Re: [syzbot] [io-uring?] [ext4?] INFO: task hung in io_write

[syzbot <syzbot+2eb3d983669d3e49d4fa@syzkaller.appspotmail.com>]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

t
[    9.311884][    T1] ntfs3: Read-only LZX/Xpress compression included
[    9.324965][    T1] jffs2: version 2.2. (NAND) (SUMMARY)  © 2001-2006 Red Hat, Inc.
[    9.339487][    T1] romfs: ROMFS MTD (C) 2007 Red Hat, Inc.
[    9.354547][    T1] QNX4 filesystem 0.2.3 registered.
[    9.358628][    T1] qnx6: QNX6 filesystem 1.0.0 registered.
[    9.374595][    T1] fuse: init (API version 7.45)
[    9.386259][    T1] orangefs_debugfs_init: called with debug mask: :none: :0:
[    9.405773][    T1] orangefs_init: module version upstream loaded
[    9.411433][    T1] JFS: nTxBlock = 6145, nTxLock = 49167
[    9.432378][    T1] SGI XFS with ACLs, security attributes, realtime, scrub, repair, quota, no debug enabled
[    9.460589][    T1] 9p: Installing v9fs 9p2000 file system support
[    9.474863][    T1] NILFS version 2 loaded
[    9.478065][    T1] befs: version: 0.9.3
[    9.481916][    T1] ocfs2: Registered cluster interface o2cb
[    9.505141][    T1] ocfs2: Registered cluster interface user
[    9.511060][    T1] OCFS2 User DLM kernel interface loaded
[    9.555232][    T1] gfs2: GFS2 installed
[    9.587926][    T1] ceph: loaded (mds proto 32)
[    9.609192][    T1] NET: Registered PF_ALG protocol family
[    9.613568][    T1] async_tx: api initialized (async)
[    9.634473][    T1] Key type asymmetric registered
[    9.638422][    T1] Asymmetric key parser 'x509' registered
[    9.643521][    T1] Asymmetric key parser 'pkcs8' registered
[    9.654318][    T1] Key type pkcs7_test registered
[    9.665499][    T1] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 239)
[    9.676502][    T1] io scheduler mq-deadline registered
[    9.694302][    T1] io scheduler kyber registered
[    9.698347][    T1] io scheduler bfq registered
[    9.703715][    T1] raid6: skipped pq benchmark and selected avx512x4
[    9.803123][    T1] ACPI: \_SB_.GSIE: Enabled at IRQ 20
[    9.844760][    T1] pcieport 0000:00:04.0: PME: Signaling with IRQ 25
[    9.855822][    T1] pcieport 0000:00:04.0: AER: enabled with IRQ 26
[    9.888231][    T1] input: Power Button as /devices/platform/LNXPWRBN:00/input/input0
[    9.907560][    T1] ACPI: button: Power Button [PWRF]
[   10.781900][    T1] ioatdma: Intel(R) QuickData Technology Driver 5.00
[   10.871170][    T1] ACPI: \_SB_.GSIF: Enabled at IRQ 21
[   10.969004][    T1] ACPI: \_SB_.GSIH: Enabled at IRQ 23
[   12.148632][    T1] N_HDLC line discipline registered with maxframe=4096
[   12.165434][    T1] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
[   12.190821][    T1] 00:03: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
[   12.338747][    T1] Non-volatile memory driver v1.3
[   12.377313][    T1] usbcore: registered new interface driver xillyusb
[   12.393087][    T1] ACPI: bus type drm_connector registered
[   12.432983][    T1] [drm] Initialized vgem 1.0.0 for vgem on minor 0
[   12.445520][    T1] usbcore: registered new interface driver udl
