In the Linux kernel, the following vulnerability has been resolved:
reboot: fix cad_pid use-after-free race
cad_pid is a single kernel-wide struct pid pointer. proc_do_cad_pid()
reads it and passes it to pid_vnr() without protecting the lifetime of
the referenced struct pid. A concurrent writer can replace cad_pid and
drop the final reference to the old struct pid after the reader has
loaded the pointer but before pid_vnr() has finished dereferencing it,
causing a use-after-free.
kill_cad_pid() has the same lifetime race when it passes cad_pid to
kill_pid().
At the time this issue was reported, an unprivileged user could reach the
sysctl
tracing: Set the trace clock before registering the histogram trigger
In the Linux kernel, the following vulnerability has been resolved:
tracing: Set the trace clock before registering the histogram trigger
hist_register_trigger() puts the trigger on the global named_triggers
list in cmd_ops->init(), and only then sets the trace clock:
if (data->cmd_ops->init) {
ret = data->cmd_ops->init(data);
if (ret < 0)
goto out;
}
if (hist_data->enable_timestamps) {
ret = tracing_set_clock(file->tr, hist_data->attrs->clock);
if (ret) {
hist_err(tr, HIST_ERR_SET_CLOCK_FAIL, errpos(clock));
goto out;
}
The clock string is not checked anywhere before that call, so a named
trigger using common_times
tracing: Take trace_array reference when opening a tracer options file
In the Linux kernel, the following vulnerability has been resolved:
tracing: Take trace_array reference when opening a tracer options file
When a tracer option file is opened, it is passed a descriptor that points
to an element on the trace_array's topts array. This element has
information to find the trace array and other information. It uses this
element to take a reference of the trace_array so that the trace_array
does not get removed while this file is opened.
Unfortunately, there's a race condition where the element itself could be
freed by the removal of the instance the trace_array represents causing a
use-after-free as this elemen
ALSA: us122l: Prevent write upgrades for read mappings
In the Linux kernel, the following vulnerability has been resolved:
ALSA: us122l: Prevent write upgrades for read mappings
The hwdep mmap callback rejects read-buffer mappings that are initially
writable, but leaves VM_MAYWRITE set on mappings created with PROT_READ.
A process that can open the hwdep node O_RDWR can later use mprotect() to
make the mapping writable.
The read allocation begins with struct usb_stream. Its read_size member is
used by the fault handler to decide which pages belong to the read buffer.
The read VMA intentionally remains expandable because pcm_usb_stream uses
mremap() after reading that size. Changing read_size f
ALSA: usbusx2y: fix in04_last array size mismatch with in04_buf
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usbusx2y: fix in04_last array size mismatch with in04_buf
The in04_last array in struct usx2ydev is declared as char[24], but
in04_buf is allocated as sizeof(struct us428_ctls) which is 21 bytes.
In i_usx2y_in04_int(), when ctl_snapshot_last == -2 (initialization
path):
memcpy(usx2y->in04_last, usx2y->in04_buf, sizeof(usx2y->in04_last));
This copies 24 bytes from a 21-byte slab allocation, reading 3 bytes
past the end of the source object.
Introduce a USX2Y_IN04_SIZE constant defined as sizeof(struct
us428_ctls) and use it consistently for the in04_last array,
ALSA: usbusx2y: validate URB actual_length in interrupt callback
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usbusx2y: validate URB actual_length in interrupt callback
i_usx2y_in04_int() processes the interrupt URB data without checking
urb->actual_length. A short transfer from a malfunctioning device
would cause the handler to process uninitialized heap data from the
kmalloc-allocated in04_buf, which is then copied to the mmap-accessible
ctl_snapshot[] array.
