In the Linux kernel, the following vulnerability has been resolved:
ovl: Use "buf" flexible array for memcpy() destination
The "buf" flexible array needs to be the memcpy() destination to avoid
false positive run-time warning from the recent FORTIFY_SOURCE
hardening:
memcpy: detected field-spanning write (size 93) of single field "&fh->fb"
at fs/overlayfs/export.c:799 (size 21)
In the Linux kernel, the following vulnerability has been resolved:
usbnet: gl620a: fix endpoint checking in genelink_bind()
Syzbot reports [1] a warning in usb_submit_urb() triggered by
inconsistencies between expected and actually present endpoints
in gl620a driver. Since genelink_bind() does not properly
verify whether specified eps are in fact provided by the device,
in this case, an artificially manufactured one, one may get a
mismatch.
Fix the issue by resorting to a usbnet utility function
usbnet_get_endpoints(), usually reserved for this very problem.
Check for endpoints and return early before proceeding further if
any are missing.
[1] Syzbot report:
usb 5-1: Manufacturer: syz
usb 5-1: SerialNumber: syz
usb 5-1: config 0 descriptor??
gl620a 5-1:0.23 usb0: register 'gl620a' at usb-dummy_hcd.0-1, ...
------------[ cut here ]------------
usb 5-1: BOGUS urb xfer, pipe 3 != type 1
WARNING: CPU: 2 PID: 1841 at drivers/usb/core/urb.c:503 usb_submit_urb+0xe4b/0x1730 drivers/usb/core/urb.c:503
Modules linked in:
CPU: 2 UID: 0 PID: 1841 Comm: kworker/2:2 Not tainted 6.12.0-syzkaller-07834-g06afb0f36106 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: mld mld_ifc_work
RIP: 0010:usb_submit_urb+0xe4b/0x1730 drivers/usb/core/urb.c:503
...
Call Trace:
<TASK>
usbnet_start_xmit+0x6be/0x2780 drivers/net/usb/usbnet.c:1467
__netdev_start_xmit include/linux/netdevice.h:5002 [inline]
netdev_start_xmit include/linux/netdevice.h:5011 [inline]
xmit_one net/core/dev.c:3590 [inline]
dev_hard_start_xmit+0x9a/0x7b0 net/core/dev.c:3606
sch_direct_xmit+0x1ae/0xc30 net/sched/sch_generic.c:343
__dev_xmit_skb net/core/dev.c:3827 [inline]
__dev_queue_xmit+0x13d4/0x43e0 net/core/dev.c:4400
dev_queue_xmit include/linux/netdevice.h:3168 [inline]
neigh_resolve_output net/core/neighbour.c:1514 [inline]
neigh_resolve_output+0x5bc/0x950 net/core/neighbour.c:1494
neigh_output include/net/neighbour.h:539 [inline]
ip6_finish_output2+0xb1b/0x2070 net/ipv6/ip6_output.c:141
__ip6_finish_output net/ipv6/ip6_output.c:215 [inline]
ip6_finish_output+0x3f9/0x1360 net/ipv6/ip6_output.c:226
NF_HOOK_COND include/linux/netfilter.h:303 [inline]
ip6_output+0x1f8/0x540 net/ipv6/ip6_output.c:247
dst_output include/net/dst.h:450 [inline]
NF_HOOK include/linux/netfilter.h:314 [inline]
NF_HOOK include/linux/netfilter.h:308 [inline]
mld_sendpack+0x9f0/0x11d0 net/ipv6/mcast.c:1819
mld_send_cr net/ipv6/mcast.c:2120 [inline]
mld_ifc_work+0x740/0xca0 net/ipv6/mcast.c:2651
process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229
process_scheduled_works kernel/workqueue.c:3310 [inline]
worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
In the Linux kernel, the following vulnerability has been resolved:
sched/core: Prevent rescheduling when interrupts are disabled
David reported a warning observed while loop testing kexec jump:
Interrupts enabled after irqrouter_resume+0x0/0x50
WARNING: CPU: 0 PID: 560 at drivers/base/syscore.c:103 syscore_resume+0x18a/0x220
kernel_kexec+0xf6/0x180
__do_sys_reboot+0x206/0x250
do_syscall_64+0x95/0x180
The corresponding interrupt flag trace:
hardirqs last enabled at (15573): [<ffffffffa8281b8e>] __up_console_sem+0x7e/0x90
hardirqs last disabled at (15580): [<ffffffffa8281b73>] __up_console_sem+0x63/0x90
That means __up_console_sem() was invoked with interrupts enabled. Further
instrumentation revealed that in the interrupt disabled section of kexec
jump one of the syscore_suspend() callbacks woke up a task, which set the
NEED_RESCHED flag. A later callback in the resume path invoked
cond_resched() which in turn led to the invocation of the scheduler:
__cond_resched+0x21/0x60
down_timeout+0x18/0x60
acpi_os_wait_semaphore+0x4c/0x80
acpi_ut_acquire_mutex+0x3d/0x100
acpi_ns_get_node+0x27/0x60
acpi_ns_evaluate+0x1cb/0x2d0
acpi_rs_set_srs_method_data+0x156/0x190
acpi_pci_link_set+0x11c/0x290
irqrouter_resume+0x54/0x60
syscore_resume+0x6a/0x200
kernel_kexec+0x145/0x1c0
__do_sys_reboot+0xeb/0x240
do_syscall_64+0x95/0x180
This is a long standing problem, which probably got more visible with
the recent printk changes. Something does a task wakeup and the
scheduler sets the NEED_RESCHED flag. cond_resched() sees it set and
invokes schedule() from a completely bogus context. The scheduler
enables interrupts after context switching, which causes the above
warning at the end.
Quite some of the code paths in syscore_suspend()/resume() can result in
triggering a wakeup with the exactly same consequences. They might not
have done so yet, but as they share a lot of code with normal operations
it's just a question of time.
The problem only affects the PREEMPT_NONE and PREEMPT_VOLUNTARY scheduling
models. Full preemption is not affected as cond_resched() is disabled and
the preemption check preemptible() takes the interrupt disabled flag into
account.
Cure the problem by adding a corresponding check into cond_resched().
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:
tomoyo: don't emit warning in tomoyo_write_control()
syzbot is reporting too large allocation warning at tomoyo_write_control(),
for one can write a very very long line without new line character. To fix
this warning, I use __GFP_NOWARN rather than checking for KMALLOC_MAX_SIZE,
for practically a valid line should be always shorter than 32KB where the
"too small to fail" memory-allocation rule applies.
One might try to write a valid line that is longer than 32KB, but such
request will likely fail with -ENOMEM. Therefore, I feel that separately
returning -EINVAL when a line is longer than KMALLOC_MAX_SIZE is redundant.
There is no need to distinguish over-32KB and over-KMALLOC_MAX_SIZE.
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:
wifi: rtlwifi: fix memory leaks and invalid access at probe error path
Deinitialize at reverse order when probe fails.
When init_sw_vars fails, rtl_deinit_core should not be called, specially
now that it destroys the rtl_wq workqueue.
And call rtl_pci_deinit and deinit_sw_vars, otherwise, memory will be
leaked.
Remove pci_set_drvdata call as it will already be cleaned up by the core
driver code and could lead to memory leaks too. cf. commit 8d450935ae7f
("wireless: rtlwifi: remove unnecessary pci_set_drvdata()") and
commit 3d86b93064c7 ("rtlwifi: Fix PCI probe error path orphaned memory").
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.