Re: [syzbot] [v9fs?] KMSAN: uninit-value in v9fs_evict_inode

From: syzbot
Date: Wed Mar 20 2024 - 01:31:12 EST

Hello,

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

can't ssh into the instance



failed to run ["ssh" "-p" "22" "-F" "/dev/null" "-o" "UserKnownHostsFile=/dev/null" "-o" "IdentitiesOnly=yes" "-o" "BatchMode=yes" "-o" "StrictHostKeyChecking=no" "-o" "ConnectTimeout=10" "root@10.128.1.150" "pwd"]: exit status 255
ssh: connect to host 10.128.1.150 port 22: Connection timed out
Pseudo-terminal will not be allocated because stdin is not a terminal.
Warning: Permanently added '[us-central1-ssh-serialport.googleapis.com]:9600' (RSA) to the list of known hosts.
SeaBIOS (version 1.8.2-google)
Total RAM Size = 0x0000000200000000 = 8192 MiB
CPUs found: 2 Max CPUs supported: 2
SeaBIOS (version 1.8.2-google)
Machine UUID 98244c28-997c-d970-fe51-cafe56332c7d
found virtio-scsi at 0:3
virtio-scsi vendor='Google' product='PersistentDisk' rev='1' type=0 removable=0
virtio-scsi blksize=512 sectors=4194304 = 2048 MiB
drive 0x000f27c0: PCHS=0/0/0 translation=lba LCHS=520/128/63 s=4194304
Sending Seabios boot VM event.
Booting from Hard Disk 0...
[ 0.000000][ T0] Linux version 6.8.0-rc1-syzkaller-00012-g22ffa13a3c01 (syzkaller@syzkaller) (Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40) #0 SMP PREEMPT_DYNAMIC now
[ 0.000000][ T0] Command line: BOOT_IMAGE=/boot/bzImage root=/dev/sda1 console=ttyS0
[ 0.000000][ T0] KERNEL supported cpus:
[ 0.000000][ T0] Intel GenuineIntel
[ 0.000000][ T0] AMD AuthenticAMD
[ 0.000000][ T0] BIOS-provided physical RAM map:
[ 0.000000][ T0] BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable
[ 0.000000][ T0] BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved
[ 0.000000][ T0] BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff] reserved
[ 0.000000][ T0] BIOS-e820: [mem 0x0000000000100000-0x00000000bfffcfff] usable
[ 0.000000][ T0] BIOS-e820: [mem 0x00000000bfffd000-0x00000000bfffffff] reserved
[ 0.000000][ T0] BIOS-e820: [mem 0x00000000fffbc000-0x00000000ffffffff] reserved
[ 0.000000][ T0] BIOS-e820: [mem 0x0000000100000000-0x000000023fffffff] usable
[ 0.000000][ T0] printk: legacy bootconsole [earlyser0] enabled
[ 0.000000][ T0] ERROR: earlyprintk= earlyser already used
[ 0.000000][ T0] ERROR: earlyprintk= earlyser already used
[ 0.000000][ T0] **********************************************************
[ 0.000000][ T0] ** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **
[ 0.000000][ T0] ** **
[ 0.000000][ T0] ** This system shows unhashed kernel memory addresses **
[ 0.000000][ T0] ** via the console, logs, and other interfaces. This **
[ 0.000000][ T0] ** might reduce the security of your system. **
[ 0.000000][ T0] ** **
[ 0.000000][ T0] ** If you see this message and you are not debugging **
[ 0.000000][ T0] ** the kernel, report this immediately to your system **
[ 0.000000][ T0] ** administrator! **
[ 0.000000][ T0] ** **
[ 0.000000][ T0] ** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **
[ 0.000000][ T0] **********************************************************
[ 0.000000][ T0] Malformed early option 'vsyscall'
[ 0.000000][ T0] nopcid: PCID feature disabled
[ 0.000000][ T0] NX (Execute Disable) protection: active
[ 0.000000][ T0] APIC: serialport: Connected to syzkaller.us-central1-c.ci-upstream-kmsan-gce-root-test-job-parallel-2 port 1 (session ID: e82a3602d26a155e10b97c8dc3c12b799a7d6f28c67e66690b6dd1b4d8c33ae3, active connections: 1).
Static calls initialized
[ 0.000000][ T0] SMBIOS 2.4 present.
[ 0.000000][ T0] DMI: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
[ 0.000000][ T0] Hypervisor detected: KVM
[ 0.000000][ T0] kvm-clock: Using msrs 4b564d01 and 4b564d00
[ 0.000006][ T0] kvm-clock: using sched offset of 5937164965 cycles
[ 0.001237][ T0] clocksource: kvm-clock: mask: 0xffffffffffffffff max_cycles: 0x1cd42e4dffb, max_idle_ns: 881590591483 ns
