| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
net/handshake: Use spin_lock_bh for hn_lock
nvmet_tcp_state_change(), a socket callback that runs in BH context,
can reach handshake_req_cancel() via nvmet_tcp_schedule_release_queue()
and tls_handshake_cancel(). handshake_req_cancel() acquires
hn->hn_lock with plain spin_lock(). If a process-context thread on
the same CPU holds hn->hn_lock when a softirq invokes the cancel path,
the lock attempt deadlocks. This is the only caller that invokes
tls_handshake_cancel() from BH context; every other consumer calls it
from process context.
Deferring the cancel to process context in the NVMe target is not
straightforward: nvmet_tcp_schedule_release_queue() must call
tls_handshake_cancel() atomically with its state transition to
DISCONNECTING. If the cancel were deferred, the handshake completion
callback could fire in the window before the cancel runs, observe the
unexpected state, and return without dropping its kref on the queue.
Reworking that interlock is considerably more invasive than hardening
the handshake lock. Convert all hn->hn_lock acquisitions from
spin_lock/spin_unlock to spin_lock_bh/spin_unlock_bh so the lock is
never taken with softirqs enabled. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/gpusvm: Fix unbalanced unlock in drm_gpusvm_scan_mm()
There is a unbalanced lock/unlock to gpusvm notifier lock:
[ 931.045868] =====================================
[ 931.046509] WARNING: bad unlock balance detected!
[ 931.047149] 6.19.0-rc6+xe-**************** #9 Tainted: G U
[ 931.048150] -------------------------------------
[ 931.048790] kworker/u5:0/51 is trying to release lock (&gpusvm->notifier_lock) at:
[ 931.049801] [<ffffffffa090c0d8>] drm_gpusvm_scan_mm+0x188/0x460 [drm_gpusvm_helper]
[ 931.050802] but there are no more locks to release!
[ 931.051463]
The drm_gpusvm_notifier_unlock() sits under err_free label and the
first jump to err_free is just before calling the
drm_gpusvm_notifier_lock() causing unbalanced unlock. |
| OW2 ASM 9.11 before 9.11.1 contains an infinite loop vulnerability in Label.resolve() caused by 16-bit forward-reference offsets truncating when rewritten methods exceed 64 KB. Attackers can supply crafted class files whose transformed code grows past 65535 bytes, hanging ClassReader.accept() and denying service to build tools, instrumenters, agents, or analyzers. |
| In the Linux kernel, the following vulnerability has been resolved:
timers/migration: Fix livelock in tmigr_handle_remote_up()
tmigr_handle_remote_cpu() skips timer_expire_remote() when cpu ==
smp_processor_id(), assuming the local softirq path already handled this
CPU's timers.
This assumption is wrong because jiffies can advance after the handling of
the CPU's global timers in run_timer_base(BASE_GLOBAL) and before
tmigr_handle_remote() evaluates the expiry times.
As a consequence a timer which expires after the CPU local timer wheel
advanced and becomes expired in the remote handling is ignored and the
callback is never invoked and removed from the timer wheel.
What's worse is that fetch_next_timer_interrupt_remote() keeps reporting it
as expired, and the event is re-queued with expires == now on each
iteration. The goto-again loop spins indefinitely.
Fix this by calling timer_expire_remote() unconditionally. That's minimal
overhead for the common case as __run_timer_base() returns immediately if
there is nothing to expire in the local wheel.
[ tglx: Amend change log and add a comment ] |
| In the Linux kernel, the following vulnerability has been resolved:
IB/isert: Reject login PDUs shorter than ISER_HEADERS_LEN
In drivers/infiniband/ulp/isert/ib_isert.c, isert_login_recv_done()
computes the login request payload length as wc->byte_len minus
ISER_HEADERS_LEN with no lower bound, and login_req_len is a signed int.
A remote iSER initiator can post a login Send work request carrying
fewer than ISER_HEADERS_LEN (76) bytes, so the subtraction underflows
and login_req_len becomes negative.
isert_rx_login_req() then reads that negative length back into a signed
int, takes size = min(rx_buflen, MAX_KEY_VALUE_PAIRS), and because the
min() is signed it keeps the negative value; the value is then passed as
the memcpy() length and sign-extended to a multi-gigabyte size_t. The
copy into the 8192-byte login->req_buf runs far out of bounds and
faults, crashing the target node. The login phase precedes iSCSI
authentication, so no credentials are required to reach this path.
