Re: [syzbot] [media?] [dri?] WARNING in udmabuf_create

[syzbot <syzbot+bfeed181d1ce9ec87a8f@syzkaller.appspotmail.com>]

Hello,

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

lost connection to test machine



Warning: Permanently added '10.128.0.238' (ED25519) to the list of known hosts.
[   97.786558][  T991] cfg80211: failed to load regulatory.db
2026/09/15 10:50:08 parsed 1 programs
2026/09/15 10:50:08 serving rpc on tcp://44173
[  102.370241][ T5634] cgroup: Unknown subsys name 'net'
[  102.510422][ T5634] cgroup: Unknown subsys name 'cpuset'
[  102.514396][ T5634] cgroup: Unknown subsys name 'rlimit'
Setting up swapspace version 1, size = 127995904 bytes
[  104.351724][ T5634] Adding 124996k swap on ./swap-file.  Priority:0 extents:1 across:124996k 
[  108.056785][ T5648] soft_limit_in_bytes is deprecated and will be removed. Writing any value to this file has no effect. Please report your usecase to linux-mm@kvack.org if you depend on this functionality.
[  108.062797][ T5648] ebtables: xtables 32bit compat interface no longer supported in namespaces and will be removed soon.
[  108.068861][ T5648] arp_tables: xtables 32bit compat interface no longer supported in namespaces and will be removed soon.
[  108.582737][ T4937] Bluetooth: hci0: unexpected cc 0x0c03 length: 249 > 1
[  108.583577][ T4937] Bluetooth: hci0: unexpected cc 0x1003 length: 249 > 9
[  108.584222][ T4937] Bluetooth: hci0: unexpected cc 0x1001 length: 249 > 9
[  108.585462][ T4937] Bluetooth: hci0: unexpected cc 0x0c23 length: 249 > 4
[  108.609300][ T4937] Bluetooth: hci0: unexpected cc 0x0c38 length: 249 > 2
[  109.734410][   T59] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[  109.734443][   T59] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
[  109.782322][ T1166] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[  109.782348][ T1166] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
[  110.483132][ T5676] ip_tables: xtables 32bit compat interface no longer supported in namespaces and will be removed soon.
[  110.483793][ T5676] ip6_tables: xtables 32bit compat interface no longer supported in namespaces and will be removed soon.
[  111.173280][ T5681] bridge0: port 1(bridge_slave_0) entered blocking state
[  111.174077][ T5681] bridge0: port 1(bridge_slave_0) entered disabled state
[  111.174210][ T5681] bridge_slave_0: entered allmulticast mode
[  111.180442][ T5681] bridge_slave_0: entered promiscuous mode
[  111.205644][ T5681] bridge0: port 2(bridge_slave_1) entered blocking state
[  111.205725][ T5681] bridge0: port 2(bridge_slave_1) entered disabled state
[  111.205839][ T5681] bridge_slave_1: entered allmulticast mode
[  111.207192][ T5681] bridge_slave_1: entered promiscuous mode
[  111.273019][ T5681] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[  111.284131][ T5681] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[  111.326721][ T5681] team0: Port device team_slave_0 added
[  111.329659][ T5681] team0: Port device team_slave_1 added
[  111.364079][ T5681] batman_adv: batadv0: Adding interface: batadv_slave_0
[  111.364095][ T5681] 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.
[  111.364120][ T5681] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[  111.371516][ T5681] batman_adv: batadv0: Adding interface: batadv_slave_1
[  111.371563][ T5681] 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.
[  111.371642][ T5681] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[  111.490683][ T5681] hsr_slave_0: entered promiscuous mode
[  111.491890][ T5681] hsr_slave_1: entered promiscuous mode
[  111.681668][ T5681] netdevsim netdevsim7 netdevsim0: renamed from eth0
[  111.695207][ T5681] 8021q: adding VLAN 0 to HW filter on device netdevsim0
[  111.698832][ T5681] netdevsim netdevsim7 netdevsim1: renamed from eth1
[  111.716309][ T5681] 8021q: adding VLAN 0 to HW filter on device netdevsim1
[  111.718026][ T5681] netdevsim netdevsim7 netdevsim2: renamed from eth2
[  111.721600][ T5681] 8021q: adding VLAN 0 to HW filter on device netdevsim2
[  111.722634][ T5681] netdevsim netdevsim7 netdevsim3: renamed from eth3
[  111.730316][ T5681] 8021q: adding VLAN 0 to HW filter on device netdevsim3
[  111.870717][ T5681] 8021q: adding VLAN 0 to HW filter on device bond0
[  111.897849][ T5681] 8021q: adding VLAN 0 to HW filter on device team0
[  111.905286][   T13] bridge0: port 1(bridge_slave_0) entered blocking state
[  111.905412][   T13] bridge0: port 1(bridge_slave_0) entered forwarding state
[  111.937788][ T1166] bridge0: port 2(bridge_slave_1) entered blocking state
[  111.937887][ T1166] bridge0: port 2(bridge_slave_1) entered forwarding state
[  112.340978][ T5681] 8021q: adding VLAN 0 to HW filter on device batadv0
[  112.604890][ T5681] veth0_vlan: entered promiscuous mode
[  112.619788][ T5681] veth1_vlan: entered promiscuous mode
[  112.660128][ T5681] veth0_macvtap: entered promiscuous mode
[  112.664268][ T5681] veth1_macvtap: entered promiscuous mode
[  112.695347][ T5681] batman_adv: batadv0: Interface activated: batadv_slave_0
[  112.714375][ T5681] batman_adv: batadv0: Interface activated: batadv_slave_1
[  112.748603][   T50] netdevsim netdevsim7 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[  112.748650][   T50] netdevsim netdevsim7 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[  112.748685][   T50] netdevsim netdevsim7 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[  112.748718][   T50] netdevsim netdevsim7 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[  112.882798][   T59] netdevsim netdevsim7 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[  112.981434][   T59] netdevsim netdevsim7 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[  113.059638][   T59] netdevsim netdevsim7 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[  113.129303][   T59] netdevsim netdevsim7 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[  114.003889][   T59] bridge_slave_1: left allmulticast mode
[  114.003941][   T59] bridge_slave_1: left promiscuous mode
[  114.005600][   T59] bridge0: port 2(bridge_slave_1) entered disabled state
[  114.040756][   T59] bridge_slave_0: left allmulticast mode
[  114.040789][   T59] bridge_slave_0: left promiscuous mode
[  114.042310][   T59] bridge0: port 1(bridge_slave_0) entered disabled state
[  114.373228][   T59] bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
[  114.391864][   T59] bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
[  114.394015][   T59] bond0 (unregistering): Released all slaves
[  114.560846][   T59] hsr_slave_0: left promiscuous mode
[  114.562142][   T59] hsr_slave_1: left promiscuous mode
[  114.563318][   T59] batman_adv: batadv0: Interface deactivated: batadv_slave_0
[  114.563353][   T59] batman_adv: batadv0: Removing interface: batadv_slave_0
[  114.565447][   T59] batman_adv: batadv0: Interface deactivated: batadv_slave_1
[  114.565470][   T59] batman_adv: batadv0: Removing interface: batadv_slave_1
[  114.626880][   T59] veth1_macvtap: left promiscuous mode
[  114.626941][   T59] veth0_macvtap: left promiscuous mode
[  114.627063][   T59] veth1_vlan: left promiscuous mode
[  114.627209][   T59] veth0_vlan: left promiscuous mode
[  114.939935][   T59] team0 (unregistering): Port device team_slave_1 removed
[  114.960914][   T59] team0 (unregistering): Port device team_slave_0 removed
[  115.141058][ T5283] 8021q: adding VLAN 0 to HW filter on device eth1
[  115.879786][ T5283] 8021q: adding VLAN 0 to HW filter on device eth2
[  116.704848][ T5283] 8021q: adding VLAN 0 to HW filter on device eth3
[  117.419422][ T5283] 8021q: adding VLAN 0 to HW filter on device eth4
execution of simple program fails: NOTFAIL: arptable checkpoint: getsockopt(ARPT_SO_GET_ENTRIES) failed. table=filter (errno 22: Invalid argument).
[  133.617311][ T1316] ieee802154 phy0 wpan0: encryption failed: -22
[  133.617371][ T1316] ieee802154 phy1 wpan1: encryption failed: -22


