Re: [syzbot] [jffs2?] KASAN: invalid-free in jffs2_free_inode

From: syzbot

Date: Sun Aug 23 2026 - 11:15:17 EST

Hello,

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

type thunderbolt registered
[ 5.109762][ T1] RAPL PMU: API unit is 2^-32 Joules, 0 fixed counters, 10737418240 ms ovfl timer
[ 5.167027][ T1] kvm_amd: CPU 1 isn't AMD or Hygon
[ 5.170858][ T1] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x257a472b559, max_idle_ns: 440795210424 ns
[ 5.178905][ T1] clocksource: Switched to clocksource tsc
[ 5.184715][ T77] kworker/u33:0 (77) used greatest stack depth: 27720 bytes left
[ 5.222205][ T1] Initialise system trusted keyrings
[ 5.227062][ T1] workingset: timestamp_bits=40 (anon: 35) max_order=20 bucket_order=0 (anon: 0)
[ 5.238398][ T1] DLM installed
[ 5.244470][ T1] squashfs: version 4.0 (2009/01/31) Phillip Lougher
[ 5.252618][ T1] NFS: Registering the id_resolver key type
[ 5.256814][ T1] Key type id_resolver registered
[ 5.260341][ T1] Key type id_legacy registered
[ 5.263954][ T1] nfs4filelayout_init: NFSv4 File Layout Driver Registering...
[ 5.269476][ T1] nfs4flexfilelayout_init: NFSv4 Flexfile Layout Driver Registering...
[ 5.277246][ T1] smbdirect: subsystem loading...
[ 5.284270][ T1] smbdirect: subsystem loaded
[ 5.297332][ T1] Key type cifs.spnego registered
[ 5.301670][ T1] Key type cifs.idmap registered
[ 5.308638][ T1] ntfs3: Enabled Linux POSIX ACLs support
[ 5.312587][ T1] ntfs3: Read-only LZX/Xpress compression included
[ 5.317633][ T1] jffs2: version 2.2. (NAND) (SUMMARY) © 2001-2006 Red Hat, Inc.
[ 5.325326][ T1] romfs: ROMFS MTD (C) 2007 Red Hat, Inc.
[ 5.329463][ T1] QNX4 filesystem 0.2.3 registered.
[ 5.333045][ T1] qnx6: QNX6 filesystem 1.0.0 registered.
[ 5.337736][ T1] fuse: init (API version 7.45)
[ 5.344075][ T1] orangefs_debugfs_init: called with debug mask: :none: :0:
[ 5.350293][ T1] orangefs_init: module version upstream loaded
[ 5.355119][ T1] JFS: nTxBlock = 8192, nTxLock = 65536
[ 5.365251][ T1] SGI XFS with ACLs, security attributes, realtime, scrub, repair, quota, no debug enabled
[ 5.377405][ T1] 9p: Installing v9fs 9p2000 file system support
[ 5.382232][ T1] NILFS version 2 loaded
[ 5.385504][ T1] befs: version: 0.9.3
[ 5.388121][ T1] ocfs2: Registered cluster interface o2cb
[ 5.391953][ T1] ocfs2: Registered cluster interface user
[ 5.395885][ T1] OCFS2 User DLM kernel interface loaded
[ 5.408845][ T1] gfs2: GFS2 installed
[ 5.419335][ T1] ceph: loaded (mds proto 32)
[ 5.428781][ T1] NET: Registered PF_ALG protocol family
[ 5.431894][ T1] async_tx: api initialized (async)
[ 5.434333][ T1] Key type asymmetric registered
[ 5.436773][ T1] Asymmetric key parser 'x509' registered
[ 5.440129][ T1] Asymmetric key parser 'pkcs8' registered
[ 5.443024][ T1] Key type pkcs7_test registered
[ 5.446111][ T1] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 239)
[ 5.461472][ T1] io scheduler mq-deadline registered
[ 5.465636][ T1] io scheduler kyber registered
[ 5.469656][ T1] io scheduler bfq registered
[ 5.482630][ T176] kworker/u33:4 (176) used greatest stack depth: 26904 bytes left
[ 5.517634][ T1] ACPI: \_SB_.GSIE: Enabled at IRQ 20
[ 5.528481][ T1] pcieport 0000:00:04.0: PME: Signaling with IRQ 25
