Message-ID: <6901bd54.050a0220.3344a1.0412.GAE@google.com>
Date: Wed, 29 Oct 2025 00:08:04 -0700
From: syzbot <syzbot+fd8af97c7227fe605d95@...kaller.appspotmail.com>
To: dmantipov@...dex.ru, linux-kernel@...r.kernel.org, 
	syzkaller-bugs@...glegroups.com
Subject: Re: [syzbot] [ocfs2?] divide error in ocfs2_block_group_fill (3)

Hello,

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

NGE): bond0: link becomes ready
[   67.659882][ T3025] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
[   67.668876][ T3025] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
[   67.678299][ T5618] 8021q: adding VLAN 0 to HW filter on device team0
[   67.696904][ T3025] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready
[   67.706412][ T3025] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready
[   67.713355][ T3025] bridge0: port 1(bridge_slave_0) entered blocking state
[   67.719917][ T3025] bridge0: port 1(bridge_slave_0) entered forwarding state
[   67.737997][ T3025] IPv6: ADDRCONF(NETDEV_CHANGE): bridge0: link becomes ready
[   67.746170][ T3025] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready
[   67.753255][ T3025] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready
[   67.761424][ T3025] bridge0: port 2(bridge_slave_1) entered blocking state
[   67.767981][ T3025] bridge0: port 2(bridge_slave_1) entered forwarding state
[   67.776501][ T3025] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready
[   67.789834][ T5618] hsr0: Slave A (hsr_slave_0) is not up; please bring it up to get a fully working HSR network
[   67.801676][ T5618] hsr0: Slave B (hsr_slave_1) is not up; please bring it up to get a fully working HSR network
[   67.811910][ T3025] IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready
[   67.819404][ T3025] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready
[   67.826626][ T3025] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready
[   67.833692][ T3025] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready
[   67.844888][ T3025] IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready
[   67.896486][ T3027] IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready
[   67.902785][ T3027] IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready
[   67.913137][ T5618] 8021q: adding VLAN 0 to HW filter on device batadv0
[   67.926115][ T3027] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready
[   67.939812][ T5618] device veth0_vlan entered promiscuous mode
[   67.946170][ T3027] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready
[   67.953459][ T3027] IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready
[   67.960715][ T3027] IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready
[   67.970061][ T5618] device veth1_vlan entered promiscuous mode
[   67.976977][ T3027] IPv6: ADDRCONF(NETDEV_CHANGE): macvlan0: link becomes ready
[   67.992070][ T5618] device veth0_macvtap entered promiscuous mode
[   67.998994][ T3027] IPv6: ADDRCONF(NETDEV_CHANGE): macvlan1: link becomes ready
[   68.006989][ T3027] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready
[   68.014090][ T3027] IPv6: ADDRCONF(NETDEV_CHANGE): macvtap0: link becomes ready
[   68.022742][ T5618] device veth1_macvtap entered promiscuous mode
[   68.035409][ T5618] batman_adv: batadv0: Interface activated: batadv_slave_0
[   68.042220][ T3027] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready
