Re: [linux-next-20250324]Kernel OOPs while running xfs/206 Test

[Carlos Maiolino]

On Wed, Mar 26, 2025 at 09:32:07PM +0530, Venkat Rao Bagalkote wrote:
> Greetings!!!
> 
> I observed kernel oops, while running xfs/206 test case on
> 6.14.0-rc7-next-20250324 only once. I am not able to reporduce this. But
> posting it here anyway, if anyone gets any clue.
> 
> Please ignore, if it dosent help.
> 
> 
> ---- Steps to Reproduce ----
> 1. git clone git://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git
> 2. cd xfstests-dev/
> 3. mkdir /mnt/loop-device /mnt/test /mnt/scratch
> 4. for i in $(seq 0 1); do fallocate -o 0 -l 9GiB
> /mnt/loop-device/file-$i.img; done
> 5. for i in $(seq 0 1); do losetup /dev/loop$i
> /mnt/loop-device/file-$i.img; done
> 6. mkfs.xfs -f /dev/loop0; mkfs.xfs -f /dev/loop1
> 7. vim local.config
> 8. make
> 9. ./check xfs/206
> 
> local.config >>>
> [xfs_4k]
> export RECREATE_TEST_DEV=true
> export TEST_DEV=/dev/loop0
> export TEST_DIR=/mnt/test
> export SCRATCH_DEV=/dev/loop1
> export SCRATCH_MNT=/mnt/scratch
> export MKFS_OPTIONS="-b size=4096"
> export FSTYP=xfs
> export MOUNT_OPTIONS=""-
> 
> 
> Traces:
> 
> [ 2272.236489] ------------[ cut here ]------------
> [ 2272.236502] WARNING: CPU: 3 PID: 1 at kernel/cgroup/rstat.c:231
> cgroup_rstat_updated_list+0x228/0x330
> [ 2272.236512] Modules linked in: overlay dm_zero dm_thin_pool
> dm_persistent_data dm_bio_prison dm_snapshot dm_bufio dm_flakey xfs loop
> dm_mod nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet
> nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct bonding nft_chain_nat
> nf_nat tls nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 rfkill sunrpc
> ip_set nf_tables nfnetlink pseries_rng vmx_crypto fuse ext4 mbcache jbd2
> sd_mod sg ibmvscsi ibmveth scsi_transport_srp [last unloaded: scsi_debug]
> [ 2272.236556] CPU: 3 UID: 0 PID: 1 Comm: systemd Kdump: loaded Not
> tainted 6.14.0-rc7-next-20250324 #1 VOLUNTARY
> [ 2272.236564] Hardware name: IBM,9080-HEX
> [ 2272.236572] NIP:  c0000000002d3af0 LR: c0000000002d3948 CTR:
> c0000000005f3728
> [ 2272.236578] REGS: c000000004b276f0 TRAP: 0700   Not tainted
> (6.14.0-rc7-next-20250324)
> [ 2272.236584] MSR:  8000000000029033 <SF,EE,ME,IR,DR,RI,LE>  CR:
> 28228442  XER: 2004006c

> [ 2272.236599] CFAR: c0000000002d399c IRQMASK: 1
> [ 2272.236599] GPR00: c0000000002d3948 c000000004b27990 c0000000016b8100
> 0000000000000001
> [ 2272.236599] GPR04: 0000000000000003 0000000000000003 0000000000000000
> 0000000ef9220000
> [ 2272.236599] GPR08: c000000091b66000 c009fffff4ca0140 c000000091b66000
> 0000000000008000
> [ 2272.236599] GPR12: c0000000005f3728 c000000effffb300 0000000000000000
> 0000000000000000
> [ 2272.236599] GPR16: 0000000000000000 0000000000000000 0000000000000000
> c0000000ac5043e0
