Message-ID: <6971293a.050a0220.706b.0016.GAE@google.com>
Date: Wed, 21 Jan 2026 11:30:02 -0800
From: syzbot <syzbot+4eb282331cab6d5b6588@...kaller.appspotmail.com>
To: axboe@...nel.dk, io-uring@...r.kernel.org, linux-kernel@...r.kernel.org, 
	syzkaller-bugs@...glegroups.com
Subject: Re: [syzbot] [io-uring?] INFO: task hung in io_wq_put_and_exit (6)

Hello,

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

text=system_u:object_r:binfmt_misc_fs_t tclass=dir permissive=1
Setting up swapspace version 1, size = 127995904 bytes
[   74.071984][   T30] audit: type=1400 audit(1769023732.299:71): avc:  denied  { mount } for  pid=5816 comm="syz-executor" name="/" dev="binfmt_misc" ino=1 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:binfmt_misc_fs_t tclass=filesystem permissive=1
[   75.027540][ T5816] Adding 124996k swap on ./swap-file.  Priority:0 extents:1 across:124996k 
[   77.035760][   T30] kauditd_printk_skb: 4 callbacks suppressed
[   77.035777][   T30] audit: type=1400 audit(1769023735.389:76): avc:  denied  { execmem } for  pid=5827 comm="syz-executor" scontext=root:sysadm_r:sysadm_t tcontext=root:sysadm_r:sysadm_t tclass=process permissive=1
[   77.115776][   T30] audit: type=1400 audit(1769023735.469:77): avc:  denied  { read } for  pid=5832 comm="syz-executor" dev="nsfs" ino=4026531833 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:nsfs_t tclass=file permissive=1
[   77.197863][   T30] audit: type=1400 audit(1769023735.469:78): avc:  denied  { open } for  pid=5832 comm="syz-executor" path="net:[4026531833]" dev="nsfs" ino=4026531833 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:nsfs_t tclass=file permissive=1
[   77.256106][   T30] audit: type=1400 audit(1769023735.469:79): avc:  denied  { mounton } for  pid=5832 comm="syz-executor" path="/" dev="sda1" ino=2 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:root_t tclass=dir permissive=1
[   77.376461][   T30] audit: type=1400 audit(1769023735.749:80): avc:  denied  { mounton } for  pid=5832 comm="syz-executor" path="/root/syzkaller.ODDuwd/syz-tmp" dev="sda1" ino=2042 scontext=root:sysadm_r:sysadm_t tcontext=root:object_r:user_home_t tclass=dir permissive=1
[   77.426222][   T30] audit: type=1400 audit(1769023735.769:81): avc:  denied  { mount } for  pid=5832 comm="syz-executor" name="/" dev="tmpfs" ino=1 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:tmpfs_t tclass=filesystem permissive=1
[   77.455015][   T30] audit: type=1400 audit(1769023735.769:82): avc:  denied  { mounton } for  pid=5832 comm="syz-executor" path="/root/syzkaller.ODDuwd/syz-tmp/newroot/dev" dev="tmpfs" ino=3 scontext=root:sysadm_r:sysadm_t tcontext=root:object_r:user_tmpfs_t tclass=dir permissive=1
[   77.480585][   T30] audit: type=1400 audit(1769023735.769:83): avc:  denied  { mount } for  pid=5832 comm="syz-executor" name="/" dev="proc" ino=1 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:proc_t tclass=filesystem permissive=1
[   77.502555][   T30] audit: type=1400 audit(1769023735.779:84): avc:  denied  { mounton } for  pid=5832 comm="syz-executor" path="/root/syzkaller.ODDuwd/syz-tmp/newroot/sys/kernel/debug" dev="debugfs" ino=1 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:debugfs_t tclass=dir permissive=1
[   77.530216][   T30] audit: type=1400 audit(1769023735.779:85): avc:  denied  { mounton } for  pid=5832 comm="syz-executor" path="/root/syzkaller.ODDuwd/syz-tmp/newroot/proc/sys/fs/binfmt_misc" dev="proc" ino=4768 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:sysctl_fs_t tclass=dir permissive=1
[   77.582717][ T5832] soft_limit_in_bytes is deprecated and will be removed. Please report your usecase to linux-mm@...ck.org if you depend on this functionality.
[   78.317095][ T5137] Bluetooth: hci0: unexpected cc 0x0c03 length: 249 > 1
[   78.335937][ T5137] Bluetooth: hci0: unexpected cc 0x1003 length: 249 > 9
[   78.343994][ T5137] Bluetooth: hci0: unexpected cc 0x1001 length: 249 > 9
[   78.352415][ T5137] Bluetooth: hci0: unexpected cc 0x0c23 length: 249 > 4
[   78.359995][ T5137] Bluetooth: hci0: unexpected cc 0x0c38 length: 249 > 2
[   79.466468][   T60] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[   79.475648][   T60] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
[   79.626085][   T60] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[   79.633927][   T60] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
[   80.241478][ T5888] chnl_net:caif_netlink_parms(): no params data found
