scx_root_enable_workfn() takes cpus_read_lock() before
scx_link_sched(sch), but the `if (ret) goto err_disable` on failure
skips the matching cpus_read_unlock() - all other err_disable gotos
along this path drop the lock first.

scx_link_sched() only returns non-zero on the sub-sched path
(parent != NULL), so the leak path is unreachable via the root
caller today. Still, the unwind is out of line with the surrounding
paths.

Drop cpus_read_lock() before goto err_disable.

v2: Correct Fixes: tag (Andrea Righi).

Fixes: 25037af712eb ("sched_ext: Add rhashtable lookup for sub-schedulers")
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

scx_prog_sched(aux) returns NULL for TRACING / SYSCALL BPF progs that
have no struct_ops association when the root scheduler has sub_attach
set. scx_bpf_task_set_slice() and scx_bpf_task_set_dsq_vtime() pass
that NULL into scx_task_on_sched(sch, p), which under
CONFIG_EXT_SUB_SCHED is rcu_access_pointer(p->scx.sched) == sch. For
any non-scx task p->scx.sched is NULL, so NULL == NULL returns true
and the authority gate is bypassed - a privileged but
non-struct_ops-associated prog can poke p->scx.slice /
p->scx.dsq_vtime on arbitrary tasks.

Reject !sch up front so the gate only admits callers with a resolved
scheduler.

Fixes: 245d09c594ea ("sched_ext: Enforce scheduler ownership when updating slice and dsq_vtime")
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>

select_cpu_from_kfunc() skipped pi_lock for @p when called from
ops.select_cpu() or another rq-locked SCX op, assuming the held lock
protects @p. scx_bpf_select_cpu_dfl() / __scx_bpf_select_cpu_and() accept an
arbitrary KF_RCU task_struct, so a caller in e.g. ops.select_cpu(p1) or
ops.enqueue(p1) can pass some other p2 - the held pi_lock / rq lock is p1's,
not p2's - and reading p2->cpus_ptr / nr_cpus_allowed races with
set_cpus_allowed_ptr() and migrate_disable_switch() on another CPU.

Abort the scheduler on cross-task calls in both branches: for
ops.select_cpu() use scx_kf_arg_task_ok() to verify @p is the wake-up
task recorded in current->scx.kf_tasks[] by SCX_CALL_OP_TASK_RET();
for other rq-locked SCX ops compare task_rq(p) against scx_locked_rq().

v2: Switch the in_select_cpu cross-task check from direct_dispatch_task
comparison to scx_kf_arg_task_ok(). The former spuriously rejects when
ops.select_cpu() calls scx_bpf_dsq_insert() first, then calls
scx_bpf_select_cpu_*() on the same task. (Andrea Righi)

Fixes: 0022b328504d ("sched_ext: Decouple kfunc unlocked-context check from kf_mask")
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andrea Righi <arighi@nvidia.com>

Two EXT_GROUP_SCHED/SUB_SCHED guards are misclassified:

- scx_root_enable_workfn()'s cgroup_get(cgrp) and the err_put_cgrp unwind
in scx_alloc_and_add_sched() are under `#if GROUP || SUB`, but the
matching cgroup_put() in scx_sched_free_rcu_work() is inside `#ifdef SUB`
only (via sch->cgrp, stored only under SUB). GROUP-only would leak a
reference on every root-sched enable.

- sch_cgroup() / set_cgroup_sched() live under `#if GROUP || SUB` but touch
SUB-only fields (sch->cgrp, cgroup->scx_sched). GROUP-only wouldn't
compile.

GROUP needs CGROUP_SCHED; SUB needs only CGROUPS. CGROUPS=y/CGROUP_SCHED=n
gives the reachable GROUP=n, SUB=y combination; GROUP=y, SUB=n isn't
reachable today (SUB is def_bool y under CGROUPS). Neither miscategorization
triggers a real bug in any reachable config, but keep the guards honest:

- Narrow cgroup_get and err_put_cgrp to `#ifdef SUB` (matches the free-side
put).
- Move sch_cgroup() and set_cgroup_sched() to a separate `#ifdef SUB` block
with no-op stubs for the !SUB case; keep root_cgroup() and scx_cgroup_{
lock,unlock}() under `#if GROUP || SUB` since those only need cgroup core.

Fixes: ebeca1f930ea ("sched_ext: Introduce cgroup sub-sched support")
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>

scx_bypass_lb_{donee,resched}_cpumask were file-scope statics shared by all
scheduler instances. With CONFIG_EXT_SUB_SCHED, multiple sched instances
each arm their own bypass_lb_timer; concurrent bypass_lb_node() calls RMW
the global cpumasks with no lock, corrupting donee/resched decisions.

Move the cpumasks into struct scx_sched, allocate them alongside the timer
in scx_alloc_and_add_sched(), free them in scx_sched_free_rcu_work().

Fixes: 95d1df610cdc ("sched_ext: Implement load balancer for bypass mode")
Cc: stable@vger.kernel.org # v6.19+
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>

scx_prio_less() runs from core-sched's pick_next_task() path with rq
locked but invokes ops.core_sched_before() with NULL locked_rq, leaving
scx_locked_rq_state NULL. If the BPF callback calls a kfunc that
re-acquires rq based on scx_locked_rq() - e.g. scx_bpf_cpuperf_set(cpu)
- it re-acquires the already-held rq.

Pass task_rq(a).

Fixes: 7b0888b7cc19 ("sched_ext: Implement core-sched support")
Cc: stable@vger.kernel.org # v6.12+
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>

scx_dump_state() walks CPUs with rq_lock_irqsave() held and invokes
ops.dump_cpu / ops.dump_task with NULL locked_rq, leaving
scx_locked_rq_state NULL. If the BPF callback calls a kfunc that
re-acquires rq based on scx_locked_rq() - e.g. scx_bpf_cpuperf_set(cpu)
- it re-acquires the already-held rq.

Pass the held rq to SCX_CALL_OP(). Thread it into scx_dump_task() too.
The pre-loop ops.dump call runs before rq_lock_irqsave() so keeps
rq=NULL.

Fixes: 07814a9439a3 ("sched_ext: Print debug dump after an error exit")
Cc: stable@vger.kernel.org # v6.12+
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>

SCX_CALL_OP{,_RET}() unconditionally clears scx_locked_rq_state to NULL on
exit. Correct at the top level, but ops can recurse via
scx_bpf_sub_dispatch(): a parent's ops.dispatch calls the helper, which
invokes the child's ops.dispatch under another SCX_CALL_OP. When the inner
call returns, the NULL clobbers the outer's state. The parent's BPF then
calls kfuncs like scx_bpf_cpuperf_set() which read scx_locked_rq()==NULL and
re-acquire the already-held rq.

Snapshot scx_locked_rq_state on entry and restore on exit. Rename the rq
parameter to locked_rq across all SCX_CALL_OP* macros so the snapshot local
can be typed as 'struct rq *' without colliding with the parameter token in
the expansion. SCX_CALL_OP_TASK{,_RET}() and SCX_CALL_OP_2TASKS_RET() funnel
through the two base macros and inherit the fix.

