In the Linux kernel, the following vulnerability has been resolved:
ksmbd: Compare MACs in constant time
To prevent timing attacks, MAC comparisons need to be constant-time.
Replace the memcmp() with the correct function, crypto_memneq().
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7925: Fix possible oob access in mt7925_mac_write_txwi_80211()
Check frame length before accessing the mgmt fields in
mt7925_mac_write_txwi_80211 in order to avoid a possible oob access.
In the Linux kernel, the following vulnerability has been resolved:
can: bcm: fix locking for bcm_op runtime updates
Commit c2aba69d0c36 ("can: bcm: add locking for bcm_op runtime updates")
added a locking for some variables that can be modified at runtime when
updating the sending bcm_op with a new TX_SETUP command in bcm_tx_setup().
Usually the RX_SETUP only handles and filters incoming traffic with one
exception: When the RX_RTR_FRAME flag is set a predefined CAN frame is
sent when a specific RTR frame is received. Therefore the rx bcm_op uses
bcm_can_tx() which uses the bcm_tx_lock that was only initialized in
bcm_tx_setup(). Add the missing spin_lock_init() when allocating the
bcm_op in bcm_rx_setup() to handle the RTR case properly.
In the Linux kernel, the following vulnerability has been resolved:
PCI: dwc: ep: Flush MSI-X write before unmapping its ATU entry
Endpoint drivers use dw_pcie_ep_raise_msix_irq() to raise an MSI-X
interrupt to the host using a writel(), which generates a PCI posted write
transaction. There's no completion for posted writes, so the writel() may
return before the PCI write completes. dw_pcie_ep_raise_msix_irq() also
unmaps the outbound ATU entry used for the PCI write, so the write races
with the unmap.
If the PCI write loses the race with the ATU unmap, the write may corrupt
host memory or cause IOMMU errors, e.g., these when running fio with a
larger queue depth against nvmet-pci-epf:
arm-smmu-v3 fc900000.iommu: 0x0000010000000010
arm-smmu-v3 fc900000.iommu: 0x0000020000000000
arm-smmu-v3 fc900000.iommu: 0x000000090000f040
arm-smmu-v3 fc900000.iommu: 0x0000000000000000
arm-smmu-v3 fc900000.iommu: event: F_TRANSLATION client: 0000:01:00.0 sid: 0x100 ssid: 0x0 iova: 0x90000f040 ipa: 0x0
arm-smmu-v3 fc900000.iommu: unpriv data write s1 "Input address caused fault" stag: 0x0
Flush the write by performing a readl() of the same address to ensure that
the write has reached the destination before the ATU entry is unmapped.
The same problem was solved for dw_pcie_ep_raise_msi_irq() in commit
8719c64e76bf ("PCI: dwc: ep: Cache MSI outbound iATU mapping"), but there
it was solved by dedicating an outbound iATU only for MSI. We can't do the
same for MSI-X because each vector can have a different msg_addr and the
msg_addr may be changed while the vector is masked.
[bhelgaas: commit log]
In the Linux kernel, the following vulnerability has been resolved:
nvme: fix admin queue leak on controller reset
When nvme_alloc_admin_tag_set() is called during a controller reset,
a previous admin queue may still exist. Release it properly before
allocating a new one to avoid orphaning the old queue.
This fixes a regression introduced by commit 03b3bcd319b3 ("nvme: fix
admin request_queue lifetime").
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix stack-out-of-bounds write in devmap
get_upper_ifindexes() iterates over all upper devices and writes their
indices into an array without checking bounds.
Also the callers assume that the max number of upper devices is
MAX_NEST_DEV and allocate excluded_devices[1+MAX_NEST_DEV] on the stack,
but that assumption is not correct and the number of upper devices could
be larger than MAX_NEST_DEV (e.g., many macvlans), causing a
stack-out-of-bounds write.
Add a max parameter to get_upper_ifindexes() to avoid the issue.
When there are too many upper devices, return -EOVERFLOW and abort the
redirect.
To reproduce, create more than MAX_NEST_DEV(8) macvlans on a device with
an XDP program attached using BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS.
Then send a packet to the device to trigger the XDP redirect path.
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: Fix error handling in slot reset
If the device has not recovered after slot reset is called, it goes to
out label for error handling. There it could make decision based on
uninitialized hive pointer and could result in accessing an uninitialized
list.
Initialize the list and hive properly so that it handles the error
situation and also releases the reset domain lock which is acquired
during error_detected callback.
(cherry picked from commit bb71362182e59caa227e4192da5a612b09349696)
In the Linux kernel, the following vulnerability has been resolved:
can: mcp251x: fix deadlock in error path of mcp251x_open
The mcp251x_open() function call free_irq() in its error path with the
mpc_lock mutex held. But if an interrupt already occurred the
interrupt handler will be waiting for the mpc_lock and free_irq() will
deadlock waiting for the handler to finish.
This issue is similar to the one fixed in commit 7dd9c26bd6cf ("can:
mcp251x: fix deadlock if an interrupt occurs during mcp251x_open") but
for the error path.
To solve this issue move the call to free_irq() after the lock is
released. Setting `priv->force_quit = 1` beforehand ensure that the IRQ
handler will exit right away once it acquired the lock.
In the Linux kernel, the following vulnerability has been resolved:
drbd: fix "LOGIC BUG" in drbd_al_begin_io_nonblock()
Even though we check that we "should" be able to do lc_get_cumulative()
while holding the device->al_lock spinlock, it may still fail,
if some other code path decided to do lc_try_lock() with bad timing.
