Security Vulnerabilities
- CVEs Published In 2024
In the Linux kernel, the following vulnerability has been resolved:
brd: defer automatic disk creation until module initialization succeeds
My colleague Wupeng found the following problems during fault injection:
BUG: unable to handle page fault for address: fffffbfff809d073
PGD 6e648067 P4D 123ec8067 PUD 123ec4067 PMD 100e38067 PTE 0
Oops: Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 5 UID: 0 PID: 755 Comm: modprobe Not tainted 6.12.0-rc3+ #17
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.1-2.fc37 04/01/2014
RIP: 0010:__asan_load8+0x4c/0xa0
...
Call Trace:
<TASK>
blkdev_put_whole+0x41/0x70
bdev_release+0x1a3/0x250
blkdev_release+0x11/0x20
__fput+0x1d7/0x4a0
task_work_run+0xfc/0x180
syscall_exit_to_user_mode+0x1de/0x1f0
do_syscall_64+0x6b/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
loop_init() is calling loop_add() after __register_blkdev() succeeds and
is ignoring disk_add() failure from loop_add(), for loop_add() failure
is not fatal and successfully created disks are already visible to
bdev_open().
brd_init() is currently calling brd_alloc() before __register_blkdev()
succeeds and is releasing successfully created disks when brd_init()
returns an error. This can cause UAF for the latter two case:
case 1:
T1:
modprobe brd
brd_init
brd_alloc(0) // success
add_disk
disk_scan_partitions
bdev_file_open_by_dev // alloc file
fput // won't free until back to userspace
brd_alloc(1) // failed since mem alloc error inject
// error path for modprobe will release code segment
// back to userspace
__fput
blkdev_release
bdev_release
blkdev_put_whole
bdev->bd_disk->fops->release // fops is freed now, UAF!
case 2:
T1: T2:
modprobe brd
brd_init
brd_alloc(0) // success
open(/dev/ram0)
brd_alloc(1) // fail
// error path for modprobe
close(/dev/ram0)
...
/* UAF! */
bdev->bd_disk->fops->release
Fix this problem by following what loop_init() does. Besides,
reintroduce brd_devices_mutex to help serialize modifications to
brd_list.
In the Linux kernel, the following vulnerability has been resolved:
PCI: endpoint: epf-mhi: Avoid NULL dereference if DT lacks 'mmio'
If platform_get_resource_byname() fails and returns NULL because DT lacks
an 'mmio' property for the MHI endpoint, dereferencing res->start will
cause a NULL pointer access. Add a check to prevent it.
[kwilczynski: error message update per the review feedback]
[bhelgaas: commit log]
In the Linux kernel, the following vulnerability has been resolved:
usb: musb: Fix hardware lockup on first Rx endpoint request
There is a possibility that a request's callback could be invoked from
usb_ep_queue() (call trace below, supplemented with missing calls):
req->complete from usb_gadget_giveback_request
(drivers/usb/gadget/udc/core.c:999)
usb_gadget_giveback_request from musb_g_giveback
(drivers/usb/musb/musb_gadget.c:147)
musb_g_giveback from rxstate
(drivers/usb/musb/musb_gadget.c:784)
rxstate from musb_ep_restart
(drivers/usb/musb/musb_gadget.c:1169)
musb_ep_restart from musb_ep_restart_resume_work
(drivers/usb/musb/musb_gadget.c:1176)
musb_ep_restart_resume_work from musb_queue_resume_work
(drivers/usb/musb/musb_core.c:2279)
musb_queue_resume_work from musb_gadget_queue
(drivers/usb/musb/musb_gadget.c:1241)
musb_gadget_queue from usb_ep_queue
(drivers/usb/gadget/udc/core.c:300)
According to the docstring of usb_ep_queue(), this should not happen:
"Note that @req's ->complete() callback must never be called from within
usb_ep_queue() as that can create deadlock situations."
In fact, a hardware lockup might occur in the following sequence:
1. The gadget is initialized using musb_gadget_enable().
2. Meanwhile, a packet arrives, and the RXPKTRDY flag is set, raising an
interrupt.
3. If IRQs are enabled, the interrupt is handled, but musb_g_rx() finds an
empty queue (next_request() returns NULL). The interrupt flag has
already been cleared by the glue layer handler, but the RXPKTRDY flag
remains set.
4. The first request is enqueued using usb_ep_queue(), leading to the call
of req->complete(), as shown in the call trace above.
5. If the callback enables IRQs and another packet is waiting, step (3)
repeats. The request queue is empty because usb_g_giveback() removes the
request before invoking the callback.
6. The endpoint remains locked up, as the interrupt triggered by hardware
setting the RXPKTRDY flag has been handled, but the flag itself remains
set.
For this scenario to occur, it is only necessary for IRQs to be enabled at
some point during the complete callback. This happens with the USB Ethernet
gadget, whose rx_complete() callback calls netif_rx(). If called in the
task context, netif_rx() disables the bottom halves (BHs). When the BHs are
re-enabled, IRQs are also enabled to allow soft IRQs to be processed. The
gadget itself is initialized at module load (or at boot if built-in), but
the first request is enqueued when the network interface is brought up,
triggering rx_complete() in the task context via ioctl(). If a packet
arrives while the interface is down, it can prevent the interface from
receiving any further packets from the USB host.
The situation is quite complicated with many parties involved. This
particular issue can be resolved in several possible ways:
1. Ensure that callbacks never enable IRQs. This would be difficult to
enforce, as discovering how netif_rx() interacts with interrupts was
already quite challenging and u_ether is not the only function driver.