Fixes: 4f8b122848db ("sched_ext: Add basic building blocks for nested sub-scheduler dispatching")
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>

dispatch_enqueue()'s FIFO-tail path used list_empty(&dsq->list) to decide
whether to set dsq->first_task on enqueue. dsq->list can contain parked BPF
iterator cursors (SCX_DSQ_LNODE_ITER_CURSOR), so list_empty() is not a
reliable "no real task" check. If the last real task is unlinked while a
cursor is parked, first_task becomes NULL; the next FIFO-tail enqueue then
sees list_empty() == false and skips the first_task update, leaving
scx_bpf_dsq_peek() returning NULL for a non-empty DSQ.

Test dsq->first_task directly, which already tracks only real tasks and is
maintained under dsq->lock.

Fixes: 44f5c8ec5b9a ("sched_ext: Add lockless peek operation for DSQs")
Cc: stable@vger.kernel.org # v6.19+
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Cc: Ryan Newton <newton@meta.com>

scx_bpf_create_dsq() resolves the calling scheduler via scx_prog_sched(aux)
and inserts the new DSQ into that scheduler's dsq_hash. Its inverse
scx_bpf_destroy_dsq() and the query helper scx_bpf_dsq_nr_queued() were
hard-coded to rcu_dereference(scx_root), so a sub-scheduler could only
destroy or query DSQs in the root scheduler's hash - never its own. If the
root had a DSQ with the same id, the sub-sched silently destroyed it and the
root aborted on the next dispatch ("invalid DSQ ID 0x0..").

Take a const struct bpf_prog_aux *aux via KF_IMPLICIT_ARGS and resolve the
scheduler with scx_prog_sched(aux), matching scx_bpf_create_dsq().

Fixes: ebeca1f930ea ("sched_ext: Introduce cgroup sub-sched support")
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>

scx_group_set_{weight,idle,bandwidth}() cache scx_root before acquiring
scx_cgroup_ops_rwsem, so the pointer can be stale by the time the op runs.
If the loaded scheduler is disabled and freed (via RCU work) and another is
enabled between the naked load and the rwsem acquire, the reader sees
scx_cgroup_enabled=true (the new scheduler's) but dereferences the freed one
- UAF on SCX_HAS_OP(sch, ...) / SCX_CALL_OP(sch, ...).

scx_cgroup_enabled is toggled only under scx_cgroup_ops_rwsem write
(scx_cgroup_{init,exit}), so reading scx_root inside the rwsem read section
correlates @sch with the enabled snapshot.

Fixes: a5bd6ba30b33 ("sched_ext: Use cgroup_lock/unlock() to synchronize against cgroup operations")
Cc: stable@vger.kernel.org # v6.18+
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>

scx_sub_enable_workfn()'s prep loop calls __scx_init_task(sch, p, false)
without transitioning task state, then sets SCX_TASK_SUB_INIT. If prep fails
partway, the abort path runs __scx_disable_and_exit_task(sch, p) on the
marked tasks. Task state is still the parent's ENABLED, so that dispatches
to the SCX_TASK_ENABLED arm and calls scx_disable_task(sch, p) - i.e.
child->ops.disable() - for tasks on which child->ops.enable() never ran. A
BPF sub-scheduler allocating per-task state in enable/freeing in disable
would operate on uninitialized state.

The dying-task branch in scx_disable_and_exit_task() has the same problem,
and scx_enabling_sub_sched was cleared before the abort cleanup loop - a
task exiting during cleanup tripped the WARN and skipped both ops.exit_task
and the SCX_TASK_SUB_INIT clear, leaking per-task resources and leaving the
task stuck.

Introduce scx_sub_init_cancel_task() that calls ops.exit_task with
cancelled=true - matching what the top-level init path does when init_task
itself returns -errno. Use it in the abort loop and in the dying-task
branch. scx_enabling_sub_sched now stays set until the abort loop finishes
clearing SUB_INIT, so concurrent exits hitting the dying-task branch can
still find @sch. That branch also clears SCX_TASK_SUB_INIT unconditionally
when seen, leaving the task unmarked even if the WARN fires.

Fixes: 337ec00b1d9c ("sched_ext: Implement cgroup sub-sched enabling and disabling")
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>

bypass_lb_cpu() transfers tasks between per-CPU bypass DSQs without
migrating them - task_cpu() only updates when the donee later consumes the
task via move_remote_task_to_local_dsq(). If the LB timer fires again before
consumption and the new DSQ becomes a donor, @p is still on the previous CPU
and task_rq(@p) != donor_rq. @p can't be moved without its own rq locked.

Skip such tasks.

Fixes: 95d1df610cdc ("sched_ext: Implement load balancer for bypass mode")
Cc: stable@vger.kernel.org # v6.19+
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>

bpf_iter_scx_dsq_new() clears kit->dsq on failure and
bpf_iter_scx_dsq_{next,destroy}() guard against that. scx_dsq_move() doesn't -
it dereferences kit->dsq immediately, so a BPF program that calls
scx_bpf_dsq_move[_vtime]() after a failed iter_new oopses the kernel.

Return false if kit->dsq is NULL.

Fixes: 4c30f5ce4f7a ("sched_ext: Implement scx_bpf_dispatch[_vtime]_from_dsq()")
Cc: stable@vger.kernel.org # v6.12+
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>

When ops.sub_attach is set, scx_alloc_and_add_sched() creates sub_kset as a
child of &sch->kobj, which pins the parent with its own reference. The
disable paths never call kset_unregister(), so the final kobject_put() in
bpf_scx_unreg() leaves a stale reference and scx_kobj_release() never runs,
leaking the whole struct scx_sched on every load/unload cycle.

Unregister sub_kset in scx_root_disable() and scx_sub_disable() before
kobject_del(&sch->kobj).

Fixes: ebeca1f930ea ("sched_ext: Introduce cgroup sub-sched support")
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>

scx_hardlockup() runs from NMI and eventually calls scx_claim_exit(),
which takes scx_sched_lock. scx_sched_lock isn't NMI-safe and grabbing
it from NMI context can lead to deadlocks.

The hardlockup handler is best-effort recovery and the disable path it
triggers runs off of irq_work anyway. Move the handle_lockup() call into
an irq_work so it runs in IRQ context.

Fixes: ebeca1f930ea ("sched_ext: Introduce cgroup sub-sched support")
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>

When unregistered my self-written scx scheduler, the following panic
occurs.

