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:

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).


Warning: Permanently added '10.128.1.174' (ED25519) to the list of known hosts.
2026/09/15 11:39:16 parsed 1 programs
2026/09/15 11:39:16 serving rpc on tcp://40329
[  164.032451][ T5644] cgroup: Unknown subsys name 'net'
[  164.136368][ T5644] cgroup: Unknown subsys name 'cpuset'
[  164.141195][ T5644] cgroup: Unknown subsys name 'rlimit'
Setting up swapspace version 1, size = 127995904 bytes
[  166.199670][ T5644] Adding 124996k swap on ./swap-file.  Priority:0 extents:1 across:124996k 
[  170.039756][ T5655] 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.
[  170.066765][ T5655] ebtables: xtables 32bit compat interface no longer supported in namespaces and will be removed soon.
[  170.069747][ T5655] arp_tables: xtables 32bit compat interface no longer supported in namespaces and will be removed soon.
[  170.748703][ T4936] Bluetooth: hci0: unexpected cc 0x0c03 length: 249 > 1
[  170.750332][ T4936] Bluetooth: hci0: unexpected cc 0x1003 length: 249 > 9
[  170.751133][ T4936] Bluetooth: hci0: unexpected cc 0x1001 length: 249 > 9
[  170.794058][ T4936] Bluetooth: hci0: unexpected cc 0x0c23 length: 249 > 4
[  170.795173][ T4936] Bluetooth: hci0: unexpected cc 0x0c38 length: 249 > 2
[  172.618702][   T13] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[  172.618731][   T13] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
[  172.704043][   T49] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[  172.704068][   T49] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
[  173.936465][ T5688] ip_tables: xtables 32bit compat interface no longer supported in namespaces and will be removed soon.
[  173.937304][ T5688] ip6_tables: xtables 32bit compat interface no longer supported in namespaces and will be removed soon.
[  174.893786][ T5695] bridge0: port 1(bridge_slave_0) entered blocking state
[  174.894352][ T5695] bridge0: port 1(bridge_slave_0) entered disabled state
[  174.894468][ T5695] bridge_slave_0: entered allmulticast mode
[  174.895993][ T5695] bridge_slave_0: entered promiscuous mode
[  174.909520][ T5695] bridge0: port 2(bridge_slave_1) entered blocking state
[  174.910196][ T5695] bridge0: port 2(bridge_slave_1) entered disabled state
[  174.910684][ T5695] bridge_slave_1: entered allmulticast mode
[  174.917803][ T5695] bridge_slave_1: entered promiscuous mode
[  174.988942][ T5695] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[  175.003307][ T5695] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[  175.039371][ T5695] team0: Port device team_slave_0 added
[  175.048961][ T5695] team0: Port device team_slave_1 added
[  175.079853][ T5695] batman_adv: batadv0: Adding interface: batadv_slave_0
[  175.079869][ T5695] 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.
[  175.079894][ T5695] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[  175.089178][ T5695] batman_adv: batadv0: Adding interface: batadv_slave_1
[  175.089247][ T5695] 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.
[  175.089313][ T5695] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[  175.219468][ T5695] hsr_slave_0: entered promiscuous mode
[  175.220866][ T5695] hsr_slave_1: entered promiscuous mode
[  175.462685][ T5695] netdevsim netdevsim8 netdevsim0: renamed from eth0
[  175.475140][ T5695] 8021q: adding VLAN 0 to HW filter on device netdevsim0
[  175.479413][ T5695] netdevsim netdevsim8 netdevsim1: renamed from eth1
[  175.504861][ T5695] 8021q: adding VLAN 0 to HW filter on device netdevsim1
[  175.505847][ T5695] netdevsim netdevsim8 netdevsim2: renamed from eth2
[  175.509981][ T5695] 8021q: adding VLAN 0 to HW filter on device netdevsim2
[  175.538865][ T5695] netdevsim netdevsim8 netdevsim3: renamed from eth3
[  175.550904][ T5695] 8021q: adding VLAN 0 to HW filter on device netdevsim3
[  175.596778][ T5695] bridge0: port 2(bridge_slave_1) entered blocking state
[  175.596992][ T5695] bridge0: port 2(bridge_slave_1) entered forwarding state
