Re: [syzbot] [fs?] WARNING in nsproxy_ns_active_put

syzbot
2025-11-07T13:44:05Z

Hello,

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

26.481884][ T1] Loading compiled-in X.509 certificates
[ 26.516950][ T1] Loaded X.509 cert 'Build time autogenerated kernel key: f5143acf1d690a3971428b7fa3c37300acff3a6e'
[ 26.900243][ T1] zswap: loaded using pool 842
[ 26.908732][ T1] Demotion targets for Node 0: null
[ 26.914058][ T1] Demotion targets for Node 1: null
[ 26.919319][ T1] debug_vm_pgtable: [debug_vm_pgtable ]: Validating architecture page table helpers
[ 29.792072][ T1] Key type .fscrypt registered
[ 29.796868][ T1] Key type fscrypt-provisioning registered
[ 29.806376][ T1] kAFS: Red Hat AFS client v0.1 registering.
[ 29.835595][ T1] Btrfs loaded, assert=on, zoned=yes, fsverity=yes
[ 29.843055][ T1] Key type big_key registered
[ 29.847786][ T1] Key type encrypted registered
[ 29.852651][ T1] AppArmor: AppArmor sha256 policy hashing enabled
[ 29.859262][ T1] ima: No TPM chip found, activating TPM-bypass!
[ 29.865703][ T1] Loading compiled-in module X.509 certificates
[ 29.898151][ T1] Loaded X.509 cert 'Build time autogenerated kernel key: f5143acf1d690a3971428b7fa3c37300acff3a6e'
[ 29.909093][ T1] ima: Allocated hash algorithm: sha256
[ 29.915206][ T1] ima: No architecture policies found
[ 29.921406][ T1] evm: Initialising EVM extended attributes:
[ 29.927394][ T1] evm: security.selinux (disabled)
[ 29.932519][ T1] evm: security.SMACK64 (disabled)
[ 29.937623][ T1] evm: security.SMACK64EXEC (disabled)
[ 29.943088][ T1] evm: security.SMACK64TRANSMUTE (disabled)
[ 29.948967][ T1] evm: security.SMACK64MMAP (disabled)
[ 29.954435][ T1] evm: security.apparmor
[ 29.958662][ T1] evm: security.ima
[ 29.962478][ T1] evm: security.capability
[ 29.966893][ T1] evm: HMAC attrs: 0x1
[ 29.973825][ T1] PM: Magic number: 1:963:583
[ 29.978800][ T1] cec cec10: hash matches
[ 29.983532][ T1] tty ptyc1: hash matches
[ 29.988103][ T1] netconsole: network logging started
[ 29.994201][ T1] gtp: GTP module loaded (pdp ctx size 128 bytes)
[ 30.007061][ T1] rdma_rxe: loaded
[ 30.013137][ T1] cfg80211: Loading compiled-in X.509 certificates for regulatory database
[ 30.024801][ T1] Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
[ 30.034477][ T1] Loaded X.509 cert 'wens: 61c038651aabdcf94bd0ac7ff06c7248db18c600'
[ 30.044095][ T1208] faux_driver regulatory: Direct firmware load for regulatory.db failed with error -2
[ 30.051936][ T1] clk: Disabling unused clocks
[ 30.053922][ T1208] faux_driver regulatory: Falling back to sysfs fallback for: regulatory.db
[ 30.058707][ T1] ALSA device list:
[ 30.071200][ T1] #0: Dummy 1
[ 30.074969][ T1] #1: Loopback 1
[ 30.078718][ T1] #2: Virtual MIDI Card 1
[ 30.086410][ T1] check access for rdinit=/init failed: -2, ignoring
[ 30.093222][ T1] md: Waiting for all devices to be available before autodetect
[ 30.100857][ T1] md: If you don't use raid, use raid=noautodetect
[ 30.107485][ T1] md: Autodetecting RAID arrays.
[ 30.112631][ T1] md: autorun ...
[ 30.116274][ T1] md: ... autorun DONE.
[ 30.242475][ T1] EXT4-fs (sda1): orphan cleanup on readonly fs
[ 30.251116][ T1] EXT4-fs (sda1): mounted filesystem 4f91c6db-4997-4bb4-91b8-7e83a20c1bf1 ro with ordered data mode. Quota mode: none.
[ 30.263959][ T1] VFS: Mounted root (ext4 filesystem) readonly on device 8:1.
[ 30.274587][ T1] devtmpfs: mounted
[ 30.350955][ T1] Freeing unused kernel image (initmem) memory: 26112K
[ 30.361768][ T1] Write protecting the kernel read-only data: 212992k
[ 30.380228][ T1] Freeing unused kernel image (text/rodata gap) memory: 1436K
[ 30.392825][ T1] Freeing unused kernel image (rodata/data gap) memory: 1240K
[ 30.528715][ T1] x86/mm: Checked W+X mappings: passed, no W+X pages found.
[ 30.536730][ T1] x86/mm: Checking user space page tables
[ 30.654084][ T1] x86/mm: Checked W+X mappings: passed, no W+X pages found.
[ 30.666870][ T1] Failed to set sysctl parameter 'max_rcu_stall_to_panic=1': parameter not found
[ 30.676750][ T1] Run /sbin/init as init process
