In the Linux kernel, the following vulnerability has been resolved:
media: dvbdev: adopts refcnt to avoid UAF
dvb_unregister_device() is known that prone to use-after-free.
That is, the cleanup from dvb_unregister_device() releases the dvb_device
even if there are pointers stored in file->private_data still refer to it.
This patch adds a reference counter into struct dvb_device and delays its
deallocation until no pointer refers to the object.
In the Linux kernel, the following vulnerability has been resolved:
drm/radeon: Add the missed acpi_put_table() to fix memory leak
When the radeon driver reads the bios information from ACPI
table in radeon_acpi_vfct_bios(), it misses to call acpi_put_table()
to release the ACPI memory after the init, so add acpi_put_table()
properly to fix the memory leak.
v2: fix text formatting (Alex)
In the Linux kernel, the following vulnerability has been resolved:
PNP: fix name memory leak in pnp_alloc_dev()
After commit 1fa5ae857bb1 ("driver core: get rid of struct device's
bus_id string array"), the name of device is allocated dynamically,
move dev_set_name() after pnp_add_id() to avoid memory leak.
In the Linux kernel, the following vulnerability has been resolved:
wifi: rtlwifi: Fix global-out-of-bounds bug in _rtl8812ae_phy_set_txpower_limit()
There is a global-out-of-bounds reported by KASAN:
BUG: KASAN: global-out-of-bounds in
_rtl8812ae_eq_n_byte.part.0+0x3d/0x84 [rtl8821ae]
Read of size 1 at addr ffffffffa0773c43 by task NetworkManager/411
CPU: 6 PID: 411 Comm: NetworkManager Tainted: G D
6.1.0-rc8+ #144 e15588508517267d37
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009),
Call Trace:
<TASK>
...
kasan_report+0xbb/0x1c0
_rtl8812ae_eq_n_byte.part.0+0x3d/0x84 [rtl8821ae]
rtl8821ae_phy_bb_config.cold+0x346/0x641 [rtl8821ae]
rtl8821ae_hw_init+0x1f5e/0x79b0 [rtl8821ae]
...
</TASK>
The root cause of the problem is that the comparison order of
"prate_section" in _rtl8812ae_phy_set_txpower_limit() is wrong. The
_rtl8812ae_eq_n_byte() is used to compare the first n bytes of the two
strings from tail to head, which causes the problem. In the
_rtl8812ae_phy_set_txpower_limit(), it was originally intended to meet
this requirement by carefully designing the comparison order.
For example, "pregulation" and "pbandwidth" are compared in order of
length from small to large, first is 3 and last is 4. However, the
comparison order of "prate_section" dose not obey such order requirement,
therefore when "prate_section" is "HT", when comparing from tail to head,
it will lead to access out of bounds in _rtl8812ae_eq_n_byte(). As
mentioned above, the _rtl8812ae_eq_n_byte() has the same function as
strcmp(), so just strcmp() is enough.
Fix it by removing _rtl8812ae_eq_n_byte() and use strcmp() barely.
Although it can be fixed by adjusting the comparison order of
"prate_section", this may cause the value of "rate_section" to not be
from 0 to 5. In addition, commit "21e4b0726dc6" not only moved driver
from staging to regular tree, but also added setting txpower limit
function during the driver config phase, so the problem was introduced
by this commit.
In the Linux kernel, the following vulnerability has been resolved:
mmc: rtsx_pci: fix return value check of mmc_add_host()
mmc_add_host() may return error, if we ignore its return value, the memory
that allocated in mmc_alloc_host() will be leaked and it will lead a kernel
crash because of deleting not added device in the remove path.
So fix this by checking the return value and calling mmc_free_host() in the
error path, beside, runtime PM also needs be disabled.
In the Linux kernel, the following vulnerability has been resolved:
mmc: moxart: fix return value check of mmc_add_host()
mmc_add_host() may return error, if we ignore its return value, the memory
that allocated in mmc_alloc_host() will be leaked and it will lead a kernel
crash because of deleting not added device in the remove path.
So fix this by checking the return value and goto error path which will call
mmc_free_host().
In the Linux kernel, the following vulnerability has been resolved:
vhost/vsock: Use kvmalloc/kvfree for larger packets.
