Attaching SST PCI device to VM causes "BUG: KASAN: slab-out-of-bounds".
kasan report:
[   19.411889] ==================================================================
[   19.413702] BUG: KASAN: slab-out-of-bounds in _isst_if_get_pci_dev+0x3d5/0x400 [isst_if_common]
[   19.415634] Read of size 8 at addr ffff888829e65200 by task cpuhp/16/113
[   19.417368]
[   19.418627] CPU: 16 PID: 113 Comm: cpuhp/16 Tainted: G            E      6.9.0 #10
[   19.420435] Hardware name: VMware, Inc. VMware20,1/440BX Desktop Reference Platform, BIOS VMW201.00V.20192059.B64.2207280713 07/28/2022
[   19.422687] Call Trace:
[   19.424091]  <TASK>
[   19.425448]  dump_stack_lvl+0x5d/0x80
[   19.426963]  ? _isst_if_get_pci_dev+0x3d5/0x400 [isst_if_common]
[   19.428694]  print_report+0x19d/0x52e
[   19.430206]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[   19.431837]  ? _isst_if_get_pci_dev+0x3d5/0x400 [isst_if_common]
[   19.433539]  kasan_report+0xf0/0x170
[   19.435019]  ? _isst_if_get_pci_dev+0x3d5/0x400 [isst_if_common]
[   19.436709]  _isst_if_get_pci_dev+0x3d5/0x400 [isst_if_common]
[   19.438379]  ? __pfx_sched_clock_cpu+0x10/0x10
[   19.439910]  isst_if_cpu_online+0x406/0x58f [isst_if_common]
[   19.441573]  ? __pfx_isst_if_cpu_online+0x10/0x10 [isst_if_common]
[   19.443263]  ? ttwu_queue_wakelist+0x2c1/0x360
[   19.444797]  cpuhp_invoke_callback+0x221/0xec0
[   19.446337]  cpuhp_thread_fun+0x21b/0x610
[   19.447814]  ? __pfx_cpuhp_thread_fun+0x10/0x10
[   19.449354]  smpboot_thread_fn+0x2e7/0x6e0
[   19.450859]  ? __pfx_smpboot_thread_fn+0x10/0x10
[   19.452405]  kthread+0x29c/0x350
[   19.453817]  ? __pfx_kthread+0x10/0x10
[   19.455253]  ret_from_fork+0x31/0x70
[   19.456685]  ? __pfx_kthread+0x10/0x10
[   19.458114]  ret_from_fork_asm+0x1a/0x30
[   19.459573]  </TASK>
[   19.460853]
[   19.462055] Allocated by task 1198:
[   19.463410]  kasan_save_stack+0x30/0x50
[   19.464788]  kasan_save_track+0x14/0x30
[   19.466139]  __kasan_kmalloc+0xaa/0xb0
[   19.467465]  __kmalloc+0x1cd/0x470
[   19.468748]  isst_if_cdev_register+0x1da/0x350 [isst_if_common]
[   19.470233]  isst_if_mbox_init+0x108/0xff0 [isst_if_mbox_msr]
[   19.471670]  do_one_initcall+0xa4/0x380
[   19.472903]  do_init_module+0x238/0x760
[   19.474105]  load_module+0x5239/0x6f00
[   19.475285]  init_module_from_file+0xd1/0x130
[   19.476506]  idempotent_init_module+0x23b/0x650
[   19.477725]  __x64_sys_finit_module+0xbe/0x130
[   19.476506]  idempotent_init_module+0x23b/0x650
[   19.477725]  __x64_sys_finit_module+0xbe/0x130
[   19.478920]  do_syscall_64+0x82/0x160
[   19.480036]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[   19.481292]
[   19.482205] The buggy address belongs to the object at ffff888829e65000
 which belongs to the cache kmalloc-512 of size 512
[   19.484818] The buggy address is located 0 bytes to the right of
 allocated 512-byte region [ffff888829e65000, ffff888829e65200)
[   19.487447]
[   19.488328] The buggy address belongs to the physical page:
[   19.489569] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888829e60c00 pfn:0x829e60
[   19.491140] head: order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
[   19.492466] anon flags: 0x57ffffc0000840(slab|head|node=1|zone=2|lastcpupid=0x1fffff)
[   19.493914] page_type: 0xffffffff()
[   19.494988] raw: 0057ffffc0000840 ffff88810004cc80 0000000000000000 0000000000000001
[   19.496451] raw: ffff888829e60c00 0000000080200018 00000001ffffffff 0000000000000000
[   19.497906] head: 0057ffffc0000840 ffff88810004cc80 0000000000000000 0000000000000001
[   19.499379] head: ffff888829e60c00 0000000080200018 00000001ffffffff 0000000000000000
[   19.500844] head: 0057ffffc0000003 ffffea0020a79801 ffffea0020a79848 00000000ffffffff
[   19.502316] head: 0000000800000000 0000000000000000 00000000ffffffff 0000000000000000
[   19.503784] page dumped because: kasan: bad access detected
[   19.505058]
[   19.505970] Memory state around the buggy address:
[   19.507172]  ffff888829e65100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   19.508599]  ffff888829e65180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   19.510013] >ffff888829e65200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[   19.510014]                    ^
[   19.510016]  ffff888829e65280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[   19.510018]  ffff888829e65300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[   19.515367] ==================================================================

