Re: [syzbot] [kernel?] KASAN: slab-use-after-free Write in bus_for_each_drv

[syzbot <syzbot+9cb1ac7fce4944ba9165@syzkaller.appspotmail.com>]

Hello,

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

-0x00000000b8600000] (64MB)
[   11.599912][    T1] ACPI: bus type thunderbolt registered
[   11.742383][    T1] RAPL PMU: API unit is 2^-32 Joules, 0 fixed counters, 10737418240 ms ovfl timer
[   11.808342][   T70] kworker/u8:3 (70) used greatest stack depth: 28424 bytes left
[   11.808482][   T71] kworker/u8:5 (71) used greatest stack depth: 27728 bytes left
[   11.908721][    T1] kvm_amd: CPU 1 isn't AMD or Hygon
[   11.908764][    T1] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x1fb63109b96, max_idle_ns: 440795265316 ns
[   11.909880][    T1] clocksource: Switched to clocksource tsc
[   11.959472][   T73] kworker/u8:5 (73) used greatest stack depth: 27312 bytes left
[   12.004111][   T75] kworker/u8:5 (75) used greatest stack depth: 26680 bytes left
[   12.171591][    T1] Initialise system trusted keyrings
[   12.188484][    T1] workingset: timestamp_bits=40 (anon: 35) max_order=21 bucket_order=0 (anon: 0)
[   12.232071][    T1] DLM installed
[   12.270720][    T1] squashfs: version 4.0 (2009/01/31) Phillip Lougher
[   12.310924][    T1] NFS: Registering the id_resolver key type
[   12.311151][    T1] Key type id_resolver registered
[   12.311167][    T1] Key type id_legacy registered
[   12.311698][    T1] nfs4filelayout_init: NFSv4 File Layout Driver Registering...
[   12.311932][    T1] nfs4flexfilelayout_init: NFSv4 Flexfile Layout Driver Registering...
[   12.349827][    T1] smbdirect: subsystem loading...
[   12.473464][    T1] smbdirect: subsystem loaded
[   12.556036][    T1] Key type cifs.spnego registered
[   12.557192][    T1] Key type cifs.idmap registered
[   12.612279][    T1] ntfs3: Enabled Linux POSIX ACLs support
[   12.612296][    T1] ntfs3: Read-only LZX/Xpress compression included
[   12.613918][    T1] jffs2: version 2.2. (NAND) (SUMMARY)  © 2001-2006 Red Hat, Inc.
[   12.707150][    T1] romfs: ROMFS MTD (C) 2007 Red Hat, Inc.
[   12.710929][    T1] QNX4 filesystem 0.2.3 registered.
[   12.728727][    T1] qnx6: QNX6 filesystem 1.0.0 registered.
[   12.777345][    T1] fuse: init (API version 7.45)
[   12.813692][    T1] orangefs_debugfs_init: called with debug mask: :none: :0:
[   12.827109][    T1] orangefs_init: module version upstream loaded
[   12.832698][    T1] JFS: nTxBlock = 8192, nTxLock = 65536
[   12.902685][    T1] SGI XFS with ACLs, security attributes, realtime, scrub, repair, quota, no debug enabled
[   12.939665][    T1] 9p: Installing v9fs 9p2000 file system support
[   12.942832][    T1] NILFS version 2 loaded
[   12.942854][    T1] befs: version: 0.9.3
[   12.946918][    T1] ocfs2: Registered cluster interface o2cb
[   12.958238][    T1] ocfs2: Registered cluster interface user
[   12.979796][    T1] OCFS2 User DLM kernel interface loaded
[   13.137006][    T1] gfs2: GFS2 installed
[   13.186192][    T1] ceph: loaded (mds proto 32)
[   13.239816][    T1] NET: Registered PF_ALG protocol family
[   13.241279][    T1] async_tx: api initialized (async)
[   13.241362][    T1] Key type asymmetric registered
