In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Avoid using sk_socket after free when sending
The sk->sk_socket is not locked or referenced in backlog thread, and
during the call to skb_send_sock(), there is a race condition with
the release of sk_socket. All types of sockets(tcp/udp/unix/vsock)
will be affected.
Race conditions:
'''
CPU0 CPU1
backlog::skb_send_sock
sendmsg_unlocked
sock_sendmsg
sock_sendmsg_nosec
close(fd):
...
ops->release() -> sock_map_close()
sk_socket->ops = NULL
free(socket)
sock->ops->sendmsg
^
panic here
'''
The ref of psock become 0 after sock_map_close() executed.
'''
void sock_map_close()
{
...
if (likely(psock)) {
...
// !! here we remove psock and the ref of psock become 0
sock_map_remove_links(sk, psock)
psock = sk_psock_get(sk);
if (unlikely(!psock))
goto no_psock; <=== Control jumps here via goto
...
cancel_delayed_work_sync(&psock->work); <=== not executed
sk_psock_put(sk, psock);
...
}
'''
Based on the fact that we already wait for the workqueue to finish in
sock_map_close() if psock is held, we simply increase the psock
reference count to avoid race conditions.
With this patch, if the backlog thread is running, sock_map_close() will
wait for the backlog thread to complete and cancel all pending work.
If no backlog running, any pending work that hasn't started by then will
fail when invoked by sk_psock_get(), as the psock reference count have
been zeroed, and sk_psock_drop() will cancel all jobs via
cancel_delayed_work_sync().
In summary, we require synchronization to coordinate the backlog thread
and close() thread.
The panic I catched:
'''
Workqueue: events sk_psock_backlog
RIP: 0010:sock_sendmsg+0x21d/0x440
RAX: 0000000000000000 RBX: ffffc9000521fad8 RCX: 0000000000000001
...
Call Trace:
<TASK>
? die_addr+0x40/0xa0
? exc_general_protection+0x14c/0x230
? asm_exc_general_protection+0x26/0x30
? sock_sendmsg+0x21d/0x440
? sock_sendmsg+0x3e0/0x440
? __pfx_sock_sendmsg+0x10/0x10
__skb_send_sock+0x543/0xb70
sk_psock_backlog+0x247/0xb80
...
'''
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7915: Fix null-ptr-deref in mt7915_mmio_wed_init()
devm_ioremap() returns NULL on error. Currently, mt7915_mmio_wed_init()
does not check for this case, which results in a NULL pointer
dereference.
Prevent null pointer dereference in mt7915_mmio_wed_init().
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath9k_htc: Abort software beacon handling if disabled
A malicious USB device can send a WMI_SWBA_EVENTID event from an
ath9k_htc-managed device before beaconing has been enabled. This causes
a device-by-zero error in the driver, leading to either a crash or an
out of bounds read.
Prevent this by aborting the handling in ath9k_htc_swba() if beacons are
not enabled.
In the Linux kernel, the following vulnerability has been resolved:
hisi_acc_vfio_pci: fix XQE dma address error
The dma addresses of EQE and AEQE are wrong after migration and
results in guest kernel-mode encryption services failure.
Comparing the definition of hardware registers, we found that
there was an error when the data read from the register was
combined into an address. Therefore, the address combination
sequence needs to be corrected.
Even after fixing the above problem, we still have an issue
where the Guest from an old kernel can get migrated to
new kernel and may result in wrong data.
In order to ensure that the address is correct after migration,
if an old magic number is detected, the dma address needs to be
updated.
In the Linux kernel, the following vulnerability has been resolved:
backlight: pm8941: Add NULL check in wled_configure()
devm_kasprintf() returns NULL when memory allocation fails. Currently,
wled_configure() does not check for this case, which results in a NULL
pointer dereference.
Add NULL check after devm_kasprintf() to prevent this issue.
In the Linux kernel, the following vulnerability has been resolved:
soc: aspeed: Add NULL check in aspeed_lpc_enable_snoop()
devm_kasprintf() returns NULL when memory allocation fails. Currently,
aspeed_lpc_enable_snoop() does not check for this case, which results in a
NULL pointer dereference.
