| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
erofs: disable LZ4 rolling decompression for now
LZ4 rolling decompression [1] was introduced to reduce the memory
footprint of temporary pages:
For many cases, it is needed for users to read small data within
a compressed extent (pcluster), either due to random small read, or
since uptodate folios (typically order-0) cannot be reused for
decompression again since decompression algorithm refills
already-uptodate folios.
Rolling decompression works because LZ4 is LZ77-based and only refers
to the most recent 64 KiB of decompressed data, so in theory only a
bounded rolling window of temporary pages is needed when decompressing.
It can save a lot of temporary memory, e.g.
601,960-byte data can be compressed into a 256k LZ4 compressed extent,
which means it needs 146 extra pages per request in the worst case if
rolling decompression is disabled.
However, the upstream LZ4 implementation is not under EROFS' control:
For example, the literal copy memmove() may still **copy long literals
backward** on x86 based on the address comparison even when the source
and destination ranges do not overlap (IOWs, inline decompression
doesn't need to be considered here). That breaks the rolling assumption
and makes the optimization broken.
Disable it for now to make sure the data correctness first since EROFS
is used everywhere now: The rolling window approach can be revived once
we either ensure that the official LZ4 code always copies forward for
non-overlapping ranges or maintain our own LZ4 implementation in EROFS.
The main impact is a higher runtime memory footprint; However, recent
commit 0f6273ab4637 ("erofs: add a reserved buffer pool for lz4
decompression") helps mitigate this when enabled but it's still not
perfect.
[1] https://www.usenix.org/conference/atc19/presentation/gao
ยง 3.3 Decompression |
| In the Linux kernel, the following vulnerability has been resolved:
net/rds: don't let rds_conn_shutdown() consume a concurrent drop
rds_conn_shutdown() finishes by moving the path from
RDS_CONN_DISCONNECTING to RDS_CONN_DOWN, and also accepts
RDS_CONN_ERROR as the starting state of that final transition, so that
a FIN processed in softirq context during the teardown does not derail
the shutdown into a noisy error path.
But consuming that RDS_CONN_ERROR also consumes the shutdown pass that
came with it: rds_conn_path_drop() sets RDS_CONN_ERROR and then queues
cp_down_w, and a pass that starts on a path already in RDS_CONN_DOWN
is a no-op. For the FIN case that is harmless - the socket the FIN
arrived on is the very socket the teardown just released. It is not
harmless for a dropper that attached something to the path first.
rds_tcp_accept_one() is such a dropper. Its path claim in
rds_tcp_accept_one_path() transitions RDS_CONN_DOWN ->
RDS_CONN_CONNECTING, and a concurrent drop - a FIN on a previous
socket in softirq context, an administrative reset - can put the path
into RDS_CONN_ERROR between that claim and the state check that
follows, which accepts RDS_CONN_ERROR. The accept then installs the
freshly accepted socket with rds_tcp_set_callbacks() while the queued
teardown - which sampled tc->t_sock before this socket existed - is
still running. rds_connect_path_complete() fails its transition to
RDS_CONN_UP and drops the path again, queueing the pass that should
reap the socket it just installed. If the in-flight shutdown's final
transition consumes that drop's RDS_CONN_ERROR, the queued pass finds
the path in RDS_CONN_DOWN and does nothing. The installed socket is
never torn down: it sits established with its callbacks armed and its
rds_tcp_connection on rds_tcp_tc_list, the peer sees a connection that
nothing ever reads, and the path is wedged in RDS_CONN_DOWN until some
later event drops it again. Reproduced with widened race windows as
an ever-growing receive queue on a socket owned by a path stuck in
RDS_CONN_DOWN, with the peer's send path wedged behind it.
Make the final transition only DISCONNECTING -> DOWN. If it fails
because the path is in RDS_CONN_ERROR, a drop raced the teardown:
cancel the reconnect timer and clear RDS_RECONNECT_PENDING - the one
piece of the skipped tail that must not be left behind - and return,
letting the pass the drop queued finish the job: it tears down
whatever attached to the path in the meantime, completes the
transition to RDS_CONN_DOWN, and re-arms the reconnect from its own
tail.