[  175.597537][ T5695] bridge0: port 1(bridge_slave_0) entered blocking state
[  175.597930][ T5695] bridge0: port 1(bridge_slave_0) entered forwarding state
[  175.709168][ T5695] 8021q: adding VLAN 0 to HW filter on device bond0
[  175.736293][   T49] bridge0: port 1(bridge_slave_0) entered disabled state
[  175.737639][   T49] bridge0: port 2(bridge_slave_1) entered disabled state
[  175.774915][ T5695] 8021q: adding VLAN 0 to HW filter on device team0
[  175.793556][ T1127] bridge0: port 1(bridge_slave_0) entered blocking state
[  175.793704][ T1127] bridge0: port 1(bridge_slave_0) entered forwarding state
[  175.826576][ T1127] bridge0: port 2(bridge_slave_1) entered blocking state
[  175.826677][ T1127] bridge0: port 2(bridge_slave_1) entered forwarding state
[  176.299025][ T5695] 8021q: adding VLAN 0 to HW filter on device batadv0
[  176.565305][ T5695] veth0_vlan: entered promiscuous mode
[  176.585921][ T5695] veth1_vlan: entered promiscuous mode
[  176.650471][ T5695] veth0_macvtap: entered promiscuous mode
[  176.669091][ T5695] veth1_macvtap: entered promiscuous mode
[  176.700205][ T5695] batman_adv: batadv0: Interface activated: batadv_slave_0
[  176.721025][ T5695] batman_adv: batadv0: Interface activated: batadv_slave_1
[  176.822810][   T13] netdevsim netdevsim8 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[  176.822864][   T13] netdevsim netdevsim8 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[  176.822902][   T13] netdevsim netdevsim8 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[  176.822938][   T13] netdevsim netdevsim8 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[  176.927812][ T1127] netdevsim netdevsim8 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[  177.042283][ T1127] netdevsim netdevsim8 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[  177.748476][ T1127] netdevsim netdevsim8 netdevsim1 (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).
[  178.374034][ T1127] netdevsim netdevsim8 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[  179.252590][ T1127] bridge_slave_1: left allmulticast mode
[  179.252632][ T1127] bridge_slave_1: left promiscuous mode
[  179.253798][ T1127] bridge0: port 2(bridge_slave_1) entered disabled state
[  179.257783][ T1127] bridge_slave_0: left allmulticast mode
[  179.257805][ T1127] bridge_slave_0: left promiscuous mode
[  179.259188][ T1127] bridge0: port 1(bridge_slave_0) entered disabled state
[  179.468567][ T1127] bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
[  179.483504][ T1127] bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
[  179.485895][ T1127] bond0 (unregistering): Released all slaves
[  179.611377][ T1127] hsr_slave_0: left promiscuous mode
[  179.613582][ T1127] hsr_slave_1: left promiscuous mode
[  179.614734][ T1127] batman_adv: batadv0: Interface deactivated: batadv_slave_0
[  179.614773][ T1127] batman_adv: batadv0: Removing interface: batadv_slave_0
[  179.618745][ T1127] batman_adv: batadv0: Interface deactivated: batadv_slave_1
[  179.618773][ T1127] batman_adv: batadv0: Removing interface: batadv_slave_1
[  179.685609][ T1127] veth1_macvtap: left promiscuous mode
[  179.685678][ T1127] veth0_macvtap: left promiscuous mode
[  179.685913][ T1127] veth1_vlan: left promiscuous mode
[  179.686015][ T1127] veth0_vlan: left promiscuous mode
[  180.098022][ T1127] team0 (unregistering): Port device team_slave_1 removed
[  180.130421][ T1127] team0 (unregistering): Port device team_slave_0 removed
[  180.315425][ T5281] 8021q: adding VLAN 0 to HW filter on device eth1
[  181.056031][ T5281] 8021q: adding VLAN 0 to HW filter on device eth2
[  181.813895][ T5281] 8021q: adding VLAN 0 to HW filter on device eth4
[  182.339157][ T5281] 8021q: adding VLAN 0 to HW filter on device eth3


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-build429373818=/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='go1.26.0'
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/cch4vc37.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.