Linux: >> Linux Kernel >> 6.1.146 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
perf/core: Fix WARN_ON(!ctx) in __free_event() for partial init
Move the get_ctx(child_ctx) call and the child_event->ctx assignment to
occur immediately after the child event is allocated. Ensure that
child_event->ctx is non-NULL before any subsequent error path within
inherit_event calls free_event(), satisfying the assumptions of the
cleanup code.
Details:
There's no clear Fixes tag, because this bug is a side-effect of
multiple interacting commits over time (up to 15 years old), not
a single regression.
The code initially incremented refcount then assigned context
immediately after the child_event was created. Later, an early
validity check for child_event was added before the
refcount/assignment. Even later, a WARN_ON_ONCE() cleanup check was
added, assuming event->ctx is valid if the pmu_ctx is valid.
The problem is that the WARN_ON_ONCE() could trigger after the initial
check passed but before child_event->ctx was assigned, violating its
precondition. The solution is to assign child_event->ctx right after
its initial validation. This ensures the context exists for any
subsequent checks or cleanup routines, resolving the WARN_ON_ONCE().
To resolve it, defer the refcount update and child_event->ctx assignment
directly after child_event->pmu_ctx is set but before checking if the
parent event is orphaned. The cleanup routine depends on
event->pmu_ctx being non-NULL before it verifies event->ctx is
non-NULL. This also maintains the author's original intent of passing
in child_ctx to find_get_pmu_context before its refcount/assignment.
[ mingo: Expanded the changelog from another email by Gabriel Shahrouzi. ]
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-09
In the Linux kernel, the following vulnerability has been resolved:
um: work around sched_yield not yielding in time-travel mode
sched_yield by a userspace may not actually cause scheduling in
time-travel mode as no time has passed. In the case seen it appears to
be a badly implemented userspace spinlock in ASAN. Unfortunately, with
time-travel it causes an extreme slowdown or even deadlock depending on
the kernel configuration (CONFIG_UML_MAX_USERSPACE_ITERATIONS).
Work around it by accounting time to the process whenever it executes a
sched_yield syscall.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-05-09
In the Linux kernel, the following vulnerability has been resolved:
usb: xhci: Fix isochronous Ring Underrun/Overrun event handling
The TRB pointer of these events points at enqueue at the time of error
occurrence on xHCI 1.1+ HCs or it's NULL on older ones. By the time we
are handling the event, a new TD may be queued at this ring position.
I can trigger this race by rising interrupt moderation to increase IRQ
handling delay. Similar delay may occur naturally due to system load.
If this ever happens after a Missed Service Error, missed TDs will be
skipped and the new TD processed as if it matched the event. It could
be given back prematurely, risking data loss or buffer UAF by the xHC.
Don't complete TDs on xrun events and don't warn if queued TDs don't
match the event's TRB pointer, which can be NULL or a link/no-op TRB.
Don't warn if there are no queued TDs at all.
Now that it's safe, also handle xrun events if the skip flag is clear.
This ensures completion of any TD stuck in 'error mid TD' state right
before the xrun event, which could happen if a driver submits a finite
number of URBs to a buggy HC and then an error occurs on the last TD.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-05-09
In the Linux kernel, the following vulnerability has been resolved:
iommu: Clear iommu-dma ops on cleanup
If iommu_device_register() encounters an error, it can end up tearing
down already-configured groups and default domains, however this
currently still leaves devices hooked up to iommu-dma (and even
historically the behaviour in this area was at best inconsistent across
architectures/drivers...) Although in the case that an IOMMU is present
whose driver has failed to probe, users cannot necessarily expect DMA to
work anyway, it's still arguable that we should do our best to put
things back as if the IOMMU driver was never there at all, and certainly
the potential for crashing in iommu-dma itself is undesirable. Make sure
we clean up the dev->dma_iommu flag along with everything else.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-09
In the Linux kernel, the following vulnerability has been resolved:
scsi: mpi3mr: Synchronous access b/w reset and tm thread for reply queue
When the task management thread processes reply queues while the reset
thread resets them, the task management thread accesses an invalid queue ID
(0xFFFF), set by the reset thread, which points to unallocated memory,
causing a crash.
