Re: [syzbot] [input?] possible deadlock in tasklet_action_common (2)
From: syzbot
Date: Tue Jul 28 2026 - 07:26:46 EST
Hello,
syzbot tried to test the proposed patch but the build/boot failed:
ftware IO TLB: mapped [mem 0x00000000b4600000-0x00000000b8600000] (64MB)
[ 5.231457][ T1] ACPI: bus type thunderbolt registered
[ 5.267653][ T1] RAPL PMU: API unit is 2^-32 Joules, 0 fixed counters, 10737418240 ms ovfl timer
[ 5.290482][ T69] kworker/u8:2 (69) used greatest stack depth: 27600 bytes left
[ 5.326325][ T1] kvm_amd: CPU 1 isn't AMD or Hygon
[ 5.326364][ T1] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x1fb63109b96, max_idle_ns: 440795265316 ns
[ 5.327055][ T1] clocksource: Switched to clocksource tsc
[ 5.371801][ T84] kworker/u8:3 (84) used greatest stack depth: 27520 bytes left
[ 5.412535][ T92] kworker/u8:2 (92) used greatest stack depth: 27072 bytes left
[ 5.417473][ T1] Initialise system trusted keyrings
[ 5.427944][ T1] workingset: timestamp_bits=40 (anon: 35) max_order=21 bucket_order=0 (anon: 0)
[ 5.446779][ T1] DLM installed
[ 5.459164][ T1] squashfs: version 4.0 (2009/01/31) Phillip Lougher
[ 5.477196][ T1] NFS: Registering the id_resolver key type
[ 5.477460][ T1] Key type id_resolver registered
[ 5.477476][ T1] Key type id_legacy registered
[ 5.477896][ T1] nfs4filelayout_init: NFSv4 File Layout Driver Registering...
[ 5.478113][ T1] nfs4flexfilelayout_init: NFSv4 Flexfile Layout Driver Registering...
[ 5.491646][ T1] smbdirect: subsystem loading...
[ 5.506822][ T110] kworker/u8:6 (110) used greatest stack depth: 25920 bytes left
[ 5.508431][ T1] smbdirect: subsystem loaded
[ 5.539305][ T1] Key type cifs.spnego registered
[ 5.539715][ T1] Key type cifs.idmap registered
[ 5.551051][ T1] ntfs3: Enabled Linux POSIX ACLs support
[ 5.551066][ T1] ntfs3: Read-only LZX/Xpress compression included
[ 5.558203][ T1] jffs2: version 2.2. (NAND) (SUMMARY) © 2001-2006 Red Hat, Inc.
[ 5.566221][ T1] romfs: ROMFS MTD (C) 2007 Red Hat, Inc.
[ 5.566524][ T1] QNX4 filesystem 0.2.3 registered.
[ 5.566946][ T1] qnx6: QNX6 filesystem 1.0.0 registered.
[ 5.568775][ T1] fuse: init (API version 7.45)
[ 5.584953][ T1] orangefs_debugfs_init: called with debug mask: :none: :0:
[ 5.588175][ T1] orangefs_init: module version upstream loaded
[ 5.589870][ T1] JFS: nTxBlock = 8192, nTxLock = 65536
[ 5.621782][ T1] SGI XFS with ACLs, security attributes, realtime, scrub, repair, quota, no debug enabled
[ 5.638686][ T1] 9p: Installing v9fs 9p2000 file system support
[ 5.640188][ T1] NILFS version 2 loaded
[ 5.640203][ T1] befs: version: 0.9.3
[ 5.648618][ T1] ocfs2: Registered cluster interface o2cb
[ 5.649909][ T1] ocfs2: Registered cluster interface user
[ 5.652213][ T1] OCFS2 User DLM kernel interface loaded
[ 5.719151][ T1] gfs2: GFS2 installed
[ 5.744685][ T1] ceph: loaded (mds proto 32)
[ 5.762757][ T1] NET: Registered PF_ALG protocol family
[ 5.763272][ T1] async_tx: api initialized (async)
[ 5.763338][ T1] Key type asymmetric registered
[ 5.763424][ T1] Asymmetric key parser 'x509' registered
[ 5.763442][ T1] Asymmetric key parser 'pkcs8' registered
[ 5.763458][ T1] Key type pkcs7_test registered
[ 5.765004][ T1] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 239)
[ 5.767721][ T1] io scheduler mq-deadline registered