> [ 2272.236599] GPR20: 0000000000000001 0000000000000000 c0000000015d11d8
> c0000000ac504000
> [ 2272.236599] GPR24: c009fffff4ca9000 c0000000ac504000 0000000000000000
> c000000efb49c4bc
> [ 2272.236599] GPR28: c000000002d0a668 0000000000000018 0000000000000003
> c000000091b66000
> [ 2272.236645] NIP [c0000000002d3af0] cgroup_rstat_updated_list+0x228/0x330
> [ 2272.236650] LR [c0000000002d3948] cgroup_rstat_updated_list+0x80/0x330
> [ 2272.236656] Call Trace:
> [ 2272.236658] [c000000004b27990] [c0000000015d11d8]
> __cpu_possible_mask+0x0/0x400 (unreliable)
> [ 2272.236665] [c000000004b279f0] [c0000000002d3f50]
> cgroup_rstat_flush+0xc8/0x5d0
> [ 2272.236672] [c000000004b27a90] [c0000000002d47d0]
> cgroup_base_stat_cputime_show+0x5c/0x2fc
> [ 2272.236678] [c000000004b27b40] [c0000000002c7fb0]
> cpu_stat_show+0x2c/0x1a4
> [ 2272.236683] [c000000004b27b80] [c0000000002c60e0]
> cgroup_seqfile_show+0x74/0x158
> [ 2272.236688] [c000000004b27bf0] [c000000000735974]
> kernfs_seq_show+0x44/0x58
> [ 2272.236693] [c000000004b27c10] [c000000000676440]
> seq_read_iter+0x264/0x6a8
> [ 2272.236700] [c000000004b27cf0] [c0000000007364c0]
> kernfs_fop_read_iter+0x4c/0x60
> [ 2272.236704] [c000000004b27d10] [c000000000628a9c] vfs_read+0x2cc/0x3a0
> [ 2272.236710] [c000000004b27dc0] [c000000000629904] ksys_read+0x84/0x144
> [ 2272.236715] [c000000004b27e10] [c000000000033498]
> system_call_exception+0x138/0x330
> [ 2272.236721] [c000000004b27e50] [c00000000000d05c]
> system_call_vectored_common+0x15c/0x2ec
> [ 2272.236728] --- interrupt: 3000 at 0x7fffa5f33d94
> [ 2272.236732] NIP:  00007fffa5f33d94 LR: 00007fffa5f33d94 CTR:
> 0000000000000000
> [ 2272.236736] REGS: c000000004b27e80 TRAP: 3000   Not tainted
> (6.14.0-rc7-next-20250324)
> [ 2272.236740] MSR:  800000000280f033
> <SF,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE>  CR: 48222442  XER: 00000000
> [ 2272.236751] IRQMASK: 0
> [ 2272.236751] GPR00: 0000000000000003 00007fffebb75a30 00007fffa6667400
> 0000000000000029
> [ 2272.236751] GPR04: 000000014998e9e0 0000000000002000 0000000000000001
> 00007fffa6bb53a0
> [ 2272.236751] GPR08: 00007fffa6badc68 0000000000000000 0000000000000000
> 0000000000000000
> [ 2272.236751] GPR12: 0000000000000000 00007fffa6bb53a0 0000000000000000
> 0000000000000807
> [ 2272.236751] GPR16: 0000000000000000 0000000000000000 0000000003ffffff
> 0000000004000000
> [ 2272.236751] GPR20: 0000000003fffffe 0000000000000000 0000000000000000
> 00007fffebb75e18
> [ 2272.236751] GPR24: 0000000000000000 00007fffa602ce18 00007fffa602d9e8
> 00007fffa602ce18
> [ 2272.236751] GPR28: 00007fffa602d748 000000014998e9e0 0000000000000000
> 0000000000002000
> [ 2272.236793] NIP [00007fffa5f33d94] 0x7fffa5f33d94
> [ 2272.236796] LR [00007fffa5f33d94] 0x7fffa5f33d94
> [ 2272.236799] --- interrupt: 3000
