In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Fix panic when calling skb_linearize
The panic can be reproduced by executing the command:
./bench sockmap -c 2 -p 1 -a --rx-verdict-ingress --rx-strp 100000
Then a kernel panic was captured:
'''
[ 657.460555] kernel BUG at net/core/skbuff.c:2178!
[ 657.462680] Tainted: [W]=WARN
[ 657.463287] Workqueue: events sk_psock_backlog
...
[ 657.469610] <TASK>
[ 657.469738] ? die+0x36/0x90
[ 657.469916] ? do_trap+0x1d0/0x270
[ 657.470118] ? pskb_expand_head+0x612/0xf40
[ 657.470376] ? pskb_expand_head+0x612/0xf40
[ 657.470620] ? do_error_trap+0xa3/0x170
[ 657.470846] ? pskb_expand_head+0x612/0xf40
[ 657.471092] ? handle_invalid_op+0x2c/0x40
[ 657.471335] ? pskb_expand_head+0x612/0xf40
[ 657.471579] ? exc_invalid_op+0x2d/0x40
[ 657.471805] ? asm_exc_invalid_op+0x1a/0x20
[ 657.472052] ? pskb_expand_head+0xd1/0xf40
[ 657.472292] ? pskb_expand_head+0x612/0xf40
[ 657.472540] ? lock_acquire+0x18f/0x4e0
[ 657.472766] ? find_held_lock+0x2d/0x110
[ 657.472999] ? __pfx_pskb_expand_head+0x10/0x10
[ 657.473263] ? __kmalloc_cache_noprof+0x5b/0x470
[ 657.473537] ? __pfx___lock_release.isra.0+0x10/0x10
[ 657.473826] __pskb_pull_tail+0xfd/0x1d20
[ 657.474062] ? __kasan_slab_alloc+0x4e/0x90
[ 657.474707] sk_psock_skb_ingress_enqueue+0x3bf/0x510
[ 657.475392] ? __kasan_kmalloc+0xaa/0xb0
[ 657.476010] sk_psock_backlog+0x5cf/0xd70
[ 657.476637] process_one_work+0x858/0x1a20
'''
The panic originates from the assertion BUG_ON(skb_shared(skb)) in
skb_linearize(). A previous commit(see Fixes tag) introduced skb_get()
to avoid race conditions between skb operations in the backlog and skb
release in the recvmsg path. However, this caused the panic to always
occur when skb_linearize is executed.
The "--rx-strp 100000" parameter forces the RX path to use the strparser
module which aggregates data until it reaches 100KB before calling sockmap
logic. The 100KB payload exceeds MAX_MSG_FRAGS, triggering skb_linearize.
To fix this issue, just move skb_get into sk_psock_skb_ingress_enqueue.
'''
sk_psock_backlog:
sk_psock_handle_skb
skb_get(skb) <== we move it into 'sk_psock_skb_ingress_enqueue'
sk_psock_skb_ingress____________
↓
|
| → sk_psock_skb_ingress_self
| sk_psock_skb_ingress_enqueue
sk_psock_verdict_apply_________________↑ skb_linearize
'''
Note that for verdict_apply path, the skb_get operation is unnecessary so
we add 'take_ref' param to control it's behavior.
In the Linux kernel, the following vulnerability has been resolved:
RDMA/cma: Fix hang when cma_netevent_callback fails to queue_work
The cited commit fixed a crash when cma_netevent_callback was called for
a cma_id while work on that id from a previous call had not yet started.
The work item was re-initialized in the second call, which corrupted the
work item currently in the work queue.
However, it left a problem when queue_work fails (because the item is
still pending in the work queue from a previous call). In this case,
cma_id_put (which is called in the work handler) is therefore not
called. This results in a userspace process hang (zombie process).
Fix this by calling cma_id_put() if queue_work fails.
In the Linux kernel, the following vulnerability has been resolved:
net: usb: aqc111: fix error handling of usbnet read calls
Syzkaller, courtesy of syzbot, identified an error (see report [1]) in
aqc111 driver, caused by incomplete sanitation of usb read calls'
results. This problem is quite similar to the one fixed in commit
920a9fa27e78 ("net: asix: add proper error handling of usb read errors").
For instance, usbnet_read_cmd() may read fewer than 'size' bytes,
even if the caller expected the full amount, and aqc111_read_cmd()
will not check its result properly. As [1] shows, this may lead
to MAC address in aqc111_bind() being only partly initialized,
triggering KMSAN warnings.
Fix the issue by verifying that the number of bytes read is
as expected and not less.
[1] Partial syzbot report:
BUG: KMSAN: uninit-value in is_valid_ether_addr include/linux/etherdevice.h:208 [inline]
BUG: KMSAN: uninit-value in usbnet_probe+0x2e57/0x4390 drivers/net/usb/usbnet.c:1830
is_valid_ether_addr include/linux/etherdevice.h:208 [inline]
usbnet_probe+0x2e57/0x4390 drivers/net/usb/usbnet.c:1830
usb_probe_interface+0xd01/0x1310 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x4d1/0xd90 drivers/base/dd.c:658
__driver_probe_device+0x268/0x380 drivers/base/dd.c:800
...
Uninit was stored to memory at:
dev_addr_mod+0xb0/0x550 net/core/dev_addr_lists.c:582
__dev_addr_set include/linux/netdevice.h:4874 [inline]
eth_hw_addr_set include/linux/etherdevice.h:325 [inline]
aqc111_bind+0x35f/0x1150 drivers/net/usb/aqc111.c:717
usbnet_probe+0xbe6/0x4390 drivers/net/usb/usbnet.c:1772
usb_probe_interface+0xd01/0x1310 drivers/usb/core/driver.c:396
...
Uninit was stored to memory at:
ether_addr_copy include/linux/etherdevice.h:305 [inline]
aqc111_read_perm_mac drivers/net/usb/aqc111.c:663 [inline]
aqc111_bind+0x794/0x1150 drivers/net/usb/aqc111.c:713
usbnet_probe+0xbe6/0x4390 drivers/net/usb/usbnet.c:1772
usb_probe_interface+0xd01/0x1310 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
...
Local variable buf.i created at:
aqc111_read_perm_mac drivers/net/usb/aqc111.c:656 [inline]
aqc111_bind+0x221/0x1150 drivers/net/usb/aqc111.c:713
usbnet_probe+0xbe6/0x4390 drivers/net/usb/usbnet.c:1772
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: 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>