Fix by using kzalloc() for in04_buf to zero-initialize the buffer,
and adding an actual_length check to skip processing on short
transfers while still resubmitting the URB.
ufs: create the root dentry after loading cylinder metadata
In the Linux kernel, the following vulnerability has been resolved:
ufs: create the root dentry after loading cylinder metadata
ufs_fill_super() installed sb->s_root before it loaded the cylinder
group structures for a writable mount:
sb->s_root = d_make_root(inode);
...
if (!sb_rdonly(sb))
if (!ufs_read_cylinder_structures(sb))
goto failed;
When ufs_read_cylinder_structures() failed, the error path freed the
in-core superblock information and set sb->s_fs_info to NULL while
sb->s_root stayed installed. get_tree_bdev() then reached
deactivate_locked_super(), and because s_root was present,
generic_shutdown_super() called sync_file
ufs: validate cylinder group metadata before caching it
In the Linux kernel, the following vulnerability has been resolved:
ufs: validate cylinder group metadata before caching it
ufs_read_cylinder() copies the cylinder group index and the rotor
positions straight from the on-disk group and caches them without any
check:
ucpi->c_cgx = fs32_to_cpu(sb, ucg->cg_cgx);
ucpi->c_rotor = fs32_to_cpu(sb, ucg->cg_rotor);
ucpi->c_frotor = fs32_to_cpu(sb, ucg->cg_frotor);
ucpi->c_irotor = fs32_to_cpu(sb, ucg->cg_irotor);
They are then used as indices during allocation and free:
- c_cgx indexes the cylinder summary array as
UFS_SB(sb)->fs_cs(ucpi->c_cgx), so a value past s_ncg writes a 32
In the Linux kernel, the following vulnerability has been resolved:
tick/broadcast: Plug clockevents replacement race
朱恺乾 reported and decoded the following race condition when a broadcast
device is replaced:
CPUA CPUB
__tick_broadcast_oneshot_control()
bc = tick_broadcast_device.evtdev;
tick_install_broadcast_device(dev)
clockevents_exchange_device(cur, dev)
shutdown(cur);
detach(cur);
cur->handler = noop;
tick_broadcast_device.evtdev = dev;
tick_broadcast_set_event(bc, next_event); <- FAIL: arms a detached device.
If the original broadcast device has a restricted interrupt affi
tracing: Free histogram the var ref when its initialization fails
In the Linux kernel, the following vulnerability has been resolved:
tracing: Free histogram the var ref when its initialization fails
create_var_ref() allocates a VAR_REF hist_field and then calls
init_var_ref() to fill it in. When that fails the field is leaked.
commit 656fe2ba85e8 ("tracing: Use hist trigger's var_ref array to destroy
var_refs") made destroy_hist_field() return early for
HIST_FIELD_FL_VAR_REF, since var refs are freed by walking the trigger's
var_refs[] array instead. create_var_ref() adds the field to that array
only after init_var_ref() has succeeded, so on this path the field is in
neither place and nothing frees it.
tracing: Free histogram var refs regardless of how often they are referenced
In the Linux kernel, the following vulnerability has been resolved:
tracing: Free histogram var refs regardless of how often they are referenced
Using the same variable three or more times in one hist trigger leaks the
variable reference and its strings when the trigger is removed.
commit 656fe2ba85e8 ("tracing: Use hist trigger's var_ref array to destroy
var_refs") made a trigger's var_refs[] array the only owner of a var ref:
destroy_hist_field() returns early for HIST_FIELD_FL_VAR_REF, so the field
expressions never destroy one. One entry, freed once, no count needed.
commit 8bcebc77e85f ("tracing: Fix histogram code when expression ha
tracing: Undo the registration when enabling the histogram trigger fails
In the Linux kernel, the following vulnerability has been resolved:
tracing: Undo the registration when enabling the histogram trigger fails
Commit 6f86bdeab633 ("tracing: Fix bad hist from corrupting named_triggers
list") described how a trigger that is registered but not on file->triggers
ends up freed while still on the global named_triggers list, and moved the
registration down so that hist_trigger_enable() follows it immediately. One
path still gets there. hist_trigger_enable() adds the trigger and takes it
straight back out when the event cannot be enabled:
list_add_tail_rcu(&data->list, &file->triggers);
update_cond_flag(file);
ASoC: sprd: validate compress buffer sizes against fixed allocations
In the Linux kernel, the following vulnerability has been resolved:
ASoC: sprd: validate compress buffer sizes against fixed allocations
sprd_platform_compr_open() allocates the stage 0 IRAM buffer (32K data
area) and the stage 1 DDR buffer (2M data area) with fixed sizes, but
sprd_platform_compr_copy() derives all copy lengths from the user
controlled runtime->fragment_size and the write() count, never
comparing them against the physical buffer sizes. The compress core
only checks fragment_size * fragments for an u32 overflow in
snd_compress_check_input(), so a local user can configure a logical
buffer of up to ~4GB via SNDRV_COMPRESS_SET_
ASoC: sti: initialize IRQ lock before requesting IRQ
In the Linux kernel, the following vulnerability has been resolved:
ASoC: sti: initialize IRQ lock before requesting IRQ
uni_reader_init() registers the shared IRQ before initializing
reader->irq_lock. A pending interrupt can invoke the handler while the
lock is still uninitialized.