> [ 2272.236801] Code: eb01ffc0 eb21ffc8 eb41ffd0 eb61ffd8 eb81ffe0
> eba1ffe8 ebc1fff0 ebe1fff8 7c0803a6 4e800020 60000000 60000000
> <0fe00000> 4bfffeac 60000000 60000000
> [ 2272.236815] ---[ end trace 0000000000000000 ]---
> [ 2272.236819] Kernel attempted to read user page (3d8) - exploit
> attempt? (uid: 0)
> [ 2272.236824] BUG: Kernel NULL pointer dereference on read at 0x000003d8
> [ 2272.236828] Faulting instruction address: 0xc0000000002d3994
> [ 2272.236832] Oops: Kernel access of bad area, sig: 11 [#1]
> [ 2272.236835] LE PAGE_SIZE=64K MMU=Radix  SMP NR_CPUS=8192 NUMA pSeries
> [ 2272.236839] Modules linked in: overlay dm_zero dm_thin_pool
> dm_persistent_data dm_bio_prison dm_snapshot dm_bufio dm_flakey xfs loop
> dm_mod nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet
> nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct bonding nft_chain_nat
> nf_nat tls nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 rfkill sunrpc
> ip_set nf_tables nfnetlink pseries_rng vmx_crypto fuse ext4 mbcache jbd2
> sd_mod sg ibmvscsi ibmveth scsi_transport_srp [last unloaded: scsi_debug]
> [ 2272.236875] CPU: 3 UID: 0 PID: 1 Comm: systemd Kdump: loaded Tainted:
> G        W           6.14.0-rc7-next-20250324 #1 VOLUNTARY
> [ 2272.236881] Tainted: [W]=WARN
> [ 2272.236883] Hardware name: IBM,9080-HEX
> [ 2272.236888] NIP:  c0000000002d3994 LR: c0000000002d3948 CTR:
> c0000000005f3728
> [ 2272.236892] REGS: c000000004b276f0 TRAP: 0300   Tainted: G       
> W            (6.14.0-rc7-next-20250324)
> [ 2272.236897] MSR:  8000000000009033 <SF,EE,ME,IR,DR,RI,LE>  CR:
> 48228442  XER: 2004006c
> [ 2272.236905] CFAR: c0000000002d39a8 DAR: 00000000000003d8 DSISR:
> 40000000 IRQMASK: 1
> [ 2272.236905] GPR00: c0000000002d3948 c000000004b27990 c0000000016b8100
> 0000000000000001
> [ 2272.236905] GPR04: 0000000000000003 0000000000000003 0000000000000000
> 0000000ef9220000
> [ 2272.236905] GPR08: c000000091b66000 c009fffff4ca0140 0000000000000000
> 0000000000008000
> [ 2272.236905] GPR12: c0000000005f3728 c000000effffb300 0000000000000000
> 0000000000000000
> [ 2272.236905] GPR16: 0000000000000000 0000000000000000 0000000000000000
> c0000000ac5043e0
> [ 2272.236905] GPR20: 0000000000000001 0000000000000000 c0000000015d11d8
> c0000000ac504000
> [ 2272.236905] GPR24: c009fffff4ca9000 c0000000ac504000 0000000000000000
> c000000efb49c4bc
> [ 2272.236905] GPR28: c000000002d0a668 0000000000000018 0000000000000003
> c000000091b66000
> [ 2272.236975] NIP [c0000000002d3994] cgroup_rstat_updated_list+0xcc/0x330
> [ 2272.236981] LR [c0000000002d3948] cgroup_rstat_updated_list+0x80/0x330
> [ 2272.236986] Call Trace:
> [ 2272.236988] [c000000004b27990] [c0000000015d11d8]
> __cpu_possible_mask+0x0/0x400 (unreliable)
> [ 2272.236995] [c000000004b279f0] [c0000000002d3f50]