Reject any login PDU shorter than ISER_HEADERS_LEN before the
subtraction, mirroring the existing early return on a failed work
completion, so login_req_len can never go negative. The upper bound was
already safe: a posted login buffer cannot deliver more than
ISER_RX_PAYLOAD_SIZE, so the difference stays at or below
MAX_KEY_VALUE_PAIRS and the existing min() clamps it; only the missing
lower bound needs to be added. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Validate node_id in arena_alloc_pages()
arena_alloc_pages() accepts a plain int node_id and forwards it through
the entire allocation chain without any bounds checking.
Validate node_id before passing it down the allocation chain in
arena_alloc_pages(). |
| In the Linux kernel, the following vulnerability has been resolved:
fs/fcntl: fix SOFTIRQ-unsafe lock order in fasync signaling
A SOFTIRQ-safe to SOFTIRQ-unsafe lock order deadlock can occur in
send_sigio() and send_sigurg() when a process group receives a signal.
When FASYNC is configured for a process group (PIDTYPE_PGID), both
functions use read_lock(&tasklist_lock) to traverse the task list.
However, they are frequently called from softirq context:
- send_sigio() via input_inject_event -> kill_fasync
- send_sigurg() via tcp_check_urg -> sk_send_sigurg (NET_RX_SOFTIRQ)
The deadlock is caused by the rwlock writer fairness mechanism:
1. CPU 0 (process context) holds read_lock(&tasklist_lock) in do_wait().
2. CPU 1 (process context) attempts write_lock(&tasklist_lock) in
fork() or exit() and spins, which blocks all new readers.
3. CPU 0 is interrupted by a softirq (e.g., TCP URG packet reception).
4. The softirq calls send_sigurg() and attempts to acquire
read_lock(&tasklist_lock), deadlocking because CPU 1 is waiting.
Since PID hashing and do_each_pid_task() traversals are already
RCU-protected, the read_lock on tasklist_lock is no longer strictly
required for safe traversal. Fix this by replacing tasklist_lock with
rcu_read_lock(), aligning the process group signaling path with the
single-PID path. This also mitigates a potential remote denial of
service vector via TCP URG packets.
Lockdep splat:
=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
[...]
Chain exists of:
&dev->event_lock --> &f_owner->lock --> tasklist_lock
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(tasklist_lock);
local_irq_disable();
lock(&dev->event_lock);
lock(&f_owner->lock);
<Interrupt>
lock(&dev->event_lock);
*** DEADLOCK *** |
| In the Linux kernel, the following vulnerability has been resolved:
io_uring/poll: fix signed comparison in io_poll_get_ownership()
io_poll_get_ownership() uses a signed comparison to check whether
poll_refs has reached the threshold for the slowpath:
if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS))
atomic_read() returns int (signed). When IO_POLL_CANCEL_FLAG
(BIT(31)) is set in poll_refs, the value becomes negative in
signed arithmetic, so the >= 128 comparison always evaluates to
false and the slowpath is never taken.
Fix this by casting the atomic_read() result to unsigned int
before the comparison, so that the cancel flag is treated as a
large positive value and correctly triggers the slowpath. |
| In the Linux kernel, the following vulnerability has been resolved:
nvmet: avoid recursive nvmet-wq flush in nvmet_ctrl_free
nvmet_tcp_release_queue_work() runs on nvmet-wq and can drop the
final controller reference through nvmet_cq_put(). If that triggers
nvmet_ctrl_free(), the teardown path flushes ctrl->async_event_work on
the same nvmet-wq.