If that happened, we logged "LOGIC BUG for enr=...",
but still did not return an error.
The rest of the code now assumed that this request has references
for the relevant activity log extents.
The implcations are that during an active resync, mutual exclusivity of
resync versus application IO is not guaranteed. And a potential crash
at this point may not realizs that these extents could have been target
of in-flight IO and would need to be resynced just in case.
Also, once the request completes, it will give up activity log references it
does not even hold, which will trigger a BUG_ON(refcnt == 0) in lc_put().
Fix:
Do not crash the kernel for a condition that is harmless during normal
operation: also catch "e->refcnt == 0", not only "e == NULL"
when being noisy about "al_complete_io() called on inactive extent %u\n".
And do not try to be smart and "guess" whether something will work, then
be surprised when it does not.
Deal with the fact that it may or may not work. If it does not, remember a
possible "partially in activity log" state (only possible for requests that
cross extent boundaries), and return an error code from
drbd_al_begin_io_nonblock().
A latter call for the same request will then resume from where we left off.
In the Linux kernel, the following vulnerability has been resolved:
ata: libata: cancel pending work after clearing deferred_qc
Syzbot reported a WARN_ON() in ata_scsi_deferred_qc_work(), caused by
ap->ops->qc_defer() returning non-zero before issuing the deferred qc.
ata_scsi_schedule_deferred_qc() is called during each command completion.
This function will check if there is a deferred QC, and if
ap->ops->qc_defer() returns zero, meaning that it is possible to queue the
deferred qc at this time (without being deferred), then it will queue the
work which will issue the deferred qc.
Once the work get to run, which can potentially be a very long time after
the work was scheduled, there is a WARN_ON() if ap->ops->qc_defer() returns
non-zero.
While we hold the ap->lock both when assigning and clearing deferred_qc,
and the work itself holds the ap->lock, the code currently does not cancel
the work after clearing the deferred qc.
This means that the following scenario can happen:
1) One or several NCQ commands are queued.
2) A non-NCQ command is queued, gets stored in ap->deferred_qc.
3) Last NCQ command gets completed, work is queued to issue the deferred
qc.
4) Timeout or error happens, ap->deferred_qc is cleared. The queued work is
currently NOT canceled.
5) Port is reset.
6) One or several NCQ commands are queued.
7) A non-NCQ command is queued, gets stored in ap->deferred_qc.
8) Work is finally run. Yet at this time, there is still NCQ commands in
flight.
The work in 8) really belongs to the non-NCQ command in 2), not to the
non-NCQ command in 7). The reason why the work is executed when it is not
supposed to, is because it was never canceled when ap->deferred_qc was
cleared in 4). Thus, ensure that we always cancel the work after clearing
ap->deferred_qc.
Another potential fix would have been to let ata_scsi_deferred_qc_work() do
nothing if ap->ops->qc_defer() returns non-zero. However, canceling the
work when clearing ap->deferred_qc seems slightly more logical, as we hold
the ap->lock when clearing ap->deferred_qc, so we know that the work cannot
be holding the lock. (The function could be waiting for the lock, but that
is okay since it will do nothing if ap->deferred_qc is not set.)
In the Linux kernel, the following vulnerability has been resolved:
x86/fred: Correct speculative safety in fred_extint()
array_index_nospec() is no use if the result gets spilled to the stack, as
it makes the believed safe-under-speculation value subject to memory
predictions.
For all practical purposes, this means array_index_nospec() must be used in
the expression that accesses the array.
As the code currently stands, it's the wrong side of irqentry_enter(), and
'index' is put into %ebp across the function call.
Remove the index variable and reposition array_index_nospec(), so it's
calculated immediately before the array access.
In the Linux kernel, the following vulnerability has been resolved:
x86/efi: defer freeing of boot services memory
efi_free_boot_services() frees memory occupied by EFI_BOOT_SERVICES_CODE
and EFI_BOOT_SERVICES_DATA using memblock_free_late().
There are two issue with that: memblock_free_late() should be used for
memory allocated with memblock_alloc() while the memory reserved with
memblock_reserve() should be freed with free_reserved_area().
More acutely, with CONFIG_DEFERRED_STRUCT_PAGE_INIT=y
efi_free_boot_services() is called before deferred initialization of the
memory map is complete.
Benjamin Herrenschmidt reports that this causes a leak of ~140MB of
RAM on EC2 t3a.nano instances which only have 512MB or RAM.
If the freed memory resides in the areas that memory map for them is
still uninitialized, they won't be actually freed because
memblock_free_late() calls memblock_free_pages() and the latter skips
uninitialized pages.
Using free_reserved_area() at this point is also problematic because
__free_page() accesses the buddy of the freed page and that again might
end up in uninitialized part of the memory map.
Delaying the entire efi_free_boot_services() could be problematic
because in addition to freeing boot services memory it updates
efi.memmap without any synchronization and that's undesirable late in
boot when there is concurrency.
More robust approach is to only defer freeing of the EFI boot services
memory.
Split efi_free_boot_services() in two. First efi_unmap_boot_services()
collects ranges that should be freed into an array then
efi_free_boot_services() later frees them after deferred init is complete.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_set_pipapo: split gc into unlink and reclaim phase
Yiming Qian reports Use-after-free in the pipapo set type:
Under a large number of expired elements, commit-time GC can run for a very
long time in a non-preemptible context, triggering soft lockup warnings and
RCU stall reports (local denial of service).