[ 5.767741][ T1] io scheduler kyber registered
[ 5.768414][ T1] io scheduler bfq registered
[ 5.770346][ T1] raid6: skipped pq benchmark and selected avx2x4
[ 5.835390][ T1] input: Power Button as /devices/platform/LNXPWRBN:00/input/input0
[ 5.839702][ T1] ACPI: button: Power Button [PWRF]
[ 5.850209][ T1] input: Sleep Button as /devices/platform/LNXSLPBN:00/input/input1
[ 5.858148][ T1] ACPI: button: Sleep Button [SLPF]
[ 5.896312][ T1] ioatdma: Intel(R) QuickData Technology Driver 5.00
[ 5.951129][ T10] ACPI: \_SB_.LNKC: Enabled at IRQ 11
[ 5.961895][ T10] virtio-pci 0000:00:03.0: virtio_pci: leaving for legacy driver
[ 6.006081][ T10] ACPI: \_SB_.LNKD: Enabled at IRQ 10
[ 6.006293][ T10] virtio-pci 0000:00:04.0: virtio_pci: leaving for legacy driver
[ 6.051096][ T10] ACPI: \_SB_.LNKB: Enabled at IRQ 10
[ 6.051252][ T10] virtio-pci 0000:00:06.0: virtio_pci: leaving for legacy driver
[ 6.097361][ T10] virtio-pci 0000:00:07.0: virtio_pci: leaving for legacy driver
[ 7.239127][ T1] N_HDLC line discipline registered with maxframe=4096
[ 7.246386][ T1] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
[ 7.265247][ T1] 00:02: ttyS0 I/O:0x3f8 (irq = 4, base_baud = 115200) is a 16550A
[ 7.304146][ T1] 00:03: ttyS1 I/O:0x2f8 (irq = 3, base_baud = 115200) is a 16550A
[ 7.338212][ T1] 00:04: ttyS2 I/O:0x3e8 (irq = 6, base_baud = 115200) is a 16550A
[ 7.372040][ T1] 00:05: ttyS3 I/O:0x2e8 (irq = 7, base_baud = 115200) is a 16550A
[ 7.437104][ T1] Non-volatile memory driver v1.3
[ 7.511268][ T1] usbcore: registered new interface driver xillyusb
[ 7.520740][ T1] ACPI: bus type drm_connector registered
[ 7.546780][ T1] [drm] Initialized vgem 1.0.0 for vgem on minor 0
[ 7.565373][ T1] ------------[ cut here ]------------
[ 7.565388][ T1] [PLANE:35:plane-0] pixel format with alpha exposed but blend mode not setup
[ 7.565410][ T1] WARNING: drivers/gpu/drm/drm_mode_config.c:873 at drm_mode_config_validate+0x1c6d/0x1e60, CPU#1: swapper/0/1
[ 7.565481][ T1] Modules linked in:
[ 7.565531][ T1] CPU: 1 UID: 0 PID: 1 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
[ 7.565555][ T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
[ 7.565575][ T1] RIP: 0010:drm_mode_config_validate+0x1cae/0x1e60
[ 7.565604][ 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 fa 9f ac fc 49 8b 16 4c 89 ef 89 ee <67> 48 0f b9 3a eb 05 e8 06 d0 3f fc 49 bd 00 00 00 00 00 fc ff df
[ 7.565627][ T1] RSP: 0000:ffffc90000067810 EFLAGS: 00010246
[ 7.565645][ T1] RAX: 1ffff11004b3fe08 RBX: dffffc0000000000 RCX: ffff88801c6f5dc0
[ 7.565662][ T1] RDX: ffff888025a33160 RSI: 0000000000000023 RDI: ffffffff8fdc7790
[ 7.565678][ T1] RBP: 0000000000000023 R08: 0000000000000000 R09: 0000000000000000
[ 7.565691][ T1] R10: dffffc0000000000 R11: fffffbfff1fa25f0 R12: dffffc0000000000
[ 7.565708][ T1] R13: ffffffff8fdc7790 R14: ffff8880259ff040 R15: ffff8880259ff030
[ 7.565724][ T1] FS: 0000000000000000(0000) GS:ffff888125add000(0000) knlGS:0000000000000000
[ 7.565742][ T1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 7.565758][ T1] CR2: 0000000000000000 CR3: 000000000e1b0000 CR4: 00000000003526f0
[ 7.565776][ T1] Call Trace:
[ 7.565783][ T1] <TASK>
[ 7.565807][ T1] ? debugfs_create_file_full+0x3f/0x60
[ 7.565847][ T1] drm_dev_register+0x7f/0xd80