[   68.052325][ T5618] batman_adv: batadv0: Interface activated: batadv_slave_1
[   68.060379][ T3027] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
[   68.069464][ T5618] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[   68.077570][ T5618] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[   68.087228][ T5618] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[   68.094986][ T5618] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[   68.108021][ T3027] ================================================================================
[   68.115942][ T3027] UBSAN: signed-integer-overflow in ./arch/x86/include/asm/atomic.h:165:11
[   68.123034][ T3027] 1282323313 + 2084770655 cannot be represented in type 'int'
[   68.130978][ T3027] CPU: 0 PID: 3027 Comm: kworker/u2:5 Not tainted syzkaller #0
[   68.137549][ T3027] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
[   68.146666][ T3027] Workqueue: wg-kex-wg0 wg_packet_handshake_send_worker
[   68.152603][ T3027] Call Trace:
[   68.155328][ T3027]  dump_stack+0xfd/0x16e
[   68.158916][ T3027]  ubsan_epilogue+0xa/0x30
[   68.162641][ T3027]  handle_overflow+0x192/0x1b0
[   68.166622][ T3027]  ? prandom_u32+0x217/0x260
[   68.170495][ T3027]  ip_idents_reserve+0x14a/0x170
[   68.174600][ T3027]  __ip_select_ident+0xe4/0x1c0
[   68.178693][ T3027]  iptunnel_xmit+0x468/0x850
[   68.182482][ T3027]  udp_tunnel_xmit_skb+0x1ba/0x290
[   68.186731][ T3027]  send4+0x5d4/0xaf0
[   68.189985][ T3027]  wg_socket_send_skb_to_peer+0xcd/0x1c0
[   68.194732][ T3027]  wg_packet_handshake_send_worker+0x16b/0x280
[   68.200781][ T3027]  process_one_work+0x85e/0xff0
[   68.204929][ T3027]  worker_thread+0xa9b/0x1430
[   68.208868][ T3027]  ? rcu_lock_release+0x20/0x20
[   68.212846][ T3027]  kthread+0x386/0x410
[   68.216206][ T3027]  ? rcu_lock_release+0x20/0x20
[   68.220336][ T3027]  ? kthread_blkcg+0xd0/0xd0
[   68.224057][ T3027]  ret_from_fork+0x1f/0x30
[   68.227707][ T3027] ================================================================================
[   68.235718][ T3027] Kernel panic - not syncing: UBSAN: panic_on_warn set ...
[   68.242148][ T3027] CPU: 0 PID: 3027 Comm: kworker/u2:5 Not tainted syzkaller #0
[   68.248871][ T3027] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
[   68.258217][ T3027] Workqueue: wg-kex-wg0 wg_packet_handshake_send_worker
[   68.264036][ T3027] Call Trace:
[   68.266727][ T3027]  dump_stack+0xfd/0x16e
[   68.270510][ T3027]  panic+0x2f0/0x9c0
[   68.273874][ T3027]  check_panic_on_warn+0x95/0xe0
[   68.277943][ T3027]  handle_overflow+0x192/0x1b0
[   68.281940][ T3027]  ? prandom_u32+0x217/0x260
[   68.285754][ T3027]  ip_idents_reserve+0x14a/0x170
[   68.289821][ T3027]  __ip_select_ident+0xe4/0x1c0
[   68.293511][ T3027]  iptunnel_xmit+0x468/0x850
[   68.297020][ T3027]  udp_tunnel_xmit_skb+0x1ba/0x290
[   68.301331][ T3027]  send4+0x5d4/0xaf0
[   68.304697][ T3027]  wg_socket_send_skb_to_peer+0xcd/0x1c0
[   68.309587][ T3027]  wg_packet_handshake_send_worker+0x16b/0x280
[   68.314737][ T3027]  process_one_work+0x85e/0xff0
[   68.318718][ T3027]  worker_thread+0xa9b/0x1430
[   68.322372][ T3027]  ? rcu_lock_release+0x20/0x20
[   68.326207][ T3027]  kthread+0x386/0x410
[   68.329499][ T3027]  ? rcu_lock_release+0x20/0x20
[   68.333489][ T3027]  ? kthread_blkcg+0xd0/0xd0
[   68.337061][ T3027]  ret_from_fork+0x1f/0x30
[   68.340939][ T3027] Kernel Offset: disabled
[   68.344406][ T3027] Rebooting in 86400 seconds..