[ 31.177715][ T5158] mount (5158) used greatest stack depth: 23576 bytes left
[ 31.225728][ T5159] EXT4-fs (sda1): re-mounted 4f91c6db-4997-4bb4-91b8-7e83a20c1bf1 r/w.
mount: mounting devtmpfs on /dev failed: Device or resource busy
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
[ 31.387784][ T5163] mount (5163) used greatest stack depth: 21672 bytes left
Starting syslogd: OK
Starting acpid: OK
Starting klogd: OK
Running sysctl: OK
Populating /dev using udev: [ 32.674421][ T5193] udevd[5193]: starting version 3.2.14
[ 32.996569][ T5194] udevd[5194]: starting eudev-3.2.14
[ 33.000117][ T5193] udevd (5193) used greatest stack depth: 18696 bytes left
done
Starting system message bus: done
Starting iptables: OK
Starting network: OK
Starting dhcpcd...
dhcpcd-10.2.0 starting
[ 56.220735][ T5488] ------------[ cut here ]------------
[ 56.226516][ T5488] WARNING: ./include/linux/ns_common.h:314 at nsfs_evict+0x18e/0x200, CPU#1: dhcpcd/5488
[ 56.236736][ T5488] Modules linked in:
[ 56.240773][ T5488] CPU: 1 UID: 0 PID: 5488 Comm: dhcpcd Not tainted syzkaller #0 PREEMPT(full)
[ 56.249797][ T5488] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
[ 56.260095][ T5488] RIP: 0010:nsfs_evict+0x18e/0x200
[ 56.265291][ T5488] Code: 4d 8b 1e 48 89 df 5b 41 5c 41 5d 41 5e 41 5f 5d 41 ff e3 cc cc cc e8 01 c7 76 ff 90 0f 0b 90 e9 1f ff ff ff e8 f3 c6 76 ff 90 <0f> 0b 90 e9 42 ff ff ff e8 e5 c6 76 ff 90 0f 0b 90 e9 72 ff ff ff
[ 56.285086][ T5488] RSP: 0018:ffffc9000389fa28 EFLAGS: 00010293
[ 56.291186][ T5488] RAX: ffffffff824b0e3d RBX: ffffffff9a180fd8 RCX: ffff888027d00000
[ 56.299224][ T5488] RDX: 0000000000000000 RSI: 00000000effffff8 RDI: 00000000effffff8
[ 56.307291][ T5488] RBP: 00000000effffff8 R08: ffffffff9a181093 R09: 1ffffffff3430212
[ 56.315341][ T5488] R10: dffffc0000000000 R11: fffffbfff3430213 R12: dffffc0000000000
[ 56.323376][ T5488] R13: 1ffffffff34301fe R14: ffff888077f26d50 R15: ffffffff9a180ff0
[ 56.331386][ T5488] FS: 00007ff1e1049740(0000) GS:ffff888125b78000(0000) knlGS:0000000000000000
[ 56.340332][ T5488] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 56.346978][ T5488] CR2: 00005604455e84a0 CR3: 000000007d5e6000 CR4: 00000000003526f0
[ 56.354995][ T5488] Call Trace:
[ 56.358288][ T5488] <TASK>
[ 56.361298][ T5488] ? __pfx_nsfs_evict+0x10/0x10
[ 56.366173][ T5488] evict+0x5f4/0xae0
[ 56.370068][ T5488] ? __pfx_evict+0x10/0x10
[ 56.374531][ T5488] ? _raw_spin_unlock+0x28/0x50
[ 56.379401][ T5488] ? iput+0xce7/0x1050
[ 56.383538][ T5488] __dentry_kill+0x209/0x660
[ 56.388147][ T5488] ? dput+0x37/0x2b0
[ 56.392093][ T5488] dput+0x19f/0x2b0
[ 56.395945][ T5488] path_put+0x39/0x60
[ 56.399929][ T5488] vfs_statx+0x36e/0x550
[ 56.404250][ T5488] ? __pfx_vfs_statx+0x10/0x10
[ 56.409209][ T5488] ? strncpy_from_user+0x150/0x2c0
[ 56.414394][ T5488] ? getname_flags+0x1e5/0x540
[ 56.419195][ T5488] vfs_fstatat+0x118/0x170
[ 56.423710][ T5488] __x64_sys_newfstatat+0x116/0x190
[ 56.428941][ T5488] ? __pfx___x64_sys_newfstatat+0x10/0x10
[ 56.434927][ T5488] ? do_syscall_64+0xbe/0xfa0
[ 56.439644][ T5488] do_syscall_64+0xfa/0xfa0
[ 56.444214][ T5488] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 56.450300][ T5488] ? clear_bhb_loop+0x60/0xb0
[ 56.455019][ T5488] entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 56.460957][ T5488] RIP: 0033:0x7ff1e113db0a
[ 56.465433][ T5488] Code: 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 41 89 ca b8 06 01 00 00 0f 05 <3d> 00 f0 ff ff 77 07 31 c0 c3 0f 1f 40 00 48 8b 15 b9 f2 0d 00 f7
[ 56.485147][ T5488] RSP: 002b:00007ffe530d70b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
[ 56.493625][ T5488] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007ff1e113db0a
[ 56.501659][ T5488] RDX: 00007ffe530d70c0 RSI: 0000560445610557 RDI: 00000000ffffff9c
[ 56.509645][ T5488] RBP: 00007ffe530d9858 R08: 0000000000000000 R09: 0000000000000000
[ 56.517679][ T5488] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe530d8230
[ 56.525708][ T5488] R13: 000056044e3fd8a0 R14: 0000000000001000 R15: 00007ff1e10496c8