The reason for this error is physical_package_ids assigned by VMware VMM
are not continuous and have gaps. This will cause value returned by
topology_physical_package_id() to be more than topology_max_packages().

Here the allocation uses topology_max_packages(). The call to
topology_max_packages() returns maximum logical package ID not physical
ID. Hence use topology_logical_package_id() instead of
topology_physical_package_id().

Fixes: 9a1aac8 ("platform/x86: ISST: PUNIT device mapping with Sub-NUMA clustering")
Cc: [email protected]
Acked-by: Srinivas Pandruvada <[email protected]>
Signed-off-by: Zach Wade <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Hans de Goede <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>

syzkaller reported a warning in __sk_skb_reason_drop().

Commit 61b95c7 ("net: ip: make ip_route_input_rcu() return
drop reasons") missed a path where -EINVAL is returned.

Then, the cited commit started to trigger the warning with the
invalid error.

Let's fix it by returning SKB_DROP_REASON_NOT_SPECIFIED.

[0]:
WARNING: CPU: 0 PID: 10 at net/core/skbuff.c:1216 __sk_skb_reason_drop net/core/skbuff.c:1216 [inline]
WARNING: CPU: 0 PID: 10 at net/core/skbuff.c:1216 sk_skb_reason_drop+0x97/0x1b0 net/core/skbuff.c:1241
Modules linked in:
CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted 6.12.0-10686-gbb18265c3aba #10 1c308307628619808b5a4a0495c4aab5637b0551
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
Workqueue: wg-crypt-wg2 wg_packet_decrypt_worker
RIP: 0010:__sk_skb_reason_drop net/core/skbuff.c:1216 [inline]
RIP: 0010:sk_skb_reason_drop+0x97/0x1b0 net/core/skbuff.c:1241
Code: 5d 41 5c 41 5d 41 5e e9 e7 9e 95 fd e8 e2 9e 95 fd 31 ff 44 89 e6 e8 58 a1 95 fd 45 85 e4 0f 85 a2 00 00 00 e8 ca 9e 95 fd 90 <0f> 0b 90 e8 c1 9e 95 fd 44 89 e6 bf 01 00 00 00 e8 34 a1 95 fd 41
RSP: 0018:ffa0000000007650 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 000000000000ffff RCX: ffffffff83bc3592
RDX: ff110001002a0000 RSI: ffffffff83bc34d6 RDI: 0000000000000007
RBP: ff11000109ee85f0 R08: 0000000000000001 R09: ffe21c00213dd0da
R10: 000000000000ffff R11: 0000000000000000 R12: 00000000ffffffea
R13: 0000000000000000 R14: ff11000109ee86d4 R15: ff11000109ee8648
FS:  0000000000000000(0000) GS:ff1100011a000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020177000 CR3: 0000000108a3d006 CR4: 0000000000771ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000600
PKRU: 55555554
Call Trace:
 <IRQ>
 kfree_skb_reason include/linux/skbuff.h:1263 [inline]
 ip_rcv_finish_core.constprop.0+0x896/0x2320 net/ipv4/ip_input.c:424
 ip_list_rcv_finish.constprop.0+0x1b2/0x710 net/ipv4/ip_input.c:610
 ip_sublist_rcv net/ipv4/ip_input.c:636 [inline]
 ip_list_rcv+0x34a/0x460 net/ipv4/ip_input.c:670
 __netif_receive_skb_list_ptype net/core/dev.c:5715 [inline]
 __netif_receive_skb_list_core+0x536/0x900 net/core/dev.c:5762
 __netif_receive_skb_list net/core/dev.c:5814 [inline]
 netif_receive_skb_list_internal+0x77c/0xdc0 net/core/dev.c:5905