[ 7.565876][ T1] vkms_create+0x40d/0x4f0
[ 7.565907][ T1] ? __pfx_vkms_init+0x10/0x10
[ 7.565952][ T1] vkms_init+0x57/0x80
[ 7.565983][ T1] do_one_initcall+0x250/0x870
[ 7.566012][ T1] ? __pfx_vkms_init+0x10/0x10
[ 7.566043][ T1] ? __pfx_do_one_initcall+0x10/0x10
[ 7.566077][ T1] ? clockevents_program_event+0x491/0x630
[ 7.566109][ T1] ? __pfx___schedule+0x10/0x10
[ 7.566149][ T1] ? irqentry_exit+0x218/0x8f0
[ 7.566173][ T1] ? lockdep_hardirqs_on+0x7a/0x110
[ 7.566196][ T1] ? irqentry_exit+0x218/0x8f0
[ 7.566218][ T1] ? trace_irq_disable+0x3b/0x140
[ 7.566253][ T1] ? parameq+0xd6/0x170
[ 7.566286][ T1] ? __pfx___sanitizer_cov_trace_cmp8+0x10/0x10
[ 7.566321][ T1] ? parameq+0x14d/0x170
[ 7.566355][ T1] ? parse_args+0x9c3/0xad0
[ 7.566403][ T1] ? trace_kmalloc+0x2a/0xf0
[ 7.566437][ T1] ? rcu_is_watching+0x15/0xb0
[ 7.566468][ T1] do_initcall_level+0x10a/0x1a0
[ 7.566494][ T1] ? kernel_init+0x22/0x1d0
[ 7.566523][ T1] do_initcalls+0x59/0xa0
[ 7.566549][ T1] kernel_init_freeable+0x29d/0x3e0
[ 7.566574][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.566606][ T1] kernel_init+0x22/0x1d0
[ 7.566634][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.566662][ T1] ret_from_fork+0x514/0xb70
[ 7.566695][ T1] ? __pfx_ret_from_fork+0x10/0x10
[ 7.566725][ T1] ? __switch_to+0xc89/0x1420
[ 7.566754][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.566785][ T1] ret_from_fork_asm+0x1a/0x30
[ 7.566831][ T1] </TASK>
[ 7.566848][ T1] Kernel panic - not syncing: kernel: panic_on_warn set ...
[ 7.566862][ T1] CPU: 1 UID: 0 PID: 1 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
[ 7.566885][ T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
[ 7.566897][ T1] Call Trace:
[ 7.566905][ T1] <TASK>
[ 7.566913][ T1] vpanic+0x56c/0xa60
[ 7.566942][ T1] ? __pfx__printk+0x10/0x10
[ 7.566969][ T1] ? __pfx_vpanic+0x10/0x10
[ 7.566988][ T1] ? is_bpf_text_address+0x292/0x2b0
[ 7.567014][ T1] ? is_bpf_text_address+0x26/0x2b0
[ 7.567048][ T1] panic+0xc5/0xd0
[ 7.567068][ T1] ? __pfx_panic+0x10/0x10
[ 7.567098][ T1] ? ret_from_fork_asm+0x1a/0x30
[ 7.567134][ T1] __warn+0x315/0x4c0
[ 7.567154][ T1] ? drm_mode_config_validate+0x1c6d/0x1e60
[ 7.567182][ T1] ? drm_mode_config_validate+0x1c6d/0x1e60
[ 7.567208][ T1] __report_bug+0x276/0x570
[ 7.567237][ T1] ? drm_mode_config_validate+0x1c6d/0x1e60
[ 7.567266][ T1] ? __pfx___report_bug+0x10/0x10
[ 7.567295][ T1] ? _raw_spin_unlock_irqrestore+0x30/0x80
[ 7.567320][ T1] ? lockdep_hardirqs_on+0x7a/0x110
[ 7.567345][ T1] ? rt_mutex_slowunlock+0x4ee/0xa20
[ 7.567377][ T1] report_bug_entry+0x19a/0x290
[ 7.567401][ T1] ? drm_mode_config_validate+0x1cae/0x1e60
[ 7.567425][ T1] ? drm_mode_config_validate+0x1cb3/0x1e60
[ 7.567451][ T1] handle_bug+0xce/0x200
[ 7.567479][ T1] exc_invalid_op+0x1a/0x50
[ 7.567506][ T1] asm_exc_invalid_op+0x1a/0x20
[ 7.567528][ T1] RIP: 0010:drm_mode_config_validate+0x1cae/0x1e60
[ 7.567555][ 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 fa 9f ac fc 49 8b 16 4c 89 ef 89 ee <67> 48 0f b9 3a eb 05 e8 06 d0 3f fc 49 bd 00 00 00 00 00 fc ff df
[ 7.567573][ T1] RSP: 0000:ffffc90000067810 EFLAGS: 00010246
[ 7.567591][ T1] RAX: 1ffff11004b3fe08 RBX: dffffc0000000000 RCX: ffff88801c6f5dc0
[ 7.567608][ T1] RDX: ffff888025a33160 RSI: 0000000000000023 RDI: ffffffff8fdc7790