Add flag 'io_admin_reset_sync' to synchronize access between the reset,
I/O, and admin threads. Before a reset, the reset handler sets this flag to
block I/O and admin processing threads. If any thread bypasses the initial
check, the reset thread waits up to 10 seconds for processing to finish. If
the wait exceeds 10 seconds, the controller is marked as unrecoverable.
CVSS Score
7.8
EPSS Score
0.001
Published
2025-05-09
In the Linux kernel, the following vulnerability has been resolved:
net: dsa: clean up FDB, MDB, VLAN entries on unbind
As explained in many places such as commit b117e1e8a86d ("net: dsa:
delete dsa_legacy_fdb_add and dsa_legacy_fdb_del"), DSA is written given
the assumption that higher layers have balanced additions/deletions.
As such, it only makes sense to be extremely vocal when those
assumptions are violated and the driver unbinds with entries still
present.
But Ido Schimmel points out a very simple situation where that is wrong:
https://lore.kernel.org/netdev/ZDazSM5UsPPjQuKr@shredder/
(also briefly discussed by me in the aforementioned commit).
Basically, while the bridge bypass operations are not something that DSA
explicitly documents, and for the majority of DSA drivers this API
simply causes them to go to promiscuous mode, that isn't the case for
all drivers. Some have the necessary requirements for bridge bypass
operations to do something useful - see dsa_switch_supports_uc_filtering().
Although in tools/testing/selftests/net/forwarding/local_termination.sh,
we made an effort to popularize better mechanisms to manage address
filters on DSA interfaces from user space - namely macvlan for unicast,
and setsockopt(IP_ADD_MEMBERSHIP) - through mtools - for multicast, the
fact is that 'bridge fdb add ... self static local' also exists as
kernel UAPI, and might be useful to someone, even if only for a quick
hack.
It seems counter-productive to block that path by implementing shim
.ndo_fdb_add and .ndo_fdb_del operations which just return -EOPNOTSUPP
in order to prevent the ndo_dflt_fdb_add() and ndo_dflt_fdb_del() from
running, although we could do that.
Accepting that cleanup is necessary seems to be the only option.
Especially since we appear to be coming back at this from a different
angle as well. Russell King is noticing that the WARN_ON() triggers even
for VLANs:
https://lore.kernel.org/netdev/Z_li8Bj8bD4-BYKQ@shell.armlinux.org.uk/
What happens in the bug report above is that dsa_port_do_vlan_del() fails,
then the VLAN entry lingers on, and then we warn on unbind and leak it.
This is not a straight revert of the blamed commit, but we now add an
informational print to the kernel log (to still have a way to see
that bugs exist), and some extra comments gathered from past years'
experience, to justify the logic.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-05-09
In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: debugfs hang_hws skip GPU with MES
debugfs hang_hws is used by GPU reset test with HWS, for MES this crash
the kernel with NULL pointer access because dqm->packet_mgr is not setup
for MES path.
Skip GPU with MES for now, MES hang_hws debugfs interface will be
supported later.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-05-09
In the Linux kernel, the following vulnerability has been resolved:
btrfs: harden block_group::bg_list against list_del() races
As far as I can tell, these calls of list_del_init() on bg_list cannot
run concurrently with btrfs_mark_bg_unused() or btrfs_mark_bg_to_reclaim(),
as they are in transaction error paths and situations where the block
group is readonly.
However, if there is any chance at all of racing with mark_bg_unused(),
or a different future user of bg_list, better to be safe than sorry.
Otherwise we risk the following interleaving (bg_list refcount in parens)
T1 (some random op) T2 (btrfs_mark_bg_unused)
!list_empty(&bg->bg_list); (1)
list_del_init(&bg->bg_list); (1)
list_move_tail (1)
btrfs_put_block_group (0)
btrfs_delete_unused_bgs
bg = list_first_entry
list_del_init(&bg->bg_list);
btrfs_put_block_group(bg); (-1)
Ultimately, this results in a broken ref count that hits zero one deref
early and the real final deref underflows the refcount, resulting in a WARNING.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-05-09
In the Linux kernel, the following vulnerability has been resolved:
spi: fsl-qspi: use devm function instead of driver remove
Driver use devm APIs to manage clk/irq/resources and register the spi
controller, but the legacy remove function will be called first during
device detach and trigger kernel panic. Drop the remove function and use
devm_add_action_or_reset() for driver cleanup to ensure the release
sequence.