[ 229.923133] Kernel text patching generated an invalid instruction at 0xffff80009bc2c1f8!
[ 229.923146] Internal error: Oops - BRK: 00000000f2000100 [#1] SMP
[ 230.077871] CPU: 48 UID: 0 PID: 1760 Comm: kworker/u583:7 Not tainted 7.0.0+ #3 PREEMPT(full)
[ 230.086677] Hardware name: NVIDIA GB200 NVL/P3809-BMC, BIOS 02.05.12 20251107
[ 230.093972] Workqueue: events_unbound bpf_map_free_deferred
[ 230.099675] Sched_ext: invariant_0.1.0_aarch64_unknown_linux_gnu_debug (disabling), task: runnable_at=-174ms
[ 230.116843] pc : 0xffff80009bc2c1f8
[ 230.120406] lr : dequeue_task_scx+0x270/0x2d0
[ 230.217749] Call trace:
[ 230.228515] 0xffff80009bc2c1f8 (P)
[ 230.232077] dequeue_task+0x84/0x188
[ 230.235728] sched_change_begin+0x1dc/0x250
[ 230.240000] __set_cpus_allowed_ptr_locked+0x17c/0x240
[ 230.245250] __set_cpus_allowed_ptr+0x74/0xf0
[ 230.249701] ___migrate_enable+0x4c/0xa0
[ 230.253707] bpf_map_free_deferred+0x1a4/0x1b0
[ 230.258246] process_one_work+0x184/0x540
[ 230.262342] worker_thread+0x19c/0x348
[ 230.266170] kthread+0x13c/0x150
[ 230.269465] ret_from_fork+0x10/0x20
[ 230.281393] Code: d4202000 d4202000 d4202000 d4202000 (d4202000)
[ 230.287621] ---[ end trace 0000000000000000 ]---
[ 231.160046] Kernel panic - not syncing: Oops - BRK: Fatal exception in interrupt

The root cause is that the JIT page backing ops->quiescent() is freed
before all callers of that function have stopped.

The expected ordering during teardown is:
bitmap_zero(sch->has_op) + synchronize_rcu()
-> guarantees no CPU will ever call sch->ops.* again
-> only THEN free the BPF struct_ops JIT page

bpf_scx_unreg() is supposed to enforce the order, but after
commit f4a6c506d118 ("sched_ext: Always bounce scx_disable() through
irq_work"), disable_work is no longer queued directly, causing
kthread_flush_work() to be a noop. Thus, the caller drops the struct_ops
map too early and poisoned with AARCH64_BREAK_FAULT before
disable_workfn ever execute.

So the subsequent dequeue_task() still sees SCX_HAS_OP(sch, quiescent)
as true and calls ops.quiescent, which hit on the poisoned page and BRK
panic.

Add a helper scx_flush_disable_work() so the future use cases that want
to flush disable_work can use it.
Also amend the call for scx_root_enable_workfn() and
scx_sub_enable_workfn() which have similar pattern in the error path.

Fixes: f4a6c506d118 ("sched_ext: Always bounce scx_disable() through irq_work")
Signed-off-by: Richard Cheng <icheng@nvidia.com>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Reviewed-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

local_dsq_post_enq() calls call_task_dequeue() with scx_root instead of
the scheduler instance actually managing the task. When
CONFIG_EXT_SUB_SCHED is enabled, tasks may be managed by a sub-scheduler
whose ops.dequeue() callback differs from root's. Using scx_root causes
the wrong scheduler's ops.dequeue() to be consulted: sub-sched tasks
dispatched to a local DSQ via scx_bpf_dsq_move_to_local() will have
SCX_TASK_IN_CUSTODY cleared but the sub-scheduler's ops.dequeue() is
never invoked, violating the custody exit semantics.

Fix by adding a 'struct scx_sched *sch' parameter to local_dsq_post_enq()
and move_local_task_to_local_dsq(), and propagating the correct scheduler
from their callers dispatch_enqueue(), move_task_between_dsqs(), and
consume_dispatch_q().

This is consistent with dispatch_enqueue()'s non-local path which already
passes 'sch' directly to call_task_dequeue() for global/bypass DSQs.

Fixes: ebf1ccff79c4 ("sched_ext: Fix ops.dequeue() semantics")
Signed-off-by: zhidao su <suzhidao@xiaomi.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

scx_fork() dispatches ops.init_task to exactly one scheduler - the one
owning the forking task's cgroup. A task forked inside a sub-scheduler's
cgroup is init'd into the sub only; the root scheduler has no task_ctx
entry for it. When that task later appears as @prev in the root's
qmap_dispatch() (or flows through core-sched comparison via task_qdist),
the bpf_task_storage_get() legitimately misses.

qmap treated those misses as fatal via scx_bpf_error("task_ctx lookup
failed") and aborted the scheduler as soon as the first cross-sched
task hit the root. Drop the error in the sites where the miss is
legitimate: lookup_task_ctx() (helper; callers already check for NULL),
qmap_dispatch()'s @prev branch (bookkeeping-only), task_qdist()
(returns 0 which makes the comparison a no-op), and qmap_select_cpu()
(returns prev_cpu as a no-op fallback instead of -ESRCH). The existing
scx_error was a paranoid guard from the pre-sub-sched world where every
task was owned by the one and only scheduler.

v2: qmap_select_cpu() returns prev_cpu on NULL instead of -ESRCH, so
the root scheduler doesn't error on cross-sched tasks that pass
through it (Andrea Righi).

Fixes: 4f8b122848db ("sched_ext: Add basic building blocks for nested sub-scheduler dispatching")
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Reviewed-by: Zhao Mengmeng <zhaomengmeng@kylinos.cn>

Inserts past 75% load call schedule_work(&ht->run_work) to kick an
async resize. If a caller holds a raw spinlock (e.g. an
insecure_elasticity user), schedule_work() under that lock records

caller_lock -> pool->lock -> pi_lock -> rq->__lock

A cycle forms if any of these locks is acquired in the reverse
direction elsewhere. sched_ext, the only current insecure_elasticity
user, hits this: it holds scx_sched_lock across rhashtable inserts of
sub-schedulers, while scx_bypass() takes rq->__lock -> scx_sched_lock.
Exercising the resize path produces:

Chain exists of:
&pool->lock --> &rq->__lock --> scx_sched_lock

Bounce the kick from the insert paths through irq_work so
schedule_work() runs from hard IRQ context with the caller's lock no
longer held. rht_deferred_worker()'s self-rearm on error stays on
schedule_work(&ht->run_work) - the worker runs in process context with
no caller lock held, and keeping the self-requeue on @run_work lets
cancel_work_sync() in rhashtable_free_and_destroy() drain it.

v3: Keep rht_deferred_worker()'s self-rearm on schedule_work(&run_work).
Routing it through irq_work in v2 broke cancel_work_sync()'s
self-requeue handling - an irq_work queued after irq_work_sync()
returned but while cancel_work_sync() was still waiting could fire
post-teardown.

v2: Bounce unconditionally instead of gating on insecure_elasticity,
as suggested by Herbert.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>

Verify that the BPF verifier rejects a non-SCX struct_ops program
(tcp_congestion_ops) that attempts to call an SCX kfunc (scx_bpf_kick_cpu).
The test expects the load to fail with -EACCES from scx_kfunc_context_filter.

Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

scx_kfunc_context_filter() currently allows non-SCX struct_ops programs
(e.g. tcp_congestion_ops) to call SCX unlocked kfuncs. This is wrong
for two reasons:

- It is semantically incorrect: a TCP congestion control program has no
business calling SCX kfuncs such as scx_bpf_kick_cpu().

- With CONFIG_EXT_SUB_SCHED=y, kfuncs like scx_bpf_kick_cpu() call
scx_prog_sched(aux), which invokes bpf_prog_get_assoc_struct_ops(aux)
and casts the result to struct sched_ext_ops * before reading ops->priv.
For a non-SCX struct_ops program the returned pointer is the kdata of
that struct_ops type, which is far smaller than sched_ext_ops, making
the read an out-of-bounds access (confirmed with KASAN).