 gro_normal_list include/net/gro.h:515 [inline]
 gro_normal_list include/net/gro.h:511 [inline]
 napi_complete_done+0x219/0x8c0 net/core/dev.c:6256
 wg_packet_rx_poll+0xbff/0x1e40 drivers/net/wireguard/receive.c:488
 __napi_poll.constprop.0+0xb3/0x530 net/core/dev.c:6877
 napi_poll net/core/dev.c:6946 [inline]
 net_rx_action+0x9eb/0xe30 net/core/dev.c:7068
 handle_softirqs+0x1ac/0x740 kernel/softirq.c:554
 do_softirq kernel/softirq.c:455 [inline]
 do_softirq+0x48/0x80 kernel/softirq.c:442
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0xed/0x110 kernel/softirq.c:382
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 ptr_ring_consume_bh include/linux/ptr_ring.h:367 [inline]
 wg_packet_decrypt_worker+0x3ba/0x580 drivers/net/wireguard/receive.c:499
 process_one_work+0x940/0x1a70 kernel/workqueue.c:3229
 process_scheduled_works kernel/workqueue.c:3310 [inline]
 worker_thread+0x639/0xe30 kernel/workqueue.c:3391
 kthread+0x283/0x350 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244
 </TASK>

Fixes: 82d9983 ("net: ip: make ip_route_input_noref() return drop reasons")
Reported-by: syzkaller <[email protected]>
Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: David Ahern <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

libtraceevent parses and returns an array of argument fields, sometimes
larger than RAW_SYSCALL_ARGS_NUM (6) because it includes "__syscall_nr",
idx will traverse to index 6 (7th element) whereas sc->fmt->arg holds 6
elements max, creating an out-of-bounds access. This runtime error is
found by UBsan. The error message:

  $ sudo UBSAN_OPTIONS=print_stacktrace=1 ./perf trace -a --max-events=1
  builtin-trace.c:1966:35: runtime error: index 6 out of bounds for type 'syscall_arg_fmt [6]'
    #0 0x5c04956be5fe in syscall__alloc_arg_fmts /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:1966
    #1 0x5c04956c0510 in trace__read_syscall_info /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:2110
    #2 0x5c04956c372b in trace__syscall_info /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:2436
    #3 0x5c04956d2f39 in trace__init_syscalls_bpf_prog_array_maps /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:3897
    #4 0x5c04956d6d25 in trace__run /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:4335
    #5 0x5c04956e112e in cmd_trace /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:5502
    #6 0x5c04956eda7d in run_builtin /home/howard/hw/linux-perf/tools/perf/perf.c:351
    #7 0x5c04956ee0a8 in handle_internal_command /home/howard/hw/linux-perf/tools/perf/perf.c:404
    #8 0x5c04956ee37f in run_argv /home/howard/hw/linux-perf/tools/perf/perf.c:448
    #9 0x5c04956ee8e9 in main /home/howard/hw/linux-perf/tools/perf/perf.c:556
    #10 0x79eb3622a3b7 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
    #11 0x79eb3622a47a in __libc_start_main_impl ../csu/libc-start.c:360
    #12 0x5c04955422d4 in _start (/home/howard/hw/linux-perf/tools/perf/perf+0x4e02d4) (BuildId: 5b6cab2d59e96a4341741765ad6914a4d784dbc6)