We must split GC in an unlink and a reclaim phase.
We cannot queue elements for freeing until pointers have been swapped.
Expired elements are still exposed to both the packet path and userspace
dumpers via the live copy of the data structure.
call_rcu() does not protect us: dump operations or element lookups starting
after call_rcu has fired can still observe the free'd element, unless the
commit phase has made enough progress to swap the clone and live pointers
before any new reader has picked up the old version.
This a similar approach as done recently for the rbtree backend in commit
35f83a75529a ("netfilter: nft_set_rbtree: don't gc elements on insert").
In the Linux kernel, the following vulnerability has been resolved:
drm/xe/queue: Call fini on exec queue creation fail
Every call to queue init should have a corresponding fini call.
Skipping this would mean skipping removal of the queue from GuC list
(which is part of guc_id allocation). A damaged queue stored in
exec_queue_lookup list would lead to invalid memory reference,
sooner or later.
Call fini to free guc_id. This must be done before any internal
LRCs are freed.
Since the finalization with this extra call became very similar to
__xe_exec_queue_fini(), reuse that. To make this reuse possible,
alter xe_lrc_put() so it can survive NULL parameters, like other
similar functions.
v2: Reuse _xe_exec_queue_fini(). Make xe_lrc_put() aware of NULLs.
(cherry picked from commit 393e5fea6f7d7054abc2c3d97a4cfe8306cd6079)
In the Linux kernel, the following vulnerability has been resolved:
HID: pidff: Fix condition effect bit clearing
As reported by MPDarkGuy on discord, NULL pointer dereferences were
happening because not all the conditional effects bits were cleared.
Properly clear all conditional effect bits from ffbit
In the Linux kernel, the following vulnerability has been resolved:
cxl: Fix race of nvdimm_bus object when creating nvdimm objects
Found issue during running of cxl-translate.sh unit test. Adding a 3s
sleep right before the test seems to make the issue reproduce fairly
consistently. The cxl_translate module has dependency on cxl_acpi and
causes orphaned nvdimm objects to reprobe after cxl_acpi is removed.
The nvdimm_bus object is registered by the cxl_nvb object when
cxl_acpi_probe() is called. With the nvdimm_bus object missing,
__nd_device_register() will trigger NULL pointer dereference when
accessing the dev->parent that points to &nvdimm_bus->dev.
[ 192.884510] BUG: kernel NULL pointer dereference, address: 000000000000006c
[ 192.895383] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS edk2-20250812-19.fc42 08/12/2025
[ 192.897721] Workqueue: cxl_port cxl_bus_rescan_queue [cxl_core]
[ 192.899459] RIP: 0010:kobject_get+0xc/0x90
[ 192.924871] Call Trace:
[ 192.925959] <TASK>
[ 192.926976] ? pm_runtime_init+0xb9/0xe0
[ 192.929712] __nd_device_register.part.0+0x4d/0xc0 [libnvdimm]
[ 192.933314] __nvdimm_create+0x206/0x290 [libnvdimm]
[ 192.936662] cxl_nvdimm_probe+0x119/0x1d0 [cxl_pmem]
[ 192.940245] cxl_bus_probe+0x1a/0x60 [cxl_core]
[ 192.943349] really_probe+0xde/0x380
This patch also relies on the previous change where
devm_cxl_add_nvdimm_bridge() is called from drivers/cxl/pmem.c instead
of drivers/cxl/core.c to ensure the dependency of cxl_acpi on cxl_pmem.
1. Set probe_type of cxl_nvb to PROBE_FORCE_SYNCHRONOUS to ensure the
driver is probed synchronously when add_device() is called.
2. Add a check in __devm_cxl_add_nvdimm_bridge() to ensure that the
cxl_nvb driver is attached during cxl_acpi_probe().
3. Take the cxl_root uport_dev lock and the cxl_nvb->dev lock in
devm_cxl_add_nvdimm() before checking nvdimm_bus is valid.
4. Set cxl_nvdimm flag to CXL_NVD_F_INVALIDATED so cxl_nvdimm_probe()
will exit with -EBUSY.
The removal of cxl_nvdimm devices should prevent any orphaned devices
from probing once the nvdimm_bus is gone.
[ dj: Fixed 0-day reported kdoc issue. ]
[ dj: Fix cxl_nvb reference leak on error. Gregory (kreview-0811365) ]
In the Linux kernel, the following vulnerability has been resolved:
can: usb: f81604: correctly anchor the urb in the read bulk callback
When submitting an urb, that is using the anchor pattern, it needs to be
anchored before submitting it otherwise it could be leaked if
usb_kill_anchored_urbs() is called. This logic is correctly done
elsewhere in the driver, except in the read bulk callback so do that
here also.