[ 5.534899][ T1] pcieport 0000:00:04.0: AER: enabled with IRQ 26
[ 5.541931][ T1] input: Power Button as /devices/platform/LNXPWRBN:00/input/input0
[ 5.546889][ T1] ACPI: button: Power Button [PWRF]
[ 5.963676][ T1] ioatdma: Intel(R) QuickData Technology Driver 5.00
[ 6.008197][ T1] ACPI: \_SB_.GSIF: Enabled at IRQ 21
[ 6.049667][ T1] ACPI: \_SB_.GSIH: Enabled at IRQ 23
[ 6.348011][ T1] N_HDLC line discipline registered with maxframe=4096
[ 6.352201][ T1] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
[ 6.359290][ T1] 00:04: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
[ 6.390332][ T1] Non-volatile memory driver v1.3
[ 6.401620][ T1] usbcore: registered new interface driver xillyusb
[ 6.409476][ T1] ACPI: bus type drm_connector registered
[ 6.416850][ T1] [drm] Initialized vgem 1.0.0 for vgem on minor 0
[ 6.420827][ T1] usbcore: registered new interface driver udl
[ 6.426172][ T1] [drm] pci: virtio-vga detected at 0000:00:01.0
[ 6.430771][ T1] virtio-pci 0000:00:01.0: vgaarb: deactivate vga console
[ 6.456693][ T1] Console: switching to colour dummy device 80x25
[ 6.462566][ T1] [drm] features: -virgl +edid -resource_blob -host_visible
[ 6.462578][ T1] [drm] features: -context_init -blob_alignment
[ 6.478536][ T1] [drm] number of scanouts: 1
[ 6.481658][ T1] [drm] number of cap sets: 0
[ 6.488101][ T1] ------------[ cut here ]------------
[ 6.491163][ T1] [PLANE:36:plane-1] pixel format with alpha exposed but blend mode not setup
[ 6.491173][ T1] WARNING: drivers/gpu/drm/drm_mode_config.c:872 at drm_mode_config_validate+0xfb4/0x1be0, CPU#0: swapper/0/1
[ 6.503437][ T1] Modules linked in:
[ 6.506212][ T1] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
[ 6.510887][ T1] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 6.516049][ T1] RIP: 0010:drm_mode_config_validate+0xfbb/0x1be0
[ 6.520305][ T1] Code: 00 49 8b 57 18 48 89 f8 48 c1 e8 03 0f b6 04 28 84 c0 74 08 3c 03 0f 8e 00 0b 00 00 48 8d 3d bc 0d 81 0b 41 8b b7 c8 00 00 00 <67> 48 0f b9 3a e9 fa fd ff ff 48 8b 5c 24 20 e8 81 9b 3c fc 48 8d
[ 6.533576][ T1] RSP: 0000:ffffc90000047908 EFLAGS: 00010246
[ 6.537738][ T1] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[ 6.542207][ T1] RDX: ffff888027607240 RSI: 0000000000000024 RDI: ffffffff914f8650
[ 6.546273][ T1] RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000
[ 6.550938][ T1] R10: 0000000000000001 R11: 0000000000000000 R12: ffffed1004f5a223
[ 6.555041][ T1] R13: ffffed1004f5a224 R14: 0000000000000001 R15: ffff888027ad1028
[ 6.559717][ T1] FS: 0000000000000000(0000) GS:ffff8880d5b88000(0000) knlGS:0000000000000000
[ 6.564530][ T1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 6.568142][ T1] CR2: ffff88817ffff000 CR3: 000000000eb94000 CR4: 0000000000352ef0
[ 6.573562][ T1] Call Trace:
[ 6.575850][ T1] <TASK>
[ 6.577858][ T1] ? queue_work_on+0xb7/0x1e0
[ 6.580881][ T1] drm_dev_register+0x56e/0x7b0
[ 6.583909][ T1] ? aperture_remove_conflicting_pci_devices+0x138/0x1e0
[ 6.588382][ T1] virtio_gpu_probe+0x271/0x360
[ 6.591589][ T1] virtio_dev_probe+0x6a2/0xbe0
[ 6.594462][ T1] ? __pfx_virtio_dev_probe+0x10/0x10
[ 6.597302][ T1] ? kernfs_create_link+0x1bd/0x240
[ 6.600098][ T1] ? kernfs_put+0x3f/0x60
