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

[syzbot]

Hello,

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

SYZFAIL: failed to recv rpc

SYZFAIL: failed to recv rpc
fd=3 want=4 recv=0 n=0 (errno 9: Bad file descriptor)
execution of simple program fails: NOTFAIL: arptable checkpoint: getsockopt(ARPT_SO_GET_ENTRIES) failed. table=filter (errno 22: Invalid argument).


no interfaces have a carrier
[   83.165290][ T5279] 8021q: adding VLAN 0 to HW filter on device bond0
[   83.176651][ T5279] eql: remember to turn off Van-Jacobson compression on your slave devices
Starting crond: OK
Starting sshd: OK

syzkaller
syzkaller login: [  114.243158][    T9] cfg80211: failed to load regulatory.db
Warning: Permanently added '10.128.0.233' (ED25519) to the list of known hosts.
2026/09/16 05:37:24 parsed 1 programs
2026/09/16 05:37:24 serving rpc on tcp://37581
[  121.891431][ T5631] cgroup: Unknown subsys name 'net'
[  122.014742][ T5631] cgroup: Unknown subsys name 'cpuset'
[  122.024234][ T5631] cgroup: Unknown subsys name 'rlimit'
Setting up swapspace version 1, size = 127995904 bytes
[  123.962440][ T5631] Adding 124996k swap on ./swap-file.  Priority:0 extents:1 across:124996k 
[  128.498958][ T5644] 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@xxxxxxxxx if you depend on this functionality.
[  128.521252][ T5644] ebtables: xtables 32bit compat interface no longer supported in namespaces and will be removed soon.
[  128.524188][ T5644] arp_tables: xtables 32bit compat interface no longer supported in namespaces and will be removed soon.
[  129.376802][ T5653] ip_tables: xtables 32bit compat interface no longer supported in namespaces and will be removed soon.
[  129.377579][ T5653] ip6_tables: xtables 32bit compat interface no longer supported in namespaces and will be removed soon.
[  129.514072][ T5659] Bluetooth: hci0: unexpected cc 0x0c03 length: 249 > 1
[  129.514855][ T5659] Bluetooth: hci0: unexpected cc 0x1003 length: 249 > 9
[  129.515648][ T5659] Bluetooth: hci0: unexpected cc 0x1001 length: 249 > 9
[  129.516637][ T5659] Bluetooth: hci0: unexpected cc 0x0c23 length: 249 > 4
[  129.517407][ T5659] Bluetooth: hci0: unexpected cc 0x0c38 length: 249 > 2
[  130.480696][   T45] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[  130.480735][   T45] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
[  130.543973][   T59] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[  130.543998][   T59] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
[  132.024638][ T5677] bridge0: port 1(bridge_slave_0) entered blocking state
[  132.025532][ T5677] bridge0: port 1(bridge_slave_0) entered disabled state
[  132.025672][ T5677] bridge_slave_0: entered allmulticast mode
[  132.027949][ T5677] bridge_slave_0: entered promiscuous mode
[  132.076170][ T5677] bridge0: port 2(bridge_slave_1) entered blocking state
[  132.076834][ T5677] bridge0: port 2(bridge_slave_1) entered disabled state
[  132.077022][ T5677] bridge_slave_1: entered allmulticast mode
[  132.102933][ T5677] bridge_slave_1: entered promiscuous mode
[  132.174547][ T5677] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[  132.187486][ T5677] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[  132.250540][ T5677] team0: Port device team_slave_0 added
[  132.254042][ T5677] team0: Port device team_slave_1 added
[  132.300085][ T5677] batman_adv: batadv0: Adding interface: batadv_slave_0
[  132.300106][ T5677] 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.
[  132.300139][ T5677] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[  132.303509][ T5677] batman_adv: batadv0: Adding interface: batadv_slave_1
[  132.303529][ T5677] 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.
[  132.303640][ T5677] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[  132.507651][ T5677] hsr_slave_0: entered promiscuous mode
[  132.509065][ T5677] hsr_slave_1: entered promiscuous mode
[  132.809314][ T5677] netdevsim netdevsim7 netdevsim0: renamed from eth0
[  132.845685][ T5677] 8021q: adding VLAN 0 to HW filter on device netdevsim0
[  132.847749][ T5677] netdevsim netdevsim7 netdevsim1: renamed from eth1
[  132.874511][ T5677] 8021q: adding VLAN 0 to HW filter on device netdevsim1
[  132.876090][ T5677] netdevsim netdevsim7 netdevsim2: renamed from eth2