[ 7.567623][ T1] RBP: 0000000000000023 R08: 0000000000000000 R09: 0000000000000000
[ 7.567635][ T1] R10: dffffc0000000000 R11: fffffbfff1fa25f0 R12: dffffc0000000000
[ 7.567651][ T1] R13: ffffffff8fdc7790 R14: ffff8880259ff040 R15: ffff8880259ff030
[ 7.567693][ T1] ? debugfs_create_file_full+0x3f/0x60
[ 7.567732][ T1] drm_dev_register+0x7f/0xd80
[ 7.567761][ T1] vkms_create+0x40d/0x4f0
[ 7.567792][ T1] ? __pfx_vkms_init+0x10/0x10
[ 7.567823][ T1] vkms_init+0x57/0x80
[ 7.567856][ T1] do_one_initcall+0x250/0x870
[ 7.567884][ T1] ? __pfx_vkms_init+0x10/0x10
[ 7.567915][ T1] ? __pfx_do_one_initcall+0x10/0x10
[ 7.567954][ T1] ? clockevents_program_event+0x491/0x630
[ 7.567986][ T1] ? __pfx___schedule+0x10/0x10
[ 7.568019][ T1] ? irqentry_exit+0x218/0x8f0
[ 7.568042][ T1] ? lockdep_hardirqs_on+0x7a/0x110
[ 7.568066][ T1] ? irqentry_exit+0x218/0x8f0
[ 7.568087][ T1] ? trace_irq_disable+0x3b/0x140
[ 7.568122][ T1] ? parameq+0xd6/0x170
[ 7.568153][ T1] ? __pfx___sanitizer_cov_trace_cmp8+0x10/0x10
[ 7.568218][ T1] ? parameq+0x14d/0x170
[ 7.568252][ T1] ? parse_args+0x9c3/0xad0
[ 7.568301][ T1] ? trace_kmalloc+0x2a/0xf0
[ 7.568334][ T1] ? rcu_is_watching+0x15/0xb0
[ 7.568364][ T1] do_initcall_level+0x10a/0x1a0
[ 7.568390][ T1] ? kernel_init+0x22/0x1d0
[ 7.568418][ T1] do_initcalls+0x59/0xa0
[ 7.568444][ T1] kernel_init_freeable+0x29d/0x3e0
[ 7.568468][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.568498][ T1] kernel_init+0x22/0x1d0
[ 7.568525][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.568552][ T1] ret_from_fork+0x514/0xb70
[ 7.568584][ T1] ? __pfx_ret_from_fork+0x10/0x10
[ 7.568613][ T1] ? __switch_to+0xc89/0x1420
[ 7.568641][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.568671][ T1] ret_from_fork_asm+0x1a/0x30
[ 7.568717][ T1] </TASK>
[ 7.569262][ T1] Kernel Offset: disabled
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-build1990016317=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/syzkaller/jobs-2/linux/gopath/src/github.com/google/syzkaller/go.mod'
GOMODCACHE='/syzkaller/jobs-2/linux/gopath/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/syzkaller/jobs-2/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 492bab153d
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=492bab153dea5e0e414bd0bbf60c3871267255ed -X github.com/google/syzkaller/prog.gitRevisionDate=20260724-151452" ./sys/syz-sysgen | grep -q false || go install -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=492bab153dea5e0e414bd0bbf60c3871267255ed -X github.com/google/syzkaller/prog.gitRevisionDate=20260724-151452" ./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=492bab153dea5e0e414bd0bbf60c3871267255ed -X github.com/google/syzkaller/prog.gitRevisionDate=20260724-151452" -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=\"492bab153dea5e0e414bd0bbf60c3871267255ed\"
/usr/bin/ld: /tmp/ccQYIykx.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=14cc51b9580000
Tested on:
commit: 0d33d21e Add linux-next specific files for 20260727
git tree: linux-next
kernel config: https://syzkaller.appspot.com/x/.config?x=830a7c02f0fee86b
dashboard link: https://syzkaller.appspot.com/bug?extid=b5d7ab56d43de3fd5aac
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
Note: no patches were applied.