In the Linux kernel, the following vulnerability has been resolved:
arm64: io: Extract user memory type in ioremap_prot()
The only caller of ioremap_prot() outside of the generic ioremap()
implementation is generic_access_phys(), which passes a 'pgprot_t' value
determined from the user mapping of the target 'pfn' being accessed by
the kernel. On arm64, the 'pgprot_t' contains all of the non-address
bits from the pte, including the permission controls, and so we end up
returning a new user mapping from ioremap_prot() which faults when
accessed from the kernel on systems with PAN:
| Unable to handle kernel read from unreadable memory at virtual address ffff80008ea89000
| ...
| Call trace:
| __memcpy_fromio+0x80/0xf8
| generic_access_phys+0x20c/0x2b8
| __access_remote_vm+0x46c/0x5b8
| access_remote_vm+0x18/0x30
| environ_read+0x238/0x3e8
| vfs_read+0xe4/0x2b0
| ksys_read+0xcc/0x178
| __arm64_sys_read+0x4c/0x68
Extract only the memory type from the user 'pgprot_t' in ioremap_prot()
and assert that we're being passed a user mapping, to protect us against
any changes in future that may require additional handling. To avoid
falsely flagging users of ioremap(), provide our own ioremap() macro
which simply wraps __ioremap_prot().
In the Linux kernel, the following vulnerability has been resolved:
crypto: ccp - Fix use-after-free on error path
In the error path of sev_tsm_init_locked(), the code dereferences 't'
after it has been freed with kfree(). The pr_err() statement attempts
to access t->tio_en and t->tio_init_done after the memory has been
released.
Move the pr_err() call before kfree(t) to access the fields while the
memory is still valid.
This issue reported by Smatch static analyser
In the Linux kernel, the following vulnerability has been resolved:
xdp: produce a warning when calculated tailroom is negative
Many ethernet drivers report xdp Rx queue frag size as being the same as
DMA write size. However, the only user of this field, namely
bpf_xdp_frags_increase_tail(), clearly expects a truesize.
Such difference leads to unspecific memory corruption issues under certain
circumstances, e.g. in ixgbevf maximum DMA write size is 3 KB, so when
running xskxceiver's XDP_ADJUST_TAIL_GROW_MULTI_BUFF, 6K packet fully uses
all DMA-writable space in 2 buffers. This would be fine, if only
rxq->frag_size was properly set to 4K, but value of 3K results in a
negative tailroom, because there is a non-zero page offset.
We are supposed to return -EINVAL and be done with it in such case, but due
to tailroom being stored as an unsigned int, it is reported to be somewhere
near UINT_MAX, resulting in a tail being grown, even if the requested
offset is too much (it is around 2K in the abovementioned test). This later
leads to all kinds of unspecific calltraces.
[ 7340.337579] xskxceiver[1440]: segfault at 1da718 ip 00007f4161aeac9d sp 00007f41615a6a00 error 6
[ 7340.338040] xskxceiver[1441]: segfault at 7f410000000b ip 00000000004042b5 sp 00007f415bffecf0 error 4
[ 7340.338179] in libc.so.6[61c9d,7f4161aaf000+160000]
[ 7340.339230] in xskxceiver[42b5,400000+69000]
[ 7340.340300] likely on CPU 6 (core 0, socket 6)
[ 7340.340302] Code: ff ff 01 e9 f4 fe ff ff 0f 1f 44 00 00 4c 39 f0 74 73 31 c0 ba 01 00 00 00 f0 0f b1 17 0f 85 ba 00 00 00 49 8b 87 88 00 00 00 <4c> 89 70 08 eb cc 0f 1f 44 00 00 48 8d bd f0 fe ff ff 89 85 ec fe
[ 7340.340888] likely on CPU 3 (core 0, socket 3)
[ 7340.345088] Code: 00 00 00 ba 00 00 00 00 be 00 00 00 00 89 c7 e8 31 ca ff ff 89 45 ec 8b 45 ec 85 c0 78 07 b8 00 00 00 00 eb 46 e8 0b c8 ff ff <8b> 00 83 f8 69 74 24 e8 ff c7 ff ff 8b 00 83 f8 0b 74 18 e8 f3 c7
[ 7340.404334] Oops: general protection fault, probably for non-canonical address 0x6d255010bdffc: 0000 [#1] SMP NOPTI
[ 7340.405972] CPU: 7 UID: 0 PID: 1439 Comm: xskxceiver Not tainted 6.19.0-rc1+ #21 PREEMPT(lazy)
[ 7340.408006] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.17.0-5.fc42 04/01/2014
[ 7340.409716] RIP: 0010:lookup_swap_cgroup_id+0x44/0x80
[ 7340.410455] Code: 83 f8 1c 73 39 48 ba ff ff ff ff ff ff ff 03 48 8b 04 c5 20 55 fa bd 48 21 d1 48 89 ca 83 e1 01 48 d1 ea c1 e1 04 48 8d 04 90 <8b> 00 48 83 c4 10 d3 e8 c3 cc cc cc cc 31 c0 e9 98 b7 dd 00 48 89
[ 7340.412787] RSP: 0018:ffffcc5c04f7f6d0 EFLAGS: 00010202
[ 7340.413494] RAX: 0006d255010bdffc RBX: ffff891f477895a8 RCX: 0000000000000010
[ 7340.414431] RDX: 0001c17e3fffffff RSI: 00fa070000000000 RDI: 000382fc7fffffff
[ 7340.415354] RBP: 00fa070000000000 R08: ffffcc5c04f7f8f8 R09: ffffcc5c04f7f7d0
[ 7340.416283] R10: ffff891f4c1a7000 R11: ffffcc5c04f7f9c8 R12: ffffcc5c04f7f7d0
[ 7340.417218] R13: 03ffffffffffffff R14: 00fa06fffffffe00 R15: ffff891f47789500
[ 7340.418229] FS: 0000000000000000(0000) GS:ffff891ffdfaa000(0000) knlGS:0000000000000000
[ 7340.419489] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 7340.420286] CR2: 00007f415bfffd58 CR3: 0000000103f03002 CR4: 0000000000772ef0
[ 7340.421237] PKRU: 55555554
[ 7340.421623] Call Trace:
[ 7340.421987] <TASK>
[ 7340.422309] ? softleaf_from_pte+0x77/0xa0
[ 7340.422855] swap_pte_batch+0xa7/0x290
[ 7340.423363] zap_nonpresent_ptes.constprop.0.isra.0+0xd1/0x270
[ 7340.424102] zap_pte_range+0x281/0x580
[ 7340.424607] zap_pmd_range.isra.0+0xc9/0x240
[ 7340.425177] unmap_page_range+0x24d/0x420
[ 7340.425714] unmap_vmas+0xa1/0x180
[ 7340.426185] exit_mmap+0xe1/0x3b0
[ 7340.426644] __mmput+0x41/0x150
[ 7340.427098] exit_mm+0xb1/0x110
[ 7340.427539] do_exit+0x1b2/0x460
[ 7340.427992] do_group_exit+0x2d/0xc0
[ 7340.428477] get_signal+0x79d/0x7e0
[ 7340.428957] arch_do_signal_or_restart+0x34/0x100
[ 7340.429571] exit_to_user_mode_loop+0x8e/0x4c0
[ 7340.430159] do_syscall_64+0x188/
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix race in cpumap on PREEMPT_RT
On PREEMPT_RT kernels, the per-CPU xdp_bulk_queue (bq) can be accessed
concurrently by multiple preemptible tasks on the same CPU.
