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

syzbot
2025-11-07T13:06:03Z

Hello,

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

970707b2'
[ 21.974518][ T1] zswap: loaded using pool 842
[ 21.982912][ T1] Demotion targets for Node 0: null
[ 21.988200][ T1] Demotion targets for Node 1: null
[ 21.993522][ T1] debug_vm_pgtable: [debug_vm_pgtable ]: Validating architecture page table helpers
[ 24.797559][ T1] Key type .fscrypt registered
[ 24.802517][ T1] Key type fscrypt-provisioning registered
[ 24.811687][ T1] kAFS: Red Hat AFS client v0.1 registering.
[ 24.837336][ T1] Btrfs loaded, assert=on, zoned=yes, fsverity=yes
[ 24.844500][ T1] Key type big_key registered
[ 24.849260][ T1] Key type encrypted registered
[ 24.854106][ T1] AppArmor: AppArmor sha256 policy hashing enabled
[ 24.860731][ T1] ima: No TPM chip found, activating TPM-bypass!
[ 24.867175][ T1] Loading compiled-in module X.509 certificates
[ 24.894366][ T1] Loaded X.509 cert 'Build time autogenerated kernel key: de56e482b03ecd8d239a6590830ee0f7970707b2'
[ 24.905348][ T1] ima: Allocated hash algorithm: sha256
[ 24.911357][ T1] ima: No architecture policies found
[ 24.917173][ T1] evm: Initialising EVM extended attributes:
[ 24.923151][ T1] evm: security.selinux (disabled)
[ 24.928238][ T1] evm: security.SMACK64 (disabled)
[ 24.933355][ T1] evm: security.SMACK64EXEC (disabled)
[ 24.938815][ T1] evm: security.SMACK64TRANSMUTE (disabled)
[ 24.944683][ T1] evm: security.SMACK64MMAP (disabled)
[ 24.950134][ T1] evm: security.apparmor
[ 24.954370][ T1] evm: security.ima
[ 24.958145][ T1] evm: security.capability
[ 24.962553][ T1] evm: HMAC attrs: 0x1
[ 24.968988][ T1] PM: Magic number: 1:272:986
[ 24.973842][ T1] net rose20: hash matches
[ 24.978361][ T1] dsp_pipeline hwec: hash matches
[ 24.984302][ T1] netconsole: network logging started
[ 24.990369][ T1] gtp: GTP module loaded (pdp ctx size 128 bytes)
[ 25.002183][ T1] rdma_rxe: loaded
[ 25.007915][ T1] cfg80211: Loading compiled-in X.509 certificates for regulatory database
[ 25.019009][ T1] Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
[ 25.026972][ T1] Loaded X.509 cert 'wens: 61c038651aabdcf94bd0ac7ff06c7248db18c600'
[ 25.038011][ T1] clk: Disabling unused clocks
[ 25.043143][ T1] ALSA device list:
[ 25.044532][ T793] faux_driver regulatory: Direct firmware load for regulatory.db failed with error -2
[ 25.046952][ T1] #0: Dummy 1
[ 25.046964][ T1] #1: Loopback 1
[ 25.056659][ T793] faux_driver regulatory: Falling back to sysfs fallback for: regulatory.db
[ 25.072704][ T1] #2: Virtual MIDI Card 1
[ 25.080464][ T1] check access for rdinit=/init failed: -2, ignoring
[ 25.087134][ T1] md: Waiting for all devices to be available before autodetect
[ 25.094786][ T1] md: If you don't use raid, use raid=noautodetect
[ 25.101311][ T1] md: Autodetecting RAID arrays.
[ 25.106328][ T1] md: autorun ...
[ 25.109974][ T1] md: ... autorun DONE.
[ 25.202934][ T1] EXT4-fs (sda1): orphan cleanup on readonly fs
[ 25.211522][ T1] EXT4-fs (sda1): mounted filesystem 4f91c6db-4997-4bb4-91b8-7e83a20c1bf1 ro with ordered data mode. Quota mode: none.