     0.000 ( 0.014 ms): Chrome_ChildIO/117244 write(fd: 238, buf: !, count: 1)                                      = 1

Fixes: 5e58fcf ("perf trace: Allow allocating sc->arg_fmt even without the syscall tracepoint")
Signed-off-by: Howard Chu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>

When the size of the range invalidated is larger than
rounddown_pow_of_two(ULONG_MAX),
The function macro roundup_pow_of_two(length) will hit an out-of-bounds
shift [1].

Use a full TLB invalidation for such cases.
v2:
- Use a define for the range size limit over which we use a full
  TLB invalidation. (Lucas)
- Use a better calculation of the limit.

[1]:
[   39.202421] ------------[ cut here ]------------
[   39.202657] UBSAN: shift-out-of-bounds in ./include/linux/log2.h:57:13
[   39.202673] shift exponent 64 is too large for 64-bit type 'long unsigned int'
[   39.202688] CPU: 8 UID: 0 PID: 3129 Comm: xe_exec_system_ Tainted: G     U             6.14.0+ #10
[   39.202690] Tainted: [U]=USER
[   39.202690] Hardware name: ASUS System Product Name/PRIME B560M-A AC, BIOS 2001 02/01/2023
[   39.202691] Call Trace:
[   39.202692]  <TASK>
[   39.202695]  dump_stack_lvl+0x6e/0xa0
[   39.202699]  ubsan_epilogue+0x5/0x30
[   39.202701]  __ubsan_handle_shift_out_of_bounds.cold+0x61/0xe6
[   39.202705]  xe_gt_tlb_invalidation_range.cold+0x1d/0x3a [xe]
[   39.202800]  ? find_held_lock+0x2b/0x80
[   39.202803]  ? mark_held_locks+0x40/0x70
[   39.202806]  xe_svm_invalidate+0x459/0x700 [xe]
[   39.202897]  drm_gpusvm_notifier_invalidate+0x4d/0x70 [drm_gpusvm]
[   39.202900]  __mmu_notifier_release+0x1f5/0x270
[   39.202905]  exit_mmap+0x40e/0x450
[   39.202912]  __mmput+0x45/0x110
[   39.202914]  exit_mm+0xc5/0x130
[   39.202916]  do_exit+0x21c/0x500
[   39.202918]  ? lockdep_hardirqs_on_prepare+0xdb/0x190
[   39.202920]  do_group_exit+0x36/0xa0
[   39.202922]  get_signal+0x8f8/0x900
[   39.202926]  arch_do_signal_or_restart+0x35/0x100
[   39.202930]  syscall_exit_to_user_mode+0x1fc/0x290
[   39.202932]  do_syscall_64+0xa1/0x180
[   39.202934]  ? do_user_addr_fault+0x59f/0x8a0
[   39.202937]  ? lock_release+0xd2/0x2a0
[   39.202939]  ? do_user_addr_fault+0x5a9/0x8a0
[   39.202942]  ? trace_hardirqs_off+0x4b/0xc0
[   39.202944]  ? clear_bhb_loop+0x25/0x80
[   39.202946]  ? clear_bhb_loop+0x25/0x80
[   39.202947]  ? clear_bhb_loop+0x25/0x80
[   39.202950]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[   39.202952] RIP: 0033:0x7fa945e543e1
[   39.202961] Code: Unable to access opcode bytes at 0x7fa945e543b7.
[   39.202962] RSP: 002b:00007ffca8fb4170 EFLAGS: 00000293
[   39.202963] RAX: 000000000000003d RBX: 0000000000000000 RCX: 00007fa945e543e3
[   39.202964] RDX: 0000000000000000 RSI: 00007ffca8fb41ac RDI: 00000000ffffffff
[   39.202964] RBP: 00007ffca8fb4190 R08: 0000000000000000 R09: 00007fa945f600a0
[   39.202965] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
[   39.202966] R13: 00007fa9460dd310 R14: 00007ffca8fb41ac R15: 0000000000000000
[   39.202970]  </TASK>
[   39.202970] ---[ end trace ]---