[ 56.533830][ T5488] </TASK>
[ 56.536879][ T5488] Kernel panic - not syncing: kernel: panic_on_warn set ...
[ 56.544239][ T5488] CPU: 1 UID: 0 PID: 5488 Comm: dhcpcd Not tainted syzkaller #0 PREEMPT(full)
[ 56.553163][ T5488] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
[ 56.563227][ T5488] Call Trace:
[ 56.566502][ T5488] <TASK>
[ 56.569528][ T5488] dump_stack_lvl+0x99/0x250
[ 56.574131][ T5488] ? __asan_memcpy+0x40/0x70
[ 56.578721][ T5488] ? __pfx_dump_stack_lvl+0x10/0x10
[ 56.583912][ T5488] ? __pfx__printk+0x10/0x10
[ 56.588500][ T5488] vpanic+0x237/0x6d0
[ 56.592733][ T5488] ? __pfx_vpanic+0x10/0x10
[ 56.597237][ T5488] ? is_bpf_text_address+0x292/0x2b0
[ 56.602529][ T5488] ? is_bpf_text_address+0x26/0x2b0
[ 56.607740][ T5488] panic+0xb9/0xc0
[ 56.611464][ T5488] ? __pfx_panic+0x10/0x10
[ 56.615906][ T5488] __warn+0x334/0x4c0
[ 56.619892][ T5488] ? nsfs_evict+0x18e/0x200
[ 56.624402][ T5488] ? nsfs_evict+0x18e/0x200
[ 56.628910][ T5488] report_bug+0x2be/0x4f0
[ 56.633248][ T5488] ? nsfs_evict+0x18e/0x200
[ 56.637754][ T5488] ? nsfs_evict+0x18e/0x200
[ 56.642261][ T5488] ? nsfs_evict+0x190/0x200
[ 56.646864][ T5488] handle_bug+0x84/0x160
[ 56.651109][ T5488] exc_invalid_op+0x1a/0x50
[ 56.655637][ T5488] asm_exc_invalid_op+0x1a/0x20
[ 56.660495][ T5488] RIP: 0010:nsfs_evict+0x18e/0x200
[ 56.665614][ T5488] Code: 4d 8b 1e 48 89 df 5b 41 5c 41 5d 41 5e 41 5f 5d 41 ff e3 cc cc cc e8 01 c7 76 ff 90 0f 0b 90 e9 1f ff ff ff e8 f3 c6 76 ff 90 <0f> 0b 90 e9 42 ff ff ff e8 e5 c6 76 ff 90 0f 0b 90 e9 72 ff ff ff
[ 56.685231][ T5488] RSP: 0018:ffffc9000389fa28 EFLAGS: 00010293
[ 56.691305][ T5488] RAX: ffffffff824b0e3d RBX: ffffffff9a180fd8 RCX: ffff888027d00000
[ 56.699276][ T5488] RDX: 0000000000000000 RSI: 00000000effffff8 RDI: 00000000effffff8
[ 56.707248][ T5488] RBP: 00000000effffff8 R08: ffffffff9a181093 R09: 1ffffffff3430212
[ 56.715395][ T5488] R10: dffffc0000000000 R11: fffffbfff3430213 R12: dffffc0000000000
[ 56.723457][ T5488] R13: 1ffffffff34301fe R14: ffff888077f26d50 R15: ffffffff9a180ff0
[ 56.731441][ T5488] ? nsfs_evict+0x18d/0x200
[ 56.735961][ T5488] ? nsfs_evict+0x18d/0x200
[ 56.740466][ T5488] ? __pfx_nsfs_evict+0x10/0x10
[ 56.745344][ T5488] evict+0x5f4/0xae0
[ 56.749272][ T5488] ? __pfx_evict+0x10/0x10
[ 56.753700][ T5488] ? _raw_spin_unlock+0x28/0x50
[ 56.758559][ T5488] ? iput+0xce7/0x1050
[ 56.762727][ T5488] __dentry_kill+0x209/0x660
[ 56.767321][ T5488] ? dput+0x37/0x2b0
[ 56.771225][ T5488] dput+0x19f/0x2b0
[ 56.775046][ T5488] path_put+0x39/0x60
[ 56.779037][ T5488] vfs_statx+0x36e/0x550
[ 56.783307][ T5488] ? __pfx_vfs_statx+0x10/0x10
[ 56.788107][ T5488] ? strncpy_from_user+0x150/0x2c0
[ 56.793251][ T5488] ? getname_flags+0x1e5/0x540
[ 56.798034][ T5488] vfs_fstatat+0x118/0x170
[ 56.802466][ T5488] __x64_sys_newfstatat+0x116/0x190
[ 56.807674][ T5488] ? __pfx___x64_sys_newfstatat+0x10/0x10
[ 56.813445][ T5488] ? do_syscall_64+0xbe/0xfa0
[ 56.818158][ T5488] do_syscall_64+0xfa/0xfa0
[ 56.822684][ T5488] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 56.828855][ T5488] ? clear_bhb_loop+0x60/0xb0
[ 56.833544][ T5488] entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 56.839529][ T5488] RIP: 0033:0x7ff1e113db0a
[ 56.844039][ T5488] Code: 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 41 89 ca b8 06 01 00 00 0f 05 <3d> 00 f0 ff ff 77 07 31 c0 c3 0f 1f 40 00 48 8b 15 b9 f2 0d 00 f7
[ 56.863750][ T5488] RSP: 002b:00007ffe530d70b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
[ 56.872366][ T5488] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007ff1e113db0a
[ 56.880429][ T5488] RDX: 00007ffe530d70c0 RSI: 0000560445610557 RDI: 00000000ffffff9c
[ 56.888417][ T5488] RBP: 00007ffe530d9858 R08: 0000000000000000 R09: 0000000000000000
[ 56.896404][ T5488] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe530d8230
[ 56.904382][ T5488] R13: 000056044e3fd8a0 R14: 0000000000001000 R15: 00007ff1e10496c8
[ 56.912381][ T5488] </TASK>
[ 56.915663][ T5488] Kernel Offset: disabled
[ 56.920100][ T5488] Rebooting in 86400 seconds..