Extend the filter to cover scx_kfunc_set_any and scx_kfunc_set_idle as
well, and deny all SCX kfuncs for any struct_ops program that is not the
SCX struct_ops. This addresses both issues: the semantic contract is
enforced at the verifier level, and the runtime out-of-bounds access
becomes unreachable.

Fixes: d1d3c1c6ae36 ("sched_ext: Add verifier-time kfunc context filter")
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

scx_sched_hash is inserted into under scx_sched_lock (raw_spinlock_irq)
in scx_link_sched(). rhashtable's sync grow path calls get_random_u32()
and does a GFP_ATOMIC allocation; both acquire regular spinlocks, which
is unsafe under raw_spinlock_t. Set insecure_elasticity to skip the
sync grow.

v2:
- Dropped dsq_hash changes. Insertion is not under raw_spin_lock.

- Switched from no_sync_grow flag to insecure_elasticity.

Fixes: 25037af712eb ("sched_ext: Add rhashtable lookup for sub-schedulers")
Signed-off-by: Tejun Heo <tj@kernel.org>

Some users of rhashtable cannot handle insertion failures, and
are happy to accept the consequences of a hash table that having
very long chains.

Restore the insecure_elasticity toggle for these users. In
addition to disabling the chain length checks, this also removes
the emergency resize that would otherwise occur when the hash
table occupancy hits 100% (an async resize is still scheduled
at 75%).

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Tejun Heo <tj@kernel.org>

Pull smbdirect updates from Steve French:
"Move smbdirect server and client code to common directory:

- temporary use of smbdirect_all_c_files.c to allow micro steps

- factor out common functions into a smbdirect.ko.

- convert cifs.ko to use smbdirect.ko

- convert ksmbd.ko to use smbdirect.ko

- let smbdirect.ko use global workqueues

- move ib_client logic from ksmbd.ko into smbdirect.ko

- remove smbdirect_all_c_files.c hack again

- some locking and teardown related fixes on top"

* tag 'v7.1-rc-part1-smbdirect-fixes' of git://git.samba.org/ksmbd: (145 commits)
smb: smbdirect: let smbdirect_connection_deregister_mr_io unlock while waiting
smb: smbdirect: fix the logic in smbdirect_socket_destroy_sync() without an error
smb: smbdirect: fix copyright header of smbdirect.h
smb: smbdirect: change smbdirect_socket_parameters.{initiator_depth,responder_resources} to __u16
smb: smbdirect: remove unused SMBDIRECT_USE_INLINE_C_FILES logic
smb: server: no longer use smbdirect_socket_set_custom_workqueue()
smb: client: no longer use smbdirect_socket_set_custom_workqueue()
smb: smbdirect: introduce global workqueues
smb: smbdirect: prepare use of dedicated workqueues for different steps
smb: smbdirect: remove unused smbdirect_connection_mr_io_recovery_work()
smb: smbdirect: wrap rdma_disconnect() in rdma_[un]lock_handler()
smb: server: make use of smbdirect_netdev_rdma_capable_mode_type()
smb: smbdirect: introduce smbdirect_netdev_rdma_capable_mode_type()
smb: server: make use of smbdirect.ko
smb: server: remove unused ksmbd_transport_ops.prepare()
smb: server: make use of smbdirect_socket_{listen,accept}()
smb: server: only use public smbdirect functions
smb: server: make use of smbdirect_socket_create_accepting()/smbdirect_socket_release()
smb: server: make use of smbdirect_{socket_init_accepting,connection_wait_for_connected}()
smb: server: make use of smbdirect_connection_send_iter() and related functions
...

Pull livepatching updates from Petr Mladek:

- Add two new selftests

* tag 'livepatching-for-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching:
selftests/livepatch: add test for module function patching
selftests: livepatch: test-ftrace: livepatch a traced function

We should not hold a mutex locked during wait_for_completion()
holding a reference is enough.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Henrique Carvalho <henrique.carvalho@suse.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Pull m68k updates from Geert Uytterhoeven:

- Add support for QEMU virt-ctrl, and use it for system reset
and power off on the virt platform

- defconfig updates

- Miscellaneous fixes and improvements

* tag 'm68k-for-v7.1-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
m68k: virt: Switch to qemu-virt-ctrl driver
power: reset: Add QEMU virt-ctrl driver
m68k: defconfig: Update defconfigs for v7.0-rc1
m68k: emu: Replace unbounded sprintf() in nfhd_init_one()
m68k: uapi: Add ucontext.h
m68k: defconfig: hp300: Enable monochrome and 16-color linux logos
m68k: q40: Remove commented out code

If smbdirect_socket_destroy_sync() and sc->first_error was not set
we should set -ESHUTDOWN, that's a better condition
doing it only implicitly with the
sc->status < SMBDIRECT_SOCKET_DISCONNECTING check.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Henrique Carvalho <henrique.carvalho@suse.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Pull EFI updates from Ard Biesheuvel:
"Again not a busy cycle for EFI, just some minor tweaks and bug fixes:

- Enable boot graphics resource table (BGRT) on Xen/x86

- Correct a misguided assumption in the memory attributes table
sanity check

- Start tagging efi_mem_reserve()'d regions as MEMBLOCK_RSRV_KERN

- Some other minor fixes and cleanups"

* tag 'efi-next-for-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
efi/capsule-loader: fix incorrect sizeof in phys array reallocation
efi: Tag memblock reservations of boot services regions as RSRV_KERN
memblock: Permit existing reserved regions to be marked RSRV_KERN
efi/memattr: Fix thinko in table size sanity check
efi: libstub: fix type of fdt 32 and 64bit variables
efi: Drop unused efi_range_is_wc() function
efi: Enable BGRT loading under Xen
efi: make efi_mem_type() and efi_mem_attributes() work on Xen PV

Register the "qemu-virt-ctrl" platform device during board
initialization to utilize the new generic power/reset driver.

Consequently, remove the legacy reset and power-off implementations
specific to the virt machine. The platform's mach_reset callback is
updated to call do_kernel_restart(), bridging the legacy m68k reboot
path to the generic kernel restart handler framework for this machine.

To prevent any regressions in reboot or power-off functionality when
the driver is not built-in, explicitly select POWER_RESET and
POWER_RESET_QEMU_VIRT_CTRL for the VIRT machine in Kconfig.machine.

Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://patch.msgid.link/20260412211952.3564033-3-visitorckw@gmail.com
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

This is basically the inverse case of commit 474eecc882ae
("selftests: livepatch: test if ftrace can trace a livepatched function")
but ensuring that livepatch would work on a traced function.

Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Tested-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Link: https://patch.msgid.link/20260220-lp-test-trace-v1-1-4b6703cd01a6@suse.com
[pmladek: Fixed a typo found by Joe.]
Signed-off-by: Petr Mladek <pmladek@suse.com>

Add a target module and livepatch pair that verify module function
patching via a proc entry. Two test cases cover both the
klp_enable_patch path (target loaded before livepatch) and the
klp_module_coming path (livepatch loaded before target).