The timer quiesce in that branch matters because the racing drop does
not always queue that pass: rds_conn_path_drop() returns without
queueing when a destroy is pending - exactly the situation during a
netns teardown or module unload, when a FIN on the dying socket is
processed while rds_conn_path_destroy() flushes cp_down_w. If the
flushed pass is the one that takes this return, no later pass exists,
and rds_conn_path_destroy() would find cp_conn_w still armed
(WARN_ON) and then free a path whose reconnect timer can still fire.
With the cancel in the branch, every exit of a shutdown pass leaves
the timer quiesced no matter which pass completes the transition.
The FIN case keeps making progress, one pass later and still without
noisy logging. Any other state keeps today's rds_conn_path_error()
handling; no current cp_state writer can leave a DISCONNECTING path
in anything but RDS_CONN_ERROR (every other writer is a cmpxchg from
a non-DISCONNECTING state), so that branch is defensive.
On kernels without the preceding patches the same hazard exists with
the sample-based quiesce; the fix applies there equally. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: reject BPF_PSEUDO_FUNC reference to the main program
fixups.c:jit_subprogs() rewrites BPF_PSEUDO_FUNC loads to contain real
function addresses. This function is invoked from bpf_jit_subprogs()
only when env->subprog_cnt > 1. Meaning that for any program like
below:
int main(void *ctx) {
void *ptr = main;
...
bpf_timer_set_callback(..., ptr);
...
}
The 'ptr' won't be ever converted to contain an address.
In combination with e.g. bpf_timer_set_callback() this would lead to a
function call at a bogus address.
Instead of complicating the implementation, just assume that no useful
program needs main to be a sync or async callback and reject
BPF_PSEUDO_FUNC loads for the main subprogram. |
| In the Linux kernel, the following vulnerability has been resolved:
tracing/probes: Fix use-after-free on field name/type of events with multiple probes
The fields of a probe-based dynamic event (kprobe, uprobe, eprobe and
fprobe events) are created in traceprobe_define_arg_fields() by handing
the probe_arg name/type strings to trace_define_field(), which only
stores the pointers without copying. Those strings are owned by the
trace_probe and are freed when that probe is removed.
An event can have several probes attached. The field list is defined
only once, by the first probe that registers the event, but it is kept
alive by any surviving sibling probe. Deleting just that first probe by
symbol -
# primary A: fields are defined from A's args
echo 'p:kprobes/ev vfs_read a1=$arg1' > kprobe_events
# append B: shares A's event call
echo 'p:kprobes/ev vfs_write a1=$arg1' >> kprobe_events
# delete only A (matched by symbol), B survives
echo '-:kprobes/ev vfs_read' >> kprobe_events
frees A's args (trace_probe_cleanup() -> traceprobe_free_probe_arg()),
but trace_probe_unlink() keeps the trace_probe_event because the probe
list is not empty. The event call stays registered via B while its
fields now reference freed memory. Any field lookup then reads it, e.g.
echo 'a1 == 1' > events/kprobes/ev/filter
BUG: KASAN: slab-use-after-free in strcmp+0xa7/0xb0
Call Trace:
strcmp
trace_find_event_field
parse_pred
process_preds
create_filter
apply_event_filter
event_filter_write
field->name references parg->name (kstrdup'd, freed with the probe) and,
for array arguments, field->type references parg->fmt (kmalloc'd, freed
with the probe) - the scalar type otherwise points at the static
fmttype rodata, which is safe.
Have traceprobe_define_arg_fields() duplicate the name and type strings
and anchor the copies on the trace_probe_event, which embeds the event
call and outlives every individual probe; trace_probe_event_free()
releases them.
The reproducer above triggers reliably; the field lookup and the delete
both run under event_mutex, so this is a dangling reference after
removal rather than a race.