[ 6.602625][ T1] ? sysfs_do_create_link_sd+0xbb/0x140
[ 6.605557][ T1] ? sysfs_create_link+0x68/0xc0
[ 6.608178][ T1] ? __pfx_virtio_dev_probe+0x10/0x10
[ 6.610892][ T1] really_probe+0x241/0xa60
[ 6.613780][ T1] __driver_probe_device+0x210/0x460
[ 6.617121][ T1] ? _raw_spin_unlock_irqrestore+0x52/0x80
[ 6.621118][ T1] driver_probe_device+0x4a/0x140
[ 6.624470][ T1] __driver_attach+0x21f/0x5b0
[ 6.627695][ T1] ? __pfx___driver_attach+0x10/0x10
[ 6.630495][ T1] bus_for_each_dev+0x13e/0x1d0
[ 6.633430][ T1] ? __pfx_bus_for_each_dev+0x10/0x10
[ 6.637053][ T1] ? bus_add_driver+0x2b5/0x5b0
[ 6.640044][ T1] bus_add_driver+0x305/0x5b0
[ 6.643236][ T1] driver_register+0x1e2/0x360
[ 6.646500][ T1] ? __pfx_virtio_gpu_driver_init+0x10/0x10
[ 6.650451][ T1] virtio_gpu_driver_init+0xc9/0x170
[ 6.654024][ T1] do_one_initcall+0x11c/0x6f0
[ 6.657271][ T1] ? __pfx_do_one_initcall+0x10/0x10
[ 6.660832][ T1] ? kernel_init_freeable+0x4ca/0x7b0
[ 6.664437][ T1] kernel_init_freeable+0x6ea/0x7b0
[ 6.668019][ T1] ? __pfx_kernel_init+0x10/0x10
[ 6.671347][ T1] kernel_init+0x21/0x1e0
[ 6.674275][ T1] ? __pfx_kernel_init+0x10/0x10
[ 6.677647][ T1] ret_from_fork+0x730/0xd60
[ 6.680708][ T1] ? __pfx_ret_from_fork+0x10/0x10
[ 6.684171][ T1] ? __switch_to+0x800/0x10f0
[ 6.687421][ T1] ? __pfx_kernel_init+0x10/0x10
[ 6.690358][ T1] ret_from_fork_asm+0x1a/0x30
[ 6.692765][ T1] </TASK>
[ 6.694318][ T1] Kernel panic - not syncing: kernel: panic_on_warn set ...
[ 6.697389][ T1] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
[ 6.697389][ T1] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 6.704590][ T1] Call Trace:
[ 6.704590][ T1] <TASK>
[ 6.704590][ T1] dump_stack_lvl+0x100/0x190
[ 6.714566][ T1] vpanic+0x553/0x970
[ 6.714566][ T1] ? __pfx_vpanic+0x10/0x10
[ 6.714566][ T1] panic+0xd1/0xe0
[ 6.714566][ T1] ? __pfx_panic+0x10/0x10
[ 6.724557][ T1] check_panic_on_warn.cold+0x19/0x34
[ 6.724557][ T1] ? drm_mode_config_validate+0xfb4/0x1be0
[ 6.724557][ T1] __warn.cold+0x191/0x318
[ 6.724557][ T1] __report_bug+0x30f/0x440
[ 6.734608][ T1] ? drm_mode_config_validate+0xfb4/0x1be0
[ 6.734608][ T1] ? __pfx___report_bug+0x10/0x10
[ 6.734608][ T1] ? __pfx___might_resched+0x10/0x10
[ 6.734608][ T1] ? schedule_timeout+0x161/0x280
[ 6.744572][ T1] report_bug_entry+0xe2/0x290
[ 6.744572][ T1] ? drm_mode_config_validate+0xfbb/0x1be0
[ 6.744572][ T1] handle_bug+0x1cd/0x2a0
[ 6.744572][ T1] exc_invalid_op+0x17/0x50
[ 6.754606][ T1] asm_exc_invalid_op+0x1a/0x20
[ 6.754606][ T1] RIP: 0010:drm_mode_config_validate+0xfbb/0x1be0
[ 6.754606][ T1] Code: 00 49 8b 57 18 48 89 f8 48 c1 e8 03 0f b6 04 28 84 c0 74 08 3c 03 0f 8e 00 0b 00 00 48 8d 3d bc 0d 81 0b 41 8b b7 c8 00 00 00 <67> 48 0f b9 3a e9 fa fd ff ff 48 8b 5c 24 20 e8 81 9b 3c fc 48 8d
[ 6.764562][ T1] RSP: 0000:ffffc90000047908 EFLAGS: 00010246
[ 6.774538][ T1] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[ 6.774538][ T1] RDX: ffff888027607240 RSI: 0000000000000024 RDI: ffffffff914f8650
[ 6.784538][ T1] RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000
[ 6.784538][ T1] R10: 0000000000000001 R11: 0000000000000000 R12: ffffed1004f5a223
[ 6.794650][ T1] R13: ffffed1004f5a224 R14: 0000000000000001 R15: ffff888027ad1028