Add NULL check after devm_kasprintf() to prevent this issue.
[arj: Fix Fixes: tag to use subject from 3772e5da4454]
In the Linux kernel, the following vulnerability has been resolved:
net: openvswitch: Fix the dead loop of MPLS parse
The unexpected MPLS packet may not end with the bottom label stack.
When there are many stacks, The label count value has wrapped around.
A dead loop occurs, soft lockup/CPU stuck finally.
stack backtrace:
UBSAN: array-index-out-of-bounds in /build/linux-0Pa0xK/linux-5.15.0/net/openvswitch/flow.c:662:26
index -1 is out of range for type '__be32 [3]'
CPU: 34 PID: 0 Comm: swapper/34 Kdump: loaded Tainted: G OE 5.15.0-121-generic #131-Ubuntu
Hardware name: Dell Inc. PowerEdge C6420/0JP9TF, BIOS 2.12.2 07/14/2021
Call Trace:
<IRQ>
show_stack+0x52/0x5c
dump_stack_lvl+0x4a/0x63
dump_stack+0x10/0x16
ubsan_epilogue+0x9/0x36
__ubsan_handle_out_of_bounds.cold+0x44/0x49
key_extract_l3l4+0x82a/0x840 [openvswitch]
? kfree_skbmem+0x52/0xa0
key_extract+0x9c/0x2b0 [openvswitch]
ovs_flow_key_extract+0x124/0x350 [openvswitch]
ovs_vport_receive+0x61/0xd0 [openvswitch]
? kernel_init_free_pages.part.0+0x4a/0x70
? get_page_from_freelist+0x353/0x540
netdev_port_receive+0xc4/0x180 [openvswitch]
? netdev_port_receive+0x180/0x180 [openvswitch]
netdev_frame_hook+0x1f/0x40 [openvswitch]
__netif_receive_skb_core.constprop.0+0x23a/0xf00
__netif_receive_skb_list_core+0xfa/0x240
netif_receive_skb_list_internal+0x18e/0x2a0
napi_complete_done+0x7a/0x1c0
bnxt_poll+0x155/0x1c0 [bnxt_en]
__napi_poll+0x30/0x180
net_rx_action+0x126/0x280
? bnxt_msix+0x67/0x80 [bnxt_en]
handle_softirqs+0xda/0x2d0
irq_exit_rcu+0x96/0xc0
common_interrupt+0x8e/0xa0
</IRQ>
In the Linux kernel, the following vulnerability has been resolved:
net: phy: mscc: Fix memory leak when using one step timestamping
Fix memory leak when running one-step timestamping. When running
one-step sync timestamping, the HW is configured to insert the TX time
into the frame, so there is no reason to keep the skb anymore. As in
this case the HW will never generate an interrupt to say that the frame
was timestamped, then the frame will never released.
Fix this by freeing the frame in case of one-step timestamping.
In the Linux kernel, the following vulnerability has been resolved:
net: phy: clear phydev->devlink when the link is deleted
There is a potential crash issue when disabling and re-enabling the
network port. When disabling the network port, phy_detach() calls
device_link_del() to remove the device link, but it does not clear
phydev->devlink, so phydev->devlink is not a NULL pointer. Then the
network port is re-enabled, but if phy_attach_direct() fails before
calling device_link_add(), the code jumps to the "error" label and
calls phy_detach(). Since phydev->devlink retains the old value from
the previous attach/detach cycle, device_link_del() uses the old value,
which accesses a NULL pointer and causes a crash. The simplified crash
log is as follows.
[ 24.702421] Call trace:
[ 24.704856] device_link_put_kref+0x20/0x120
[ 24.709124] device_link_del+0x30/0x48
[ 24.712864] phy_detach+0x24/0x168
[ 24.716261] phy_attach_direct+0x168/0x3a4
[ 24.720352] phylink_fwnode_phy_connect+0xc8/0x14c
[ 24.725140] phylink_of_phy_connect+0x1c/0x34
Therefore, phydev->devlink needs to be cleared when the device link is
deleted.