The original code assumes bq_enqueue() and __cpu_map_flush() run
atomically with respect to each other on the same CPU, relying on
local_bh_disable() to prevent preemption. However, on PREEMPT_RT,
local_bh_disable() only calls migrate_disable() (when
PREEMPT_RT_NEEDS_BH_LOCK is not set) and does not disable
preemption, which allows CFS scheduling to preempt a task during
bq_flush_to_queue(), enabling another task on the same CPU to enter
bq_enqueue() and operate on the same per-CPU bq concurrently.
This leads to several races:
1. Double __list_del_clearprev(): after bq->count is reset in
bq_flush_to_queue(), a preempting task can call bq_enqueue() ->
bq_flush_to_queue() on the same bq when bq->count reaches
CPU_MAP_BULK_SIZE. Both tasks then call __list_del_clearprev()
on the same bq->flush_node, the second call dereferences the
prev pointer that was already set to NULL by the first.
2. bq->count and bq->q[] races: concurrent bq_enqueue() can corrupt
the packet queue while bq_flush_to_queue() is processing it.
The race between task A (__cpu_map_flush -> bq_flush_to_queue) and
task B (bq_enqueue -> bq_flush_to_queue) on the same CPU:
Task A (xdp_do_flush) Task B (cpu_map_enqueue)
---------------------- ------------------------
bq_flush_to_queue(bq)
spin_lock(&q->producer_lock)
/* flush bq->q[] to ptr_ring */
bq->count = 0
spin_unlock(&q->producer_lock)
bq_enqueue(rcpu, xdpf)
<-- CFS preempts Task A --> bq->q[bq->count++] = xdpf
/* ... more enqueues until full ... */
bq_flush_to_queue(bq)
spin_lock(&q->producer_lock)
/* flush to ptr_ring */
spin_unlock(&q->producer_lock)
__list_del_clearprev(flush_node)
/* sets flush_node.prev = NULL */
<-- Task A resumes -->
__list_del_clearprev(flush_node)
flush_node.prev->next = ...
/* prev is NULL -> kernel oops */
Fix this by adding a local_lock_t to xdp_bulk_queue and acquiring it
in bq_enqueue() and __cpu_map_flush(). These paths already run under
local_bh_disable(), so use local_lock_nested_bh() which on non-RT is
a pure annotation with no overhead, and on PREEMPT_RT provides a
per-CPU sleeping lock that serializes access to the bq.
To reproduce, insert an mdelay(100) between bq->count = 0 and
__list_del_clearprev() in bq_flush_to_queue(), then run reproducer
provided by syzkaller.
In the Linux kernel, the following vulnerability has been resolved:
accel/amdxdna: Fix crash when destroying a suspended hardware context
If userspace issues an ioctl to destroy a hardware context that has
already been automatically suspended, the driver may crash because the
mailbox channel pointer is NULL for the suspended context.
Fix this by checking the mailbox channel pointer in aie2_destroy_context()
before accessing it.
In the Linux kernel, the following vulnerability has been resolved:
net: sched: avoid qdisc_reset_all_tx_gt() vs dequeue race for lockless qdiscs
When shrinking the number of real tx queues,
netif_set_real_num_tx_queues() calls qdisc_reset_all_tx_gt() to flush
qdiscs for queues which will no longer be used.
qdisc_reset_all_tx_gt() currently serializes qdisc_reset() with
qdisc_lock(). However, for lockless qdiscs, the dequeue path is
serialized by qdisc_run_begin/end() using qdisc->seqlock instead, so
qdisc_reset() can run concurrently with __qdisc_run() and free skbs
while they are still being dequeued, leading to UAF.
This can easily be reproduced on e.g. virtio-net by imposing heavy
traffic while frequently changing the number of queue pairs:
iperf3 -ub0 -c $peer -t 0 &
while :; do
ethtool -L eth0 combined 1
ethtool -L eth0 combined 2
done
With KASAN enabled, this leads to reports like:
BUG: KASAN: slab-use-after-free in __qdisc_run+0x133f/0x1760
...