> cgroup_rstat_flush+0xc8/0x5d0
> [ 2272.237001] [c000000004b27a90] [c0000000002d47d0]
> cgroup_base_stat_cputime_show+0x5c/0x2fc
> [ 2272.237008] [c000000004b27b40] [c0000000002c7fb0]
> cpu_stat_show+0x2c/0x1a4
> [ 2272.237013] [c000000004b27b80] [c0000000002c60e0]
> cgroup_seqfile_show+0x74/0x158
> [ 2272.237018] [c000000004b27bf0] [c000000000735974]
> kernfs_seq_show+0x44/0x58
> [ 2272.237022] [c000000004b27c10] [c000000000676440]
> seq_read_iter+0x264/0x6a8
> [ 2272.237028] [c000000004b27cf0] [c0000000007364c0]
> kernfs_fop_read_iter+0x4c/0x60
> [ 2272.237033] [c000000004b27d10] [c000000000628a9c] vfs_read+0x2cc/0x3a0
> [ 2272.237037] [c000000004b27dc0] [c000000000629904] ksys_read+0x84/0x144
> [ 2272.237042] [c000000004b27e10] [c000000000033498]
> system_call_exception+0x138/0x330
> [ 2272.237048] [c000000004b27e50] [c00000000000d05c]
> system_call_vectored_common+0x15c/0x2ec
> [ 2272.237054] --- interrupt: 3000 at 0x7fffa5f33d94
> [ 2272.237057] NIP:  00007fffa5f33d94 LR: 00007fffa5f33d94 CTR:
> 0000000000000000
> [ 2272.237061] REGS: c000000004b27e80 TRAP: 3000   Tainted: G       
> W            (6.14.0-rc7-next-20250324)
> [ 2272.237066] MSR:  800000000280f033
> <SF,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE>  CR: 48222442  XER: 00000000
> [ 2272.237076] IRQMASK: 0
> [ 2272.237076] GPR00: 0000000000000003 00007fffebb75a30 00007fffa6667400
> 0000000000000029
> [ 2272.237076] GPR04: 000000014998e9e0 0000000000002000 0000000000000001
> 00007fffa6bb53a0
> [ 2272.237076] GPR08: 00007fffa6badc68 0000000000000000 0000000000000000
> 0000000000000000
> [ 2272.237076] GPR12: 0000000000000000 00007fffa6bb53a0 0000000000000000
> 0000000000000807
> [ 2272.237076] GPR16: 0000000000000000 0000000000000000 0000000003ffffff
> 0000000004000000
> [ 2272.237076] GPR20: 0000000003fffffe 0000000000000000 0000000000000000
> 00007fffebb75e18
> [ 2272.237076] GPR24: 0000000000000000 00007fffa602ce18 00007fffa602d9e8
> 00007fffa602ce18
> [ 2272.237076] GPR28: 00007fffa602d748 000000014998e9e0 0000000000000000
> 0000000000002000
> [ 2272.237118] NIP [00007fffa5f33d94] 0x7fffa5f33d94
> [ 2272.237121] LR [00007fffa5f33d94] 0x7fffa5f33d94
> [ 2272.237124] --- interrupt: 3000
> [ 2272.237127] Code: 4182013c e91900c0 2c280000 41820044 7cfce82a
> e92803d8 7d293a14 e94900a0 7c395040 41820268 60000000 7c285040
> <e92a03d8> 7d274a14 41820154 e94900a8
> [ 2272.237140] ---[ end trace 0000000000000000 ]--
> 
> 
> If you happen to fix this, please add below tag.
> 
> 
> Reproted-by: Venkat Rao Bagalkote <venkat88@xxxxxxxxxxxxx>

There is nothing in this report that appears to point to a XFS problem other
than the fact you hit it while running xfstests. Is there anything I'm missing
here? This just looks like to be cgroups related.

Carlos.

> 
> 
> Regards,
> 
> Venkat.
> 
>