[   12.455961][    T1] [drm] pci: virtio-vga detected at 0000:00:01.0
[   12.460653][    T1] virtio-pci 0000:00:01.0: vgaarb: deactivate vga console
[   12.515474][    T1] Console: switching to colour dummy device 80x25
[   12.523215][    T1] [drm] features: -virgl +edid -resource_blob -host_visible
[   12.523225][    T1] [drm] features: -context_init -blob_alignment
[   12.542435][    T1] [drm] number of scanouts: 1
[   12.545813][    T1] [drm] number of cap sets: 0
[   12.554747][    T1] ------------[ cut here ]------------
[   12.558333][    T1] [PLANE:36:plane-1] pixel format with alpha exposed but blend mode not setup
[   12.558342][    T1] WARNING: drivers/gpu/drm/drm_mode_config.c:873 at drm_mode_config_validate+0x1c6a/0x1e60, CPU#0: swapper/0/1
[   12.573118][    T1] Modules linked in:
[   12.576385][    T1] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) 
[   12.582807][    T1] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[   12.590090][    T1] RIP: 0010:drm_mode_config_validate+0x1cab/0x1e60
[   12.594850][    T1] Code: 0f 85 ae 00 00 00 4d 8d 77 10 8b 6d 00 4c 89 f0 48 c1 e8 03 80 3c 18 00 74 08 4c 89 f7 e8 bd a5 a3 fc 49 8b 16 4c 89 ef 89 ee <67> 48 0f b9 3a eb 05 e8 c9 54 32 fc 49 bd 00 00 00 00 00 fc ff df
[   12.608988][    T1] RSP: 0000:ffffc900001af450 EFLAGS: 00010246
[   12.613447][    T1] RAX: 1ffff11000029408 RBX: dffffc0000000000 RCX: ffff88801ceb0000
[   12.619368][    T1] RDX: ffff88801f5db780 RSI: 0000000000000024 RDI: ffffffff9085b000
[   12.625154][    T1] RBP: 0000000000000024 R08: ffffffff8ec2b347 R09: 1ffffffff1d85668
[   12.631012][    T1] R10: dffffc0000000000 R11: fffffbfff1d85669 R12: dffffc0000000000
[   12.636862][    T1] R13: ffffffff9085b000 R14: ffff88800014a040 R15: ffff88800014a030
[   12.642683][    T1] FS:  0000000000000000(0000) GS:ffff88808c2e6000(0000) knlGS:0000000000000000
[   12.649778][    T1] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   12.654807][    T1] CR2: ffff88801af19000 CR3: 000000000eb46000 CR4: 0000000000352ef0
[   12.660778][    T1] Call Trace:
[   12.663243][    T1]  <TASK>
[   12.665510][    T1]  ? __pfx_autoremove_wake_function+0x10/0x10
[   12.669917][    T1]  drm_dev_register+0x7c/0xd80
[   12.673383][    T1]  virtio_gpu_probe+0x1cb/0x290
[   12.677087][    T1]  virtio_dev_probe+0xdf6/0x10c0
[   12.680755][    T1]  ? up_write+0x19d/0x4a0
[   12.684009][    T1]  ? __pfx_virtio_dev_probe+0x10/0x10
[   12.687928][    T1]  ? driver_sysfs_add+0x1fe/0x210
[   12.691505][    T1]  ? __pfx_virtio_dev_probe+0x10/0x10
[   12.695595][    T1]  really_probe+0x254/0xae0
[   12.698866][    T1]  __driver_probe_device+0x1e8/0x360
[   12.702663][    T1]  driver_probe_device+0x4f/0x240
[   12.706350][    T1]  __driver_attach+0x339/0x600
[   12.709736][    T1]  bus_for_each_dev+0x23b/0x2c0
[   12.713247][    T1]  ? __pfx___driver_attach+0x10/0x10
[   12.717330][    T1]  ? __pfx_bus_for_each_dev+0x10/0x10
[   12.721241][    T1]  ? do_raw_spin_unlock+0x4d/0x200
[   12.724984][    T1]  bus_add_driver+0x345/0x670
[   12.728449][    T1]  driver_register+0x23a/0x320
[   12.732054][    T1]  ? __pfx_virtio_gpu_driver_init+0x10/0x10