Call Trace:
<TASK>
...
__qdisc_run+0x133f/0x1760
__dev_queue_xmit+0x248f/0x3550
ip_finish_output2+0xa42/0x2110
ip_output+0x1a7/0x410
ip_send_skb+0x2e6/0x480
udp_send_skb+0xb0a/0x1590
udp_sendmsg+0x13c9/0x1fc0
...
</TASK>
Allocated by task 1270 on cpu 5 at 44.558414s:
...
alloc_skb_with_frags+0x84/0x7c0
sock_alloc_send_pskb+0x69a/0x830
__ip_append_data+0x1b86/0x48c0
ip_make_skb+0x1e8/0x2b0
udp_sendmsg+0x13a6/0x1fc0
...
Freed by task 1306 on cpu 3 at 44.558445s:
...
kmem_cache_free+0x117/0x5e0
pfifo_fast_reset+0x14d/0x580
qdisc_reset+0x9e/0x5f0
netif_set_real_num_tx_queues+0x303/0x840
virtnet_set_channels+0x1bf/0x260 [virtio_net]
ethnl_set_channels+0x684/0xae0
ethnl_default_set_doit+0x31a/0x890
...
Serialize qdisc_reset_all_tx_gt() against the lockless dequeue path by
taking qdisc->seqlock for TCQ_F_NOLOCK qdiscs, matching the
serialization model already used by dev_reset_queue().
Additionally clear QDISC_STATE_NON_EMPTY after reset so the qdisc state
reflects an empty queue, avoiding needless re-scheduling.
In the Linux kernel, the following vulnerability has been resolved:
nfc: nci: free skb on nci_transceive early error paths
nci_transceive() takes ownership of the skb passed by the caller,
but the -EPROTO, -EINVAL, and -EBUSY error paths return without
freeing it.
Due to issues clearing NCI_DATA_EXCHANGE fixed by subsequent changes
the nci/nci_dev selftest hits the error path occasionally in NIPA,
and kmemleak detects leaks:
unreferenced object 0xff11000015ce6a40 (size 640):
comm "nci_dev", pid 3954, jiffies 4295441246
hex dump (first 32 bytes):
6b 6b 6b 6b 00 a4 00 0c 02 e1 03 6b 6b 6b 6b 6b kkkk.......kkkkk
6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
backtrace (crc 7c40cc2a):
kmem_cache_alloc_node_noprof+0x492/0x630
__alloc_skb+0x11e/0x5f0
alloc_skb_with_frags+0xc6/0x8f0
sock_alloc_send_pskb+0x326/0x3f0
nfc_alloc_send_skb+0x94/0x1d0
rawsock_sendmsg+0x162/0x4c0
do_syscall_64+0x117/0xfc0
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu/userq: Do not allow userspace to trivially triger kernel warnings
Userspace can either deliberately pass in the too small num_fences, or the
required number can legitimately grow between the two calls to the userq
wait ioctl. In both cases we do not want the emit the kernel warning
backtrace since nothing is wrong with the kernel and userspace will simply
get an errno reported back. So lets simply drop the WARN_ONs.
(cherry picked from commit 2c333ea579de6cc20ea7bc50e9595ef72863e65c)
In the Linux kernel, the following vulnerability has been resolved:
pinctrl: pinconf-generic: Fix memory leak in pinconf_generic_parse_dt_config()
In pinconf_generic_parse_dt_config(), if parse_dt_cfg() fails, it returns
directly. This bypasses the cleanup logic and results in a memory leak of
the cfg buffer.
Fix this by jumping to the out label on failure, ensuring kfree(cfg) is
called before returning.
In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: cancel rfkill_block work in wiphy_unregister()
There is a use-after-free error in cfg80211_shutdown_all_interfaces found
by syzkaller:
BUG: KASAN: use-after-free in cfg80211_shutdown_all_interfaces+0x213/0x220
Read of size 8 at addr ffff888112a78d98 by task kworker/0:5/5326
CPU: 0 UID: 0 PID: 5326 Comm: kworker/0:5 Not tainted 6.19.0-rc2 #2 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Workqueue: events cfg80211_rfkill_block_work
Call Trace:
<TASK>
dump_stack_lvl+0x116/0x1f0
print_report+0xcd/0x630
kasan_report+0xe0/0x110
cfg80211_shutdown_all_interfaces+0x213/0x220
cfg80211_rfkill_block_work+0x1e/0x30
process_one_work+0x9cf/0x1b70
worker_thread+0x6c8/0xf10
kthread+0x3c5/0x780
ret_from_fork+0x56d/0x700
ret_from_fork_asm+0x1a/0x30
</TASK>
The problem arises due to the rfkill_block work is not cancelled when wiphy
is being unregistered. In order to fix the issue cancel the corresponding
work in wiphy_unregister().
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
In the Linux kernel, the following vulnerability has been resolved:
RDMA/irdma: Fix kernel stack leak in irdma_create_user_ah()
struct irdma_create_ah_resp { // 8 bytes, no padding
__u32 ah_id; // offset 0 - SET (uresp.ah_id = ah->sc_ah.ah_info.ah_idx)
__u8 rsvd[4]; // offset 4 - NEVER SET <- LEAK
};
rsvd[4]: 4 bytes of stack memory leaked unconditionally. Only ah_id is assigned before ib_respond_udata().
