In the Linux kernel, the following vulnerability has been resolved:
f2fs: initialize locks earlier in f2fs_fill_super()
syzbot is reporting lockdep warning at f2fs_handle_error() [1], for
spin_lock(&sbi->error_lock) is called before spin_lock_init() is called.
For safe locking in error handling, move initialization of locks (and
obvious structures) in f2fs_fill_super() to immediately after memory
allocation.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: allow exp not to be removed in nf_ct_find_expectation
Currently nf_conntrack_in() calling nf_ct_find_expectation() will
remove the exp from the hash table. However, in some scenario, we
expect the exp not to be removed when the created ct will not be
confirmed, like in OVS and TC conntrack in the following patches.
This patch allows exp not to be removed by setting IPS_CONFIRMED
in the status of the tmpl.
In the Linux kernel, the following vulnerability has been resolved:
acct: perform last write from workqueue
In [1] it was reported that the acct(2) system call can be used to
trigger NULL deref in cases where it is set to write to a file that
triggers an internal lookup. This can e.g., happen when pointing acc(2)
to /sys/power/resume. At the point the where the write to this file
happens the calling task has already exited and called exit_fs(). A
lookup will thus trigger a NULL-deref when accessing current->fs.
Reorganize the code so that the the final write happens from the
workqueue but with the caller's credentials. This preserves the
(strange) permission model and has almost no regression risk.
This api should stop to exist though.
In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Avoid use of NULL after WARN_ON_ONCE
There is a WARN_ON_ONCE to catch an unlikely situation when
domain_remove_dev_pasid can't find the `pasid`. In case it nevertheless
happens we must avoid using a NULL pointer.
In the Linux kernel, the following vulnerability has been resolved:
ubifs: skip dumping tnc tree when zroot is null
Clearing slab cache will free all znode in memory and make
c->zroot.znode = NULL, then dumping tnc tree will access
c->zroot.znode which cause null pointer dereference.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: pcm: oss: Fix race at SNDCTL_DSP_SYNC
There is a small race window at snd_pcm_oss_sync() that is called from
OSS PCM SNDCTL_DSP_SYNC ioctl; namely the function calls
snd_pcm_oss_make_ready() at first, then takes the params_lock mutex
for the rest. When the stream is set up again by another thread
between them, it leads to inconsistency, and may result in unexpected
results such as NULL dereference of OSS buffer as a fuzzer spotted
recently.
The fix is simply to cover snd_pcm_oss_make_ready() call into the same
params_lock mutex with snd_pcm_oss_make_ready_locked() variant.
In the Linux kernel, the following vulnerability has been resolved:
fbdev: omap: use threaded IRQ for LCD DMA
When using touchscreen and framebuffer, Nokia 770 crashes easily with:
BUG: scheduling while atomic: irq/144-ads7846/82/0x00010000
Modules linked in: usb_f_ecm g_ether usb_f_rndis u_ether libcomposite configfs omap_udc ohci_omap ohci_hcd
CPU: 0 UID: 0 PID: 82 Comm: irq/144-ads7846 Not tainted 6.12.7-770 #2
Hardware name: Nokia 770
Call trace:
unwind_backtrace from show_stack+0x10/0x14
show_stack from dump_stack_lvl+0x54/0x5c
dump_stack_lvl from __schedule_bug+0x50/0x70
__schedule_bug from __schedule+0x4d4/0x5bc
__schedule from schedule+0x34/0xa0
schedule from schedule_preempt_disabled+0xc/0x10