The issue was found by the autokbug dynamic kernel fuzzer at Tencent
Yunding Lab. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: zstd: fix lost wakeup when waiting for a workspace
A writer can sleep forever in zstd_get_workspace() even though a workspace
is free. When zstd_alloc_workspace() fails, the task is queued on
zwsm->wait and schedules unconditionally, never re-testing the pool.
zstd_put_workspace() publishes the workspace and then calls cond_wake_up(),
which only wakes when a sleeper is already visible, so a workspace returned
between the failed allocation and prepare_to_wait() wakes nobody. The
window is wide: zstd_alloc_workspace() goes through kvmalloc() and may
enter reclaim.
Only a max level workspace triggers the wakeup and one is deliberately kept
allocated as the fallback every waiter waits for, so once its wakeup is
lost the writer stays in TASK_UNINTERRUPTIBLE until some other task happens
to return one. Re-check the pool after prepare_to_wait() has published the
waiter, and use the workspace if one turned up. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: do not force reloc root creation during qgroup_account_snapshot()
[BUG]
When running btrfs/252 with quota enabled through MKFS_OPTIONS="-O quota",
it has a high chance to trigger the following kernel warning and flips
the fs RO:
BTRFS info (device dm-2): relocating block group 30408704 flags metadata|dup
------------[ cut here ]------------
WARNING: fs/btrfs/extent-tree.c:879 at lookup_inline_extent_backref+0x74b/0x960 [btrfs], CPU#4: btrfs/2173
CPU: 4 UID: 0 PID: 2173 Comm: btrfs Not tainted 7.2.0-rc6-custom+ #457 PREEMPT(full) 3adc6528fb66f7a55fe1095385818e742f200aab
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022
RIP: 0010:lookup_inline_extent_backref+0x74b/0x960 [btrfs]
Call Trace:
<TASK>
insert_inline_extent_backref+0x7c/0x160 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
__btrfs_inc_extent_ref+0xa9/0x270 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
__btrfs_run_delayed_refs+0x4af/0x11c0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
btrfs_run_delayed_refs+0x9d/0xf0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
create_pending_snapshot+0x39d/0xf00 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
create_pending_snapshots+0x9b/0xc0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
btrfs_commit_transaction+0x280/0xeb0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
prepare_to_relocate+0x147/0x200 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
relocate_block_group+0x6b/0x5e0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
btrfs_relocate_block_group+0x92c/0x2380 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
btrfs_relocate_chunk+0x3f/0x1a0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
btrfs_balance+0xa2c/0x19c0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
btrfs_ioctl+0x2839/0x2d30 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
__x64_sys_ioctl+0x416/0x9a0
do_syscall_64+0xe1/0x790
entry_SYSCALL_64_after_hwframe+0x4b/0x53
</TASK>
---[ end trace 0000000000000000 ]---
BTRFS info (device dm-2): leaf 4593991680 gen 233 total ptrs 175 free space 5953 owner 2
BTRFS info (device dm-2): refs 3 lock_owner 2173 current 2173
item 0 key (166772736 METADATA_ITEM 1) itemoff 16250 itemsize 33
extent refs 1 gen 222 flags 2
ref#0: tree block backref root 266
[ Skip the tree dump ]
item 174 key (263225344 METADATA_ITEM 0) itemoff 10328 itemsize 33
extent refs 1 gen 162 flags 258
ref#0: tree block backref root 267
BTRFS error (device dm-2): extent item not found for insert, bytenr 179847168 num_bytes 16384 parent 4594335744 root_objectid 273 owner 0 offset 0
BTRFS error (device dm-2): failed to run delayed ref for logical 179847168 num_bytes 16384 type 182 action 1 ref_mod 1: -117
[CAUSE]
The above error is showing that there is a tree reference to a metadata
extent that is no longer there.