Signed-off-by: Pablo Alessandro Santos Hugen <phugen@redhat.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Tested-by: Petr Mladek <pmladek@suse.com>
Link: https://patch.msgid.link/20260320201135.1203992-1-phugen@redhat.com
Signed-off-by: Petr Mladek <pmladek@suse.com>

Everything in smbdirect.h was taken from my out of
tree prototype.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Henrique Carvalho <henrique.carvalho@suse.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Pull VFIO updates from Alex Williamson:

- Update QAT vfio-pci variant driver for Gen 5, 420xx devices (Vijay
Sundar Selvamani, Suman Kumar Chakraborty, Giovanni Cabiddu)

- Fix vfio selftest MMIO DMA mapping selftest (Alex Mastro)

- Conversions to const struct class in support of class_create()
deprecation (Jori Koolstra)

- Improve selftest compiler compatibility by avoiding initializer on
variable-length array (Manish Honap)

- Define new uAPI for drivers supporting migration to advise user-
space of new initial data for reducing target startup latency.
Implemented for mlx5 vfio-pci variant driver (Yishai Hadas)

- Enable vfio selftests on aarch64, not just cross-compiles reporting
arm64 (Ted Logan)

- Update vfio selftest driver support to include additional DSA devices
(Yi Lai)

- Unconditionally include debugfs root pointer in vfio device struct,
avoiding a build failure seen in hisi_acc variant driver without
debugfs otherwise (Arnd Bergmann)

- Add support for the s390 ISM (Internal Shared Memory) device via a
new variant driver. The device is unique in the size of its BAR space
(256TiB) and lack of mmap support (Julian Ruess)

- Enforce that vfio-pci drivers implement a name in their ops structure
for use in sequestering SR-IOV VFs (Alex Williamson)

- Prune leftover group notifier code (Paolo Bonzini)

- Fix Xe vfio-pci variant driver to avoid migration support as a
dependency in the reset path and missing release call (Michał
Winiarski)

* tag 'vfio-v7.1-rc1' of https://github.com/awilliam/linux-vfio: (23 commits)
vfio/xe: Add a missing vfio_pci_core_release_dev()
vfio/xe: Reorganize the init to decouple migration from reset
vfio: remove dead notifier code
vfio/pci: Require vfio_device_ops.name
MAINTAINERS: add VFIO ISM PCI DRIVER section
vfio/ism: Implement vfio_pci driver for ISM devices
vfio/pci: Rename vfio_config_do_rw() to vfio_pci_config_rw_single() and export it
vfio: unhide vdev->debug_root
vfio/qat: add support for Intel QAT 420xx VFs
vfio: selftests: Support DMR and GNR-D DSA devices
vfio: selftests: Build tests on aarch64
vfio/mlx5: Add REINIT support to VFIO_MIG_GET_PRECOPY_INFO
vfio/mlx5: consider inflight SAVE during PRE_COPY
net/mlx5: Add IFC bits for migration state
vfio: Adapt drivers to use the core helper vfio_check_precopy_ioctl
vfio: Add support for VFIO_DEVICE_FEATURE_MIG_PRECOPY_INFOv2
vfio: Define uAPI for re-init initial bytes during the PRE_COPY phase
vfio: selftests: Fix VLA initialisation in vfio_pci_irq_set()
vfio: uapi: fix comment typo
vfio: mdev: replace mtty_dev->vd_class with a const struct class
...

The krealloc() call for cap_info->phys in __efi_capsule_setup_info() uses
sizeof(phys_addr_t *) instead of sizeof(phys_addr_t), which might be
causing an undersized allocation.

The allocation is also inconsistent with the initial array allocation in
efi_capsule_open() that allocates one entry with sizeof(phys_addr_t),
and the efi_capsule_write() function that stores phys_addr_t values (not
pointers) via page_to_phys().

On 64-bit systems where sizeof(phys_addr_t) == sizeof(phys_addr_t *), this
goes unnoticed. On 32-bit systems with PAE where phys_addr_t is 64-bit but
pointers are 32-bit, this allocates half the required space, which might
lead to a heap buffer overflow when storing physical addresses.

This is similar to the bug fixed in commit fccfa646ef36 ("efi/capsule-loader:
fix incorrect allocation size") which fixed the same issue at the initial
allocation site.

Fixes: f24c4d478013 ("efi/capsule-loader: Reinstate virtual capsule mapping")
Assisted-by: Claude:claude-sonnet-4-5
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Add a new driver for the 'virt-ctrl' device found on QEMU virt machines
(e.g. m68k). This device provides a simple interface for system reset
and power off [1].

This driver utilizes the modern system-off API to register callbacks
for both system restart and power off. It also registers a reboot
notifier to catch SYS_HALT events, ensuring that LINUX_REBOOT_CMD_HALT
is properly handled. It is designed to be generic and can be reused by
other architectures utilizing this QEMU device.

Link: https://gitlab.com/qemu-project/qemu/-/blob/v10.2.0/hw/misc/virt_ctrl.c [1]
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://patch.msgid.link/20260412211952.3564033-2-visitorckw@gmail.com
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

Pull livepatching updates from Petr Mladek:

- Support both paths where tracefs is typically mounted in selftests

- Make old_sympos 0 and 1 equal. They both are valid when there is only
one symbol with the given name.

* tag 'livepatching-for-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching:
selftests: livepatch: use canonical ftrace path
livepatch: Match old_sympos 0 and 1 in klp_find_func()

We still limit this to U8_MAX as the rdma api only uses __u8
and that's also the limit for Infiniband and RoCE*,
while iWarp would be able to support larger values at
the protocol level.

As struct smbdirect_socket_parameters will be part
of the uapi for IPPROTO_SMBDIRECT in future, change it
now even if userspace sockets won't be supported yet.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Acked-by: Henrique Carvalho <henrique.carvalho@suse.com>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Pull jfs updates from Dave Kleikamp:
"More robust data integrity checking and some fixes"

* tag 'jfs-7.1' of github.com:kleikamp/linux-shaggy:
jfs: avoid -Wtautological-constant-out-of-range-compare warning again
JFS: always load filesystem UUID during mount
jfs: hold LOG_LOCK on umount to avoid null-ptr-deref
jfs: Set the lbmDone flag at the end of lbmIODone
jfs: fix corrupted list in dbUpdatePMap
jfs: add dmapctl integrity check to prevent invalid operations
jfs: add dtpage integrity check to prevent index/pointer overflows
jfs: add dtroot integrity check to prevent index out-of-bounds

The driver is implementing its own .release(), which means that it needs
to call vfio_pci_core_release_dev().
Add the missing call.

Fixes: 1f5556ec8b9ef ("vfio/xe: Add device specific vfio_pci driver variant for Intel graphics")
Reported-by: Niklas Schnelle <schnelle@linux.ibm.com>
Closes: https://lore.kernel.org/kvm/408e262c507e8fd628a71e39904fedd99fa0ee8e.camel@linux.ibm.com/
Cc: stable@vger.kernel.org
Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20260410224948.900550-2-michal.winiarski@intel.com
Signed-off-by: Alex Williamson <alex@shazbot.org>

By definition, EFI memory regions of type boot services code or data
have no special significance to the firmware at runtime, only to the OS.
In some cases, the firmware will allocate tables and other assets that
are passed in memory in regions of this type, and leave it up to the OS
to decide whether or not to treat the allocation as special, or simply
consume the contents at boot and recycle the RAM for ordinary use. The
reason for this approach is that it avoids needless memory reservations
for assets that the OS knows nothing about, and therefore doesn't know
how to free either.