Similar "bugs" could be hidden in other drivers as well.
2. Disable MUSB interrupts in musb_g_giveback() before calling the callback
and re-enable them afterwars (by calling musb_{dis,en}able_interrupts(),
for example). This would ensure that MUSB interrupts are not handled
during the callback, even if IRQs are enabled. In fact, it would allow
IRQs to be enabled when releasing the lock. However, this feels like an
inelegant hack.
3. Modify the interrupt handler to clear the RXPKTRDY flag if the request
queue is empty. While this approach also feels like a hack, it wastes
CPU time by attempting to handle incoming packets when the software is
not ready to process them.
4. Flush the Rx FIFO instead of calling rxstate() in musb_ep_restart().
This ensures that the hardware can receive packets when there is at
least one request in the queue. Once I
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
sunrpc: clear XPRT_SOCK_UPD_TIMEOUT when reset transport
Since transport->sock has been set to NULL during reset transport,
XPRT_SOCK_UPD_TIMEOUT also needs to be cleared. Otherwise, the
xs_tcp_set_socket_timeouts() may be triggered in xs_tcp_send_request()
to dereference the transport->sock that has been set to NULL.
In the Linux kernel, the following vulnerability has been resolved:
irqchip/riscv-aplic: Prevent crash when MSI domain is missing
If the APLIC driver is probed before the IMSIC driver, the parent MSI
domain will be missing, which causes a NULL pointer dereference in
msi_create_device_irq_domain().
Avoid this by deferring probe until the parent MSI domain is available. Use
dev_err_probe() to avoid printing an error message when returning
-EPROBE_DEFER.
In the Linux kernel, the following vulnerability has been resolved:
powerpc/mm/fault: Fix kfence page fault reporting
copy_from_kernel_nofault() can be called when doing read of /proc/kcore.
/proc/kcore can have some unmapped kfence objects which when read via
copy_from_kernel_nofault() can cause page faults. Since *_nofault()
functions define their own fixup table for handling fault, use that
instead of asking kfence to handle such faults.
Hence we search the exception tables for the nip which generated the
fault. If there is an entry then we let the fixup table handler handle the
page fault by returning an error from within ___do_page_fault().
This can be easily triggered if someone tries to do dd from /proc/kcore.
eg. dd if=/proc/kcore of=/dev/null bs=1M
Some example false negatives:
===============================
BUG: KFENCE: invalid read in copy_from_kernel_nofault+0x9c/0x1a0
Invalid read at 0xc0000000fdff0000:
copy_from_kernel_nofault+0x9c/0x1a0
0xc00000000665f950
read_kcore_iter+0x57c/0xa04
proc_reg_read_iter+0xe4/0x16c
vfs_read+0x320/0x3ec
ksys_read+0x90/0x154
system_call_exception+0x120/0x310
system_call_vectored_common+0x15c/0x2ec
BUG: KFENCE: use-after-free read in copy_from_kernel_nofault+0x9c/0x1a0
Use-after-free read at 0xc0000000fe050000 (in kfence-#2):
copy_from_kernel_nofault+0x9c/0x1a0
0xc00000000665f950
read_kcore_iter+0x57c/0xa04
proc_reg_read_iter+0xe4/0x16c
vfs_read+0x320/0x3ec
ksys_read+0x90/0x154
system_call_exception+0x120/0x310
system_call_vectored_common+0x15c/0x2ec
A connection hijacking vulnerability exists in some Huawei home routers. Successful exploitation of this vulnerability may cause DoS or information leakage.(Vulnerability ID:HWPSIRT-2023-34408)
This vulnerability has been assigned a (CVE)ID:CVE-2023-52718
Some Huawei home routers have a connection hijacking vulnerability. Successful exploitation of this vulnerability may cause DoS or information leakage.(Vulnerability ID:HWPSIRT-2023-76605)
This vulnerability has been assigned a (CVE)ID:CVE-2023-7266
There are multiple out of bounds (OOB) read vulnerabilities in the implementation of the Common Open Policy Service (COPS) protocol of some Huawei products. The specific decoding function may occur out-of-bounds read when processes an incoming data packet. Successful exploit of these vulnerabilities may disrupt service on the affected device. (Vulnerability ID: HWPSIRT-2018-12275,HWPSIRT-2018-12276,HWPSIRT-2018-12277,HWPSIRT-2018-12278,HWPSIRT-2018-12279,HWPSIRT-2018-12280 and HWPSIRT-2018-12289)
The seven vulnerabilities have been assigned seven Common Vulnerabilities and Exposures (CVE) IDs: CVE-2020-1818, CVE-2020-1819, CVE-2020-1820, CVE-2020-1821, CVE-2020-1822, CVE-2020-1823 and CVE-2020-1824.
There are multiple out of bounds (OOB) read vulnerabilities in the implementation of the Common Open Policy Service (COPS) protocol of some Huawei products. The specific decoding function may occur out-of-bounds read when processes an incoming data packet. Successful exploit of these vulnerabilities may disrupt service on the affected device. (Vulnerability ID: HWPSIRT-2018-12275,HWPSIRT-2018-12276,HWPSIRT-2018-12277,HWPSIRT-2018-12278,HWPSIRT-2018-12279,HWPSIRT-2018-12280 and HWPSIRT-2018-12289)
The seven vulnerabilities have been assigned seven Common Vulnerabilities and Exposures (CVE) IDs: CVE-2020-1818, CVE-2020-1819, CVE-2020-1820, CVE-2020-1821, CVE-2020-1822, CVE-2020-1823 and CVE-2020-1824.