Call chain:
nvmet_tcp_schedule_release_queue()
kref_put(&queue->kref, nvmet_tcp_release_queue)
nvmet_tcp_release_queue()
queue_work(nvmet_wq, &queue->release_work) <--- nvmet_wq
process_one_work()
nvmet_tcp_release_queue_work()
nvmet_cq_put(&queue->nvme_cq)
nvmet_cq_destroy()
nvmet_ctrl_put(cq->ctrl)
nvmet_ctrl_free()
flush_work(&ctrl->async_event_work) <--- nvmet_wq
Previously Scheduled by :-
nvmet_add_async_event
queue_work(nvmet_wq, &ctrl->async_event_work);
This trips lockdep with a possible recursive locking warning.
[ 5223.015876] run blktests nvme/003 at 2026-04-07 20:53:55
[ 5223.061801] loop0: detected capacity change from 0 to 2097152
[ 5223.072206] nvmet: adding nsid 1 to subsystem blktests-subsystem-1
[ 5223.088368] nvmet_tcp: enabling port 0 (127.0.0.1:4420)
[ 5223.126086] nvmet: Created discovery controller 1 for subsystem nqn.2014-08.org.nvmexpress.discovery for NQN nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349.
[ 5223.128453] nvme nvme1: new ctrl: NQN "nqn.2014-08.org.nvmexpress.discovery", addr 127.0.0.1:4420, hostnqn: nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349
[ 5233.199447] nvme nvme1: Removing ctrl: NQN "nqn.2014-08.org.nvmexpress.discovery"
[ 5233.227718] ============================================
[ 5233.231283] WARNING: possible recursive locking detected
[ 5233.234696] 7.0.0-rc3nvme+ #20 Tainted: G O N
[ 5233.238434] --------------------------------------------
[ 5233.241852] kworker/u192:6/2413 is trying to acquire lock:
[ 5233.245429] ffff888111632548 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: touch_wq_lockdep_map+0x26/0x90
[ 5233.251438]
but task is already holding lock:
[ 5233.255254] ffff888111632548 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: process_one_work+0x5cc/0x6e0
[ 5233.261125]
other info that might help us debug this:
[ 5233.265333] Possible unsafe locking scenario:
[ 5233.269217] CPU0
[ 5233.270795] ----
[ 5233.272436] lock((wq_completion)nvmet-wq);
[ 5233.275241] lock((wq_completion)nvmet-wq);
[ 5233.278020]
*** DEADLOCK ***
[ 5233.281793] May be due to missing lock nesting notation
[ 5233.286195] 3 locks held by kworker/u192:6/2413:
[ 5233.289192] #0: ffff888111632548 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: process_one_work+0x5cc/0x6e0
[ 5233.294569] #1: ffffc9000e2a7e40 ((work_completion)(&queue->release_work)){+.+.}-{0:0}, at: process_one_work+0x1c5/0x6e0
[ 5233.300128] #2: ffffffff82d7dc40 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x62/0x530
[ 5233.304290]
stack backtrace:
[ 5233.306520] CPU: 4 UID: 0 PID: 2413 Comm: kworker/u192:6 Tainted: G O N 7.0.0-rc3nvme+ #20 PREEMPT(full)
[ 5233.306524] Tainted: [O]=OOT_MODULE, [N]=TEST
[ 5233.306525] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014
[ 5233.306527] Workqueue: nvmet-wq nvmet_tcp_release_queue_work [nvmet_tcp]
[ 5233.306532] Call Trace:
[ 5233.306534] <TASK>
[ 5233.306536] dump_stack_lvl+0x73/0xb0
[ 5233.306552] print_deadlock_bug+0x225/0x2f0
[ 5233.306556] __lock_acquire+0x13f0/0x2290
[ 5233.306563] lock_acquire+0xd0/0x300
[ 5233.306565] ? touch_wq_lockdep_map+0x26/0x90
[ 5233.306571] ? __flush_work+0x20b/0x530
[ 5233.306573] ? touch_wq_lockdep_map+0x26/0x90
[ 5233.306577] touch_wq_lockdep_map+0x3b/0x90
[ 5233.306580] ? touch_wq_lockdep_map+0x26/0x90
[ 52
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
ceph: only d_add() negative dentries when they are unhashed
Ceph can call d_add(dentry, NULL) on a negative dentry that is already
present in the primary dcache hash.