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-build3988901650=/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='go1.24.4'
GOWORK=''
PKG_CONFIG='pkg-config'

git status (err=<nil>)
HEAD detached at a6c9c731229
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=a6c9c7312290da5bca2fc1be4872a7aeefb6e3ea -X github.com/google/syzkaller/prog.gitRevisionDate=20251104-181356" ./sys/syz-sysgen | grep -q false || go install -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=a6c9c7312290da5bca2fc1be4872a7aeefb6e3ea -X github.com/google/syzkaller/prog.gitRevisionDate=20251104-181356" ./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=a6c9c7312290da5bca2fc1be4872a7aeefb6e3ea -X github.com/google/syzkaller/prog.gitRevisionDate=20251104-181356" -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 -DGOOS_linux=1 -DGOARCH_amd64=1 \
-DHOSTGOOS_linux=1 -DGIT_REVISION=\"a6c9c7312290da5bca2fc1be4872a7aeefb6e3ea\"
/usr/bin/ld: /tmp/ccZrqXJp.o: in function `Connection::Connect(char const*, char const*)':
executor.cc:(.text._ZN10Connection7ConnectEPKcS1_[_ZN10Connection7ConnectEPKcS1_]+0x104): 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

Error text is too large and was truncated, full error text is at:
https://syzkaller.appspot.com/x/error.txt?x=14843812580000

Tested on:

commit: 9c0826a5 Add linux-next specific files for 20251107
git tree: linux-next
kernel config: https://syzkaller.appspot.com/x/.config?x=4f8fcc6438a785e7
dashboard link: https://syzkaller.appspot.com/bug?extid=0b2e79f91ff6579bfa5b
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
patch: https://syzkaller.appspot.com/x/patch.diff?x=167110b4580000