Initialize the lock before registering the IRQ so the interrupt path
always sees valid lock state.
Bluetooth: btqcomsmd: destroy RPMsg endpoints before freeing hci_dev
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btqcomsmd: destroy RPMsg endpoints before freeing hci_dev
The command and ACL RPMsg endpoints store struct btqcomsmd as their
callback private data. The receive callbacks dereference btq->hdev
without taking an hci_dev reference.
The current teardown order frees the hci_dev before destroying the RPMsg
endpoints in both the hci_register_dev() error path and the driver remove
path. If WCNSS delivers data in that window, the endpoint callback can
run with an already freed hci_dev and pass it to the Bluetooth core.
For qcom_smd endpoints, rpmsg_destroy_ept() closes
cpufreq: zero-initialize policy cpumask before sysfs publication
In the Linux kernel, the following vulnerability has been resolved:
cpufreq: zero-initialize policy cpumask before sysfs publication
cpufreq_policy_alloc() allocates policy->cpus with alloc_cpumask_var(),
i.e. without __GFP_ZERO, unlike the sibling related_cpus and real_cpus
masks. With CONFIG_CPUMASK_OFFSTACK=y the mask is a separate
kmalloc_node() allocation, so its bitmap holds whatever the slab allocator
left behind:
cpufreq_online()
cpufreq_policy_alloc()
alloc_cpumask_var(&policy->cpus) /* bitmap is uninitialized */
kobject_init_and_add() /* policy%u/ appears in sysfs */
cpufreq_policy_online()
cpufreq: initialize policy rwsem before sysfs publication
In the Linux kernel, the following vulnerability has been resolved:
cpufreq: initialize policy rwsem before sysfs publication
cpufreq_policy_alloc() initializes policy->rwsem after
kobject_init_and_add() has created the policy sysfs directory and its
default attributes. A sysfs access can therefore reach a policy callback
before the semaphore has been initialized.
Initialize policy->rwsem before publishing the policy kobject so sysfs
callbacks always see an initialized semaphore.
net/sched: act_api: release all action references on NEWACTION failure
In the Linux kernel, the following vulnerability has been resolved:
net/sched: act_api: release all action references on NEWACTION failure
When a batched RTM_NEWACTION request replaces an existing action,
tcf_idr_check_alloc() takes a temporary reference on it. If a later
action fails to initialize, tcf_action_destroy() uses strict release
semantics to clean up the actions initialized so far. For an action
bound to a filter, the strict check returns -EPERM without dropping
the temporary reference.
This error also makes tcf_action_destroy() return before releasing
subsequent entries. Any new action initialized between the bound
action and t
net: mpls: clear inner_protocol when the last label is popped
In the Linux kernel, the following vulnerability has been resolved:
net: mpls: clear inner_protocol when the last label is popped
skb_mpls_push() records the pre-encapsulation network header once, gated
on !skb->inner_protocol. skb_mpls_pop() never clears that record, so it
outlives the encapsulation it describes.
Open vSwitch can then re-push MPLS onto a packet whose
inner_network_header still points at the older, deeper offset: push a
label, pop every label, recirculate (ovs_flow_key_update() re-derives
key->eth.type and resets network_header, but leaves inner_*), then push
again. ovs_fragment() trusts the record:
skb->network_header =
netfilter: nf_log: unregister loggers before per-net teardown
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_log: unregister loggers before per-net teardown
nf_log_syslog and nfnetlink_log unregister their per-network namespace
operations before unregistering their global logger backends. This
leaves a window where a sysctl or netlink writer can rebind the still-
registered logger after the per-net pre-exit callback cleared the old
selection.
The race looks like this:
CPU 0 CPU 1
---- ----
unregister_pernet_subsys()
nf_log_unset(net, logger)
net->nf.nf_loggers[pf] = NULL