[ 25.224301][ T1] VFS: Mounted root (ext4 filesystem) readonly on device 8:1.
[ 25.234167][ T1] devtmpfs: mounted
[ 25.311718][ T1] Freeing unused kernel image (initmem) memory: 26112K
[ 25.322460][ T1] Write protecting the kernel read-only data: 212992k
[ 25.341592][ T1] Freeing unused kernel image (text/rodata gap) memory: 1436K
[ 25.353977][ T1] Freeing unused kernel image (rodata/data gap) memory: 1240K
[ 25.458459][ T1] x86/mm: Checked W+X mappings: passed, no W+X pages found.
[ 25.466412][ T1] x86/mm: Checking user space page tables
[ 25.555644][ T1] x86/mm: Checked W+X mappings: passed, no W+X pages found.
[ 25.568271][ T1] Failed to set sysctl parameter 'max_rcu_stall_to_panic=1': parameter not found
[ 25.578126][ T1] Run /sbin/init as init process
[ 25.833630][ T5157] mount (5157) used greatest stack depth: 23816 bytes left
[ 25.885026][ T5158] EXT4-fs (sda1): re-mounted 4f91c6db-4997-4bb4-91b8-7e83a20c1bf1 r/w.
[ 25.897827][ T5158] mount (5158) used greatest stack depth: 23624 bytes left
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
[ 26.026823][ T5162] mount (5162) used greatest stack depth: 21672 bytes left
Starting syslogd: OK
Starting acpid: [ 26.448559][ T5177] acpid (5177) used greatest stack depth: 20968 bytes left
OK
Starting klogd: OK
Running sysctl: OK
Populating /dev using udev: [ 27.039741][ T5192] udevd[5192]: starting version 3.2.14
[ 27.206253][ T5193] udevd[5193]: starting eudev-3.2.14
[ 27.210256][ T5192] udevd (5192) used greatest stack depth: 18088 bytes left
done
Starting system message bus: done
Starting iptables: OK
Starting network: OK
Starting dhcpcd...
dhcpcd-10.2.0 starting
[ 46.776298][ T5487] ------------[ cut here ]------------
[ 46.781953][ T5487] WARNING: ./include/linux/ns_common.h:314 at nsfs_evict+0x18e/0x200, CPU#1: dhcpcd/5487
[ 46.792403][ T5487] Modules linked in:
[ 46.796337][ T5487] CPU: 1 UID: 0 PID: 5487 Comm: dhcpcd Not tainted syzkaller #0 PREEMPT(full)
[ 46.805316][ T5487] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
[ 46.815409][ T5487] RIP: 0010:nsfs_evict+0x18e/0x200
[ 46.820563][ T5487] 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
[ 46.840207][ T5487] RSP: 0018:ffffc900039afa28 EFLAGS: 00010293
[ 46.846262][ T5487] RAX: ffffffff824b0e3d RBX: ffffffff9a180fd8 RCX: ffff88802e6d1e80
[ 46.854272][ T5487] RDX: 0000000000000000 RSI: 00000000effffff8 RDI: 00000000effffff8
[ 46.862272][ T5487] RBP: 00000000effffff8 R08: ffffffff9a181093 R09: 1ffffffff3430212
[ 46.870298][ T5487] R10: dffffc0000000000 R11: fffffbfff3430213 R12: dffffc0000000000
[ 46.878265][ T5487] R13: 1ffffffff34301fe R14: ffff88807a7cf248 R15: ffffffff9a180ff0
[ 46.886301][ T5487] FS: 00007f5b3bc92740(0000) GS:ffff888125b78000(0000) knlGS:0000000000000000
[ 46.895267][ T5487] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 46.901937][ T5487] CR2: 0000563ddc89c4a0 CR3: 000000006f210000 CR4: 00000000003526f0