[   80.459107][ T5888] bridge0: port 1(bridge_slave_0) entered blocking state
[   80.470259][ T5888] bridge0: port 1(bridge_slave_0) entered disabled state
[   80.477785][ T5888] bridge_slave_0: entered allmulticast mode
[   80.484650][ T5888] bridge_slave_0: entered promiscuous mode
[   80.494287][ T5888] bridge0: port 2(bridge_slave_1) entered blocking state
[   80.501686][ T5888] bridge0: port 2(bridge_slave_1) entered disabled state
[   80.509461][ T5888] bridge_slave_1: entered allmulticast mode
[   80.516827][ T5888] bridge_slave_1: entered promiscuous mode
[   80.549445][ T5888] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[   80.562530][ T5888] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[   80.602734][ T5888] team0: Port device team_slave_0 added
[   80.611369][ T5888] team0: Port device team_slave_1 added
[   80.637661][ T5888] batman_adv: batadv0: Adding interface: batadv_slave_0
[   80.644602][ T5888] batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[   80.670855][ T5888] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[   80.685512][ T5888] batman_adv: batadv0: Adding interface: batadv_slave_1
[   80.692580][ T5888] batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[   80.719042][ T5888] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[   80.754334][ T5888] hsr_slave_0: entered promiscuous mode
[   80.760681][ T5888] hsr_slave_1: entered promiscuous mode
[   80.873414][ T5888] netdevsim netdevsim2 netdevsim0: renamed from eth0
[   80.885521][ T5888] netdevsim netdevsim2 netdevsim1: renamed from eth1
[   80.895484][ T5888] netdevsim netdevsim2 netdevsim2: renamed from eth2
[   80.905604][ T5888] netdevsim netdevsim2 netdevsim3: renamed from eth3
[   80.931341][ T5888] bridge0: port 2(bridge_slave_1) entered blocking state
[   80.938615][ T5888] bridge0: port 2(bridge_slave_1) entered forwarding state
[   80.947289][ T5888] bridge0: port 1(bridge_slave_0) entered blocking state
[   80.954444][ T5888] bridge0: port 1(bridge_slave_0) entered forwarding state
[   80.998830][ T5888] 8021q: adding VLAN 0 to HW filter on device bond0
[   81.015302][   T60] bridge0: port 1(bridge_slave_0) entered disabled state
[   81.024604][   T60] bridge0: port 2(bridge_slave_1) entered disabled state
[   81.041085][ T5888] 8021q: adding VLAN 0 to HW filter on device team0
[   81.052143][   T12] bridge0: port 1(bridge_slave_0) entered blocking state
[   81.059263][   T12] bridge0: port 1(bridge_slave_0) entered forwarding state
[   81.071460][   T60] bridge0: port 2(bridge_slave_1) entered blocking state
[   81.078564][   T60] bridge0: port 2(bridge_slave_1) entered forwarding state
[   81.211172][ T5888] 8021q: adding VLAN 0 to HW filter on device batadv0
[   81.248210][ T5888] veth0_vlan: entered promiscuous mode
[   81.259263][ T5888] veth1_vlan: entered promiscuous mode
[   81.283687][ T5888] veth0_macvtap: entered promiscuous mode
[   81.292476][ T5888] veth1_macvtap: entered promiscuous mode
[   81.308568][ T5888] batman_adv: batadv0: Interface activated: batadv_slave_0
[   81.321101][ T5888] batman_adv: batadv0: Interface activated: batadv_slave_1
[   81.336539][   T60] netdevsim netdevsim2 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[   81.348097][   T60] netdevsim netdevsim2 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[   81.357060][   T60] netdevsim netdevsim2 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[   81.367258][   T60] netdevsim netdevsim2 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
2026/01/21 19:28:59 executed programs: 0
[   81.507631][   T90] cfg80211: failed to load regulatory.db
[   81.536157][   T52] Bluetooth: hci0: unexpected cc 0x0c03 length: 249 > 1
[   81.544946][   T52] Bluetooth: hci0: unexpected cc 0x1003 length: 249 > 9
[   81.553349][   T52] Bluetooth: hci0: unexpected cc 0x1001 length: 249 > 9
[   81.564963][   T52] Bluetooth: hci0: unexpected cc 0x0c23 length: 249 > 4
[   81.584394][   T52] Bluetooth: hci0: unexpected cc 0x0c38 length: 249 > 2
[   81.880379][ T5930] chnl_net:caif_netlink_parms(): no params data found
[   81.938870][ T5930] bridge0: port 1(bridge_slave_0) entered blocking state
[   81.946021][ T5930] bridge0: port 1(bridge_slave_0) entered disabled state
[   81.953134][ T5930] bridge_slave_0: entered allmulticast mode
[   81.960371][ T5930] bridge_slave_0: entered promiscuous mode
[   81.969459][ T5930] bridge0: port 2(bridge_slave_1) entered blocking state
[   81.976697][ T5930] bridge0: port 2(bridge_slave_1) entered disabled state