Trigger kernel panic on i.MX8MQ by
echo 30bb0000.spi >/sys/bus/platform/drivers/fsl-quadspi/unbind
CVSS Score
5.5
EPSS Score
0.001
Published
2025-05-09
In the Linux kernel, the following vulnerability has been resolved:
net/niu: Niu requires MSIX ENTRY_DATA fields touch before entry reads
Fix niu_try_msix() to not cause a fatal trap on sparc systems.
Set PCI_DEV_FLAGS_MSIX_TOUCH_ENTRY_DATA_FIRST on the struct pci_dev to
work around a bug in the hardware or firmware.
For each vector entry in the msix table, niu chips will cause a fatal
trap if any registers in that entry are read before that entries'
ENTRY_DATA register is written to. Testing indicates writes to other
registers are not sufficient to prevent the fatal trap, however the value
does not appear to matter. This only needs to happen once after power up,
so simply rebooting into a kernel lacking this fix will NOT cause the
trap.
NON-RESUMABLE ERROR: Reporting on cpu 64
NON-RESUMABLE ERROR: TPC [0x00000000005f6900] <msix_prepare_msi_desc+0x90/0xa0>
NON-RESUMABLE ERROR: RAW [4010000000000016:00000e37f93e32ff:0000000202000080:ffffffffffffffff
NON-RESUMABLE ERROR: 0000000800000000:0000000000000000:0000000000000000:0000000000000000]
NON-RESUMABLE ERROR: handle [0x4010000000000016] stick [0x00000e37f93e32ff]
NON-RESUMABLE ERROR: type [precise nonresumable]
NON-RESUMABLE ERROR: attrs [0x02000080] < ASI sp-faulted priv >
NON-RESUMABLE ERROR: raddr [0xffffffffffffffff]
NON-RESUMABLE ERROR: insn effective address [0x000000c50020000c]
NON-RESUMABLE ERROR: size [0x8]
NON-RESUMABLE ERROR: asi [0x00]
CPU: 64 UID: 0 PID: 745 Comm: kworker/64:1 Not tainted 6.11.5 #63
Workqueue: events work_for_cpu_fn
TSTATE: 0000000011001602 TPC: 00000000005f6900 TNPC: 00000000005f6904 Y: 00000000 Not tainted
TPC: <msix_prepare_msi_desc+0x90/0xa0>
g0: 00000000000002e9 g1: 000000000000000c g2: 000000c50020000c g3: 0000000000000100
g4: ffff8000470307c0 g5: ffff800fec5be000 g6: ffff800047a08000 g7: 0000000000000000
o0: ffff800014feb000 o1: ffff800047a0b620 o2: 0000000000000011 o3: ffff800047a0b620
o4: 0000000000000080 o5: 0000000000000011 sp: ffff800047a0ad51 ret_pc: 00000000005f7128
RPC: <__pci_enable_msix_range+0x3cc/0x460>
l0: 000000000000000d l1: 000000000000c01f l2: ffff800014feb0a8 l3: 0000000000000020
l4: 000000000000c000 l5: 0000000000000001 l6: 0000000020000000 l7: ffff800047a0b734
i0: ffff800014feb000 i1: ffff800047a0b730 i2: 0000000000000001 i3: 000000000000000d
i4: 0000000000000000 i5: 0000000000000000 i6: ffff800047a0ae81 i7: 00000000101888b0
I7: <niu_try_msix.constprop.0+0xc0/0x130 [niu]>
Call Trace:
[<00000000101888b0>] niu_try_msix.constprop.0+0xc0/0x130 [niu]
[<000000001018f840>] niu_get_invariants+0x183c/0x207c [niu]
[<00000000101902fc>] niu_pci_init_one+0x27c/0x2fc [niu]
[<00000000005ef3e4>] local_pci_probe+0x28/0x74
[<0000000000469240>] work_for_cpu_fn+0x8/0x1c
[<000000000046b008>] process_scheduled_works+0x144/0x210
[<000000000046b518>] worker_thread+0x13c/0x1c0
[<00000000004710e0>] kthread+0xb8/0xc8
[<00000000004060c8>] ret_from_fork+0x1c/0x2c
[<0000000000000000>] 0x0
Kernel panic - not syncing: Non-resumable error.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-08