[ 0.004814][ T0] tsc: Detected 2200.220 MHz processor
[ 0.014663][ T0] last_pfn = 0x240000 max_arch_pfn = 0x400000000
[ 0.015844][ T0] MTRR map: 4 entries (3 fixed + 1 variable; max 19), built from 8 variable MTRRs
[ 0.017132][ T0] x86/PAT: Configuration [0-7]: WB WC UC- UC WB WP UC- WT
[ 0.018305][ T0] last_pfn = 0xbfffd max_arch_pfn = 0x400000000
[ 0.026836][ T0] found SMP MP-table at [mem 0x000f2a80-0x000f2a8f]
[ 0.027980][ T0] Using GB pages for direct mapping
[ 0.033174][ T0] ACPI: Early table checksum verification disabled
[ 0.034898][ T0] ACPI: RSDP 0x00000000000F2800 000014 (v00 Google)
[ 0.036101][ T0] ACPI: RSDT 0x00000000BFFFFFA0 000038 (v01 Google GOOGRSDT 00000001 GOOG 00000001)
[ 0.037818][ T0] ACPI: FACP 0x00000000BFFFF330 0000F4 (v02 Google GOOGFACP 00000001 GOOG 00000001)
[ 0.040688][ T0] ACPI: DSDT 0x00000000BFFFD8C0 001A64 (v01 Google GOOGDSDT 00000001 GOOG 00000001)
[ 0.042664][ T0] ACPI: FACS 0x00000000BFFFD880 000040
[ 0.043578][ T0] ACPI: FACS 0x00000000BFFFD880 000040
[ 0.044351][ T0] ACPI: SRAT 0x00000000BFFFFE60 0000C8 (v03 Google GOOGSRAT 00000001 GOOG 00000001)
[ 0.046684][ T0] ACPI: APIC 0x00000000BFFFFDB0 000076 (v05 Google GOOGAPIC 00000001 GOOG 00000001)
[ 0.048111][ T0] ACPI: SSDT 0x00000000BFFFF430 000980 (v01 Google GOOGSSDT 00000001 GOOG 00000001)
[ 0.049684][ T0] ACPI: WAET 0x00000000BFFFFE30 000028 (v01 Google GOOGWAET 00000001 GOOG 00000001)
[ 0.051316][ T0] ACPI: Reserving FACP table memory at [mem 0xbffff330-0xbffff423]
[ 0.052796][ T0] ACPI: Reserving DSDT table memory at [mem 0xbfffd8c0-0xbffff323]
[ 0.054251][ T0] ACPI: Reserving FACS table memory at [mem 0xbfffd880-0xbfffd8bf]
[ 0.057326][ T0] ACPI: Reserving FACS table memory at [mem 0xbfffd880-0xbfffd8bf]
[ 0.058824][ T0] ACPI: Reserving SRAT table memory at [mem 0xbffffe60-0xbfffff27]
[ 0.060203][ T0] ACPI: Reserving APIC table memory at [mem 0xbffffdb0-0xbffffe25]
[ 0.061415][ T0] ACPI: Reserving SSDT table memory at [mem 0xbffff430-0xbffffdaf]
[ 0.062677][ T0] ACPI: Reserving WAET table memory at [mem 0xbffffe30-0xbffffe57]
[ 0.064154][ T0] SRAT: PXM 0 -> APIC 0x00 -> Node 0
[ 0.065317][ T0] SRAT: PXM 0 -> APIC 0x01 -> Node 0
[ 0.066315][ T0] ACPI: SRAT: Node 0 PXM 0 [mem 0x00000000-0x0009ffff]
[ 0.067376][ T0] ACPI: SRAT: Node 0 PXM 0 [mem 0x00100000-0xbfffffff]
[ 0.068405][ T0] ACPI: SRAT: Node 0 PXM 0 [mem 0x100000000-0x23fffffff]
[ 0.069822][ T0] NUMA: Node 0 [mem 0x00000000-0x0009ffff] + [mem 0x00100000-0xbfffffff] -> [mem 0x00000000-0xbfffffff]
[ 0.072881][ T0] NUMA: Node 0 [mem 0x00000000-0xbfffffff] + [mem 0x100000000-0x23fffffff] -> [mem 0x00000000-0x23fffffff]
[ 0.074935][ T0] Faking node 0 at [mem 0x0000000000000000-0x000000013fffffff] (5120MB)
[ 0.076263][ T0] Faking node 1 at [mem 0x0000000140000000-0x000000023fffffff] (4096MB)
[ 0.078438][ T0] NODE_DATA(0) allocated [mem 0x13fffa000-0x13fffffff]
[ 0.080018][ T0] NODE_DATA(1) allocated [mem 0x23fff7000-0x23fffcfff]
[ 0.104240][ T0] Zone ranges:
[ 0.104983][ T0] DMA [mem 0x0000000000001000-0x0000000000ffffff]
[ 0.106799][ T0] DMA32 [mem 0x0000000001000000-0x00000000ffffffff]
[ 0.107775][ T0] Normal [mem 0x0000000100000000-0x000000023fffffff]
[ 0.109311][ T0] Device empty
[ 0.109927][ T0] Movable zone start for each node
[ 0.111401][ T0] Early memory node ranges
[ 0.112665][ T0] node 0: [mem 0x0000000000001000-0x000000000009efff]
[ 0.113948][ T0] node 0: [mem 0x0000000000100000-0x00000000bfffcfff]
[ 0.115931][ T0] node 0: [mem 0x0000000100000000-0x000000013fffffff]
[ 0.117551][ T0] node 1: [mem 0x0000000140000000-0x000000023fffffff]
[ 0.118915][ T0] Initmem setup node 0 [mem 0x0000000000001000-0x000000013fffffff]
[ 0.120744][ T0] Initmem setup node 1 [mem 0x0000000140000000-0x000000023fffffff]
[ 0.122511][ T0] On node 0, zone DMA: 1 pages in unavailable ranges
[ 0.124062][ T0] On node 0, zone DMA: 97 pages in unavailable ranges