In the current VFS that is not safe. d_add() goes through __d_add()
to __d_rehash(), which unconditionally reinserts dentry->d_hash into
the hlist_bl bucket. If the dentry is already hashed, reinserting the
same node can corrupt the bucket, including creating a self-loop.
Once that happens, __d_lookup() can spin forever in the hlist_bl walk,
typically looping only on the d_name.hash mismatch check and
eventually triggering RCU stall reports like this one:
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: 87-....: (2100 ticks this GP) idle=3a4c/1/0x4000000000000000 softirq=25003319/25003319 fqs=829
rcu: (t=2101 jiffies g=79058445 q=698988 ncpus=192)
CPU: 87 UID: 2952868916 PID: 3933303 Comm: php-cgi8.3 Not tainted 6.18.17-i1-amd #950 NONE
Hardware name: Dell Inc. PowerEdge R7615/0G9DHV, BIOS 1.6.6 09/22/2023
RIP: 0010:__d_lookup+0x46/0xb0
Code: c1 e8 07 48 8d 04 c2 48 8b 00 49 89 fc 49 89 f5 48 89 c3 48 83 e3 fe 48 83 f8 01 77 0f eb 2d 0f 1f 44 00 00 48 8b 1b 48 85 db <74> 20 39 6b 18 75 f3 48 8d 7b 78 e8 ba 85 d0 00 4c 39 63 10 74 1f
RSP: 0018:ff745a70c8253898 EFLAGS: 00000282
RAX: ff26e470054cb208 RBX: ff26e470054cb208 RCX: 000000006e958966
RDX: ff26e48267340000 RSI: ff745a70c82539b0 RDI: ff26e458f74655c0
RBP: 000000006e958966 R08: 0000000000000180 R09: 9cd08d909b919a89
R10: ff26e458f74655c0 R11: 0000000000000000 R12: ff26e458f74655c0
R13: ff745a70c82539b0 R14: d0d0d0d0d0d0d0d0 R15: 2f2f2f2f2f2f2f2f
FS: 00007f5770896980(0000) GS:ff26e482c5d88000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5764de50c0 CR3: 000000a72abb5001 CR4: 0000000000771ef0
PKRU: 55555554
Call Trace:
<TASK>
lookup_fast+0x9f/0x100
walk_component+0x1f/0x150
link_path_walk+0x20e/0x3d0
path_lookupat+0x68/0x180
filename_lookup+0xdc/0x1e0
vfs_statx+0x6c/0x140
vfs_fstatat+0x67/0xa0
__do_sys_newfstatat+0x24/0x60
do_syscall_64+0x6a/0x230
entry_SYSCALL_64_after_hwframe+0x76/0x7e
This is reachable with reused cached negative dentries. A Ceph lookup
or atomic_open can be handed a negative dentry that is already hashed,
and fs/ceph/dir.c then hits one of two paths that incorrectly assume
"negative" also means "unhashed":
- ceph_finish_lookup():
MDS reply is -ENOENT with no trace
-> d_add(dentry, NULL)
- ceph_lookup():
local ENOENT fast path for a complete directory with shared caps
-> d_add(dentry, NULL)
Both paths can therefore re-add an already-hashed negative dentry.
Ceph already uses the correct pattern elsewhere: ceph_fill_trace() only
calls d_add(dn, NULL) for a negative null-dentry reply when d_unhashed(dn)
is true.
Fix both fs/ceph/dir.c sites the same way: only call d_add() for a
negative dentry when it is actually unhashed. If the negative dentry
is already hashed, leave it in place and reuse it as-is.
This preserves the existing behavior for unhashed dentries while
avoiding d_hash list corruption for reused hashed negatives. |
| In the Linux kernel, the following vulnerability has been resolved:
iommu/amd: move wait_on_sem() out of spinlock
With iommu.strict=1, the existing completion wait path can cause soft
lockups under stressed environment, as wait_on_sem() busy-waits under the
spinlock with interrupts disabled.