Fixes: 332dd01 ("drm/xe: Add range based TLB invalidations")
Cc: Matthew Brost <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Cc: <[email protected]> # v6.8+
Signed-off-by: Thomas Hellström <[email protected]>
Reviewed-by: Lucas De Marchi <[email protected]> #v1
Link: https://lore.kernel.org/r/[email protected]
(cherry picked from commit b88f48f)
Signed-off-by: Lucas De Marchi <[email protected]>

Both jbd2_log_do_checkpoint() and jbd2_journal_shrink_checkpoint_list()
periodically release j_list_lock after processing a batch of buffers to
avoid long hold times on the j_list_lock. However, since both functions
contend for j_list_lock, the combined time spent waiting and processing
can be significant.

jbd2_journal_shrink_checkpoint_list() explicitly calls cond_resched() when
need_resched() is true to avoid softlockups during prolonged operations.
But jbd2_log_do_checkpoint() only exits its loop when need_resched() is
true, relying on potentially sleeping functions like __flush_batch() or
wait_on_buffer() to trigger rescheduling. If those functions do not sleep,
the kernel may hit a softlockup.

watchdog: BUG: soft lockup - CPU#3 stuck for 156s! [kworker/u129:2:373]
CPU: 3 PID: 373 Comm: kworker/u129:2 Kdump: loaded Not tainted 6.6.0+ #10
Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.27 06/13/2017
Workqueue: writeback wb_workfn (flush-7:2)
pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : native_queued_spin_lock_slowpath+0x358/0x418
lr : jbd2_log_do_checkpoint+0x31c/0x438 [jbd2]
Call trace:
 native_queued_spin_lock_slowpath+0x358/0x418
 jbd2_log_do_checkpoint+0x31c/0x438 [jbd2]
 __jbd2_log_wait_for_space+0xfc/0x2f8 [jbd2]
 add_transaction_credits+0x3bc/0x418 [jbd2]
 start_this_handle+0xf8/0x560 [jbd2]
 jbd2__journal_start+0x118/0x228 [jbd2]
 __ext4_journal_start_sb+0x110/0x188 [ext4]
 ext4_do_writepages+0x3dc/0x740 [ext4]
 ext4_writepages+0xa4/0x190 [ext4]
 do_writepages+0x94/0x228
 __writeback_single_inode+0x48/0x318
 writeback_sb_inodes+0x204/0x590
 __writeback_inodes_wb+0x54/0xf8
 wb_writeback+0x2cc/0x3d8
 wb_do_writeback+0x2e0/0x2f8
 wb_workfn+0x80/0x2a8
 process_one_work+0x178/0x3e8
 worker_thread+0x234/0x3b8
 kthread+0xf0/0x108
 ret_from_fork+0x10/0x20

So explicitly call cond_resched() in jbd2_log_do_checkpoint() to avoid
softlockup.