[ 6.794650][ T1] ? drm_mode_config_validate+0xf76/0x1be0
[ 6.804557][ T1] ? queue_work_on+0xb7/0x1e0
[ 6.804557][ T1] drm_dev_register+0x56e/0x7b0
[ 6.804557][ T1] ? aperture_remove_conflicting_pci_devices+0x138/0x1e0
[ 6.814658][ T1] virtio_gpu_probe+0x271/0x360
[ 6.814658][ T1] virtio_dev_probe+0x6a2/0xbe0
[ 6.814658][ T1] ? __pfx_virtio_dev_probe+0x10/0x10
[ 6.814658][ T1] ? kernfs_create_link+0x1bd/0x240
[ 6.824614][ T1] ? kernfs_put+0x3f/0x60
[ 6.824614][ T1] ? sysfs_do_create_link_sd+0xbb/0x140
[ 6.824614][ T1] ? sysfs_create_link+0x68/0xc0
[ 6.824614][ T1] ? __pfx_virtio_dev_probe+0x10/0x10
[ 6.834654][ T1] really_probe+0x241/0xa60
[ 6.834654][ T1] __driver_probe_device+0x210/0x460
[ 6.834654][ T1] ? _raw_spin_unlock_irqrestore+0x52/0x80
[ 6.844578][ T1] driver_probe_device+0x4a/0x140
[ 6.844578][ T1] __driver_attach+0x21f/0x5b0
[ 6.844578][ T1] ? __pfx___driver_attach+0x10/0x10
[ 6.844578][ T1] bus_for_each_dev+0x13e/0x1d0
[ 6.854598][ T1] ? __pfx_bus_for_each_dev+0x10/0x10
[ 6.854598][ T1] ? bus_add_driver+0x2b5/0x5b0
[ 6.854598][ T1] bus_add_driver+0x305/0x5b0
[ 6.854598][ T1] driver_register+0x1e2/0x360
[ 6.864548][ T1] ? __pfx_virtio_gpu_driver_init+0x10/0x10
[ 6.864548][ T1] virtio_gpu_driver_init+0xc9/0x170
[ 6.874559][ T1] do_one_initcall+0x11c/0x6f0
[ 6.874656][ T1] ? __pfx_do_one_initcall+0x10/0x10
[ 6.874656][ T1] ? kernel_init_freeable+0x4ca/0x7b0
[ 6.884575][ T1] kernel_init_freeable+0x6ea/0x7b0
[ 6.884575][ T1] ? __pfx_kernel_init+0x10/0x10
[ 6.884575][ T1] kernel_init+0x21/0x1e0
[ 6.884575][ T1] ? __pfx_kernel_init+0x10/0x10
[ 6.894652][ T1] ret_from_fork+0x730/0xd60
[ 6.894652][ T1] ? __pfx_ret_from_fork+0x10/0x10
[ 6.894652][ T1] ? __switch_to+0x800/0x10f0
[ 6.904553][ T1] ? __pfx_kernel_init+0x10/0x10
[ 6.904553][ T1] ret_from_fork_asm+0x1a/0x30
[ 6.904553][ T1] </TASK>
[ 6.904553][ T1] Kernel Offset: disabled
[ 6.904553][ T1] 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-build600613633=/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 1e72964b011
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=1e72964b0111319984575e60f266d1fa0a98abb5 -X github.com/google/syzkaller/prog.gitRevisionDate=20260817-123423" ./sys/syz-sysgen | grep -q false || go install -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=1e72964b0111319984575e60f266d1fa0a98abb5 -X github.com/google/syzkaller/prog.gitRevisionDate=20260817-123423" ./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=1e72964b0111319984575e60f266d1fa0a98abb5 -X github.com/google/syzkaller/prog.gitRevisionDate=20260817-123423" -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=\"1e72964b0111319984575e60f266d1fa0a98abb5\"
/usr/bin/ld: /tmp/ccsT1b7a.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

Error text is too large and was truncated, full error text is at:
https://syzkaller.appspot.com/x/error.txt?x=1226d549580000

Tested on:

commit: 2709dd5a Merge tag 'sched-urgent-2026-08-22' of git://..
git tree: upstream
kernel config: https://syzkaller.appspot.com/x/.config?x=b0978f5ed2905b98
dashboard link: https://syzkaller.appspot.com/bug?extid=675e84fdf3dde67b4946
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
patch: https://syzkaller.appspot.com/x/patch.diff?x=11bcc625580000