With "ref_verify" mount option (requires CONFIG_BTRFS_DEBUG), there is
some extra debug output:
BTRFS error (device dm-2): dumping block entry [180961280 16384], num_refs 0, metadata 1, from disk 0
BTRFS error (device dm-2): root entry 256, num_refs 18446744073709551615
BTRFS error (device dm-2): root entry 273, num_refs 18446744073709551615
BTRFS error (device dm-2): Ref action 3, root 273, ref_root 273, parent 0, owner 0, offset 0, num_refs 1
btrfs_force_cow_block+0x129/0x7d0 [btrfs]
btrfs_cow_block+0x10a/0x250 [btrfs]
btrfs_search_slot+0x5eb/0xf40 [btrfs]
btrfs_insert_empty_items+0x3a/0x70 [btrfs]
insert_with_overflow+0x53/0x130 [btrfs]
btrfs_insert_dir_item+0x125/0x290 [btrfs]
btrfs_add_link+0xaa/0x410 [btrfs]
btrfs_rename+0x5ea/0xcd0 [btrfs]
btrfs_rename2+0x28/0x60 [btrfs]
vfs_rename+0x5b2/0xe10
filename_renameat2+0x244/0x430
__x64_sys_rename+0x48/0x70
do_syscall_64+0xe1/0x790
entry_SYSCALL_64_after_hwframe+0x4b/0x53
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
vhost-vdpa: protect config_ctx from being freed under the config callback
vhost_vdpa_config_cb() loads v->config_ctx and signals it without taking
a reference and without holding any lock:
struct eventfd_ctx *config_ctx = v->config_ctx;
if (config_ctx)
eventfd_signal(config_ctx);
VHOST_VDPA_SET_CONFIG_CALL replaces that field and drops what is normally
the last reference to the old context:
swap(ctx, v->config_ctx);
if (ctx)
eventfd_ctx_put(ctx);
eventfd_ctx_put() drops the last kref and frees the context immediately,
with no RCU grace period, so a callback that has already loaded the
pointer goes on to dereference freed memory. The two sides share no
lock: the ioctl runs under vhost_dev.mutex, while the parent invokes the
callback from its own interrupt or workqueue context.
This is not the reopen refcount underflow fixed by commit f6bbf0010ba0
("vhost-vdpa: fix use-after-free of v->config_ctx"), which was about
vhost_vdpa_config_put() leaving a stale pointer behind. Here the pointer
is maintained correctly and it is the read side that is unprotected.
With VDUSE as the parent this is reachable from userspace with access to
/dev/vduse (root by default). VDUSE_DEV_INJECT_CONFIG_IRQ queues
dev->inject, and vduse_dev_irq_inject() runs the callback under VDUSE's
own dev->irq_lock, which vhost does not hold. vduse_dev_reset() does
flush_work(&dev->inject), but VHOST_VDPA_SET_CONFIG_CALL never goes
through reset, so an inject already in flight is not waited for. A
process that injects config interrupts on the VDUSE fd while another
thread swaps the call fd on the vhost-vdpa fd hits it in seconds:
BUG: KASAN: slab-use-after-free in native_queued_spin_lock_slowpath
Read of size 4 at addr ffff888107d21808 by task kworker/u17:1/2993
Workqueue: vduse-irq vduse_dev_irq_inject
Call Trace:
native_queued_spin_lock_slowpath+0x97/0x5b0
_raw_spin_lock_irqsave+0xd4/0xe0
eventfd_signal_mask+0x69/0x120
vhost_vdpa_config_cb+0x34/0x50
vduse_dev_irq_inject+0x46/0x60
process_one_work+0x468/0x950
Allocated by task 2992:
do_eventfd+0x50/0x200
__x64_sys_eventfd2+0x2e/0x40
Freed by task 2992:
eventfd_ctx_put+0xb9/0xc0
vhost_vdpa_unlocked_ioctl+0x116c/0x2190
Add a spinlock covering every access to config_ctx, so the callback
either signals a context that is still alive or observes NULL, and the
put happens only once no callback can reach the old value.