[ 0.255653][ T0] On node 0, zone Normal: 3 pages in unavailable ranges
[ 0.389510][ T0] ACPI: PM-Timer IO Port: 0xb008
[ 0.390772][ T0] ACPI: LAPIC_NMI (acpi_id[0xff] dfl dfl lint[0x1])
[ 0.391910][ T0] IOAPIC[0]: apic_id 0, version 17, address 0xfec00000, GSI 0-23
[ 0.393482][ T0] ACPI: INT_SRC_OVR (bus 0 bus_irq 5 global_irq 5 high level)
[ 0.394556][ T0] ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 high level)
[ 0.395755][ T0] ACPI: INT_SRC_OVR (bus 0 bus_irq 10 global_irq 10 high level)
[ 0.396841][ T0] ACPI: INT_SRC_OVR (bus 0 bus_irq 11 global_irq 11 high level)
[ 0.398015][ T0] ACPI: Using ACPI (MADT) for SMP configuration information
[ 0.399103][ T0] smpboot: Allowing 2 CPUs, 0 hotplug CPUs
[ 0.400346][ T0] PM: hibernation: Registered nosave memory: [mem 0x00000000-0x00000fff]
[ 0.401793][ T0] PM: hibernation: Registered nosave memory: [mem 0x0009f000-0x0009ffff]
[ 0.402955][ T0] PM: hibernation: Registered nosave memory: [mem 0x000a0000-0x000effff]
[ 0.404185][ T0] PM: hibernation: Registered nosave memory: [mem 0x000f0000-0x000fffff]
[ 0.406414][ T0] PM: hibernation: Registered nosave memory: [mem 0xbfffd000-0xbfffffff]
[ 0.407862][ T0] PM: hibernation: Registered nosave memory: [mem 0xc0000000-0xfffbbfff]
[ 0.409210][ T0] PM: hibernation: Registered nosave memory: [mem 0xfffbc000-0xffffffff]
[ 0.410396][ T0] [mem 0xc0000000-0xfffbbfff] available for PCI devices
[ 0.411464][ T0] Booting paravirtualized kernel on KVM
[ 0.412453][ T0] clocksource: refined-jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
[ 0.414424][ T0] setup_percpu: NR_CPUS:8 nr_cpumask_bits:2 nr_cpu_ids:2 nr_node_ids:2
[ 0.416586][ T0] percpu: Embedded 176 pages/cpu s683016 r8192 d29688 u1048576
[ 0.418172][ T0] Kernel command line: earlyprintk=serial net.ifnames=0 sysctl.kernel.hung_task_all_cpu_backtrace=1 ima_policy=tcb nf-conntrack-ftp.ports=20000 nf-conntrack-tftp.ports=20000 nf-conntrack-sip.ports=20000 nf-conntrack-irc.ports=20000 nf-conntrack-sane.ports=20000 binder.debug_mask=0 rcupdate.rcu_expedited=1 rcupdate.rcu_cpu_stall_cputime=1 no_hash_pointers page_owner=on sysctl.vm.nr_hugepages=4 sysctl.vm.nr_overcommit_hugepages=4 secretmem.enable=1 sysctl.max_rcu_stall_to_panic=1 msr.allow_writes=off coredump_filter=0xffff root=/dev/sda console=ttyS0 vsyscall=native numa=fake=2 kvm-intel.nested=1 spec_store_bypass_disable=prctl nopcid vivid.n_devs=16 vivid.multiplanar=1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2 netrom.nr_ndevs=16 rose.rose_ndevs=16 smp.csd_lock_timeout=100000 watchdog_thresh=55 workqueue.watchdog_thresh=140 sysctl.net.core.netdev_unregister_timeout_secs=140 dummy_hcd.num=8 kmsan.panic=1 BOOT_IMAGE=/boot/bzImage root=/dev/sda1 console=ttyS0
[ 0.438759][ T0] Unknown kernel command line parameters "page_owner=on spec_store_bypass_disable=prctl watchdog_thresh=55 BOOT_IMAGE=/boot/bzImage", will be passed to user space.
[ 0.441672][ T0] random: crng init done
[ 0.442824][ T0] Fallback order for Node 0: 0 1
[ 0.442869][ T0] Fallback order for Node 1: 1 0
[ 0.442885][ T0] Built 2 zonelists, mobility grouping on. Total pages: 2055933
[ 0.445747][ T0] Policy zone: Normal
[ 0.446410][ T0] mem auto-init: stack:off, heap alloc:off, heap free:off
[ 0.746915][ T0] stackdepot: allocating hash table via alloc_large_system_hash
[ 0.748679][ T0] stackdepot hash table entries: 524288 (order: 11, 8388608 bytes, linear)
[ 0.753267][ T0] software IO TLB: area num 2.
[ 0.852827][ T0] Memory: 2290736K/8388204K available (237568K kernel code, 9701K rwdata, 18212K rodata, 36392K init, 2524K bss, 1508228K reserved, 0K cma-reserved)
[ 0.857739][ T0] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=2, Nodes=2
[ 0.859241][ T0] Kernel/User page tables isolation: enabled
[ 0.860598][ T0] Starting KernelMemorySanitizer
[ 0.861422][ T0] ATTENTION: KMSAN is a debugging tool! Do not use it on production machines!