[   12.736511][    T1]  virtio_gpu_driver_init+0x96/0x110
[   12.740363][    T1]  do_one_initcall+0x250/0x870
[   12.743753][    T1]  ? __pfx_virtio_gpu_driver_init+0x10/0x10
[   12.747725][    T1]  ? __pfx_do_one_initcall+0x10/0x10
[   12.750854][    T1]  ? __pfx___schedule+0x10/0x10
[   12.754246][    T1]  ? irqentry_exit+0x218/0x910
[   12.757543][    T1]  ? lockdep_hardirqs_on+0x7b/0x110
[   12.760932][    T1]  ? irqentry_exit+0x218/0x910
[   12.764435][    T1]  ? trace_irq_disable+0x3b/0x140
[   12.767922][    T1]  ? parameq+0x37/0x170
[   12.770899][    T1]  ? next_arg+0x4a0/0x5e0
[   12.773885][    T1]  ? parameq+0x14d/0x170
[   12.776877][    T1]  ? parse_args+0x9c3/0xad0
[   12.779988][    T1]  ? rcu_is_watching+0x16/0xb0
[   12.783393][    T1]  do_initcall_level+0x10a/0x1a0
[   12.787027][    T1]  ? kernel_init+0x22/0x1d0
[   12.790245][    T1]  do_initcalls+0x59/0xa0
[   12.793486][    T1]  kernel_init_freeable+0x29d/0x3e0
[   12.796995][    T1]  ? __pfx_kernel_init+0x10/0x10
[   12.800223][    T1]  kernel_init+0x22/0x1d0
[   12.803175][    T1]  ? __pfx_kernel_init+0x10/0x10
[   12.806784][    T1]  ret_from_fork+0x514/0xb70
[   12.809992][    T1]  ? __pfx_ret_from_fork+0x10/0x10
[   12.813663][    T1]  ? __switch_to+0xc89/0x1420
[   12.817141][    T1]  ? __pfx_kernel_init+0x10/0x10
[   12.820600][    T1]  ret_from_fork_asm+0x1a/0x30
[   12.824086][    T1]  </TASK>
[   12.826409][    T1] Kernel panic - not syncing: kernel: panic_on_warn set ...
[   12.831660][    T1] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) 
[   12.836273][    T1] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[   12.836273][    T1] Call Trace:
[   12.836273][    T1]  <TASK>
[   12.836273][    T1]  vpanic+0x56d/0xa60
[   12.836273][    T1]  ? __pfx__printk+0x10/0x10
[   12.836273][    T1]  ? __pfx_vpanic+0x10/0x10
[   12.836273][    T1]  ? is_bpf_text_address+0x292/0x2b0
[   12.836273][    T1]  ? is_bpf_text_address+0x26/0x2b0
[   12.836273][    T1]  panic+0xc5/0xd0
[   12.836273][    T1]  ? __pfx_panic+0x10/0x10
[   12.836273][    T1]  ? ret_from_fork_asm+0x1a/0x30
[   12.836273][    T1]  __warn+0x315/0x4c0
[   12.836273][    T1]  ? drm_mode_config_validate+0x1c6a/0x1e60
[   12.836273][    T1]  ? drm_mode_config_validate+0x1c6a/0x1e60
[   12.836273][    T1]  __report_bug+0x276/0x570
[   12.836273][    T1]  ? blocking_notifier_chain_register+0x50/0xc0
[   12.836273][    T1]  ? drm_mode_config_validate+0x1c6a/0x1e60
[   12.836273][    T1]  ? __pfx___report_bug+0x10/0x10
[   12.836273][    T1]  ? blocking_notifier_chain_register+0x6b/0xc0
[   12.836273][    T1]  report_bug_entry+0x19b/0x290
[   12.836273][    T1]  ? drm_mode_config_validate+0x1cab/0x1e60
[   12.836273][    T1]  ? drm_mode_config_validate+0x1cb0/0x1e60
[   12.836273][    T1]  handle_bug+0xce/0x200
[   12.836273][    T1]  exc_invalid_op+0x1a/0x50
[   12.836273][    T1]  asm_exc_invalid_op+0x1a/0x20
[   12.836273][    T1] RIP: 0010:drm_mode_config_validate+0x1cab/0x1e60
[   12.836273][    T1] Code: 0f 85 ae 00 00 00 4d 8d 77 10 8b 6d 00 4c 89 f0 48 c1 e8 03 80 3c 18 00 74 08 4c 89 f7 e8 bd a5 a3 fc 49 8b 16 4c 89 ef 89 ee <67> 48 0f b9 3a eb 05 e8 c9 54 32 fc 49 bd 00 00 00 00 00 fc ff df
