Linux: >> Linux Kernel >> 5.14.21 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
drm/msm: fix use-after-free on probe deferral
The bridge counter was never reset when tearing down the DRM device so
that stale pointers to deallocated structures would be accessed on the
next tear down (e.g. after a second late bind deferral).
Given enough bridges and a few probe deferrals this could currently also
lead to data beyond the bridge array being corrupted.
Patchwork: https://patchwork.freedesktop.org/patch/502665/
CVSS Score
7.8
EPSS Score
0.0
Published
2025-10-04
In the Linux kernel, the following vulnerability has been resolved:
scsi: qla2xxx: Fix crash when I/O abort times out
While performing CPU hotplug, a crash with the following stack was seen:
Call Trace:
qla24xx_process_response_queue+0x42a/0x970 [qla2xxx]
qla2x00_start_nvme_mq+0x3a2/0x4b0 [qla2xxx]
qla_nvme_post_cmd+0x166/0x240 [qla2xxx]
nvme_fc_start_fcp_op.part.0+0x119/0x2e0 [nvme_fc]
blk_mq_dispatch_rq_list+0x17b/0x610
__blk_mq_sched_dispatch_requests+0xb0/0x140
blk_mq_sched_dispatch_requests+0x30/0x60
__blk_mq_run_hw_queue+0x35/0x90
__blk_mq_delay_run_hw_queue+0x161/0x180
blk_execute_rq+0xbe/0x160
__nvme_submit_sync_cmd+0x16f/0x220 [nvme_core]
nvmf_connect_admin_queue+0x11a/0x170 [nvme_fabrics]
nvme_fc_create_association.cold+0x50/0x3dc [nvme_fc]
nvme_fc_connect_ctrl_work+0x19/0x30 [nvme_fc]
process_one_work+0x1e8/0x3c0
On abort timeout, completion was called without checking if the I/O was
already completed.
Verify that I/O and abort request are indeed outstanding before attempting
completion.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-04
In the Linux kernel, the following vulnerability has been resolved:
thermal: intel_powerclamp: Use get_cpu() instead of smp_processor_id() to avoid crash
When CPU 0 is offline and intel_powerclamp is used to inject
idle, it generates kernel BUG:
BUG: using smp_processor_id() in preemptible [00000000] code: bash/15687
caller is debug_smp_processor_id+0x17/0x20
CPU: 4 PID: 15687 Comm: bash Not tainted 5.19.0-rc7+ #57
Call Trace:
<TASK>
dump_stack_lvl+0x49/0x63
dump_stack+0x10/0x16
check_preemption_disabled+0xdd/0xe0
debug_smp_processor_id+0x17/0x20
powerclamp_set_cur_state+0x7f/0xf9 [intel_powerclamp]
...
...
Here CPU 0 is the control CPU by default and changed to the current CPU,
if CPU 0 offlined. This check has to be performed under cpus_read_lock(),
hence the above warning.
Use get_cpu() instead of smp_processor_id() to avoid this BUG.
[ rjw: Subject edits ]
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-04
In the Linux kernel, the following vulnerability has been resolved:
dm cache: Fix UAF in destroy()
Dm_cache also has the same UAF problem when dm_resume()
and dm_destroy() are concurrent.
Therefore, cancelling timer again in destroy().
CVSS Score
7.8
EPSS Score
0.0
Published
2025-10-04
In the Linux kernel, the following vulnerability has been resolved:
binfmt_misc: fix shift-out-of-bounds in check_special_flags
UBSAN reported a shift-out-of-bounds warning:
left shift of 1 by 31 places cannot be represented in type 'int'
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x8d/0xcf lib/dump_stack.c:106
ubsan_epilogue+0xa/0x44 lib/ubsan.c:151
__ubsan_handle_shift_out_of_bounds+0x1e7/0x208 lib/ubsan.c:322
check_special_flags fs/binfmt_misc.c:241 [inline]
create_entry fs/binfmt_misc.c:456 [inline]
bm_register_write+0x9d3/0xa20 fs/binfmt_misc.c:654
vfs_write+0x11e/0x580 fs/read_write.c:582
ksys_write+0xcf/0x120 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x34/0x80 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x4194e1
Since the type of Node's flags is unsigned long, we should define these
macros with same type too.
CVSS Score
7.1
EPSS Score
0.0
Published
2025-10-04
In the Linux kernel, the following vulnerability has been resolved:
eth: alx: take rtnl_lock on resume
Zbynek reports that alx trips an rtnl assertion on resume:
RTNL: assertion failed at net/core/dev.c (2891)
RIP: 0010:netif_set_real_num_tx_queues+0x1ac/0x1c0
Call Trace:
<TASK>
__alx_open+0x230/0x570 [alx]
alx_resume+0x54/0x80 [alx]
? pci_legacy_resume+0x80/0x80
dpm_run_callback+0x4a/0x150
device_resume+0x8b/0x190
async_resume+0x19/0x30
async_run_entry_fn+0x30/0x130
process_one_work+0x1e5/0x3b0
indeed the driver does not hold rtnl_lock during its internal close
and re-open functions during suspend/resume. Note that this is not
a huge bug as the driver implements its own locking, and does not
implement changing the number of queues, but we need to silence
the splat.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-04
In the Linux kernel, the following vulnerability has been resolved:
net: enetc: avoid buffer leaks on xdp_do_redirect() failure
Before enetc_clean_rx_ring_xdp() calls xdp_do_redirect(), each software
BD in the RX ring between index orig_i and i can have one of 2 refcount
values on its page.