Clearing the parent's callback before the put would not be enough: of the
in-tree set_config_cb() implementations only VDUSE takes a lock, the rest
store the pointer unlocked, so that would not order against an in-flight
invocation. |
| In the Linux kernel, the following vulnerability has been resolved:
vhost-vdpa: don't install the eventfd_ctx_fdget() error in config_ctx
vhost_vdpa_set_config_call() swaps the eventfd_ctx_fdget() return value
into v->config_ctx before checking it, so on failure the field briefly
holds an ERR_PTR:
ctx = fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(fd);
swap(ctx, v->config_ctx);
if (!IS_ERR_OR_NULL(ctx))
eventfd_ctx_put(ctx);
if (IS_ERR(v->config_ctx)) {
long ret = PTR_ERR(v->config_ctx);
v->config_ctx = NULL;
return ret;
}
Commit 0bde59c1723a ("vhost-vdpa: set v->config_ctx to NULL if
eventfd_ctx_fdget() fails") added that clearing, and spelled out the
invariant the rest of the file relies on: "we consider 'v->config_ctx'
valid if it is not NULL". The window between the swap and the clearing
still breaks it. vhost_vdpa_config_cb() only tests for NULL, so a config
interrupt delivered inside the window hands the ERR_PTR to
eventfd_signal().
Check the fd before installing it instead. That closes the window and
matches how vhost_vring_ioctl() handles the same failure for the vq call
fd.
It also stops a rejected fd from tearing down a config interrupt that was
working: until now the swap replaced the live context and put it, so
after an EBADF the device silently stopped delivering config interrupts
until userspace installed a new fd. |
| In the Linux kernel, the following vulnerability has been resolved:
virtio: fix use-after-free in unregister_virtio_device()
device_unregister() is device_del() plus put_device(). When the caller
holds no extra reference, that drops the last one and runs the release
callback, which for several transports frees the memory the embedded
struct virtio_device sits in. unregister_virtio_device() then calls
virtio_debug_device_exit(), which reads dev->debugfs_dir out of the freed
object.
Affected transports are the ones whose release callback frees and whose
remove path takes no reference: virtio_mmio, virtio_vdpa, virtio_uml,
mlxbf-tmfifo and virtio_ccw. virtio_pci is unaffected because
virtio_pci_remove() brackets the call with get_device() and put_device().
Remove the debugfs entries before the device can go away. They are only
accessed through the protected debugfs interface, so
debugfs_remove_recursive() waits for in-progress file operations before
returning. Tearing them down while the device is still alive is therefore
safe.
Reproduced on User-Mode Linux with CONFIG_KASAN and CONFIG_VIRTIO_DEBUG
by unbinding a virtio-uml device:
BUG: KASAN: slab-use-after-free in virtio_debug_device_exit+0x36/0x4d
Read of size 8 at addr 00000000616e0b10 by task init/1
__asan_report_load8_noabort
virtio_debug_device_exit+0x36/0x4d
unregister_virtio_device+0x48/0x75
virtio_uml_remove
platform_remove
device_release_driver_internal
unbind_store
Freed by task 1:
kfree
virtio_uml_release_dev
device_release
kobject_put
put_device
device_unregister
With this applied, the report is gone and unbind is clean. |
| In the Linux kernel, the following vulnerability has been resolved:
hwmon: Fix potential UAF in pec_store
Sashiko reports:
In pec_store(), a guard(mutex)(&hwdev->lock) is taken. If the chip write
operation returns an error other than -EOPNOTSUPP, the code jumps to the
put label, which calls put_device(hdev). If this drops the final reference,
the device is freed. When the function then returns, the guard cleanup
function runs and attempts to unlock the freed mutex.
Use scoped_guard() instead of guard() to avoid the problem. |
| In the Linux kernel, the following vulnerability has been resolved:
iommu/amd: Fix ineffective error check in nested domain allocation
amd_iommu_pdom_id_alloc() returns an int: a domain ID on success, or the
negative errno from ida_alloc_range() when the ID space is exhausted or
memory is short. amd_iommu_alloc_domain_nested() stores that return value
in gdom_info->hdom_id, which is a u32, and only then tests it:
gdom_info->hdom_id = amd_iommu_pdom_id_alloc();
if (gdom_info->hdom_id <= 0) {
The assignment discards the sign, so -ENOSPC becomes 0xffffffe4 and the
test never fires. The nested domain is then set up with a host domain ID
that was never allocated, instead of the allocation failing with -ENOSPC.