syzkaller build log:
go env (err=<nil>)
GO111MODULE='auto'
GOARCH='amd64'
GOBIN=''
GOCACHE='/syzkaller/.cache/go-build'
GOENV='/syzkaller/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
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'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.21.4'
GCCGO='gccgo'
GOAMD64='v1'
AR='ar'
CC='gcc'
CXX='g++'
CGO_ENABLED='1'
GOMOD='/syzkaller/jobs-2/linux/gopath/src/github.com/google/syzkaller/go.mod'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build716133879=/tmp/go-build -gno-record-gcc-switches'

git status (err=<nil>)
HEAD detached at d615901c7
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}}' ./sys/syz-sysgen | grep -q false || go install ./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=d615901c739a765329b688494cee2f8e1b5037cb -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240314-145638'" "-tags=syz_target syz_os_linux syz_arch_amd64 " -o ./bin/linux_amd64/syz-fuzzer github.com/google/syzkaller/syz-fuzzer
GOOS=linux GOARCH=amd64 go build "-ldflags=-s -w -X github.com/google/syzkaller/prog.GitRevision=d615901c739a765329b688494cee2f8e1b5037cb -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240314-145638'" "-tags=syz_target syz_os_linux syz_arch_amd64 " -o ./bin/linux_amd64/syz-execprog github.com/google/syzkaller/tools/syz-execprog
GOOS=linux GOARCH=amd64 go build "-ldflags=-s -w -X github.com/google/syzkaller/prog.GitRevision=d615901c739a765329b688494cee2f8e1b5037cb -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240314-145638'" "-tags=syz_target syz_os_linux syz_arch_amd64 " -o ./bin/linux_amd64/syz-stress github.com/google/syzkaller/tools/syz-stress
mkdir -p ./bin/linux_amd64
gcc -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 -fpermissive -w -DGOOS_linux=1 -DGOARCH_amd64=1 \
-DHOSTGOOS_linux=1 -DGIT_REVISION=\"d615901c739a765329b688494cee2f8e1b5037cb\"



Tested on:

commit: 22ffa13a fs/9p: fix uninitialized values during inode ..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs.git b4/fix-evict-uninitialized-value
kernel config: https://syzkaller.appspot.com/x/.config?x=fdd94870bd281651
dashboard link: https://syzkaller.appspot.com/bug?extid=eb83fe1cce5833cd66a0
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Note: no patches were applied.