[   12.836273][    T1] RSP: 0000:ffffc900001af450 EFLAGS: 00010246
[   12.836273][    T1] RAX: 1ffff11000029408 RBX: dffffc0000000000 RCX: ffff88801ceb0000
[   12.836273][    T1] RDX: ffff88801f5db780 RSI: 0000000000000024 RDI: ffffffff9085b000
[   12.836273][    T1] RBP: 0000000000000024 R08: ffffffff8ec2b347 R09: 1ffffffff1d85668
[   12.836273][    T1] R10: dffffc0000000000 R11: fffffbfff1d85669 R12: dffffc0000000000
[   12.836273][    T1] R13: ffffffff9085b000 R14: ffff88800014a040 R15: ffff88800014a030
[   12.836273][    T1]  ? __pfx_autoremove_wake_function+0x10/0x10
[   12.836273][    T1]  drm_dev_register+0x7c/0xd80
[   12.836273][    T1]  virtio_gpu_probe+0x1cb/0x290
[   12.836273][    T1]  virtio_dev_probe+0xdf6/0x10c0
[   12.836273][    T1]  ? up_write+0x19d/0x4a0
[   12.836273][    T1]  ? __pfx_virtio_dev_probe+0x10/0x10
[   12.836273][    T1]  ? driver_sysfs_add+0x1fe/0x210
[   12.836273][    T1]  ? __pfx_virtio_dev_probe+0x10/0x10
[   12.836273][    T1]  really_probe+0x254/0xae0
[   12.836273][    T1]  __driver_probe_device+0x1e8/0x360
[   12.836273][    T1]  driver_probe_device+0x4f/0x240
[   12.836273][    T1]  __driver_attach+0x339/0x600
[   12.836273][    T1]  bus_for_each_dev+0x23b/0x2c0
[   12.836273][    T1]  ? __pfx___driver_attach+0x10/0x10
[   12.836273][    T1]  ? __pfx_bus_for_each_dev+0x10/0x10
[   12.836273][    T1]  ? do_raw_spin_unlock+0x4d/0x200
[   12.836273][    T1]  bus_add_driver+0x345/0x670
[   12.836273][    T1]  driver_register+0x23a/0x320
[   12.836273][    T1]  ? __pfx_virtio_gpu_driver_init+0x10/0x10
[   12.836273][    T1]  virtio_gpu_driver_init+0x96/0x110
[   12.836273][    T1]  do_one_initcall+0x250/0x870
[   12.836273][    T1]  ? __pfx_virtio_gpu_driver_init+0x10/0x10
[   12.836273][    T1]  ? __pfx_do_one_initcall+0x10/0x10
[   12.836273][    T1]  ? __pfx___schedule+0x10/0x10
[   12.836273][    T1]  ? irqentry_exit+0x218/0x910
[   12.836273][    T1]  ? lockdep_hardirqs_on+0x7b/0x110
[   12.836273][    T1]  ? irqentry_exit+0x218/0x910
[   12.836273][    T1]  ? trace_irq_disable+0x3b/0x140
[   12.836273][    T1]  ? parameq+0x37/0x170
[   12.836273][    T1]  ? next_arg+0x4a0/0x5e0
[   12.836273][    T1]  ? parameq+0x14d/0x170
[   12.836273][    T1]  ? parse_args+0x9c3/0xad0
[   12.836273][    T1]  ? rcu_is_watching+0x16/0xb0
[   12.836273][    T1]  do_initcall_level+0x10a/0x1a0
[   12.836273][    T1]  ? kernel_init+0x22/0x1d0
[   12.836273][    T1]  do_initcalls+0x59/0xa0
[   12.836273][    T1]  kernel_init_freeable+0x29d/0x3e0
[   12.836273][    T1]  ? __pfx_kernel_init+0x10/0x10
[   12.836273][    T1]  kernel_init+0x22/0x1d0
[   12.836273][    T1]  ? __pfx_kernel_init+0x10/0x10
[   12.836273][    T1]  ret_from_fork+0x514/0xb70
[   12.836273][    T1]  ? __pfx_ret_from_fork+0x10/0x10
[   12.836273][    T1]  ? __switch_to+0xc89/0x1420
[   12.836273][    T1]  ? __pfx_kernel_init+0x10/0x10
[   12.836273][    T1]  ret_from_fork_asm+0x1a/0x30
[   12.836273][    T1]  </TASK>
[   12.836273][    T1] Kernel Offset: disabled
[   12.836273][    T1] Rebooting in 86400 seconds..