VM DIAGNOSIS:
07:07:22  Registers:
info registers vcpu 0

CPU#0
RAX=1ffffffff2c32060 RBX=00000000000003fd RCX=0000000000000000 RDX=00000000000003fd
RSI=0000000000000000 RDI=0000000000000020 RBP=0000000000000020 RSP=ffffc90000a1f488
R8 =dffffc0000000000 R9 =fffff52000143e9e R10=fffff52000143e9e R11=ffffffff83f95e70
R12=dffffc0000000000 R13=1ffffffff2ad4c63 R14=ffffffff961903c0 R15=0000000000000000
RIP=ffffffff83f95ee3 RFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0000 0000000000000000 ffffffff 00c00000
CS =0010 0000000000000000 ffffffff 00a09b00 DPL=0 CS64 [-RA]
SS =0018 0000000000000000 ffffffff 00c09300 DPL=0 DS   [-WA]
DS =0000 0000000000000000 ffffffff 00c00000
FS =0000 0000000000000000 ffffffff 00c00000
GS =0000 ffff888020600000 ffffffff 00c00000
LDT=0000 0000000000000000 ffffffff 00c00000
TR =0040 fffffe0000003000 00004087 00008b00 DPL=0 TSS64-busy
GDT=     fffffe0000001000 0000007f
IDT=     fffffe0000000000 00000fff
CR0=80050033 CR2=00007fc76d01b6b0 CR3=000000003bbb8000 CR4=00350ef0
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 
DR6=00000000fffe0ff0 DR7=0000000000000400
EFER=0000000000000d01
FCW=037f FSW=0000 [ST=0] FTW=00 MXCSR=00001f80
FPR0=0000000000000000 0000 FPR1=0000000000000000 0000
FPR2=0000000000000000 0000 FPR3=0000000000000000 0000
FPR4=0000000000000000 0000 FPR5=0000000000000000 0000
FPR6=0000000000000000 0000 FPR7=0000000000000000 0000
Opmask00=0000000040410888 Opmask01=0000000000000fff Opmask02=00000000ffffffef Opmask03=0000000000000000
Opmask04=0000000000000000 Opmask05=0000000000000000 Opmask06=0000000000000000 Opmask07=0000000000000000
ZMM00=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 4fbe43ac9f8dee1f 13ce8330a1ae1a97
ZMM01=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 72ec250c5763c9fd 529fd701c037efee
ZMM02=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 c1f3a78accefb53d 505a38d2fce3eab4
ZMM03=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 5c4df8ddb4770ea3 dbe5344bbf7daa56
ZMM04=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 00000000ffffffff 00000000000000b4
ZMM05=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000034
ZMM06=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 a077df95440950b9 0c00cc7265aa82be
ZMM07=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 d81ebb973342967d 0000000000000000
ZMM08=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 8efeaa65cdb9a13e d150fd9eae3be657
ZMM09=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 ddc10fdc00000000 e4660e17edb0aedd
ZMM10=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 a0e979bdc8075c8b a5c0b2d4b44f4d4b
ZMM11=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 345505ce4c1a3a43 40c8945a3b014bfb
ZMM12=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000
ZMM13=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000
ZMM14=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 a54ff53a3c6ef372 bb67ae856a09e667
ZMM15=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 5be0cd191f83d9ab 9b05688c510e527f
ZMM16=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000
ZMM17=0000000000000000 0000000000000000 0000000000000000 0000000000000000 2525252525252525 2525252525252525 2525252525252525 2525252525252525
ZMM18=0000000000000000 0000000000000000 0000000000000000 0000000000000000 00306e6170737265 0030657267367069 00306c6e74367069 00306974765f3670
ZMM19=0000000000000000 0000000000000000 0000000000000000 0000000000000000 6900306974765f70 6900306c6e757400 3074697300326777 0031677700306777
ZMM20=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000
ZMM21=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000
ZMM22=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000
ZMM23=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000
ZMM24=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000
ZMM25=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000
ZMM26=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000
ZMM27=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000
ZMM28=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000
ZMM29=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000
ZMM30=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000
ZMM31=0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000


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-build2361257849=/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 c0460fcde70
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=c0460fcde7051a8d07612ec2a17718d3c3019bb0 -X github.com/google/syzkaller/prog.gitRevisionDate=20251022-142038"  ./sys/syz-sysgen | grep -q false || go install -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=c0460fcde7051a8d07612ec2a17718d3c3019bb0 -X github.com/google/syzkaller/prog.gitRevisionDate=20251022-142038"  ./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=c0460fcde7051a8d07612ec2a17718d3c3019bb0 -X github.com/google/syzkaller/prog.gitRevisionDate=20251022-142038"  -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=\"c0460fcde7051a8d07612ec2a17718d3c3019bb0\"
/usr/bin/ld: /tmp/ccCE9RT8.o: in function `Connection::Connect(char const*, char const*)':
executor.cc:(.text._ZN10Connection7ConnectEPKcS1_[_ZN10Connection7ConnectEPKcS1_]+0x104): 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=102fc32f980000


Tested on:

commit:         d3d0b4e2 Linux 5.10.245
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git linux-5.10.y
kernel config:  https://syzkaller.appspot.com/x/.config?x=7686d7adbdbe480
dashboard link: https://syzkaller.appspot.com/bug?extid=fd8af97c7227fe605d95
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=123a9932580000

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