Move the completion wait in iommu_completion_wait() out of the spinlock.
wait_on_sem() only polls the hardware-updated cmd_sem and does not require
iommu->lock, so holding the lock during the busy wait unnecessarily
increases contention and extends the time with interrupts disabled. |
| In the Linux kernel, the following vulnerability has been resolved:
Input: uinput - fix circular locking dependency with ff-core
A lockdep circular locking dependency warning can be triggered
reproducibly when using a force-feedback gamepad with uinput (for
example, playing ELDEN RING under Wine with a Flydigi Vader 5
controller):
ff->mutex -> udev->mutex -> input_mutex -> dev->mutex -> ff->mutex
The cycle is caused by four lock acquisition paths:
1. ff upload: input_ff_upload() holds ff->mutex and calls
uinput_dev_upload_effect() -> uinput_request_submit() ->
uinput_request_send(), which acquires udev->mutex.
2. device create: uinput_ioctl_handler() holds udev->mutex and calls
uinput_create_device() -> input_register_device(), which acquires
input_mutex.
3. device register: input_register_device() holds input_mutex and
calls kbd_connect() -> input_register_handle(), which acquires
dev->mutex.
4. evdev release: evdev_release() calls input_flush_device() under
dev->mutex, which calls input_ff_flush() acquiring ff->mutex.
Fix this by introducing a new state_lock spinlock to protect
udev->state and udev->dev access in uinput_request_send() instead of
acquiring udev->mutex. The function only needs to atomically check
device state and queue an input event into the ring buffer via
uinput_dev_event() -- both operations are safe under a spinlock
(ktime_get_ts64() and wake_up_interruptible() do not sleep). This
breaks the ff->mutex -> udev->mutex link since a spinlock is a leaf in
the lock ordering and cannot form cycles with mutexes.
To keep state transitions visible to uinput_request_send(), protect
writes to udev->state in uinput_create_device() and
uinput_destroy_device() with the same state_lock spinlock.
Additionally, move init_completion(&request->done) from
uinput_request_send() to uinput_request_submit() before
uinput_request_reserve_slot(). Once the slot is allocated,
uinput_flush_requests() may call complete() on it at any time from
the destroy path, so the completion must be initialised before the
request becomes visible.
Lock ordering after the fix:
ff->mutex -> state_lock (spinlock, leaf)
udev->mutex -> state_lock (spinlock, leaf)
udev->mutex -> input_mutex -> dev->mutex -> ff->mutex (no back-edge) |
| In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix possible deadlock between unlink and dio_end_io_write
ocfs2_unlink takes orphan dir inode_lock first and then ip_alloc_sem,
while in ocfs2_dio_end_io_write, it acquires these locks in reverse order.
This creates an ABBA lock ordering violation on lock classes
ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE] and
ocfs2_file_ip_alloc_sem_key.
Lock Chain #0 (orphan dir inode_lock -> ip_alloc_sem):
ocfs2_unlink
ocfs2_prepare_orphan_dir
ocfs2_lookup_lock_orphan_dir
inode_lock(orphan_dir_inode) <- lock A
__ocfs2_prepare_orphan_dir
ocfs2_prepare_dir_for_insert
ocfs2_extend_dir
ocfs2_expand_inline_dir
down_write(&oi->ip_alloc_sem) <- Lock B
Lock Chain #1 (ip_alloc_sem -> orphan dir inode_lock):
ocfs2_dio_end_io_write
down_write(&oi->ip_alloc_sem) <- Lock B
ocfs2_del_inode_from_orphan()
inode_lock(orphan_dir_inode) <- Lock A
Deadlock Scenario:
CPU0 (unlink) CPU1 (dio_end_io_write)
------ ------
inode_lock(orphan_dir_inode)
down_write(ip_alloc_sem)
down_write(ip_alloc_sem)
inode_lock(orphan_dir_inode)
Since ip_alloc_sem is to protect allocation changes, which is unrelated
with operations in ocfs2_del_inode_from_orphan. So move
ocfs2_del_inode_from_orphan out of ip_alloc_sem to fix the deadlock. |
| libIEC61850 is an open-source implementation of IEC 61850 client and server protocols including MMS, GOOSE, Sampled Values, and R-Session. Prior to 1.6.2, parseUserInformation in src/mms/iso_acse/acse.c checks len for zero before validating the negative bufPos returned by BerDecoder_decodeLength for a truncated long-form length. The continue path therefore swallows the error, reads buffer[-1], resets parsing to the beginning, and repeats the same malformed state. An unauthenticated remote peer can send a malformed AARE PDU during association to cause an infinite CPU loop under a normal allocator or a one-byte out-of-bounds read and process abort when the preceding byte is inaccessible. This issue is fixed in version 1.6.2. |
