Re: [syzbot] [io-uring?] KMSAN: uninit-value in io_req_cqe_overflow (3)

[syzbot]

Hello,

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

6.343044][    T1] openvswitch: Open vSwitch switching datapath
[   46.363888][    T1] NET: Registered PF_VSOCK protocol family
[   46.372367][    T1] mpls_gso: MPLS GSO support
[   46.524387][    T1] IPI shorthand broadcast: enabled
[   48.017346][    T1] sched_clock: Marking stable (47990050167, 17795964)->(48016243838, -8397707)
[   49.133874][    T1] Timer migration: 1 hierarchy levels; 8 children per group; 0 crossnode level
[   49.302883][    T1] registered taskstats version 1
[   49.367583][    T1] Loading compiled-in X.509 certificates
[   49.405812][    T1] Loaded X.509 cert 'Build time autogenerated kernel key: ef5392d16e2343e2e997a1a8439f31430dca794f'
[   49.643401][    T1] zswap: loaded using pool lzo/zsmalloc
[   49.652895][    T1] Demotion targets for Node 0: null
[   49.658483][    T1] Demotion targets for Node 1: null
[   49.665807][    T1] Key type .fscrypt registered
[   49.672365][    T1] Key type fscrypt-provisioning registered
[   49.679915][    T1] kAFS: Red Hat AFS client v0.1 registering.
[   49.713149][    T1] Btrfs loaded, assert=on, ref-verify=on, zoned=yes, fsverity=yes
[   49.740050][    T1] Key type encrypted registered
[   49.745095][    T1] AppArmor: AppArmor sha256 policy hashing enabled
[   49.753397][    T1] ima: No TPM chip found, activating TPM-bypass!
[   49.759983][    T1] Loading compiled-in module X.509 certificates
[   49.802303][    T1] Loaded X.509 cert 'Build time autogenerated kernel key: ef5392d16e2343e2e997a1a8439f31430dca794f'
[   49.813515][    T1] ima: Allocated hash algorithm: sha256
[   49.819655][    T1] ima: No architecture policies found
[   49.826134][    T1] evm: Initialising EVM extended attributes:
[   49.832247][    T1] evm: security.selinux (disabled)
[   49.837410][    T1] evm: security.SMACK64 (disabled)
[   49.842758][    T1] evm: security.SMACK64EXEC (disabled)
[   49.848460][    T1] evm: security.SMACK64TRANSMUTE (disabled)
[   49.854407][    T1] evm: security.SMACK64MMAP (disabled)
[   49.860131][    T1] evm: security.apparmor
[   49.864545][    T1] evm: security.ima
[   49.868491][    T1] evm: security.capability
[   49.872958][    T1] evm: HMAC attrs: 0x1
[   49.882187][    T1] PM:   Magic number: 12:875:156
[   49.888285][    T1] usb usb36-port7: hash matches
[   49.894166][    T1] bdi 1:8: hash matches
[   49.900642][    T1] printk: legacy console [netcon0] enabled
[   49.906787][    T1] netconsole: network logging started
[   49.913765][    T1] gtp: GTP module loaded (pdp ctx size 128 bytes)
[   49.922755][    T1] rdma_rxe: loaded
[   49.928813][    T1] cfg80211: Loading compiled-in X.509 certificates for regulatory database
[   49.950799][    T1] Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
[   49.969818][    T1] Loaded X.509 cert 'wens: 61c038651aabdcf94bd0ac7ff06c7248db18c600'
[   49.978593][    T1] clk: Disabling unused clocks
[   49.983531][    T1] ALSA device list:
[   49.987431][    T1]   #0: Dummy 1
[   49.991050][    T1]   #1: Loopback 1
[   49.994878][    T1]   #2: Virtual MIDI Card 1
[   50.005050][   T10] platform regulatory.0: Direct firmware load for regulatory.db failed with error -2
[   50.014970][   T10] platform regulatory.0: Falling back to sysfs fallback for: regulatory.db
[   50.024723][    T1] md: Waiting for all devices to be available before autodetect
[   50.032705][    T1] md: If you don't use raid, use raid=noautodetect
[   50.039465][    T1] md: Autodetecting RAID arrays.
[   50.044595][    T1] md: autorun ...
[   50.048512][    T1] md: ... autorun DONE.
[   50.117733][    T1] EXT4-fs (sda1): mounted filesystem 5941fea2-f5fa-4b4e-b5ef-9af118b27b95 ro with ordered data mode. Quota mode: none.
[   50.131603][    T1] VFS: Mounted root (ext4 filesystem) readonly on device 8:1.
[   50.144403][    T1] devtmpfs: mounted
[   50.408360][    T1] Freeing unused kernel image (initmem) memory: 37036K
[   50.420188][    T1] Write protecting the kernel read-only data: 262144k
[   50.467096][    T1] Freeing unused kernel image (rodata/data gap) memory: 1804K
[   52.119267][    T1] x86/mm: Checked W+X mappings: passed, no W+X pages found.
[   52.129621][    T1] x86/mm: Checking user space page tables
[   53.636226][    T1] x86/mm: Checked W+X mappings: passed, no W+X pages found.
[   53.645529][    T1] Failed to set sysctl parameter 'kernel.hung_task_all_cpu_backtrace=1': parameter not found
[   53.666750][    T1] Failed to set sysctl parameter 'max_rcu_stall_to_panic=1': parameter not found
[   53.678915][    T1] Run /sbin/init as init process
[   55.261831][ T4447] mount (4447) used greatest stack depth: 7808 bytes left
[   55.340544][ T4448] EXT4-fs (sda1): re-mounted 5941fea2-f5fa-4b4e-b5ef-9af118b27b95 r/w. Quota mode: none.
mount: mounting smackfs on /sys/fs/smackfs failed: No such file or directory
mount: mounting selinuxfs on /sys/fs/selinux failed: No such file or directory
[   55.675477][ T4451] mount (4451) used greatest stack depth: 5568 bytes left
Starting syslogd: OK
Starting acpid: OK
Starting klogd: OK
Running sysctl: OK
Populating /dev using udev: [   59.510303][ T4481] udevd[4481]: starting version 3.2.11
[   63.097528][ T4482] udevd[4482]: starting eudev-3.2.11
[   63.110491][ T4481] udevd (4481) used greatest stack depth: 5232 bytes left
done
Starting system message bus: done
Starting iptables: OK
Starting network: OK
Starting dhcpcd...
dhcpcd-9.4.1 starting
dev: loaded udev
DUID 00:04:c7:fd:4a:df:9d:a6:e9:60:55:7b:b4:5b:1f:77:00:5c
forked to background, child pid 4695
[  110.977706][ T4696] 8021q: adding VLAN 0 to HW filter on device bond0
[  111.031404][ T4696] eql: remember to turn off Van-Jacobson compression on your slave devices
[  111.650739][   T10] cfg80211: failed to load regulatory.db
Starting sshd: OK