This means that any memblock reservations covering such regions can be
marked as MEMBLOCK_RSRV_KERN - this is a better match semantically, and
is useful on x86 to distinguish true reservations from temporary
reservations that are only needed to work around firmware bugs.

Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

- Restore the state of the standard black-and-white and 16-color Linux
logos (no longer auto-enabled since commit 994fcd4b107d747b
("video/logo: don't select LOGO_LINUX_MONO and LOGO_LINUX_VGA16 by
default")).

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://patch.msgid.link/67dd5553e9289757c274d79ce1b13fca33fde25d.1772446429.git.geert@linux-m68k.org

Pull sched_ext updates from Tejun Heo:

- Improve recovery from misbehaving BPF schedulers.

When a scheduler puts many tasks with varying affinity restrictions
on a shared DSQ, CPUs scanning through tasks they cannot run can
overwhelm the system, causing lockups.

Bypass mode now uses per-CPU DSQs with a load balancer to avoid this,
and hooks into the hardlockup detector to attempt recovery.

Add scx_cpu0 example scheduler to demonstrate this scenario.

- Add lockless peek operation for DSQs to reduce lock contention for
schedulers that need to query queue state during load balancing.

- Allow scx_bpf_reenqueue_local() to be called from anywhere in
preparation for deprecating cpu_acquire/release() callbacks in favor
of generic BPF hooks.

- Prepare for hierarchical scheduler support: add
scx_bpf_task_set_slice() and scx_bpf_task_set_dsq_vtime() kfuncs,
make scx_bpf_dsq_insert*() return bool, and wrap kfunc args in
structs for future aux__prog parameter.

- Implement cgroup_set_idle() callback to notify BPF schedulers when a
cgroup's idle state changes.

- Fix migration tasks being incorrectly downgraded from
stop_sched_class to rt_sched_class across sched_ext enable/disable.
Applied late as the fix is low risk and the bug subtle but needs
stable backporting.

- Various fixes and cleanups including cgroup exit ordering,
SCX_KICK_WAIT reliability, and backward compatibility improvements.

* tag 'sched_ext-for-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: (44 commits)
sched_ext: Fix incorrect sched_class settings for per-cpu migration tasks
sched_ext: tools: Removing duplicate targets during non-cross compilation
sched_ext: Use kvfree_rcu() to release per-cpu ksyncs object
sched_ext: Pass locked CPU parameter to scx_hardlockup() and add docs
sched_ext: Update comments replacing breather with aborting mechanism
sched_ext: Implement load balancer for bypass mode
sched_ext: Factor out abbreviated dispatch dequeue into dispatch_dequeue_locked()
sched_ext: Factor out scx_dsq_list_node cursor initialization into INIT_DSQ_LIST_CURSOR
sched_ext: Add scx_cpu0 example scheduler
sched_ext: Hook up hardlockup detector
sched_ext: Make handle_lockup() propagate scx_verror() result
sched_ext: Refactor lockup handlers into handle_lockup()
sched_ext: Make scx_exit() and scx_vexit() return bool
sched_ext: Exit dispatch and move operations immediately when aborting
sched_ext: Simplify breather mechanism with scx_aborting flag
sched_ext: Use per-CPU DSQs instead of per-node global DSQs in bypass mode
sched_ext: Refactor do_enqueue_task() local and global DSQ paths
sched_ext: Use shorter slice in bypass mode
sched_ext: Mark racy bitfields to prevent adding fields that can't tolerate races
sched_ext: Minor cleanups to scx_task_iter
...

Since v4.1 kernel, a new interface for ftrace called "tracefs" was
introduced, which is usually mounted in /sys/kernel/tracing. Therefore,
tracing files can now be accessed via either the legacy path
/sys/kernel/debug/tracing or the newer path /sys/kernel/tracing.

Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Tested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>

We always build as standalone module (or as part of the core kernel).

This also removes unused elements from struct smbdirect_socket
and unused exports.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Pull ext2, udf, quota updates from Jan Kara:

- A fix for a race in quota code that can expose ocfs2 to
use-after-free issues

- UDF fix to avoid memory corruption in face of corrupted format

- Couple of ext2 fixes for better handling of fs corruption

- Some more various code cleanups in UDF & ext2

* tag 'fs_for_v7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
ext2: reject inodes with zero i_nlink and valid mode in ext2_iget()
ext2: use get_random_u32() where appropriate
quota: Fix race of dquot_scan_active() with quota deactivation
udf: fix partition descriptor append bookkeeping
ext2: avoid drop_nlink() during unlink of zero-nlink inode in ext2_unlink()
ext2: guard reservation window dump with EXT2FS_DEBUG
ext2: replace BUG_ON with WARN_ON_ONCE in ext2_get_blocks
ext2: remove stale TODO about kmap
fs: udf: avoid assignment in condition when selecting allocation goal

The comparison of an __s8 value against DTPAGEMAXSLOT is still trivially
true, causing a harmless (default disabled) warning with clang:

fs/jfs/jfs_dtree.c:4419:25: error: result of comparison of constant 128 with expression of type 's8' (aka 'signed char') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
4419 | p->header.freelist >= DTPAGEMAXSLOT)) {
| ~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~

I previously worked around two of these in commit 7833570dae83 ("jfs: avoid
-Wtautological-constant-out-of-range-compare warning"), but now a new one has
come up, so address the same way by dropping the redundant range check.

Fixes: 119e448bb50a ("jfs: add dtpage integrity check to prevent index/pointer overflows")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>

Attempting to issue reset on VF devices that don't support migration
leads to the following:

BUG: unable to handle page fault for address: 00000000000011f8
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 2 UID: 0 PID: 7443 Comm: xe_sriov_flr Tainted: G S U 7.0.0-rc1-lgci-xe-xe-4588-cec43d5c2696af219-nodebug+ #1 PREEMPT(lazy)
Tainted: [S]=CPU_OUT_OF_SPEC, [U]=USER
Hardware name: Intel Corporation Alder Lake Client Platform/AlderLake-P DDR4 RVP, BIOS RPLPFWI1.R00.4035.A00.2301200723 01/20/2023
RIP: 0010:xe_sriov_vfio_wait_flr_done+0xc/0x80 [xe]
Code: ff c3 cc cc cc cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 41 54 53 <83> bf f8 11 00 00 02 75 61 41 89 f4 85 f6 74 52 48 8b 47 08 48 89
RSP: 0018:ffffc9000f7c39b8 EFLAGS: 00010202
RAX: ffffffffa04d8660 RBX: ffff88813e3e4000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000f7c39c8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888101a48800
R13: ffff88813e3e4150 R14: ffff888130d0d008 R15: ffff88813e3e40d0
FS: 00007877d3d0d940(0000) GS:ffff88890b6d3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000011f8 CR3: 000000015a762000 CR4: 0000000000f52ef0
PKRU: 55555554
Call Trace:
<TASK>
xe_vfio_pci_reset_done+0x49/0x120 [xe_vfio_pci]
pci_dev_restore+0x3b/0x80
pci_reset_function+0x109/0x140
reset_store+0x5c/0xb0
dev_attr_store+0x17/0x40
sysfs_kf_write+0x72/0x90
kernfs_fop_write_iter+0x161/0x1f0
vfs_write+0x261/0x440
ksys_write+0x69/0xf0
__x64_sys_write+0x19/0x30
x64_sys_call+0x259/0x26e0
do_syscall_64+0xcb/0x1500
? __fput+0x1a2/0x2d0
? fput_close_sync+0x3d/0xa0
? __x64_sys_close+0x3e/0x90
? x64_sys_call+0x1b7c/0x26e0
? do_syscall_64+0x109/0x1500
? __task_pid_nr_ns+0x68/0x100
? __do_sys_getpid+0x1d/0x30
? x64_sys_call+0x10b5/0x26e0
? do_syscall_64+0x109/0x1500
? putname+0x41/0x90
? do_faccessat+0x1e8/0x300
? __x64_sys_access+0x1c/0x30
? x64_sys_call+0x1822/0x26e0
? do_syscall_64+0x109/0x1500
? tick_program_event+0x43/0xa0
? hrtimer_interrupt+0x126/0x260
? irqentry_exit+0xb2/0x710
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7877d5f1c5a4
Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d a5 ea 0e 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89
RSP: 002b:00007fff48e5f908 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007877d5f1c5a4
RDX: 0000000000000001 RSI: 00007877d621b0c9 RDI: 0000000000000009
RBP: 0000000000000001 R08: 00005fb49113b010 R09: 0000000000000007
R10: 0000000000000000 R11: 0000000000000202 R12: 00007877d621b0c9
R13: 0000000000000009 R14: 00007fff48e5fac0 R15: 00007fff48e5fac0
</TASK>

This is caused by the fact that some of the xe_vfio_pci_core_device
members needed for handling reset are only initialized as part of
migration init.

Fix the problem by reorganizing the code to decouple VF init from
migration init.

Fixes: 1f5556ec8b9ef ("vfio/xe: Add device specific vfio_pci driver variant for Intel graphics")
Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/work_items/7352
Cc: stable@vger.kernel.org
Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20260410224948.900550-1-michal.winiarski@intel.com
Signed-off-by: Alex Williamson <alex@shazbot.org>

Permit existing memblock reservations to be marked as RSRV_KERN. This
will be used by the EFI code on x86 to distinguish between reservations
of boot services data regions that have actual significance to the
kernel and regions that are reserved temporarily to work around buggy
firmware.

Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Replace unbounded sprintf() with the safer snprintf().

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://patch.msgid.link/20260318001632.2974-3-thorsten.blum@linux.dev
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

Pull cgroup updates from Tejun Heo:

- Defer task cgroup unlink until after the dying task's final context
switch so that controllers see the cgroup properly populated until
the task is truly gone

- cpuset cleanups and simplifications.

Enforce that domain isolated CPUs stay in root or isolated partitions
and fail if isolated+nohz_full would leave no housekeeping CPU. Fix
sched/deadline root domain handling during CPU hot-unplug and race
for tasks in attaching cpusets

- Misc fixes including memory reclaim protection documentation and
selftest KTAP conformance

* tag 'cgroup-for-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits)
cpuset: Treat cpusets in attaching as populated
sched/deadline: Walk up cpuset hierarchy to decide root domain when hot-unplug
cgroup/cpuset: Introduce cpuset_cpus_allowed_locked()
docs: cgroup: No special handling of unpopulated memcgs
docs: cgroup: Note about sibling relative reclaim protection
docs: cgroup: Explain reclaim protection target
selftests/cgroup: conform test to KTAP format output
cpuset: remove need_rebuild_sched_domains
cpuset: remove global remote_children list
cpuset: simplify node setting on error
cgroup: include missing header for struct irq_work
cgroup: Fix sleeping from invalid context warning on PREEMPT_RT
cgroup/cpuset: Globally track isolated_cpus update
cgroup/cpuset: Ensure domain isolated CPUs stay in root or isolated partition
cgroup/cpuset: Move up prstate_housekeeping_conflict() helper
cgroup/cpuset: Fail if isolated and nohz_full don't leave any housekeeping
cgroup/cpuset: Rename update_unbound_workqueue_cpumask() to update_isolation_cpumasks()
cgroup: Defer task cgroup unlink until after the task is done switching out
cgroup: Move dying_tasks cleanup from cgroup_task_release() to cgroup_task_free()
cgroup: Rename cgroup lifecycle hooks to cgroup_task_*()
...

When loading the ebpf scheduler, the tasks in the scx_tasks list will
be traversed and invoke __setscheduler_class() to get new sched_class.
however, this would also incorrectly set the per-cpu migration
task's->sched_class to rt_sched_class, even after unload, the per-cpu
migration task's->sched_class remains sched_rt_class.

The log for this issue is as follows:

./scx_rustland --stats 1
[ 199.245639][ T630] sched_ext: "rustland" does not implement cgroup cpu.weight
[ 199.269213][ T630] sched_ext: BPF scheduler "rustland" enabled
04:25:09 [INFO] RustLand scheduler attached

bpftrace -e 'iter:task /strcontains(ctx->task->comm, "migration")/
{ printf("%s:%d->%pS\n", ctx->task->comm, ctx->task->pid, ctx->task->sched_class); }'
Attaching 1 probe...
migration/0:24->rt_sched_class+0x0/0xe0
migration/1:27->rt_sched_class+0x0/0xe0
migration/2:33->rt_sched_class+0x0/0xe0
migration/3:39->rt_sched_class+0x0/0xe0
migration/4:45->rt_sched_class+0x0/0xe0
migration/5:52->rt_sched_class+0x0/0xe0
migration/6:58->rt_sched_class+0x0/0xe0
migration/7:64->rt_sched_class+0x0/0xe0

sched_ext: BPF scheduler "rustland" disabled (unregistered from user space)
EXIT: unregistered from user space
04:25:21 [INFO] Unregister RustLand scheduler

bpftrace -e 'iter:task /strcontains(ctx->task->comm, "migration")/
{ printf("%s:%d->%pS\n", ctx->task->comm, ctx->task->pid, ctx->task->sched_class); }'
Attaching 1 probe...
migration/0:24->rt_sched_class+0x0/0xe0
migration/1:27->rt_sched_class+0x0/0xe0
migration/2:33->rt_sched_class+0x0/0xe0
migration/3:39->rt_sched_class+0x0/0xe0
migration/4:45->rt_sched_class+0x0/0xe0
migration/5:52->rt_sched_class+0x0/0xe0
migration/6:58->rt_sched_class+0x0/0xe0
migration/7:64->rt_sched_class+0x0/0xe0

This commit therefore generate a new scx_setscheduler_class() and
add check for stop_sched_class to replace __setscheduler_class().

