[BUG] KCSAN: data-race in _find_next_bit+0x42/0xf0

[Mirsad Todorovac]

Hi,

This is your friendly bug reporter :-)

This is probably the last one for today from the KCSAN series.

The setup is vanilla torvalds kernel, Ubuntu 22.04 LTS and a Ryzen 7950X box.

NOTE: There are no proprietary modules to my knowledge, the Canonical Livepatch did not work for this
kernel, but I suspect the taint was turned on by the previous instances of bugs.

Please find complete dmesg output and lshw output attached.

dmesg output except:

[10026.864497] ==================================================================
[10026.864516] BUG: KCSAN: data-race in _find_next_bit+0x42/0xf0

[10026.864544] race at unknown origin, with read to 0xffff9b7440075408 of 8 bytes by interrupt on cpu 0:
[10026.864562]  _find_next_bit+0x42/0xf0
[10026.864577]  _nohz_idle_balance.isra.0+0x1ff/0x3f0
[10026.864594]  run_rebalance_domains+0x75/0x90
[10026.864610]  __do_softirq+0xda/0x330
[10026.864626]  __irq_exit_rcu+0x75/0xa0
[10026.864640]  irq_exit_rcu+0xe/0x20
[10026.864654]  sysvec_call_function_single+0x96/0xb0
[10026.864671]  asm_sysvec_call_function_single+0x1b/0x20
[10026.864690]  cpuidle_enter_state+0x1df/0x520
[10026.864709]  cpuidle_enter+0x41/0x70
[10026.864725]  call_cpuidle+0x23/0x60
[10026.864742]  do_idle+0x1f1/0x250
[10026.864754]  cpu_startup_entry+0x20/0x30
[10026.864767]  rest_init+0x121/0x140
[10026.864786]  arch_call_rest_init+0xe/0x30
[10026.864803]  start_kernel+0x8e3/0xd70
[10026.864819]  x86_64_start_reservations+0x18/0x30
[10026.864835]  x86_64_start_kernel+0xc0/0x110
[10026.864848]  secondary_startup_64_no_verify+0x17e/0x18b

[10026.864876] value changed: 0x00000000ffffffcf -> 0x00000000ffffffff

[10026.864897] Reported by Kernel Concurrency Sanitizer on:
[10026.864908] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G             L     6.5.0-rc6-net-cfg-kcsan-00038-g16931859a650 #35
[10026.864926] Hardware name: ASRock X670E PG Lightning/X670E PG Lightning, BIOS 1.21 04/26/2023
[10026.864936] ==================================================================

Best regards,
Mirsad Todorovac

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Attachment: lshw.txt.xz
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