syzkaller

syzkaller login: [  114.063784][    C0] =====================================================
[  114.071021][    C0] BUG: KMSAN: uninit-value in receive_buf+0x25e3/0x5fd0
[  114.078922][    C0]  receive_buf+0x25e3/0x5fd0
[  114.083796][    C0]  virtnet_poll+0xd1c/0x23c0
[  114.088752][    C0]  __napi_poll+0xe7/0x980
[  114.093517][    C0]  net_rx_action+0x82a/0x1850
[  114.098512][    C0]  handle_softirqs+0x1ce/0x800
[  114.103581][    C0]  __irq_exit_rcu+0x68/0x120
[  114.108412][    C0]  irq_exit_rcu+0x12/0x20
[  114.112996][    C0]  common_interrupt+0x94/0xa0
[  114.118086][    C0]  asm_common_interrupt+0x2b/0x40
[  114.123480][    C0]  __msan_metadata_ptr_for_load_8+0x18/0x40
[  114.129797][    C0]  filemap_map_pages+0xe81/0x2e30
[  114.135034][    C0]  handle_mm_fault+0x6f36/0xe610
[  114.140206][    C0]  exc_page_fault+0x41b/0x700
[  114.145072][    C0]  asm_exc_page_fault+0x2b/0x30
[  114.150167][    C0] 
[  114.152572][    C0] Uninit was created at:
[  114.156953][    C0]  __alloc_pages_noprof+0x9d6/0xe70
[  114.162368][    C0]  alloc_pages_mpol_noprof+0x299/0x990
[  114.168132][    C0]  alloc_pages_noprof+0x1bf/0x1e0
[  114.173274][    C0]  skb_page_frag_refill+0x2bf/0x7c0
[  114.178692][    C0]  virtnet_rq_alloc+0x43/0xbb0
[  114.183610][    C0]  try_fill_recv+0x3f0/0x2f50
[  114.188492][    C0]  virtnet_open+0x1cc/0xb00
[  114.193392][    C0]  __dev_open+0x546/0x6f0
[  114.197955][    C0]  __dev_change_flags+0x309/0x9a0
[  114.203263][    C0]  dev_change_flags+0x8e/0x1d0
[  114.208266][    C0]  devinet_ioctl+0x13ec/0x22c0
[  114.213265][    C0]  inet_ioctl+0x4bd/0x6d0
[  114.217709][    C0]  sock_do_ioctl+0xb7/0x540
[  114.222474][    C0]  sock_ioctl+0x727/0xd70
[  114.226915][    C0]  __se_sys_ioctl+0x261/0x450
[  114.231888][    C0]  __x64_sys_ioctl+0x96/0xe0
[  114.236624][    C0]  x64_sys_call+0x18c0/0x3b90
[  114.241782][    C0]  do_syscall_64+0xcd/0x1e0
[  114.246586][    C0]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[  114.252971][    C0] 
[  114.255409][    C0] CPU: 0 PID: 4803 Comm: rm Not tainted 6.10.0-rc3-syzkaller-00102-ga3027fbd92ad #0
[  114.265197][    C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
[  114.275517][    C0] =====================================================
[  114.282666][    C0] Disabling lock debugging due to kernel taint
[  114.289094][    C0] Kernel panic - not syncing: kmsan.panic set ...
[  114.295774][    C0] CPU: 0 PID: 4803 Comm: rm Tainted: G    B              6.10.0-rc3-syzkaller-00102-ga3027fbd92ad #0
[  114.307012][    C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
[  114.317158][    C0] Call Trace:
[  114.320500][    C0]  <IRQ>
[  114.323392][    C0]  dump_stack_lvl+0x216/0x2d0
[  114.328201][    C0]  ? kmsan_get_shadow_origin_ptr+0x4d/0xb0
[  114.334149][    C0]  dump_stack+0x1e/0x30
[  114.338426][    C0]  panic+0x4e2/0xcd0
[  114.342445][    C0]  ? kmsan_get_metadata+0xb1/0x1d0
[  114.348148][    C0]  kmsan_report+0x2d5/0x2e0
[  114.352948][    C0]  ? kmsan_get_metadata+0x146/0x1d0
[  114.358285][    C0]  ? __msan_warning+0x95/0x120
[  114.363159][    C0]  ? receive_buf+0x25e3/0x5fd0
[  114.368024][    C0]  ? virtnet_poll+0xd1c/0x23c0
[  114.372882][    C0]  ? __napi_poll+0xe7/0x980
[  114.377788][    C0]  ? net_rx_action+0x82a/0x1850
[  114.382798][    C0]  ? handle_softirqs+0x1ce/0x800
[  114.387868][    C0]  ? __irq_exit_rcu+0x68/0x120
[  114.392766][    C0]  ? irq_exit_rcu+0x12/0x20
[  114.397357][    C0]  ? common_interrupt+0x94/0xa0
[  114.402324][    C0]  ? asm_common_interrupt+0x2b/0x40
[  114.407634][    C0]  ? __msan_metadata_ptr_for_load_8+0x18/0x40
[  114.413807][    C0]  ? filemap_map_pages+0xe81/0x2e30