We are the owner of the current buffer that is being processed, so the
refcount will be at least 1.
If the current owner of the buffer at the diametrically opposed index
in the RX ring (i.o.w, the other half of this page) has not yet called
kfree(), this page's refcount could even be 2.
enetc_page_reusable() in enetc_flip_rx_buff() tests for the page
refcount against 1, and [ if it's 2 ] does not attempt to reuse it.
But if enetc_flip_rx_buff() is put after the xdp_do_redirect() call,
the page refcount can have one of 3 values. It can also be 0, if there
is no owner of the other page half, and xdp_do_redirect() for this
buffer ran so far that it triggered a flush of the devmap/cpumap bulk
queue, and the consumers of those bulk queues also freed the buffer,
all by the time xdp_do_redirect() returns the execution back to enetc.
This is the reason why enetc_flip_rx_buff() is called before
xdp_do_redirect(), but there is a big flaw with that reasoning:
enetc_flip_rx_buff() will set rx_swbd->page = NULL on both sides of the
enetc_page_reusable() branch, and if xdp_do_redirect() returns an error,
we call enetc_xdp_free(), which does not deal gracefully with that.
In fact, what happens is quite special. The page refcounts start as 1.
enetc_flip_rx_buff() figures they're reusable, transfers these
rx_swbd->page pointers to a different rx_swbd in enetc_reuse_page(), and
bumps the refcount to 2. When xdp_do_redirect() later returns an error,
we call the no-op enetc_xdp_free(), but we still haven't lost the
reference to that page. A copy of it is still at rx_ring->next_to_alloc,
but that has refcount 2 (and there are no concurrent owners of it in
flight, to drop the refcount). What really kills the system is when
we'll flip the rx_swbd->page the second time around. With an updated
refcount of 2, the page will not be reusable and we'll really leak it.
Then enetc_new_page() will have to allocate more pages, which will then
eventually leak again on further errors from xdp_do_redirect().
The problem, summarized, is that we zeroize rx_swbd->page before we're
completely done with it, and this makes it impossible for the error path
to do something with it.
Since the packet is potentially multi-buffer and therefore the
rx_swbd->page is potentially an array, manual passing of the old
pointers between enetc_flip_rx_buff() and enetc_xdp_free() is a bit
difficult.
For the sake of going with a simple solution, we accept the possibility
of racing with xdp_do_redirect(), and we move the flip procedure to
execute only on the redirect success path. By racing, I mean that the
page may be deemed as not reusable by enetc (having a refcount of 0),
but there will be no leak in that case, either.
Once we accept that, we have something better to do with buffers on
XDP_REDIRECT failure. Since we haven't performed half-page flipping yet,
we won't, either (and this way, we can avoid enetc_xdp_free()
completely, which gives the entire page to the slab allocator).
Instead, we'll call enetc_xdp_drop(), which will recycle this half of
the buffer back to the RX ring.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-04
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Fix potential memory leaks
When the driver hits -ENOMEM at allocating a URB or a buffer, it
aborts and goes to the error path that releases the all previously
allocated resources. However, when -ENOMEM hits at the middle of the
sync EP URB allocation loop, the partially allocated URBs might be
left without released, because ep->nurbs is still zero at that point.
Fix it by setting ep->nurbs at first, so that the error handler loops
over the full URB list.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-04
In the Linux kernel, the following vulnerability has been resolved:
ext4: add EXT4_IGET_BAD flag to prevent unexpected bad inode
There are many places that will get unhappy (and crash) when ext4_iget()
returns a bad inode. However, if iget the boot loader inode, allows a bad
inode to be returned, because the inode may not be initialized. This
mechanism can be used to bypass some checks and cause panic. To solve this
problem, we add a special iget flag EXT4_IGET_BAD. Only with this flag
we'd be returning bad inode from ext4_iget(), otherwise we always return
the error code if the inode is bad inode.(suggested by Jan Kara)
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-04
In the Linux kernel, the following vulnerability has been resolved:
net: ethernet: ti: Fix return type of netcp_ndo_start_xmit()
With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG),
indirect call targets are validated against the expected function
pointer prototype to make sure the call target is valid to help mitigate
ROP attacks. If they are not identical, there is a failure at run time,
which manifests as either a kernel panic or thread getting killed. A
proposed warning in clang aims to catch these at compile time, which
reveals:
drivers/net/ethernet/ti/netcp_core.c:1944:21: error: incompatible function pointer types initializing 'netdev_tx_t (*)(struct sk_buff *, struct net_device *)' (aka 'enum netdev_tx (*)(struct sk_buff *, struct net_device *)') with an expression of type 'int (struct sk_buff *, struct net_device *)' [-Werror,-Wincompatible-function-pointer-types-strict]
.ndo_start_xmit = netcp_ndo_start_xmit,
^~~~~~~~~~~~~~~~~~~~
1 error generated.
->ndo_start_xmit() in 'struct net_device_ops' expects a return type of
'netdev_tx_t', not 'int'. Adjust the return type of
netcp_ndo_start_xmit() to match the prototype's to resolve the warning
and CFI failure.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-04