The reserved members of the structure were not zeroed.
In the Linux kernel, the following vulnerability has been resolved:
can: usb: f81604: handle short interrupt urb messages properly
If an interrupt urb is received that is not the correct length, properly
detect it and don't attempt to treat the data as valid.
In the Linux kernel, the following vulnerability has been resolved:
cpufreq: intel_pstate: Fix crash during turbo disable
When the system is booted with kernel command line argument "nosmt" or
"maxcpus" to limit the number of CPUs, disabling turbo via:
echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo
results in a crash:
PF: supervisor read access in kernel mode
PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP PTI
...
RIP: 0010:store_no_turbo+0x100/0x1f0
...
This occurs because for_each_possible_cpu() returns CPUs even if they
are not online. For those CPUs, all_cpu_data[] will be NULL. Since
commit 973207ae3d7c ("cpufreq: intel_pstate: Rearrange max frequency
updates handling code"), all_cpu_data[] is dereferenced even for CPUs
which are not online, causing the NULL pointer dereference.
To fix that, pass CPU number to intel_pstate_update_max_freq() and use
all_cpu_data[] for those CPUs for which there is a valid cpufreq policy.
In the Linux kernel, the following vulnerability has been resolved:
udp: Unhash auto-bound connected sk from 4-tuple hash table when disconnected.
Let's say we bind() an UDP socket to the wildcard address with a
non-zero port, connect() it to an address, and disconnect it from
the address.
bind() sets SOCK_BINDPORT_LOCK on sk->sk_userlocks (but not
SOCK_BINDADDR_LOCK), and connect() calls udp_lib_hash4() to put
the socket into the 4-tuple hash table.
Then, __udp_disconnect() calls sk->sk_prot->rehash(sk).
It computes a new hash based on the wildcard address and moves
the socket to a new slot in the 4-tuple hash table, leaving a
garbage in the chain that no packet hits.
Let's remove such a socket from 4-tuple hash table when disconnected.
Note that udp_sk(sk)->udp_portaddr_hash needs to be udpated after
udp_hash4_dec(hslot2) in udp_unhash4().
In the Linux kernel, the following vulnerability has been resolved:
accel/amdxdna: Fix NULL pointer dereference of mgmt_chann
mgmt_chann may be set to NULL if the firmware returns an unexpected
error in aie2_send_mgmt_msg_wait(). This can later lead to a NULL
pointer dereference in aie2_hw_stop().
Fix this by introducing a dedicated helper to destroy mgmt_chann
and by adding proper NULL checks before accessing it.
In the Linux kernel, the following vulnerability has been resolved:
xsk: Fix fragment node deletion to prevent buffer leak
After commit b692bf9a7543 ("xsk: Get rid of xdp_buff_xsk::xskb_list_node"),
the list_node field is reused for both the xskb pool list and the buffer
free list, this causes a buffer leak as described below.
xp_free() checks if a buffer is already on the free list using
list_empty(&xskb->list_node). When list_del() is used to remove a node
from the xskb pool list, it doesn't reinitialize the node pointers.
This means list_empty() will return false even after the node has been
removed, causing xp_free() to incorrectly skip adding the buffer to the
free list.
Fix this by using list_del_init() instead of list_del() in all fragment
handling paths, this ensures the list node is reinitialized after removal,
allowing the list_empty() to work correctly.
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7996: Fix possible oob access in mt7996_mac_write_txwi_80211()
Check frame length before accessing the mgmt fields in
mt7996_mac_write_txwi_80211 in order to avoid a possible oob access.
In the Linux kernel, the following vulnerability has been resolved:
can: usb: etas_es58x: correctly anchor the urb in the read bulk callback
When submitting an urb, that is using the anchor pattern, it needs to be
anchored before submitting it otherwise it could be leaked if
usb_kill_anchored_urbs() is called. This logic is correctly done
elsewhere in the driver, except in the read bulk callback so do that
here also.
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (macsmc) Fix regressions in Apple Silicon SMC hwmon driver
The recently added macsmc-hwmon driver contained several critical
bugs in its sensor population logic and float conversion routines.
Specifically:
- The voltage sensor population loop used the wrong prefix ("volt-"
instead of "voltage-") and incorrectly assigned sensors to the
temperature sensor array (hwmon->temp.sensors) instead of the
voltage sensor array (hwmon->volt.sensors). This would lead to
out-of-bounds memory access or data corruption when both temperature
and voltage sensors were present.
- The float conversion in macsmc_hwmon_write_f32() had flawed exponent
logic for values >= 2^24 and lacked masking for the mantissa, which
could lead to incorrect values being written to the SMC.
Fix these issues to ensure correct sensor registration and reliable
manual fan control.
Confirm that the reported overflow in FIELD_PREP is fixed by declaring
macsmc_hwmon_write_f32() as __always_inline for a compile test.
In the Linux kernel, the following vulnerability has been resolved:
ipmi: Fix use-after-free and list corruption on sender error
The analysis from Breno:
When the SMI sender returns an error, smi_work() delivers an error
response but then jumps back to restart without cleaning up properly:
1. intf->curr_msg is not cleared, so no new message is pulled
2. newmsg still points to the message, causing sender() to be called
again with the same message
3. If sender() fails again, deliver_err_response() is called with
the same recv_msg that was already queued for delivery
This causes list_add corruption ("list_add double add") because the
recv_msg is added to the user_msgs list twice. Subsequently, the
corrupted list leads to use-after-free when the memory is freed and
reused, and eventually a NULL pointer dereference when accessing
recv_msg->done.