When copying a large file over sftp over vsock, data size is usually 32kB,
and kmalloc seems to fail to try to allocate 32 32kB regions.
vhost-5837: page allocation failure: order:4, mode:0x24040c0
Call Trace:
[<ffffffffb6a0df64>] dump_stack+0x97/0xdb
[<ffffffffb68d6aed>] warn_alloc_failed+0x10f/0x138
[<ffffffffb68d868a>] ? __alloc_pages_direct_compact+0x38/0xc8
[<ffffffffb664619f>] __alloc_pages_nodemask+0x84c/0x90d
[<ffffffffb6646e56>] alloc_kmem_pages+0x17/0x19
[<ffffffffb6653a26>] kmalloc_order_trace+0x2b/0xdb
[<ffffffffb66682f3>] __kmalloc+0x177/0x1f7
[<ffffffffb66e0d94>] ? copy_from_iter+0x8d/0x31d
[<ffffffffc0689ab7>] vhost_vsock_handle_tx_kick+0x1fa/0x301 [vhost_vsock]
[<ffffffffc06828d9>] vhost_worker+0xf7/0x157 [vhost]
[<ffffffffb683ddce>] kthread+0xfd/0x105
[<ffffffffc06827e2>] ? vhost_dev_set_owner+0x22e/0x22e [vhost]
[<ffffffffb683dcd1>] ? flush_kthread_worker+0xf3/0xf3
[<ffffffffb6eb332e>] ret_from_fork+0x4e/0x80
[<ffffffffb683dcd1>] ? flush_kthread_worker+0xf3/0xf3
Work around by doing kvmalloc instead.
In the Linux kernel, the following vulnerability has been resolved:
USB: uhci: fix memory leak with using debugfs_lookup()
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
In the Linux kernel, the following vulnerability has been resolved:
net: openvswitch: fix race on port output
assume the following setup on a single machine:
1. An openvswitch instance with one bridge and default flows
2. two network namespaces "server" and "client"
3. two ovs interfaces "server" and "client" on the bridge
4. for each ovs interface a veth pair with a matching name and 32 rx and
tx queues
5. move the ends of the veth pairs to the respective network namespaces
6. assign ip addresses to each of the veth ends in the namespaces (needs
to be the same subnet)
7. start some http server on the server network namespace
8. test if a client in the client namespace can reach the http server
when following the actions below the host has a chance of getting a cpu
stuck in a infinite loop:
1. send a large amount of parallel requests to the http server (around
3000 curls should work)
2. in parallel delete the network namespace (do not delete interfaces or
stop the server, just kill the namespace)
there is a low chance that this will cause the below kernel cpu stuck
message. If this does not happen just retry.
Below there is also the output of bpftrace for the functions mentioned
in the output.
The series of events happening here is:
1. the network namespace is deleted calling
`unregister_netdevice_many_notify` somewhere in the process
2. this sets first `NETREG_UNREGISTERING` on both ends of the veth and
then runs `synchronize_net`
3. it then calls `call_netdevice_notifiers` with `NETDEV_UNREGISTER`
4. this is then handled by `dp_device_event` which calls
`ovs_netdev_detach_dev` (if a vport is found, which is the case for
the veth interface attached to ovs)
5. this removes the rx_handlers of the device but does not prevent
packages to be sent to the device
6. `dp_device_event` then queues the vport deletion to work in
background as a ovs_lock is needed that we do not hold in the
unregistration path
7. `unregister_netdevice_many_notify` continues to call
`netdev_unregister_kobject` which sets `real_num_tx_queues` to 0
8. port deletion continues (but details are not relevant for this issue)
9. at some future point the background task deletes the vport
If after 7. but before 9. a packet is send to the ovs vport (which is
not deleted at this point in time) which forwards it to the
`dev_queue_xmit` flow even though the device is unregistering.
In `skb_tx_hash` (which is called in the `dev_queue_xmit`) path there is
a while loop (if the packet has a rx_queue recorded) that is infinite if
`dev->real_num_tx_queues` is zero.
To prevent this from happening we update `do_output` to handle devices
without carrier the same as if the device is not found (which would
be the code path after 9. is done).
Additionally we now produce a warning in `skb_tx_hash` if we will hit
the infinite loop.
bpftrace (first word is function name):
__dev_queue_xmit server: real_num_tx_queues: 1, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 1
netdev_core_pick_tx server: addr: 0xffff9f0a46d4a000 real_num_tx_queues: 1, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 1
dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 2, reg_state: 1
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 6, reg_state: 2
ovs_netdev_detach_dev server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, reg_state: 2
netdev_rx_handler_unregister server: real_num_tx_queues: 1, cpu: 9, pid: 21024, tid: 21024, reg_state: 2
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
netdev_rx_handler_unregister ret server: real_num_tx_queues: 1, cpu: 9, pid: 21024, tid: 21024, reg_state: 2
dp_
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