[  114.419117][    C0]  ? handle_mm_fault+0x6f36/0xe610
[  114.424461][    C0]  ? exc_page_fault+0x41b/0x700
[  114.429619][    C0]  ? asm_exc_page_fault+0x2b/0x30
[  114.434797][    C0]  ? kmsan_get_metadata+0x146/0x1d0
[  114.440132][    C0]  ? kmsan_get_metadata+0x146/0x1d0
[  114.445631][    C0]  ? kmsan_internal_memmove_metadata+0x17b/0x230
[  114.452123][    C0]  ? kmsan_get_metadata+0x146/0x1d0
[  114.457453][    C0]  ? kmsan_get_metadata+0x146/0x1d0
[  114.462794][    C0]  ? page_to_skb+0xdae/0x1620
[  114.467694][    C0]  ? kmsan_get_metadata+0x146/0x1d0
[  114.473057][    C0]  __msan_warning+0x95/0x120
[  114.477746][    C0]  receive_buf+0x25e3/0x5fd0
[  114.482558][    C0]  ? kmsan_get_metadata+0x146/0x1d0
[  114.488004][    C0]  ? kmsan_get_shadow_origin_ptr+0x4d/0xb0
[  114.493964][    C0]  virtnet_poll+0xd1c/0x23c0
[  114.498684][    C0]  ? __pfx_virtnet_poll+0x10/0x10
[  114.503816][    C0]  __napi_poll+0xe7/0x980
[  114.508269][    C0]  ? kmsan_get_metadata+0x146/0x1d0
[  114.513605][    C0]  net_rx_action+0x82a/0x1850
[  114.518407][    C0]  ? sched_clock_cpu+0x55/0x870
[  114.523437][    C0]  ? __pfx_net_rx_action+0x10/0x10
[  114.528662][    C0]  handle_softirqs+0x1ce/0x800
[  114.533665][    C0]  __irq_exit_rcu+0x68/0x120
[  114.538379][    C0]  irq_exit_rcu+0x12/0x20
[  114.542838][    C0]  common_interrupt+0x94/0xa0
[  114.547656][    C0]  </IRQ>
[  114.550894][    C0]  <TASK>
[  114.553890][    C0]  asm_common_interrupt+0x2b/0x40
[  114.559040][    C0] RIP: 0010:__msan_metadata_ptr_for_load_8+0x18/0x40
[  114.565833][    C0] Code: 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 48 89 e5 53 48 83 ec 10 9c 8f 45 e8 0f 01 ca 48 8b 5d e8 <be> 08 00 00 00 31 d2 e8 9c 25 00 00 48 89 5d f0 ff 75 f0 9d 48 83
[  114.585747][    C0] RSP: 0000:ffff88811852fa60 EFLAGS: 00000286
[  114.591926][    C0] RAX: 0000000000000000 RBX: 0000000000000286 RCX: ffff888116094180
[  114.600091][    C0] RDX: 0000000000000000 RSI: 0000000000000036 RDI: ffff88811852fa90
[  114.608158][    C0] RBP: ffff88811852fa78 R08: ffffffff8203f34a R09: ffffffff8203e5a8
[  114.616220][    C0] R10: 0000000000000002 R11: ffff888116094180 R12: 0000000002b000d1
[  114.624272][    C0] R13: 000000000000000c R14: 000000000000000b R15: 0000000000000000
[  114.632317][    C0]  ? next_uptodate_folio+0x4c8/0x1730
[  114.637792][    C0]  ? next_uptodate_folio+0x126a/0x1730
[  114.643393][    C0]  filemap_map_pages+0xe81/0x2e30
[  114.648516][    C0]  ? kmsan_get_metadata+0x146/0x1d0
[  114.653822][    C0]  ? kmsan_get_shadow_origin_ptr+0x4d/0xb0
[  114.659840][    C0]  ? kmsan_get_metadata+0x146/0x1d0
[  114.665189][    C0]  handle_mm_fault+0x6f36/0xe610
[  114.670266][    C0]  ? kmsan_get_metadata+0x146/0x1d0
[  114.675574][    C0]  ? kmsan_get_metadata+0x146/0x1d0
[  114.681161][    C0]  ? __pfx_filemap_map_pages+0x10/0x10
[  114.686733][    C0]  exc_page_fault+0x41b/0x700
[  114.691535][    C0]  asm_exc_page_fault+0x2b/0x30
[  114.696492][    C0] RIP: 0033:0x7fc22a8cdd20
[  114.701001][    C0] Code: Unable to access opcode bytes at 0x7fc22a8cdcf6.
[  114.708193][    C0] RSP: 002b:00007ffd152fccc0 EFLAGS: 00010202
[  114.714661][    C0] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[  114.722723][    C0] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[  114.730785][    C0] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[  114.738829][    C0] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[  114.747002][    C0] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[  114.755163][    C0]  </TASK>
[  114.758494][    C0] Kernel Offset: disabled
[  114.762888][    C0] Rebooting in 86400 seconds..