Keep the value in an int, test it there, and store it only once it is
known to be valid, which is what the other amd_iommu_pdom_id_alloc()
callers already do. |
| In the Linux kernel, the following vulnerability has been resolved:
iommu/amd: Do not reallocate GA log buffers on resume
Commit c5e1a1eb9279 ("iommu/amd: Simplify and Consolidate Virtual APIC
(AVIC) Enablement") moved the GA log allocation from iommu_init_pci()
to enable_iommus_vapic(), which is called on every resume.
iommu_init_ga_log() assigns iommu->ga_log and iommu->ga_log_tail
unconditionally. Each resume therefore replaces the boot-time pointers
and leaks both old allocations. The function also uses GFP_KERNEL from a
syscore resume callback, where interrupts are disabled and the non-boot
CPUs are offline.
Return early if both buffers are already allocated. Clear the pointers
in free_ga_log() so a partial allocation failure cannot leave ga_log
dangling. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: caiaq: Decoupling ep1_in_urb in caiaq dev
The epq_in_urb object belonging to the caiaq device is coupled within
the struct snd_usb_caiaqdev. After usb_submit_urb(epq_in_urb, GFP_KERNEL)
executes successfully, epq_in_urb is successfully added to the urbp_list
queue of the dummy HCD driver (userspace specifies dummy_hcd as the HCD
layer driver for the caiaq USB device).
When init_card() calls snd_usb_caiaq_send_command() which subsequently
fails due to a timeout, and proceeds to call snd_card_free() to release
the card, the embedded ep1_in_urb object is also freed. When the dummy
HCD driver detects that the URB has been unlinked, it returns the URB
(by usb_hcd_giveback_urb()), which triggers [1].
Decouple the ep1_in_urb object from the struct snd_usb_caiaqdev and switch
to using a pointer instead. Separately allocate and manage the memory for
ep1_in_urb to prevent the release of the snd_card memory object from
interfering with it.
midi_out_urb has the same issue as ep1_in_urb and is handled in the same
way.
[1]
BUG: KASAN: slab-use-after-free in usb_free_urb+0x24/0x120 drivers/usb/core/urb.c:96
Write of size 4 at addr ffff88803cee1050 by task ktimers/1/29
Call Trace:
usb_free_urb+0x24/0x120 drivers/usb/core/urb.c:96
dummy_timer+0xaac/0x4d50 drivers/usb/gadget/udc/dummy_hcd.c:2019
__run_hrtimer kernel/time/hrtimer.c:2067 [inline]
__hrtimer_run_queues+0x3eb/0xaf0 kernel/time/hrtimer.c:2124
hrtimer_run_softirq+0x1e1/0x2e0 kernel/time/hrtimer.c:2141
Allocated by task 36:
snd_card_new+0x7b/0x110 sound/core/init.c:184
create_card sound/usb/caiaq/device.c:429 [inline]
snd_probe+0x236/0x1af0 sound/usb/caiaq/device.c:544
Freed by task 36:
snd_card_free_when_closed sound/core/init.c:630 [inline]
snd_card_free+0x138/0x1d0 sound/core/init.c:662
snd_probe+0x162b/0x1af0 sound/usb/caiaq/device.c:553 |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: drr: clamp quantum in change class
drr_change_class() rejects explicit quantum==0 but falls back to
psched_mtu() with no floor. With a crafted size table qdisc_pkt_len
reaches ~2 GiB, so quantum=1 (or a zero psched_mtu on a headerless
device) makes the deficit-refill loop spin under the qdisc lock.
Add clamp_t(u32, quantum, 256, 1<<20) after the zero reject and on the
fallback path. The explicit-zero reject is preserved.
Conditions to recreate the bug:
CONFIG_NET_SCH_DRR=y. Requires CAP_NET_ADMIN (namespace-local via
unshare -Urn suffices).
tc qdisc add dev dummy0 root drr
tc class add dev dummy0 parent 1: classid 1:1 drr quantum 1 |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: hhf: clamp quantum in change and init paths
hhf_change() accepts any quantum from userspace, including 1. With a
crafted size table qdisc_pkt_len reaches ~2 GiB, so quantum=1 makes
the deficit-refill loop spin ~2^31 times under the qdisc lock
(a soft lockup / denial of service).
