
<cpu offline>
[91855.126115] BUG: kernel NULL pointer dereference, address: 0000000000000188
[91855.165103] #PF: supervisor read access in kernel mode
[91855.194506] #PF: error_code(0x0000) - not-present page
[91855.224445] PGD 0 P4D 0
[91855.238508] Oops: 0000 [#1] PREEMPT SMP PTI
...
[91855.342716] RIP: 0010:sysfs_remove_group+0xc/0x80
...
[91855.796571] Call Trace:
[91855.810524] coretemp_cpu_offline+0x12b/0x1dd [coretemp]
[91855.841738] ? coretemp_cpu_online+0x180/0x180 [coretemp]
[91855.871107] cpuhp_invoke_callback+0x105/0x4b0
[91855.893432] cpuhp_thread_fun+0x8e/0x150
...
Fix this by checking for NULL first.
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (coretemp) fix pci device refcount leak in nv1a_ram_new()
As comment of pci_get_domain_bus_and_slot() says, it returns
a pci device with refcount increment, when finish using it,
the caller must decrement the reference count by calling
pci_dev_put(). So call it after using to avoid refcount leak.
In the Linux kernel, the following vulnerability has been resolved:
net: hsr: Fix potential use-after-free
The skb is delivered to netif_rx() which may free it, after calling this,
dereferencing skb may trigger use-after-free.
In the Linux kernel, the following vulnerability has been resolved:
ASoC: soc-pcm: Add NULL check in BE reparenting
Add NULL check in dpcm_be_reparent API, to handle
kernel NULL pointer dereference error.
The issue occurred in fuzzing test.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: seq: Fix function prototype mismatch in snd_seq_expand_var_event
With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG),
indirect call targets are validated against the expected function
pointer prototype to make sure the call target is valid to help mitigate
ROP attacks. If they are not identical, there is a failure at run time,
which manifests as either a kernel panic or thread getting killed.
seq_copy_in_user() and seq_copy_in_kernel() did not have prototypes
matching snd_seq_dump_func_t. Adjust this and remove the casts. There
are not resulting binary output differences.
This was found as a result of Clang's new -Wcast-function-type-strict
flag, which is more sensitive than the simpler -Wcast-function-type,
which only checks for type width mismatches.
In the Linux kernel, the following vulnerability has been resolved:
memcg: fix possible use-after-free in memcg_write_event_control()
memcg_write_event_control() accesses the dentry->d_name of the specified
control fd to route the write call. As a cgroup interface file can't be
renamed, it's safe to access d_name as long as the specified file is a
regular cgroup file. Also, as these cgroup interface files can't be
removed before the directory, it's safe to access the parent too.
Prior to 347c4a874710 ("memcg: remove cgroup_event->cft"), there was a
call to __file_cft() which verified that the specified file is a regular
cgroupfs file before further accesses. The cftype pointer returned from
__file_cft() was no longer necessary and the commit inadvertently dropped
the file type check with it allowing any file to slip through. With the
invarients broken, the d_name and parent accesses can now race against
renames and removals of arbitrary files and cause use-after-free's.
Fix the bug by resurrecting the file type check in __file_cft(). Now that
cgroupfs is implemented through kernfs, checking the file operations needs
to go through a layer of indirection. Instead, let's check the superblock
and dentry type.
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: fix use-after-free during gpu recovery
[Why]
[ 754.862560] refcount_t: underflow; use-after-free.
[ 754.862898] Call Trace:
[ 754.862903] <TASK>
[ 754.862913] amdgpu_job_free_cb+0xc2/0xe1 [amdgpu]
[ 754.863543] drm_sched_main.cold+0x34/0x39 [amd_sched]
[How]
The fw_fence may be not init, check whether dma_fence_init
is performed before job free
In the Linux kernel, the following vulnerability has been resolved:
xen-netfront: Fix NULL sring after live migration
A NAPI is setup for each network sring to poll data to kernel
The sring with source host is destroyed before live migration and
new sring with target host is setup after live migration.
The NAPI for the old sring is not deleted until setup new sring
with target host after migration. With busy_poll/busy_read enabled,
the NAPI can be polled before got deleted when resume VM.
BUG: unable to handle kernel NULL pointer dereference at
0000000000000008
IP: xennet_poll+0xae/0xd20
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
Call Trace:
finish_task_switch+0x71/0x230
timerqueue_del+0x1d/0x40
hrtimer_try_to_cancel+0xb5/0x110
xennet_alloc_rx_buffers+0x2a0/0x2a0
napi_busy_loop+0xdb/0x270
sock_poll+0x87/0x90
do_sys_poll+0x26f/0x580
tracing_map_insert+0x1d4/0x2f0
event_hist_trigger+0x14a/0x260
finish_task_switch+0x71/0x230
__schedule+0x256/0x890
recalc_sigpending+0x1b/0x50
xen_sched_clock+0x15/0x20
__rb_reserve_next+0x12d/0x140
ring_buffer_lock_reserve+0x123/0x3d0
event_triggers_call+0x87/0xb0
trace_event_buffer_commit+0x1c4/0x210
xen_clocksource_get_cycles+0x15/0x20
ktime_get_ts64+0x51/0xf0
SyS_ppoll+0x160/0x1a0
SyS_ppoll+0x160/0x1a0
do_syscall_64+0x73/0x130
entry_SYSCALL_64_after_hwframe+0x41/0xa6
...
RIP: xennet_poll+0xae/0xd20 RSP: ffffb4f041933900
CR2: 0000000000000008
---[ end trace f8601785b354351c ]---
xen frontend should remove the NAPIs for the old srings before live
migration as the bond srings are destroyed
There is a tiny window between the srings are set to NULL and
the NAPIs are disabled, It is safe as the NAPI threads are still
frozen at that time
In the Linux kernel, the following vulnerability has been resolved:
gpio: amd8111: Fix PCI device reference count leak
for_each_pci_dev() is implemented by pci_get_device(). The comment of
pci_get_device() says that it will increase the reference count for the
returned pci_dev and also decrease the reference count for the input
pci_dev @from if it is not NULL.
If we break for_each_pci_dev() loop with pdev not NULL, we need to call
pci_dev_put() to decrease the reference count. Add the missing
pci_dev_put() after the 'out' label. Since pci_dev_put() can handle NULL
input parameter, there is no problem for the 'Device not found' branch.
For the normal path, add pci_dev_put() in amd_gpio_exit().