[syzbot] [ntfs3?] WARNING in attr_data_get_block_locked

[syzbot] [ntfs3?] WARNING in attr_data_get_block_locked

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    956b9cbd7f15 Merge tag 'kbuild-fixes-7.0-1' of git://git.k..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=148bb15a580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=65722f41f7edc17e
dashboard link: https://syzkaller.appspot.com/bug?extid=c1e9aedbd913fadad617
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14f61ffa580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15833b3a580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-956b9cbd.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f0b3757a15ed/vmlinux-956b9cbd.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c564e8613b4e/bzImage-956b9cbd.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/30f6900c6fc3/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c1e9aedbd913fadad617@syzkaller.appspotmail.com

------------[ cut here ]------------
1
WARNING: fs/ntfs3/attrib.c:1222 at attr_data_get_block_locked+0x174a/0x22a0 fs/ntfs3/attrib.c:1222, CPU#0: syz.0.17/5462
Modules linked in:
CPU: 0 UID: 0 PID: 5462 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:attr_data_get_block_locked+0x174a/0x22a0 fs/ntfs3/attrib.c:1222
Code: 89 ee 49 89 d6 e8 d6 19 a6 fe 4d 89 f2 44 89 ac 24 bc 00 00 00 45 29 ea 73 1e e8 01 18 a6 fe e9 47 f9 ff ff e8 f7 17 a6 fe 90 <0f> 0b 90 41 bf ea ff ff ff e9 d6 fa ff ff 48 b8 00 00 00 00 00 fc
RSP: 0018:ffffc900049079c0 EFLAGS: 00010293
RAX: ffffffff831f83a9 RBX: 00000000ffffffff RCX: ffff888000ea0000
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 00000000ffffffff
RBP: ffffc90004907be8 R08: 0000000000000000 R09: 1ffff11002487041
R10: dffffc0000000000 R11: ffffed1002487042 R12: 0000000000000002
R13: dffffc0000000000 R14: 0000000000002000 R15: 0000000000000007
FS:  000055558ba85500(0000) GS:ffff88808ca5b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd19d7909c0 CR3: 0000000012819000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 attr_data_get_block+0x250/0x310 fs/ntfs3/attrib.c:982
 ntfs_fallocate+0xfac/0x1220 fs/ntfs3/file.c:677
 vfs_fallocate+0x669/0x7e0 fs/open.c:340
 ksys_fallocate fs/open.c:364 [inline]
 __do_sys_fallocate fs/open.c:369 [inline]
 __se_sys_fallocate fs/open.c:367 [inline]
 __x64_sys_fallocate+0xc0/0x110 fs/open.c:367
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1e3d39c629
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffbfb65448 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007f1e3d615fa0 RCX: 00007f1e3d39c629
RDX: 0000000000007351 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 00007f1e3d432b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000008001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1e3d615fac R14: 00007f1e3d615fa0 R15: 00007f1e3d615fa0
 </TASK>


---
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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
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(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
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If you want to undo deduplication, reply with:
#syz undup

Re: [syzbot] [ntfs3?] WARNING in attr_data_get_block_locked

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
lost connection to test machine



Tested on:

commit:         8a30aeb0 Merge tag 'nfsd-7.0-2' of git://git.kernel.or..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16dd5ed6580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9407f5fef8dc9d23
dashboard link: https://syzkaller.appspot.com/bug?extid=c1e9aedbd913fadad617
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=10917352580000

Re: [syzbot] [ntfs3?] WARNING in attr_data_get_block_locked

[syzbot]

Hello,

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

failed to copy syz-executor to VM: failed to run ["scp" "-P" "37514" "-F" "/dev/null" "-o" "UserKnownHostsFile=/dev/null" "-o" "IdentitiesOnly=yes" "-o" "BatchMode=yes" "-o" "StrictHostKeyChecking=no" "-o" "ConnectTimeout=10" "/syzkaller/jobs/linux/gopath/src/github.com/google/syzkaller/bin/linux_amd64/syz-executor" "root@localhost:/syz-executor"]: exit status 1



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-build209602508=/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 746545b8b1e4
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=746545b8b1e4c3a128db8652b340d3df90ce61db -X github.com/google/syzkaller/prog.gitRevisionDate=20260218-171117"  ./sys/syz-sysgen | grep -q false || go install -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=746545b8b1e4c3a128db8652b340d3df90ce61db -X github.com/google/syzkaller/prog.gitRevisionDate=20260218-171117"  ./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=746545b8b1e4c3a128db8652b340d3df90ce61db -X github.com/google/syzkaller/prog.gitRevisionDate=20260218-171117"  -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=\"746545b8b1e4c3a128db8652b340d3df90ce61db\"
/usr/bin/ld: /tmp/ccyhXpL5.o: in function `Connection::Connect(char const*, char const*)':
executor.cc:(.text._ZN10Connection7ConnectEPKcS1_[_ZN10Connection7ConnectEPKcS1_]+0x386): 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



Tested on:

commit:         8a30aeb0 Merge tag 'nfsd-7.0-2' of git://git.kernel.or..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=9407f5fef8dc9d23
dashboard link: https://syzkaller.appspot.com/bug?extid=c1e9aedbd913fadad617
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=16f472da580000