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-build3857553325=/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 85995287a88
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=85995287a888340d8818a8f3c43e2e89555eea21 -X github.com/google/syzkaller/prog.gitRevisionDate=20260902-115702"  ./sys/syz-sysgen | grep -q false || go install -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=85995287a888340d8818a8f3c43e2e89555eea21 -X github.com/google/syzkaller/prog.gitRevisionDate=20260902-115702"  ./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=85995287a888340d8818a8f3c43e2e89555eea21 -X github.com/google/syzkaller/prog.gitRevisionDate=20260902-115702"  -o ./bin/linux_amd64/syz-execprog github.com/google/syzkaller/tools/syz-execprog
mkdir -p ./bin/linux_386
x86_64-linux-gnu-g++ -o ./bin/linux_386/syz-executor executor/executor.cc \
	-m32 -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_386=1 \
	-DHOSTGOOS_linux=1 -DGIT_REVISION=\"85995287a888340d8818a8f3c43e2e89555eea21\"
/usr/bin/ld: /tmp/ccoD0zzS.o: in function `Connection::Connect(char const*, char const*)':
executor.cc:(.text._ZN10Connection7ConnectEPKcS1_[_ZN10Connection7ConnectEPKcS1_]+0x145): 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
[INFO] Unsupported architecture '386', skipping check.



Tested on:

commit:         0d2c6557 dma-buf: udmabuf: cap page count to allocatio..
git tree:       https://github.com/yutao-intel/linux.git fix-dri-udmabuf_create
kernel config:  https://syzkaller.appspot.com/x/.config?x=5e4e3a0e188a497e
dashboard link: https://syzkaller.appspot.com/bug?extid=bfeed181d1ce9ec87a8f
compiler:       Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
userspace arch: i386

Note: no patches were applied.