ZFS Bug / array-index-out-of-bounds


Active Member
Dec 2, 2019
ProxMox users, developers, et alia:

Follows hereupon an excerpt from my /var/log/kern.log of what appears to be a problem in the ZFS code. In researching the issue I found some information that seems related, but I am not fully sure yet (see link #1 below). Has anyone seen such behavior before where ProxMox is running on an IBM x3650 M3?

2023-08-28T18:09:26.977526-07:00 pve4-x3650-m3 kernel: [26946.138017] UBSAN: array-index-out-of-bounds in /build/proxmox-kernel-6.2-dH6W6b/proxmox-kernel-6.2-6.2.16/modules/pkg-zfs/module/zstd/lib/zstd.c:20390:24
2023-08-28T18:09:26.982889-07:00 pve4-x3650-m3 kernel: [26946.151942] index 36 is out of range for type 'U32 [36]'
2023-08-28T18:09:26.982905-07:00 pve4-x3650-m3 kernel: [26946.157303] CPU: 9 PID: 475005 Comm: z_wr_iss Tainted: P O 6.2.16-10-pve #1
2023-08-28T18:09:27.131393-07:00 pve4-x3650-m3 kernel: [26946.165703] Hardware name: IBM System x3650 M3 -[7945AC1]-/69Y4438, BIOS -[D6E164AUS-1.22]- 06/04/2018
2023-08-28T18:09:27.131421-07:00 pve4-x3650-m3 kernel: [26946.175058] Call Trace:
2023-08-28T18:09:27.131424-07:00 pve4-x3650-m3 kernel: [26946.177526] <TASK>
2023-08-28T18:09:27.131425-07:00 pve4-x3650-m3 kernel: [26946.179649] dump_stack_lvl+0x48/0x70
2023-08-28T18:09:27.131426-07:00 pve4-x3650-m3 kernel: [26946.183352] dump_stack+0x10/0x20
2023-08-28T18:09:27.131428-07:00 pve4-x3650-m3 kernel: [26946.186695] __ubsan_handle_out_of_bounds+0xc6/0x110
2023-08-28T18:09:27.131430-07:00 pve4-x3650-m3 kernel: [26946.191697] ZSTD_initStats_ultra+0x4b2f/0x4ba0 [zzstd]
2023-08-28T18:09:27.131431-07:00 pve4-x3650-m3 kernel: [26946.196993] zfs_ZSTD_compressBlock_btultra2+0x40ff/0x42b0 [zzstd]
2023-08-28T18:09:27.131432-07:00 pve4-x3650-m3 kernel: [26946.203232] ? zstd_mempool_alloc+0x242/0x2b0 [zzstd]
2023-08-28T18:09:27.131434-07:00 pve4-x3650-m3 kernel: [26946.208338] ? zstd_alloc+0x19/0x40 [zzstd]
2023-08-28T18:09:27.131435-07:00 pve4-x3650-m3 kernel: [26946.212577] ? ZSTD_resetCCtx_internal+0xee4/0x1290 [zzstd]
2023-08-28T18:09:27.131436-07:00 pve4-x3650-m3 kernel: [26946.218216] ZSTD_buildSeqStore+0x18b/0x310 [zzstd]
2023-08-28T18:09:27.131438-07:00 pve4-x3650-m3 kernel: [26946.223148] ZSTD_compressBlock_internal+0x34/0x3e0 [zzstd]
2023-08-28T18:09:27.131439-07:00 pve4-x3650-m3 kernel: [26946.228784] ZSTD_compressContinue_internal+0x433/0x6d0 [zzstd]
2023-08-28T18:09:27.131440-07:00 pve4-x3650-m3 kernel: [26946.234768] zfs_ZSTD_compressEnd+0x28/0x180 [zzstd]
2023-08-28T18:09:27.131441-07:00 pve4-x3650-m3 kernel: [26946.239789] zfs_ZSTD_compressStream2+0x1e6/0x860 [zzstd]
2023-08-28T18:09:27.131443-07:00 pve4-x3650-m3 kernel: [26946.245248] zfs_ZSTD_compress2+0x63/0xb0 [zzstd]
2023-08-28T18:09:27.131445-07:00 pve4-x3650-m3 kernel: [26946.250013] ? zfs_ZSTD_compress2+0x63/0xb0 [zzstd]
2023-08-28T18:09:27.131446-07:00 pve4-x3650-m3 kernel: [26946.254948] zfs_zstd_compress+0x103/0x1e0 [zzstd]
2023-08-28T18:09:27.131447-07:00 pve4-x3650-m3 kernel: [26946.259789] zio_compress_data+0xd3/0x130 [zfs]
2023-08-28T18:09:27.131447-07:00 pve4-x3650-m3 kernel: [26946.264694] zio_write_compress+0x59b/0xa40 [zfs]
2023-08-28T18:09:27.131449-07:00 pve4-x3650-m3 kernel: [26946.269652] zio_execute+0x97/0x170 [zfs]
2023-08-28T18:09:27.131450-07:00 pve4-x3650-m3 kernel: [26946.273931] taskq_thread+0x2af/0x4d0 [spl]
2023-08-28T18:09:27.131451-07:00 pve4-x3650-m3 kernel: [26946.278172] ? __pfx_default_wake_function+0x10/0x10
2023-08-28T18:09:27.131453-07:00 pve4-x3650-m3 kernel: [26946.283175] ? __pfx_zio_execute+0x10/0x10 [zfs]
2023-08-28T18:09:27.131454-07:00 pve4-x3650-m3 kernel: [26946.288148] ? __pfx_taskq_thread+0x10/0x10 [spl]
2023-08-28T18:09:27.131456-07:00 pve4-x3650-m3 kernel: [26946.292917] kthread+0xe9/0x110
2023-08-28T18:09:27.131457-07:00 pve4-x3650-m3 kernel: [26946.296090] ? __pfx_kthread+0x10/0x10
2023-08-28T18:09:27.131458-07:00 pve4-x3650-m3 kernel: [26946.299871] ret_from_fork+0x2c/0x50
2023-08-28T18:09:27.131459-07:00 pve4-x3650-m3 kernel: [26946.303479] </TASK>
2023-08-28T18:09:27.131460-07:00 pve4-x3650-m3 kernel: [26946.305721] ================================================================================