[ 46.909942][ T5487] Call Trace:
[ 46.913233][ T5487] <TASK>
[ 46.916163][ T5487] ? __pfx_nsfs_evict+0x10/0x10
[ 46.921065][ T5487] evict+0x5f4/0xae0
[ 46.925002][ T5487] ? __pfx_evict+0x10/0x10
[ 46.929539][ T5487] ? _raw_spin_unlock+0x28/0x50
[ 46.934391][ T5487] ? iput+0xce7/0x1050
[ 46.938444][ T5487] __dentry_kill+0x209/0x660
[ 46.943076][ T5487] ? dput+0x37/0x2b0
[ 46.946973][ T5487] dput+0x19f/0x2b0
[ 46.950799][ T5487] path_put+0x39/0x60
[ 46.954833][ T5487] vfs_statx+0x36e/0x550
[ 46.959106][ T5487] ? __pfx_vfs_statx+0x10/0x10
[ 46.963873][ T5487] ? strncpy_from_user+0x150/0x2c0
[ 46.969019][ T5487] ? getname_flags+0x1e5/0x540
[ 46.973824][ T5487] vfs_fstatat+0x118/0x170
[ 46.978223][ T5487] __x64_sys_newfstatat+0x116/0x190
[ 46.983447][ T5487] ? __pfx___x64_sys_newfstatat+0x10/0x10
[ 46.989202][ T5487] ? do_syscall_64+0xbe/0xfa0
[ 46.993883][ T5487] do_syscall_64+0xfa/0xfa0
[ 46.998365][ T5487] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 47.004477][ T5487] ? clear_bhb_loop+0x60/0xb0
[ 47.009189][ T5487] entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 47.015094][ T5487] RIP: 0033:0x7f5b3bd86b0a
[ 47.019580][ T5487] 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
[ 47.039327][ T5487] RSP: 002b:00007ffc209e1718 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
[ 47.047744][ T5487] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f5b3bd86b0a
[ 47.055741][ T5487] RDX: 00007ffc209e1720 RSI: 0000563ddc8c4557 RDI: 00000000ffffff9c
[ 47.063747][ T5487] RBP: 00007ffc209e3eb8 R08: 0000000000000000 R09: 0000000000000000
[ 47.071763][ T5487] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc209e2890
[ 47.079775][ T5487] R13: 0000563e1752d8a0 R14: 0000000000001000 R15: 00007f5b3bc926c8
[ 47.087762][ T5487] </TASK>
[ 47.090819][ T5487] Kernel panic - not syncing: kernel: panic_on_warn set ...
[ 47.098094][ T5487] CPU: 1 UID: 0 PID: 5487 Comm: dhcpcd Not tainted syzkaller #0 PREEMPT(full)
[ 47.107008][ T5487] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
[ 47.117042][ T5487] Call Trace:
[ 47.120305][ T5487] <TASK>
[ 47.123217][ T5487] dump_stack_lvl+0x99/0x250
[ 47.127804][ T5487] ? __asan_memcpy+0x40/0x70
[ 47.132372][ T5487] ? __pfx_dump_stack_lvl+0x10/0x10
[ 47.137549][ T5487] ? __pfx__printk+0x10/0x10
[ 47.142123][ T5487] vpanic+0x237/0x6d0
[ 47.146171][ T5487] ? __pfx_vpanic+0x10/0x10
[ 47.150648][ T5487] ? is_bpf_text_address+0x292/0x2b0
[ 47.155913][ T5487] ? is_bpf_text_address+0x26/0x2b0
[ 47.161096][ T5487] panic+0xb9/0xc0
[ 47.164798][ T5487] ? __pfx_panic+0x10/0x10
[ 47.169202][ T5487] __warn+0x334/0x4c0
[ 47.173160][ T5487] ? nsfs_evict+0x18e/0x200
[ 47.177641][ T5487] ? nsfs_evict+0x18e/0x200
[ 47.182126][ T5487] report_bug+0x2be/0x4f0
[ 47.186436][ T5487] ? nsfs_evict+0x18e/0x200
[ 47.190915][ T5487] ? nsfs_evict+0x18e/0x200
[ 47.195395][ T5487] ? nsfs_evict+0x190/0x200