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-build2855798142=/tmp/go-build -gno-record-gcc-switches'

git status (err=<nil>)
HEAD detached at 2aa5052fed
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
go fmt ./sys/... >/dev/null
touch .descriptions
GOOS=linux GOARCH=amd64 go build "-ldflags=-s -w -X github.com/google/syzkaller/prog.GitRevision=2aa5052fed5f8993afacfce02174322df0f03ec4 -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240612-135002'" "-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=2aa5052fed5f8993afacfce02174322df0f03ec4 -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240612-135002'" "-tags=syz_target syz_os_linux syz_arch_amd64 " -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 -fpermissive -w -DGOOS_linux=1 -DGOARCH_amd64=1 \
	-DHOSTGOOS_linux=1 -DGIT_REVISION=\"2aa5052fed5f8993afacfce02174322df0f03ec4\"


Error text is too large and was truncated, full error text is at:
https://syzkaller.appspot.com/x/error.txt?x=12e30256980000


Tested on:

commit:         a3027fbd Merge branch 'master' into syz-test
git tree:       git://git.kernel.dk/linux.git syz-test
kernel config:  https://syzkaller.appspot.com/x/.config?x=3486f1660f47f855
dashboard link: https://syzkaller.appspot.com/bug?extid=e6616d0dc8ded5dc56d6
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Note: no patches were applied.