Fixes: f0e1a0643a59 ("sched_ext: Implement BPF extensible scheduler class")
Cc: stable@vger.kernel.org # v6.12+
Signed-off-by: Zqiang <qiang.zhang@linux.dev>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

When there is only one function of the same name, old_sympos of 0 and 1
are logically identical. Match them in klp_find_func().

This is to avoid a corner case with different toolchain behavior.

In this specific issue, two versions of kpatch-build were used to
build livepatch for the same kernel. One assigns old_sympos == 0 for
unique local functions, the other assigns old_sympos == 1 for unique
local functions. Both versions work fine by themselves. (PS: This
behavior change was introduced in a downstream version of kpatch-build.
This change does not exist in upstream kpatch-build.)

However, during livepatch upgrade (with the replace flag set) from a
patch built with one version of kpatch-build to the same fix built with
the other version of kpatch-build, livepatching fails with errors like:

[ 14.218706] sysfs: cannot create duplicate filename 'xxx/somefunc,1'
...
[ 14.219466] Call Trace:
[ 14.219468] <TASK>
[ 14.219469] dump_stack_lvl+0x47/0x60
[ 14.219474] sysfs_warn_dup.cold+0x17/0x27
[ 14.219476] sysfs_create_dir_ns+0x95/0xb0
[ 14.219479] kobject_add_internal+0x9e/0x260
[ 14.219483] kobject_add+0x68/0x80
[ 14.219485] ? kstrdup+0x3c/0xa0
[ 14.219486] klp_enable_patch+0x320/0x830
[ 14.219488] patch_init+0x443/0x1000 [ccc_0_6]
[ 14.219491] ? 0xffffffffa05eb000
[ 14.219492] do_one_initcall+0x2e/0x190
[ 14.219494] do_init_module+0x67/0x270
[ 14.219496] init_module_from_file+0x75/0xa0
[ 14.219499] idempotent_init_module+0x15a/0x240
[ 14.219501] __x64_sys_finit_module+0x61/0xc0
[ 14.219503] do_syscall_64+0x5b/0x160
[ 14.219505] entry_SYSCALL_64_after_hwframe+0x4b/0x53
[ 14.219507] RIP: 0033:0x7f545a4bd96d
...
[ 14.219516] kobject: kobject_add_internal failed for somefunc,1 with
-EEXIST, don't try to register things with the same name ...

This happens because klp_find_func() thinks somefunc with old_sympos==0
is not the same as somefunc with old_sympos==1, and klp_add_object_nops
adds another xxx/func,1 to the list of functions to patch.

Signed-off-by: Song Liu <song@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
[pmladek@suse.com: Fixed some typos.]
Reviewed-by: Petr Mladek <pmladek@suse.com>
Tested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>

smbdirect.ko has global workqueues now, so we should use these
default once.

Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Pull fsnotify updates from Jan Kara:
"A couple of small fsnotify fixes and cleanups"

* tag 'fsnotify_for_v7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
fanotify: replace deprecated strcpy in fanotify_info_copy_{name,name2}
fsnotify: inotify: pass mark connector to fsnotify_recalc_mask()
fanotify: call fanotify_events_supported() before path_permission() and security_path_notify()
fanotify: avoid/silence premature LSM capability checks
inotify: fix watch count leak when fsnotify_add_inode_mark_locked() fails

ext2_iget() already rejects inodes with i_nlink == 0 when i_mode is
zero or i_dtime is set, treating them as deleted. However, the case of
i_nlink == 0 with a non-zero mode and zero dtime slips through. Since
ext2 has no orphan list, such a combination can only result from
filesystem corruption - a legitimate inode deletion always sets either
i_dtime or clears i_mode before freeing the inode.

A crafted image can exploit this gap to present such an inode to the
VFS, which then triggers WARN_ON inside drop_nlink() (fs/inode.c) via
ext2_unlink(), ext2_rename() and ext2_rmdir():

WARNING: CPU: 3 PID: 609 at fs/inode.c:336 drop_nlink+0xad/0xd0 fs/inode.c:336
CPU: 3 UID: 0 PID: 609 Comm: syz-executor Not tainted 6.12.77+ #1
Call Trace:
<TASK>
inode_dec_link_count include/linux/fs.h:2518 [inline]
ext2_unlink+0x26c/0x300 fs/ext2/namei.c:295
vfs_unlink+0x2fc/0x9b0 fs/namei.c:4477
do_unlinkat+0x53e/0x730 fs/namei.c:4541
__x64_sys_unlink+0xc6/0x110 fs/namei.c:4587
do_syscall_64+0xf5/0x220 arch/x86/entry/common.c:78
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>

WARNING: CPU: 0 PID: 646 at fs/inode.c:336 drop_nlink+0xad/0xd0 fs/inode.c:336
CPU: 0 UID: 0 PID: 646 Comm: syz.0.17 Not tainted 6.12.77+ #1
Call Trace:
<TASK>
inode_dec_link_count include/linux/fs.h:2518 [inline]
ext2_rename+0x35e/0x850 fs/ext2/namei.c:374
vfs_rename+0xf2f/0x2060 fs/namei.c:5021
do_renameat2+0xbe2/0xd50 fs/namei.c:5178
__x64_sys_rename+0x7e/0xa0 fs/namei.c:5223
do_syscall_64+0xf5/0x220 arch/x86/entry/common.c:78
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>

WARNING: CPU: 0 PID: 634 at fs/inode.c:336 drop_nlink+0xad/0xd0 fs/inode.c:336
CPU: 0 UID: 0 PID: 634 Comm: syz-executor Not tainted 6.12.77+ #1
Call Trace:
<TASK>
inode_dec_link_count include/linux/fs.h:2518 [inline]
ext2_rmdir+0xca/0x110 fs/ext2/namei.c:311
vfs_rmdir+0x204/0x690 fs/namei.c:4348
do_rmdir+0x372/0x3e0 fs/namei.c:4407
__x64_sys_unlinkat+0xf0/0x130 fs/namei.c:4577
do_syscall_64+0xf5/0x220 arch/x86/entry/common.c:78
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>

Extend the existing i_nlink == 0 check to also catch this case,
reporting the corruption via ext2_error() and returning -EFSCORRUPTED.
This rejects the inode at load time and prevents it from reaching any
of the namei.c paths.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Vasiliy Kovalev <kovalev@altlinux.org>
Link: https://patch.msgid.link/20260404152011.2590197-1-kovalev@altlinux.org
Signed-off-by: Jan Kara <jack@suse.cz>

The filesystem UUID was only being loaded into super_block sb when an
external journal device was in use. When mounting without an external
journal, the UUID remained unset, which prevented the computation of
a filesystem ID (fsid), which could be confirmed via `stat -f -c "%i"`
and thus user space could not use fanotify correctly.

A missing filesystem ID causes fanotify to return ENODEV when marking
the filesystem for events like FAN_CREATE, FAN_DELETE, FAN_MOVED_TO,
and FAN_MOVED_FROM. As a result, applications relying on fanotify
could not monitor these events on JFS filesystems without an external
journal.

Moved the UUID initialization so it is always performed during mount,
ensuring the superblock UUID is consistently available.

Signed-off-by: João Paredes <joaommp@yahoo.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>