Re: [syzbot] [nilfs?] KMSAN: uninit-value in nilfs_add_checksums_on_logs (2)

[Ryusuke Konishi]

On Wed, Mar 6, 2024 at 4:07 PM xingwei lee wrote:
> On 3 Mar 2024, at 20:45, Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx> wrote:
>
> Hi, sorry for the delayed response.
>
> I test my reproducer in the linux 6.8-rc4 with KMSAN kernel config for one hours, it doesn’t trigger any crash or report as follows:
>
> [  315.607028][   T37] audit: type=1804 audit(1709708422.469:31293): pid=86478 uid=0 auid=0 ses=1 subj=unconfined op=invalid_pcr cause=0
> [  315.608038][T86480] 884-0[86480]: segfault at 5c7ade ip 00000000005c7ade sp 00000000200001f8 error 14 likely on CPU 2 (core 2, socke)
> [  315.611270][T86480] Code: Unable to access opcode bytes at 0x5c7ab4.
> [  320.575680][   T37] kauditd_printk_skb: 1253 callbacks suppressed
> [  320.575689][   T37] audit: type=1804 audit(1709708427.439:32130): pid=88573 uid=0 auid=0 ses=1 subj=unconfined op=invalid_pcr cause=0
> [  320.576419][T88575] 884-0[88575]: segfault at 5c7ade ip 00000000005c7ade sp 00000000200001f8 error 14
> [  320.576695][   T37] audit: type=1804 audit(1709708427.439:32131): pid=88574 uid=0 auid=0 ses=1 subj=unconfined op=invalid_pcr cause=0
> [  320.579042][T88575]  likely on CPU 0 (core 0, socket 0)
> [  320.584184][T88575] Code: Unable to access opcode bytes at 0x5c7ab4.
> [  320.593832][   T37] audit: type=1804 audit(1709708427.459:32132): pid=88578 uid=0 auid=0 ses=1 subj=unconfined op=invalid_pcr cause=0
> [  320.594549][T88580] 884-0[88580]: segfault at 5c7ade ip 00000000005c7ade sp 00000000200001f8 error 14 likely on CPU 1 (core 1, socke)
> [  320.596256][   T37] audit: type=1804 audit(1709708427.459:32133): pid=88579 uid=0 auid=0 ses=1 subj=unconfined op=invalid_pcr cause=0
> [  320.597901][T88580] Code: Unable to access opcode bytes at 0x5c7ab4.
> [  320.610954][   T37] audit: type=1804 audit(1709708427.479:32134): pid=88583 uid=0 auid=0 ses=1 subj=unconfined op=invalid_pcr cause=0
> [  320.611700][T88585] 884-0[88585]: segfault at 5c7ade ip 00000000005c7ade sp 00000000200001f8 error 14 likely on CPU 2 (core 2, socke)
> [  320.613455][   T37] audit: type=1804 audit(1709708427.479:32135): pid=88584 uid=0 auid=0 ses=1 subj=unconfined op=invalid_pcr cause=0
> [  320.615959][T88585] Code: Unable to access opcode bytes at 0x5c7ab4.
> [  320.628571][   T37] audit: type=1804 audit(1709708427.489:32136): pid=88588 uid=0 auid=0 ses=1 subj=unconfined op=invalid_pcr cause=0
> [  325.582663][   T37] kauditd_printk_skb: 1280 callbacks suppressed
> [  325.582673][   T37] audit: type=1804 audit(1709708432.449:32990): pid=90727 uid=0 auid=0 ses=1 subj=unconfined op=invalid_pcr cause=0
> [  325.583320][T90729] 884-0[90729]: segfault at 5c7ade ip 00000000005c7ade sp 00000000200001f8 error 14
> [  325.583460][   T37] audit: type=1804 audit(1709708432.449:32991): pid=90728 uid=0 auid=0 ses=1 subj=unconfined op=invalid_pcr cause=0
> [  325.585838][T90729]  likely on CPU 1 (core 1, socket 0)
> [  325.590985][T90729] Code: Unable to access opcode bytes at 0x5c7ab4.
> [  325.599620][   T37] audit: type=1804 audit(1709708432.459:32992): pid=90732 uid=0 auid=0 ses=1 subj=unconfined op=invalid_pcr cause=0
> [  325.601818][T90734] 884-0[90734]: segfault at 5c7ade ip 00000000005c7ade sp 00000000200001f8 error 14
> [  325.601827][   T37] audit: type=1804 audit(1709708432.459:32993): pid=90733 uid=0 auid=0 ses=1 subj=unconfined op=invalid_pcr cause=0
> [  325.603945][T90734]  likely on CPU 2 (core 2, socket 0)
> [  325.607037][T90734] Code: Unable to access opcode bytes at 0x5c7ab4.
> [  325.617928][   T37] audit: type=1804 audit(1709708432.479:32994): pid=90737 uid=0 auid=0 ses=1 subj=unconfined op=invalid_pcr cause=0
> [  325.618862][T90739] 884-0[90739]: segfault at 5c7ade ip 00000000005c7ade sp 00000000200001f8 error 14
> [  325.620190][   T37] audit: type=1804 audit(1709708432.479:32995): pid=90738 uid=0 auid=0 ses=1 subj=unconfined op=invalid_pcr cause=0
> [  325.623238][T90739]  likely on CPU 0 (core 0, socket 0)
> [  325.623803][T90739] Code: Unable to access opcode bytes at 0x5c7ab4.
> [  325.632693][   T37] audit: type=1804 audit(1709708432.499:32996): pid=90742 uid=0 auid=0 ses=1 subj=unconfined op=invalid_pcr cause=0
>
> It’s seems this issue have been fixed.
>
> I'd like to isolate that the issue is still not fixed with the latest
> fixes, but I need to do some trial and error to reestablish a testable
> (bootable) KMSAN-enabled kernel config.
>
> Thanks,
> Ryusuke Konishi
>
>
> I hope it helps.
> Best regards
> xingwei Lee

Thank you!
That helps a lot.

Regards,
Ryusuke Konishi