[ 47.199876][ T5487] handle_bug+0x84/0x160
[ 47.204114][ T5487] exc_invalid_op+0x1a/0x50
[ 47.208629][ T5487] asm_exc_invalid_op+0x1a/0x20
[ 47.213486][ T5487] RIP: 0010:nsfs_evict+0x18e/0x200
[ 47.218605][ T5487] 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
[ 47.238215][ T5487] RSP: 0018:ffffc900039afa28 EFLAGS: 00010293
[ 47.244897][ T5487] RAX: ffffffff824b0e3d RBX: ffffffff9a180fd8 RCX: ffff88802e6d1e80
[ 47.252860][ T5487] RDX: 0000000000000000 RSI: 00000000effffff8 RDI: 00000000effffff8
[ 47.260822][ T5487] RBP: 00000000effffff8 R08: ffffffff9a181093 R09: 1ffffffff3430212
[ 47.268783][ T5487] R10: dffffc0000000000 R11: fffffbfff3430213 R12: dffffc0000000000
[ 47.276756][ T5487] R13: 1ffffffff34301fe R14: ffff88807a7cf248 R15: ffffffff9a180ff0
[ 47.284739][ T5487] ? nsfs_evict+0x18d/0x200
[ 47.289248][ T5487] ? nsfs_evict+0x18d/0x200
[ 47.293742][ T5487] ? __pfx_nsfs_evict+0x10/0x10
[ 47.298581][ T5487] evict+0x5f4/0xae0
[ 47.302483][ T5487] ? __pfx_evict+0x10/0x10
[ 47.306894][ T5487] ? _raw_spin_unlock+0x28/0x50
[ 47.311737][ T5487] ? iput+0xce7/0x1050
[ 47.315801][ T5487] __dentry_kill+0x209/0x660
[ 47.320380][ T5487] ? dput+0x37/0x2b0
[ 47.324265][ T5487] dput+0x19f/0x2b0
[ 47.328059][ T5487] path_put+0x39/0x60
[ 47.332030][ T5487] vfs_statx+0x36e/0x550
[ 47.336284][ T5487] ? __pfx_vfs_statx+0x10/0x10
[ 47.341048][ T5487] ? strncpy_from_user+0x150/0x2c0
[ 47.346174][ T5487] ? getname_flags+0x1e5/0x540
[ 47.350940][ T5487] vfs_fstatat+0x118/0x170
[ 47.355369][ T5487] __x64_sys_newfstatat+0x116/0x190
[ 47.360640][ T5487] ? __pfx___x64_sys_newfstatat+0x10/0x10
[ 47.366383][ T5487] ? do_syscall_64+0xbe/0xfa0
[ 47.371078][ T5487] do_syscall_64+0xfa/0xfa0
[ 47.375592][ T5487] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 47.381648][ T5487] ? clear_bhb_loop+0x60/0xb0
[ 47.386425][ T5487] entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 47.392748][ T5487] RIP: 0033:0x7f5b3bd86b0a
[ 47.397245][ T5487] 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
[ 47.416866][ T5487] RSP: 002b:00007ffc209e1718 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
[ 47.425277][ T5487] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f5b3bd86b0a
[ 47.433236][ T5487] RDX: 00007ffc209e1720 RSI: 0000563ddc8c4557 RDI: 00000000ffffff9c
[ 47.441215][ T5487] RBP: 00007ffc209e3eb8 R08: 0000000000000000 R09: 0000000000000000
[ 47.449171][ T5487] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc209e2890
[ 47.457124][ T5487] R13: 0000563e1752d8a0 R14: 0000000000001000 R15: 00007f5b3bc926c8
[ 47.465097][ T5487] </TASK>
[ 47.468346][ T5487] Kernel Offset: disabled
[ 47.472660][ T5487] 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-build1222549954=/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/ccl2NrsB.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=17b05084580000

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=11e03812580000