syzkaller build log:
go env (err=<nil>)
AR='ar'
CC='gcc'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='g++'
GCCGO='gccgo'
GO111MODULE='auto'
GOAMD64='v1'
GOARCH='amd64'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/syzkaller/.cache/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/syzkaller/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build2134465290=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/syzkaller/jobs/linux/gopath/src/github.com/google/syzkaller/go.mod'
GOMODCACHE='/syzkaller/jobs/linux/gopath/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/syzkaller/jobs/linux/gopath'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/syzkaller/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.26.0'
GOWORK=''
PKG_CONFIG='pkg-config'

git status (err=<nil>)
HEAD detached at 680aa3e19b5
nothing to commit, working tree clean


tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
go list -f '{{.Stale}}' -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=680aa3e19b52574eca8bcba3c41aa18235367abe -X github.com/google/syzkaller/prog.gitRevisionDate=20260907-094615"  ./sys/syz-sysgen | grep -q false || go install -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=680aa3e19b52574eca8bcba3c41aa18235367abe -X github.com/google/syzkaller/prog.gitRevisionDate=20260907-094615"  ./sys/syz-sysgen
make .descriptions
tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
bin/syz-sysgen
touch .descriptions
GOOS=linux GOARCH=amd64 go build -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=680aa3e19b52574eca8bcba3c41aa18235367abe -X github.com/google/syzkaller/prog.gitRevisionDate=20260907-094615"  -o ./bin/linux_amd64/syz-execprog github.com/google/syzkaller/tools/syz-execprog
mkdir -p ./bin/linux_amd64
g++ -o ./bin/linux_amd64/syz-executor executor/executor.cc \
	-m64 -O2 -pthread -Wall -Werror -Wparentheses -Wunused-const-variable -Wframe-larger-than=16384 -Wno-stringop-overflow -Wno-array-bounds -Wno-format-overflow -Wno-unused-but-set-variable -Wno-unused-command-line-argument -static-pie -std=c++17 -I. -Iexecutor/_include   -DGOOS_linux=1 -DGOARCH_amd64=1 \
	-DHOSTGOOS_linux=1 -DGIT_REVISION=\"680aa3e19b52574eca8bcba3c41aa18235367abe\"
go: downloading google.golang.org/grpc v1.83.1
go: downloading go.opentelemetry.io/contrib/detectors/gcp v1.44.0
go: downloading github.com/GoogleCloudPlatform/opentelemetry-operations-go/detectors/gcp v1.33.0
go: downloading github.com/klauspost/compress v1.18.7
go: downloading github.com/spiffe/go-spiffe/v2 v2.7.0
/usr/bin/ld: /tmp/ccpIPst8.o: in function `Connection::Connect(char const*, char const*)':
executor.cc:(.text._ZN10Connection7ConnectEPKcS1_[_ZN10Connection7ConnectEPKcS1_]+0x386): warning: Using 'gethostbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
./tools/check-syzos.sh 2>/dev/null


Error text is too large and was truncated, full error text is at:
https://syzkaller.appspot.com/x/error.txt?x=161cf125580000


Tested on:

commit:         2cf20c4e io_uring/waitid: avoid siginfo copy during ri..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux.git io_uring-7.3
kernel config:  https://syzkaller.appspot.com/x/.config?x=780bb9a5c10069a1
dashboard link: https://syzkaller.appspot.com/bug?extid=2eb3d983669d3e49d4fa
compiler:       Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

Note: no patches were applied.