Cc: [email protected]
Signed-off-by: Baokun Li <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

…dlock

When a user creates a dualpi2 qdisc it automatically sets a timer. This
timer will run constantly and update the qdisc's probability field.
The issue is that the timer acquires the qdisc root lock and runs in
hardirq. The qdisc root lock is also acquired in dev.c whenever a packet
arrives for this qdisc. Since the dualpi2 timer callback runs in hardirq,
it may interrupt the packet processing running in softirq. If that happens
and it runs on the same CPU, it will acquire the same lock and cause a
deadlock. The following splat shows up when running a kernel compiled with
lock debugging:

[  +0.000224] WARNING: inconsistent lock state
[  +0.000224] 6.16.0+ #10 Not tainted
[  +0.000169] --------------------------------
[  +0.000029] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
[  +0.000000] ping/156 [HC0[0]:SC0[2]:HE1:SE0] takes:
[  +0.000000] ffff897841242110 (&sch->root_lock_key){?.-.}-{3:3}, at: __dev_queue_xmit+0x86d/0x1140
[  +0.000000] {IN-HARDIRQ-W} state was registered at:
[  +0.000000]   lock_acquire.part.0+0xb6/0x220
[  +0.000000]   _raw_spin_lock+0x31/0x80
[  +0.000000]   dualpi2_timer+0x6f/0x270
[  +0.000000]   __hrtimer_run_queues+0x1c5/0x360
[  +0.000000]   hrtimer_interrupt+0x115/0x260
[  +0.000000]   __sysvec_apic_timer_interrupt+0x6d/0x1a0
[  +0.000000]   sysvec_apic_timer_interrupt+0x6e/0x80
[  +0.000000]   asm_sysvec_apic_timer_interrupt+0x1a/0x20
[  +0.000000]   pv_native_safe_halt+0xf/0x20
[  +0.000000]   default_idle+0x9/0x10
[  +0.000000]   default_idle_call+0x7e/0x1e0
[  +0.000000]   do_idle+0x1e8/0x250
[  +0.000000]   cpu_startup_entry+0x29/0x30
[  +0.000000]   rest_init+0x151/0x160
[  +0.000000]   start_kernel+0x6f3/0x700
[  +0.000000]   x86_64_start_reservations+0x24/0x30
[  +0.000000]   x86_64_start_kernel+0xc8/0xd0
[  +0.000000]   common_startup_64+0x13e/0x148
[  +0.000000] irq event stamp: 6884
[  +0.000000] hardirqs last  enabled at (6883): [<ffffffffa75700b3>] neigh_resolve_output+0x223/0x270
[  +0.000000] hardirqs last disabled at (6882): [<ffffffffa7570078>] neigh_resolve_output+0x1e8/0x270
[  +0.000000] softirqs last  enabled at (6880): [<ffffffffa757006b>] neigh_resolve_output+0x1db/0x270
[  +0.000000] softirqs last disabled at (6884): [<ffffffffa755b533>] __dev_queue_xmit+0x73/0x1140
[  +0.000000]
              other info that might help us debug this:
[  +0.000000]  Possible unsafe locking scenario:

[  +0.000000]        CPU0
[  +0.000000]        ----
[  +0.000000]   lock(&sch->root_lock_key);
[  +0.000000]   <Interrupt>
[  +0.000000]     lock(&sch->root_lock_key);
[  +0.000000]
               *** DEADLOCK ***

[  +0.000000] 4 locks held by ping/156:
[  +0.000000]  #0: ffff897842332e08 (sk_lock-AF_INET){+.+.}-{0:0}, at: raw_sendmsg+0x41e/0xf40
[  +0.000000]  #1: ffffffffa816f880 (rcu_read_lock){....}-{1:3}, at: ip_output+0x2c/0x190
[  +0.000000]  #2: ffffffffa816f880 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0xad/0x950
[  +0.000000]  #3: ffffffffa816f840 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x73/0x1140

I am able to reproduce it consistently when running the following:

tc qdisc add dev lo handle 1: root dualpi2
ping -f 127.0.0.1

To fix it, make the timer run in softirq.

Fixes: 320d031 ("sched: Struct definition and parsing of dualpi2 qdisc")
Reviewed-by: Jamal Hadi Salim <[email protected]>
Signed-off-by: Victor Nogueira <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>