Security Vulnerabilities - CVEs Published In March 2026
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.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-03-25
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").
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-25
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) ]
CVSS Score
4.7
EPSS Score
0.0
Published
2026-03-25
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
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-25
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)
CVSS Score
7.8
EPSS Score
0.0
Published
2026-03-25
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").
CVSS Score
7.8
EPSS Score
0.0
Published
2026-03-25
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.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-25
In the Linux kernel, the following vulnerability has been resolved:
ice: fix crash in ethtool offline loopback test
Since the conversion of ice to page pool, the ethtool loopback test
crashes:
BUG: kernel NULL pointer dereference, address: 000000000000000c
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 1100f1067 P4D 0
Oops: Oops: 0002 [#1] SMP NOPTI
CPU: 23 UID: 0 PID: 5904 Comm: ethtool Kdump: loaded Not tainted 6.19.0-0.rc7.260128g1f97d9dcf5364.49.eln154.x86_64 #1 PREEMPT(lazy)
Hardware name: [...]
RIP: 0010:ice_alloc_rx_bufs+0x1cd/0x310 [ice]
Code: 83 6c 24 30 01 66 41 89 47 08 0f 84 c0 00 00 00 41 0f b7 dc 48 8b 44 24 18 48 c1 e3 04 41 bb 00 10 00 00 48 8d 2c 18 8b 04 24 <89> 45 0c 41 8b 4d 00 49 d3 e3 44 3b 5c 24 24 0f 83 ac fe ff ff 44
RSP: 0018:ff7894738aa1f768 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000700 RDI: 0000000000000000
RBP: 0000000000000000 R08: ff16dcae79880200 R09: 0000000000000019
R10: 0000000000000001 R11: 0000000000001000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ff16dcae6c670000
FS: 00007fcf428850c0(0000) GS:ff16dcb149710000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000000000c CR3: 0000000121227005 CR4: 0000000000773ef0
PKRU: 55555554
Call Trace:
<TASK>
ice_vsi_cfg_rxq+0xca/0x460 [ice]
ice_vsi_cfg_rxqs+0x54/0x70 [ice]
ice_loopback_test+0xa9/0x520 [ice]
ice_self_test+0x1b9/0x280 [ice]
ethtool_self_test+0xe5/0x200
__dev_ethtool+0x1106/0x1a90
dev_ethtool+0xbe/0x1a0
dev_ioctl+0x258/0x4c0
sock_do_ioctl+0xe3/0x130
__x64_sys_ioctl+0xb9/0x100
do_syscall_64+0x7c/0x700
entry_SYSCALL_64_after_hwframe+0x76/0x7e
[...]
It crashes because we have not initialized libeth for the rx ring.
Fix it by treating ICE_VSI_LB VSIs slightly more like normal PF VSIs and
letting them have a q_vector. It's just a dummy, because the loopback
test does not use interrupts, but it contains a napi struct that can be
passed to libeth_rx_fq_create() called from ice_vsi_cfg_rxq() ->
ice_rxq_pp_create().
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-25
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.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-03-25
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.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-25