[   81.983848][ T5930] bridge_slave_1: entered allmulticast mode
[   81.991570][ T5930] bridge_slave_1: entered promiscuous mode
[   82.025152][ T5930] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[   82.037968][ T5930] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[   82.063977][ T5930] team0: Port device team_slave_0 added
[   82.073260][ T5930] team0: Port device team_slave_1 added
[   82.096729][ T5930] batman_adv: batadv0: Adding interface: batadv_slave_0
[   82.103675][ T5930] batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[   82.129911][ T5930] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[   82.141687][ T5930] batman_adv: batadv0: Adding interface: batadv_slave_1
[   82.148881][ T5930] batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[   82.175166][ T5930] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[   82.213049][ T5930] hsr_slave_0: entered promiscuous mode
[   82.219381][ T5930] hsr_slave_1: entered promiscuous mode
[   82.225304][ T5930] debugfs: 'hsr0' already exists in 'hsr'
[   82.231462][ T5930] Cannot create hsr debugfs directory
[   82.338888][ T5930] netdevsim netdevsim0 netdevsim0: renamed from eth0
[   82.349132][ T5930] netdevsim netdevsim0 netdevsim1: renamed from eth1
[   82.359560][ T5930] netdevsim netdevsim0 netdevsim2: renamed from eth2
[   82.369490][ T5930] netdevsim netdevsim0 netdevsim3: renamed from eth3
[   82.431937][ T5930] 8021q: adding VLAN 0 to HW filter on device bond0
[   82.451444][ T5930] 8021q: adding VLAN 0 to HW filter on device team0
[   82.462384][   T60] bridge0: port 1(bridge_slave_0) entered blocking state
[   82.469488][   T60] bridge0: port 1(bridge_slave_0) entered forwarding state
[   82.488405][   T60] bridge0: port 2(bridge_slave_1) entered blocking state
[   82.495478][   T60] bridge0: port 2(bridge_slave_1) entered forwarding state
[   82.634014][ T5930] 8021q: adding VLAN 0 to HW filter on device batadv0
[   82.669589][ T5930] veth0_vlan: entered promiscuous mode
[   82.679859][ T5930] veth1_vlan: entered promiscuous mode
[   82.704326][ T5930] veth0_macvtap: entered promiscuous mode
[   82.715368][ T5930] veth1_macvtap: entered promiscuous mode
[   82.734887][ T5930] batman_adv: batadv0: Interface activated: batadv_slave_0
[   82.750652][ T5930] batman_adv: batadv0: Interface activated: batadv_slave_1
[   82.762618][   T60] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[   82.772242][   T60] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[   82.782190][   T60] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[   82.793148][   T60] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[   82.852368][   T12] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[   82.860711][   T12] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
[   82.885601][   T60] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[   82.893556][   T60] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
SYZFAIL: failed to recv rpc
[   83.392967][   T60] netdevsim netdevsim2 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0


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-build277648876=/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='go1.24.4'
GOWORK=''
PKG_CONFIG='pkg-config'

git status (err=<nil>)
HEAD detached at d6526ea3e6
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=d6526ea3e6ad9081c902859bbb80f9f840377cb4 -X github.com/google/syzkaller/prog.gitRevisionDate=20251126-113115"  ./sys/syz-sysgen | grep -q false || go install -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=d6526ea3e6ad9081c902859bbb80f9f840377cb4 -X github.com/google/syzkaller/prog.gitRevisionDate=20251126-113115"  ./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=d6526ea3e6ad9081c902859bbb80f9f840377cb4 -X github.com/google/syzkaller/prog.gitRevisionDate=20251126-113115"  -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=\"d6526ea3e6ad9081c902859bbb80f9f840377cb4\"
/usr/bin/ld: /tmp/cc0bwYtF.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=131087fc580000


Tested on:

commit:         994089e6 io_uring/io-wq: don't trigger hung task for s..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux.git syztest
kernel config:  https://syzkaller.appspot.com/x/.config?x=8f75eb998b5774eb
dashboard link: https://syzkaller.appspot.com/bug?extid=4eb282331cab6d5b6588
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44

Note: no patches were applied.

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