Add max(256U, ...) in hhf_change() matching fq_codel_change(). Clamp
hhf_init() to [256, 1<<20] matching the siblings, and remove the old
fallback that only set quantum=256 on overflow.
Conditions to recreate the bug:
CONFIG_NET_SCH_HHF=y. Requires CAP_NET_ADMIN (namespace-local via
unshare -Urn suffices).
tc qdisc add dev dummy0 root hhf
tc qdisc change dev dummy0 root hhf quantum 1 stab data 32768 size_log 15 cell_log 0 |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: sfq: clamp quantum in change path
sfq_change() accepts any non-negative quantum (only rejects
(int)ctl->quantum < 0). With a crafted size table qdisc_pkt_len reaches
~2 GiB, so quantum=1 makes the deficit-refill loop spin ~2^31 times
under the qdisc lock (a soft lockup / denial of service).
Add max(256U, ...) matching fq_codel_change(). Reject quantum > 1<<20
with -EINVAL, matching fq_codel_change() and the init clamp.
Conditions to recreate the bug:
CONFIG_NET_SCH_SFQ=y. Requires CAP_NET_ADMIN (namespace-local via
unshare -Urn suffices).
tc qdisc add dev dummy0 root sfq
tc qdisc change dev dummy0 root sfq quantum 1 stab data 32768 size_log 15 cell_log 0 |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: E-Switch: fix use-after-free in mlx5_eswitch_termtbl_put
In mlx5_eswitch_termtbl_put(), the zero-ref cleanup check reads
tt->ref_count after termtbl_mutex has been released. Two concurrent
callers on the same mlx5_termtbl_handle race: one decrements ref_count
to zero, removes the hash entry, and calls kfree(tt) while the other
has already dropped the mutex and is about to evaluate
if (!tt->ref_count), producing a use-after-free.
Fix this by capturing the result of the decrement into a stack-local
last variable before dropping the mutex. The cleanup decision is now
made entirely under termtbl_mutex, and tt is not touched after
kfree. |
| In the Linux kernel, the following vulnerability has been resolved:
net: dsa: bcm_sf2: bound the CFP rule dump by the caller's buffer size
bcm_sf2_cfp_rule_get_all() walks the whole cfp.unique bitmap into
rule_locs[] without consulting nfc->rule_cnt, which is how many entries
the caller had room for. ETHTOOL_GRXCLSRLALL requires no CAP_NET_ADMIN
and the ioctl sizes the buffer from the rule_cnt userspace passes in, so
once an admin has installed CFP rules any user can ask for fewer slots
than there are rules and run off the end of the allocation. A rule_cnt
of 0 leaves the buffer pointer NULL and the walk dereferences it. |
| In the Linux kernel, the following vulnerability has been resolved:
net: dsa: mv88e6xxx: bound the policy rule dump by the caller's buffer size
mv88e6xxx_get_rxnfc() uses rxnfc->rule_cnt as the write index while
dumping the policy IDR, clobbering the input value before it has been
looked at. That input is the number of entries the caller had room for.
ETHTOOL_GRXCLSRLALL requires no CAP_NET_ADMIN and the ioctl sizes the
buffer from the rule_cnt userspace passes in, so once an admin has
installed policy rules any user can ask for fewer slots than there are
rules and run off the end of the allocation. A rule_cnt of 0 leaves the
buffer pointer NULL and the walk dereferences it.
Count into a local so the caller's limit survives the walk, and stop with
-EMSGSIZE once it is reached. |
| In the Linux kernel, the following vulnerability has been resolved:
net: mctp: i3c: serialize probe with bus removal
mctp_i3c_probe() drops busdevs_lock after finding the matching bus. A
concurrent I3C_NOTIFY_BUS_REMOVE can then unregister and free the bus
netdev before probe passes its private data to mctp_i3c_add_device().
The latter consequently adds a list node through a freed mbus pointer.
Keep busdevs_lock held until the device has been added. This also
satisfies the __must_hold annotation on mctp_i3c_add_device(). |