schedule_preempt_disabled from __mutex_lock.constprop.0+0x218/0x3b4
__mutex_lock.constprop.0 from clk_prepare_lock+0x38/0xe4
clk_prepare_lock from clk_set_rate+0x18/0x154
clk_set_rate from sossi_read_data+0x4c/0x168
sossi_read_data from hwa742_read_reg+0x5c/0x8c
hwa742_read_reg from send_frame_handler+0xfc/0x300
send_frame_handler from process_pending_requests+0x74/0xd0
process_pending_requests from lcd_dma_irq_handler+0x50/0x74
lcd_dma_irq_handler from __handle_irq_event_percpu+0x44/0x130
__handle_irq_event_percpu from handle_irq_event+0x28/0x68
handle_irq_event from handle_level_irq+0x9c/0x170
handle_level_irq from generic_handle_domain_irq+0x2c/0x3c
generic_handle_domain_irq from omap1_handle_irq+0x40/0x8c
omap1_handle_irq from generic_handle_arch_irq+0x28/0x3c
generic_handle_arch_irq from call_with_stack+0x1c/0x24
call_with_stack from __irq_svc+0x94/0xa8
Exception stack(0xc5255da0 to 0xc5255de8)
5da0: 00000001 c22fc620 00000000 00000000 c08384a8 c106fc00 00000000 c240c248
5dc0: c113a600 c3f6ec30 00000001 00000000 c22fc620 c5255df0 c22fc620 c0279a94
5de0: 60000013 ffffffff
__irq_svc from clk_prepare_lock+0x4c/0xe4
clk_prepare_lock from clk_get_rate+0x10/0x74
clk_get_rate from uwire_setup_transfer+0x40/0x180
uwire_setup_transfer from spi_bitbang_transfer_one+0x2c/0x9c
spi_bitbang_transfer_one from spi_transfer_one_message+0x2d0/0x664
spi_transfer_one_message from __spi_pump_transfer_message+0x29c/0x498
__spi_pump_transfer_message from __spi_sync+0x1f8/0x2e8
__spi_sync from spi_sync+0x24/0x40
spi_sync from ads7846_halfd_read_state+0x5c/0x1c0
ads7846_halfd_read_state from ads7846_irq+0x58/0x348
ads7846_irq from irq_thread_fn+0x1c/0x78
irq_thread_fn from irq_thread+0x120/0x228
irq_thread from kthread+0xc8/0xe8
kthread from ret_from_fork+0x14/0x28
As a quick fix, switch to a threaded IRQ which provides a stable system.
In the Linux kernel, the following vulnerability has been resolved:
net: let net.core.dev_weight always be non-zero
The following problem was encountered during stability test:
(NULL net_device): NAPI poll function process_backlog+0x0/0x530 \
returned 1, exceeding its budget of 0.
------------[ cut here ]------------
list_add double add: new=ffff88905f746f48, prev=ffff88905f746f48, \
next=ffff88905f746e40.
WARNING: CPU: 18 PID: 5462 at lib/list_debug.c:35 \
__list_add_valid_or_report+0xf3/0x130
CPU: 18 UID: 0 PID: 5462 Comm: ping Kdump: loaded Not tainted 6.13.0-rc7+
RIP: 0010:__list_add_valid_or_report+0xf3/0x130
Call Trace:
? __warn+0xcd/0x250
? __list_add_valid_or_report+0xf3/0x130
enqueue_to_backlog+0x923/0x1070
netif_rx_internal+0x92/0x2b0
__netif_rx+0x15/0x170
loopback_xmit+0x2ef/0x450
dev_hard_start_xmit+0x103/0x490
__dev_queue_xmit+0xeac/0x1950
ip_finish_output2+0x6cc/0x1620
ip_output+0x161/0x270
ip_push_pending_frames+0x155/0x1a0
raw_sendmsg+0xe13/0x1550
__sys_sendto+0x3bf/0x4e0
__x64_sys_sendto+0xdc/0x1b0
do_syscall_64+0x5b/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The reproduction command is as follows:
sysctl -w net.core.dev_weight=0
ping 127.0.0.1
This is because when the napi's weight is set to 0, process_backlog() may
return 0 and clear the NAPI_STATE_SCHED bit of napi->state, causing this
napi to be re-polled in net_rx_action() until __do_softirq() times out.
Since the NAPI_STATE_SCHED bit has been cleared, napi_schedule_rps() can
be retriggered in enqueue_to_backlog(), causing this issue.
Making the napi's weight always non-zero solves this problem.
Triggering this issue requires system-wide admin (setting is
not namespaced).