Pull locking fix from Ingo Molnar:
 "Fix lockdep block chain corruption resulting in KASAN warnings"

* tag 'locking-urgent-2023-11-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Fix block chain corruption

Kent reported an occasional KASAN splat in lockdep. Mark then noted:

> I suspect the dodgy access is to chain_block_buckets[-1], which hits the last 4
> bytes of the redzone and gets (incorrectly/misleadingly) attributed to
> nr_large_chain_blocks.

That would mean @size == 0, at which point size_to_bucket() returns -1
and the above happens.

alloc_chain_hlocks() has 'size - req', for the first with the
precondition 'size >= rq', which allows the 0.

This code is trying to split a block, del_chain_block() takes what we
need, and add_chain_block() puts back the remainder, except in the
above case the remainder is 0 sized and things go sideways.

Fixes: 810507fe6fd5 ("locking/lockdep: Reuse freed chain_hlocks entries")
Reported-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Kent Overstreet <kent.overstreet@linux.dev>
Link: https://lkml.kernel.org/r/20231121114126.GH8262@noisy.programming.kicks-ass.net

Pull networking fixes from Jakub Kicinski:
 "Including fixes from bpf.

  Current release - regressions:

   - Revert "net: r8169: Disable multicast filter for RTL8168H and
     RTL8107E"

   - kselftest: rtnetlink: fix ip route command typo

  Current release - new code bugs:

   - s390/ism: make sure ism driver implies smc protocol in kconfig

   - two build fixes for tools/net

  Previous releases - regressions:

   - rxrpc: couple of ACK/PING/RTT handling fixes

  Previous releases - always broken:

   - bpf: verify bpf_loop() callbacks as if they are called unknown
     number of times

   - improve stability of auto-bonding with Hyper-V

   - account BPF-neigh-redirected traffic in interface statistics

  Misc:

   - net: fill in some more MODULE_DESCRIPTION()s"

* tag 'net-6.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (58 commits)
  tools: ynl: fix duplicate op name in devlink
  tools: ynl: fix header path for nfsd
  net: ipa: fix one GSI register field width
  tls: fix NULL deref on tls_sw_splice_eof() with empty record
  net: axienet: Fix check for partial TX checksum
  vsock/test: fix SEQPACKET message bounds test
  i40e: Fix adding unsupported cloud filters
  ice: restore timestamp configuration after device reset
  ice: unify logic for programming PFINT_TSYN_MSK
  ice: remove ptp_tx ring parameter flag
  amd-xgbe: propagate the correct speed and duplex status
  amd-xgbe: handle the corner-case during tx completion
  amd-xgbe: handle corner-case during sfp hotplug
  net: veth: fix ethtool stats reporting
  octeontx2-pf: Fix ntuple rule creation to direct packet to VF with higher Rx queue than its PF
  net: usb: qmi_wwan: claim interface 4 for ZTE MF290
  Revert "net: r8169: Disable multicast filter for RTL8168H and RTL8107E"
  net/smc: avoid data corruption caused by decline
  nfc: virtual_ncidev: Add variable to check if ndev is running
  dpll: Fix potential msg memleak when genlmsg_put_reply failed
  ...

In some cases verifier can't infer convergence of the bpf_loop()
iteration. E.g. for the following program:

    static int cb(__u32 idx, struct num_context* ctx)
    {
        ctx->i++;
        return 0;
    }

    SEC("?raw_tp")
    int prog(void *_)
    {
        struct num_context ctx = { .i = 0 };
        __u8 choice_arr[2] = { 0, 1 };

        bpf_loop(2, cb, &ctx, 0);
        return choice_arr[ctx.i];
    }

Each 'cb' simulation would eventually return to 'prog' and reach
'return choice_arr[ctx.i]' statement. At which point ctx.i would be
marked precise, thus forcing verifier to track multitude of separate
states with {.i=0}, {.i=1}, ... at bpf_loop() callback entry.

This commit allows "brute force" handling for such cases by limiting
number of callback body simulations using 'umax' value of the first
bpf_loop() parameter.

For this, extend bpf_func_state with 'callback_depth' field.
Increment this field when callback visiting state is pushed to states
traversal stack. For frame #N it's 'callback_depth' field counts how
many times callback with frame depth N+1 had been executed.
Use bpf_func_state specifically to allow independent tracking of
callback depths when multiple nested bpf_loop() calls are present.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231121020701.26440-11-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Callbacks are similar to open coded iterators, so add imprecise
widening logic for callback body processing. This makes callback based
loops behave identically to open coded iterators, e.g. allowing to
verify programs like below:

  struct ctx { u32 i; };
  int cb(u32 idx, struct ctx* ctx)
  {
          ++ctx->i;
          return 0;
  }
  ...
  struct ctx ctx = { .i = 0 };
  bpf_loop(100, cb, &ctx, 0);
  ...

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231121020701.26440-9-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Prior to this patch callbacks were handled as regular function calls,
execution of callback body was modeled exactly once.
This patch updates callbacks handling logic as follows:
- introduces a function push_callback_call() that schedules callback
  body verification in env->head stack;
- updates prepare_func_exit() to reschedule callback body verification
  upon BPF_EXIT;
- as calls to bpf_*_iter_next(), calls to callback invoking functions
  are marked as checkpoints;
- is_state_visited() is updated to stop callback based iteration when
  some identical parent state is found.

Paths with callback function invoked zero times are now verified first,
which leads to necessity to modify some selftests:
- the following negative tests required adding release/unlock/drop
  calls to avoid previously masked unrelated error reports:
  - cb_refs.c:underflow_prog
  - exceptions_fail.c:reject_rbtree_add_throw
  - exceptions_fail.c:reject_with_cp_reference
- the following precision tracking selftests needed change in expected
  log trace:
  - verifier_subprog_precision.c:callback_result_precise
    (note: r0 precision is no longer propagated inside callback and
           I think this is a correct behavior)
  - verifier_subprog_precision.c:parent_callee_saved_reg_precise_with_callback
  - verifier_subprog_precision.c:parent_stack_slot_precise_with_callback

Reported-by: Andrew Werner <awerner32@gmail.com>
Closes: https://lore.kernel.org/bpf/CA+vRuzPChFNXmouzGG+wsy=6eMcfr1mFG0F3g7rbg-sedGKW3w@mail.gmail.com/
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231121020701.26440-7-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Move code for simulated stack frame creation to a separate utility
function. This function would be used in the follow-up change for
callbacks handling.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231121020701.26440-6-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Split check_reg_arg() into two utility functions:
- check_reg_arg() operating on registers from current verifier state;
- __check_reg_arg() operating on a specific set of registers passed as
  a parameter;

The __check_reg_arg() function would be used by a follow-up change for
callbacks handling.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231121020701.26440-5-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Pull timer fix from Borislav Petkov:

 - Do the push of pending hrtimers away from a CPU which is being
   offlined earlier in the offlining process in order to prevent a
   deadlock

* tag 'timers_urgent_for_v6.7_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hrtimers: Push pending hrtimers away from outgoing CPU earlier

Pull scheduler fixes from Borislav Petkov:

 - Fix virtual runtime calculation when recomputing a sched entity's
   weights

 - Fix wrongly rejected unprivileged poll requests to the cgroup psi
   pressure files

 - Make sure the load balancing is done by only one CPU

* tag 'sched_urgent_for_v6.7_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix the decision for load balance
  sched: psi: fix unprivileged polling against cgroups
  sched/eevdf: Fix vruntime adjustment on reweight