Link #1: https://bugzilla.kernel.org/show_bug.cgi?id=215943

Thanks in advance!

Last edited:
  • Like
Reactions: Stoiko Ivanov
Fiona, et alia:

Yes, I’ve hit this issue multiple times.

When might the patch be hitting ProxMox?

Then I'm surprised nobody else seems to have.

I'm afraid I can't give you any time window for that. Let's see what upstream ZFS says.

I understand.

Thank you for your research and for opening an issue with ZFS.

Fiona, et alia:

I took notice that no one has actioned or commented on the bug you raised with upstream ZFS. Interesting, I’ve always seen ZFS as a very active project.

Fiona, et alia:

I presume at this juncture the current version of ProxMox has a newer version of ZFS and as such is inclusive of the fix for the aforementioned issue?

what's the effect of this bug? does it cause data corruption?
I'm pretty sure then it would've been addressed a long time ago. Disclaimer: I have no idea about zstd, but telling from the function names, it might just cause a non-ideal cost calculation during compression.
  • Like
Reactions: RolandK
FYI, I just got this message but I'm not sure if it's not a side effect of a more global crash.
The full log is attached.

2024-02-22T14:08:55.044549+01:00 heimdall kernel: [5447587.192484] show_signal_msg: 13 callbacks suppressed
2024-02-22T14:08:55.044566+01:00 heimdall kernel: [5447587.192489] CPU 6/KVM[897247]: segfault at 9000000 ip 0000000009000000 sp 00007fb2089aff88 error 14 in qemu-system-x86_64[558a46e1e000+316000] likely on CPU 18 (core 2, socket 0)
2024-02-22T14:08:55.044567+01:00 heimdall kernel: [5447587.192510] Code: Unable to access opcode bytes at 0x8ffffd6.
2024-02-22T14:08:55.046982+01:00 heimdall systemd[1]: Looping too fast. Throttling execution a little.
2024-02-22T14:08:55.060538+01:00 heimdall kernel: [5447587.208708] traps: worker[2862804] trap invalid opcode ip:5556c6a13aca sp:7fe2d9ff61f0 error:0 in qemu-system-x86_64[5556c6447000+612000]
2024-02-22T14:08:55.072693+01:00 heimdall kernel: [5447587.218787] spiceproxy work[2330788]: segfault at 5585e19d9370 ip 000055865fd14285 sp 00007ffe3d5c0590 error 4 in perl[55865fb96000+195000] likely on CPU 7 (core 7, socket 0)
2024-02-22T14:08:55.072699+01:00 heimdall kernel: [5447587.218802] Code: 21 00 49 8b 04 24 49 8b 6c 24 10 4c 8b 40 10 4c 8a 44 24 10 48 8b 54 24 08 4c 89 33 49 01 c8 4c 05 fa 41 f6 44 24 0f 20 7d 11 <48> 8b 83 d0 00 00 80 8b 40 38 f7 d0 83 e0 98 09 c5 41 89 e9 4c 89
2024-02-22T14:08:55.076557+01:00 heimdall kernel: [5447587.225639] traps: spiceproxy[3422] trap invalid opcode ip:55865fd09a8b sp:7ffe3d5bfff8 error:0 in perl[55865fb96000+195000]
2024-02-22T14:08:55.180616+01:00 heimdall kernel: [5447587.255496] ================================================================================
2024-02-22T14:08:55.180628+01:00 heimdall kernel: [5447587.255510] UBSAN: array-index-out-of-bounds in /home/tom/sources/pve/pve-kernel/proxmox-kernel-6.2.16/modules/pkg-zfs/module/zfs/dbuf.c:2870:32
2024-02-22T14:08:55.180630+01:00 heimdall kernel: [5447587.255520] index 16777216 is out of range for type 'dbuf_cache_t [2]'
2024-02-22T14:08:55.180630+01:00 heimdall kernel: [5447587.255526] CPU: 18 PID: 897247 Comm: CPU 6/KVM Tainted: P           O       6.2.16-15-pve #1
2024-02-22T14:08:55.180632+01:00 heimdall kernel: [5447587.255530] Hardware name: Gigabyte Technology Co., Ltd. X399 DESIGNARE EX/X399 DESIGNARE EX-CF, BIOS F12 12/11/2019


  • syslog_crash.log
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