| The Okta RADIUS Agent does not validate the sub-attribute length when parsing a Vendor-Specific attribute. A sub-attribute length of zero causes the parser to loop indefinitely, resulting in worker-thread exhaustion and denial of new RADIUS authentication requests. |
| L-SMASH through 2.14.5 contains an infinite loop vulnerability in vc1_importer_probe() in importer/vc1_imp.c that allows attackers to hang applications via crafted input files. Attackers can supply a file consisting only of zero bytes, which lsmash_read_file() probes automatically, causing indefinite CPU consumption and denial of service. |
| MP4Parser does not adequately validate MP4 box sizes. A malformed box can cause parsing to make no forward progress and repeatedly process the same input. |
| Frame poisoning in the Layout component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: avoid livelock while updating retransmit path
sctp_assoc_update_retran_path() can loop forever when every remaining
transport, including retran_path, is SCTP_UNCONFIRMED: the state check
runs before the wraparound test, so the loop cannot observe that it has
completed a full pass.
Fix this by considering a transport only when it is not UNCONFIRMED,
then checking whether the walk has returned to retran_path. This makes
the full-pass termination independent of the transport state while
preserving the existing fallback selection semantics.
Also restore the NULL guard around the retran_path assignment. In the
all-UNCONFIRMED case there is no eligible replacement transport, and
installing NULL would leave later retransmit-path users and the debug
print with a NULL path. |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_hfsc: bound the classify inner-filter walk with a drift budget
hfsc_classify() applies the "filter may only point downwards" level check
only when the filter result carries no bound class. A filter created with
a flowid gets res.class set once at bind time, so the check never runs for
it during classification. hfsc_adjust_levels() can later raise a class's
level without revalidating existing bindings, leaving two binds that were
each legal at bind time pointing at each other; the classify walk then
bounces between two interior classes forever with the qdisc lock held and
BH disabled — a soft lockup from a single packet. The stuck walk trips
the watchdog:
watchdog: BUG: soft lockup - CPU#3 stuck for 13s! [ping:444]
RIP: 0010:u32_classify+0x542/0x17f0
...
tcf_classify+0x66/0xa0
hfsc_enqueue+0x166/0xdf0
Bound the traversal with a budget of non-descending hops, the only way a
configured walk can move without descending the class tree once levels
drift after bind time. The budget is cumulative over the whole walk and
is deliberately not reset on a descending hop: a chain that alternates a
descent with a lateral hop would return the budget every lap and never
trip. Descending hops never decrement it, so legitimately deep trees are
unaffected and a terminating lateral chain still classifies normally.
Drop the packet with a rate-limited warning once the budget is exhausted,
mirroring the merged HTB fix.
This is a follow-up to commit 729c4896ab82 ("net/sched: sch_htb: limit
htb_classify inner-class filter hops"), which bounded the same classify
loop on the HTB side but left the HFSC walk unbounded.
Conditions to recreate the bug:
- CONFIG_NET_SCHED, CONFIG_NET_SCH_HFSC, CONFIG_NET_CLS_U32,
CONFIG_LOCKUP_DETECTOR.
- Build a cycle with two legal-at-bind-time flowid binds and a level
drift: class X 1:1 (child of root) with leaf child 1:10; class Y 1:2
(sibling of X) with children 1:20 and 1:200; root u32 filter flowid
1:1; filter on X flowid 1:2 (legal when Y is a leaf); after Y's level
rises to 2, filter on Y flowid 1:1 (legal then). Send one packet (ping
on the device). Unfixed kernel: classify spins with the qdisc lock
held; with softlockup_panic=1 it panics.
- Reachable from unprivileged user via unshare -Urn (CAP_NET_ADMIN). |