The buggy sequence:
sender() fails
-> deliver_err_response(recv_msg) // recv_msg queued for delivery
-> goto restart // curr_msg not cleared!
sender() fails again (same message!)
-> deliver_err_response(recv_msg) // tries to queue same recv_msg
-> LIST CORRUPTION
Fix this by freeing the message and setting it to NULL on a send error.
Also, always free the newmsg on a send error, otherwise it will leak.
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix a UAF issue in bpf_trampoline_link_cgroup_shim
The root cause of this bug is that when 'bpf_link_put' reduces the
refcount of 'shim_link->link.link' to zero, the resource is considered
released but may still be referenced via 'tr->progs_hlist' in
'cgroup_shim_find'. The actual cleanup of 'tr->progs_hlist' in
'bpf_shim_tramp_link_release' is deferred. During this window, another
process can cause a use-after-free via 'bpf_trampoline_link_cgroup_shim'.
Based on Martin KaFai Lau's suggestions, I have created a simple patch.
To fix this:
Add an atomic non-zero check in 'bpf_trampoline_link_cgroup_shim'.
Only increment the refcount if it is not already zero.
Testing:
I verified the fix by adding a delay in
'bpf_shim_tramp_link_release' to make the bug easier to trigger:
static void bpf_shim_tramp_link_release(struct bpf_link *link)
{
/* ... */
if (!shim_link->trampoline)
return;
+ msleep(100);
WARN_ON_ONCE(bpf_trampoline_unlink_prog(&shim_link->link,
shim_link->trampoline, NULL));
bpf_trampoline_put(shim_link->trampoline);
}
Before the patch, running a PoC easily reproduced the crash(almost 100%)
with a call trace similar to KaiyanM's report.
After the patch, the bug no longer occurs even after millions of
iterations.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Use correct version for UAC3 header validation
The entry of the validators table for UAC3 AC header descriptor is
defined with the wrong protocol version UAC_VERSION_2, while it should
have been UAC_VERSION_3. This results in the validator never matching
for actual UAC3 devices (protocol == UAC_VERSION_3), causing their
header descriptors to bypass validation entirely. A malicious USB
device presenting a truncated UAC3 header could exploit this to cause
out-of-bounds reads when the driver later accesses unvalidated
descriptor fields.
The bug was introduced in the same commit as the recently fixed UAC3
feature unit sub-type typo, and appears to be from the same copy-paste
error when the UAC3 section was created from the UAC2 section.
In the Linux kernel, the following vulnerability has been resolved:
drm/vmwgfx: Return the correct value in vmw_translate_ptr functions
Before the referenced fixes these functions used a lookup function that
returned a pointer. This was changed to another lookup function that
returned an error code with the pointer becoming an out parameter.
The error path when the lookup failed was not changed to reflect this
change and the code continued to return the PTR_ERR of the now
uninitialized pointer. This could cause the vmw_translate_ptr functions
to return success when they actually failed causing further uninitialized
and OOB accesses.
In the Linux kernel, the following vulnerability has been resolved:
net: ipv4: fix ARM64 alignment fault in multipath hash seed
`struct sysctl_fib_multipath_hash_seed` contains two u32 fields
(user_seed and mp_seed), making it an 8-byte structure with a 4-byte
alignment requirement.
In `fib_multipath_hash_from_keys()`, the code evaluates the entire
struct atomically via `READ_ONCE()`:
mp_seed = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_seed).mp_seed;
While this silently works on GCC by falling back to unaligned regular
loads which the ARM64 kernel tolerates, it causes a fatal kernel panic
when compiled with Clang and LTO enabled.
Commit e35123d83ee3 ("arm64: lto: Strengthen READ_ONCE() to acquire
when CONFIG_LTO=y") strengthens `READ_ONCE()` to use Load-Acquire
instructions (`ldar` / `ldapr`) to prevent compiler reordering bugs
under Clang LTO. Since the macro evaluates the full 8-byte struct,
Clang emits a 64-bit `ldar` instruction. ARM64 architecture strictly
requires `ldar` to be naturally aligned, thus executing it on a 4-byte
aligned address triggers a strict Alignment Fault (FSC = 0x21).
Fix the read side by moving the `READ_ONCE()` directly to the `u32`
member, which emits a safe 32-bit `ldar Wn`.
Furthermore, Eric Dumazet pointed out that `WRITE_ONCE()` on the entire
struct in `proc_fib_multipath_hash_set_seed()` is also flawed. Analysis
shows that Clang splits this 8-byte write into two separate 32-bit
`str` instructions. While this avoids an alignment fault, it destroys
atomicity and exposes a tear-write vulnerability. Fix this by
explicitly splitting the write into two 32-bit `WRITE_ONCE()`
operations.
Finally, add the missing `READ_ONCE()` when reading `user_seed` in
`proc_fib_multipath_hash_seed()` to ensure proper pairing and
concurrency safety.
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: Fix possible oob access in mt76_connac2_mac_write_txwi_80211()
Check frame length before accessing the mgmt fields in
mt76_connac2_mac_write_txwi_80211 in order to avoid a possible oob
access.
[fix check to also cover mgmt->u.action.u.addba_req.capab,
correct Fixes tag]