[  132.884908][ T5677] 8021q: adding VLAN 0 to HW filter on device netdevsim2
[  132.887927][ T5677] netdevsim netdevsim7 netdevsim3: renamed from eth3
[  132.915834][ T5677] 8021q: adding VLAN 0 to HW filter on device netdevsim3
[  133.036266][ T5677] 8021q: adding VLAN 0 to HW filter on device bond0
[  133.070741][ T5677] 8021q: adding VLAN 0 to HW filter on device team0
[  133.079036][ T2225] bridge0: port 1(bridge_slave_0) entered blocking state
[  133.079162][ T2225] bridge0: port 1(bridge_slave_0) entered forwarding state
[  133.126108][   T45] bridge0: port 2(bridge_slave_1) entered blocking state
[  133.126199][   T45] bridge0: port 2(bridge_slave_1) entered forwarding state
[  133.813277][ T5677] 8021q: adding VLAN 0 to HW filter on device batadv0
[  134.186699][ T5677] veth0_vlan: entered promiscuous mode
[  134.207669][ T5677] veth1_vlan: entered promiscuous mode
[  134.293216][ T5677] veth0_macvtap: entered promiscuous mode
[  134.311660][ T5677] veth1_macvtap: entered promiscuous mode
[  134.349115][ T5677] batman_adv: batadv0: Interface activated: batadv_slave_0
[  134.379343][ T5677] batman_adv: batadv0: Interface activated: batadv_slave_1
[  134.492045][   T62] netdevsim netdevsim7 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[  134.551786][ T2225] netdevsim netdevsim7 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[  134.552284][ T2225] netdevsim netdevsim7 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[  134.620447][   T62] netdevsim netdevsim7 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[  134.799248][   T59] netdevsim netdevsim7 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[  135.874694][   T59] netdevsim netdevsim7 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
SYZFAIL: failed to recv rpc
fd=3 want=4 recv=0 n=0 (errno 9: Bad file descriptor)
execution of simple program fails: NOTFAIL: arptable checkpoint: getsockopt(ARPT_SO_GET_ENTRIES) failed. table=filter (errno 22: Invalid argument).
[  136.855213][   T59] netdevsim netdevsim7 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[  136.952225][   T59] netdevsim netdevsim7 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[  137.224278][   T59] bridge_slave_1: left allmulticast mode
[  137.224334][   T59] bridge_slave_1: left promiscuous mode
[  137.226112][   T59] bridge0: port 2(bridge_slave_1) entered disabled state
[  137.275171][   T59] bridge_slave_0: left allmulticast mode
[  137.275201][   T59] bridge_slave_0: left promiscuous mode
[  137.275530][   T59] bridge0: port 1(bridge_slave_0) entered disabled state
[  137.665003][   T59] bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
[  137.680748][   T59] bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
[  137.682596][   T59] bond0 (unregistering): Released all slaves
[  137.832212][   T59] hsr_slave_0: left promiscuous mode
[  137.832917][   T59] hsr_slave_1: left promiscuous mode
[  137.833650][   T59] batman_adv: batadv0: Interface deactivated: batadv_slave_0
[  137.833676][   T59] batman_adv: batadv0: Removing interface: batadv_slave_0
[  137.836225][   T59] batman_adv: batadv0: Interface deactivated: batadv_slave_1
[  137.836252][   T59] batman_adv: batadv0: Removing interface: batadv_slave_1
[  137.888093][   T59] veth1_macvtap: left promiscuous mode
[  137.888147][   T59] veth0_macvtap: left promiscuous mode
[  137.888227][   T59] veth1_vlan: left promiscuous mode
[  137.888334][   T59] veth0_vlan: left promiscuous mode
[  138.251598][   T59] team0 (unregistering): Port device team_slave_1 removed
[  138.291619][   T59] team0 (unregistering): Port device team_slave_0 removed
[  138.436400][ T5279] 8021q: adding VLAN 0 to HW filter on device eth1
[  139.193435][ T5279] 8021q: adding VLAN 0 to HW filter on device eth2
[  139.758608][ T5279] 8021q: adding VLAN 0 to HW filter on device eth3
[  139.843453][ T1313] ieee802154 phy0 wpan0: encryption failed: -22
[  139.843541][ T1313] ieee802154 phy1 wpan1: encryption failed: -22
[  140.207942][ T5279] 8021q: adding VLAN 0 to HW filter on device eth4


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-build264506101=/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/cc3OdTDn.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:         e7c98468 udmabuf: cap page count to allocation-safe li..
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.