[   13.241613][    T1] Asymmetric key parser 'x509' registered
[   13.241642][    T1] Asymmetric key parser 'pkcs8' registered
[   13.241663][    T1] Key type pkcs7_test registered
[   13.244006][    T1] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 239)
[   13.247405][    T1] io scheduler mq-deadline registered
[   13.247428][    T1] io scheduler kyber registered
[   13.251382][    T1] io scheduler bfq registered
[   13.274291][    T1] raid6: skipped pq benchmark and selected avx2x4
[   13.482571][    T1] input: Power Button as /devices/platform/LNXPWRBN:00/input/input0
[   13.514265][    T1] ACPI: button: Power Button [PWRF]
[   13.537302][    T1] input: Sleep Button as /devices/platform/LNXSLPBN:00/input/input1
[   13.568912][    T1] ACPI: button: Sleep Button [SLPF]
[   13.662280][    T1] ioatdma: Intel(R) QuickData Technology Driver 5.00
[   13.795622][   T10] ACPI: \_SB_.LNKC: Enabled at IRQ 11
[   13.796273][   T10] virtio-pci 0000:00:03.0: virtio_pci: leaving for legacy driver
[   13.911245][   T10] ACPI: \_SB_.LNKD: Enabled at IRQ 10
[   13.911473][   T10] virtio-pci 0000:00:04.0: virtio_pci: leaving for legacy driver
[   14.036923][   T10] ACPI: \_SB_.LNKB: Enabled at IRQ 10
[   14.037334][   T10] virtio-pci 0000:00:06.0: virtio_pci: leaving for legacy driver
[   14.134871][   T10] virtio-pci 0000:00:07.0: virtio_pci: leaving for legacy driver
[   14.455961][  T276] kworker/u8:3 (276) used greatest stack depth: 26536 bytes left
[   16.547826][    T1] N_HDLC line discipline registered with maxframe=4096
[   16.550769][    T1] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
[   16.605843][    T1] 00:02: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
[   16.671871][    T1] 00:03: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200) is a 16550A
[   16.730076][    T1] 00:04: ttyS2 at I/O 0x3e8 (irq = 6, base_baud = 115200) is a 16550A
[   16.805136][    T1] 00:05: ttyS3 at I/O 0x2e8 (irq = 7, base_baud = 115200) is a 16550A
[   16.949551][    T1] Non-volatile memory driver v1.3
[   17.132363][    T1] usbcore: registered new interface driver xillyusb
[   17.183391][    T1] ACPI: bus type drm_connector registered
[   17.243108][    T1] [drm] Initialized vgem 1.0.0 for vgem on minor 0
[   17.314892][    T1] ------------[ cut here ]------------
[   17.314909][    T1] [PLANE:35:plane-0] pixel format with alpha exposed but blend mode not setup
[   17.314933][    T1] WARNING: drivers/gpu/drm/drm_mode_config.c:873 at drm_mode_config_validate+0x1c6d/0x1e60, CPU#0: swapper/0/1
[   17.315009][    T1] Modules linked in:
[   17.315074][    T1] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
[   17.315098][    T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
[   17.315123][    T1] RIP: 0010:drm_mode_config_validate+0x1cae/0x1e60
[   17.315929][    T1] Code: 0f 85 ae 00 00 00 4d 8d 77 10 8b 6d 00 4c 89 f0 48 c1 e8 03 80 3c 18 00 74 08 4c 89 f7 e8 5a d7 af fc 49 8b 16 4c 89 ef 89 ee <67> 48 0f b9 3a eb 05 e8 56 4a 44 fc 49 bd 00 00 00 00 00 fc ff df
[   17.315949][    T1] RSP: 0000:ffffc90000067810 EFLAGS: 00010246
[   17.315969][    T1] RAX: 1ffff11004bcd808 RBX: dffffc0000000000 RCX: ffff88801c6b5dc0
[   17.315986][    T1] RDX: ffff888025a56980 RSI: 0000000000000023 RDI: ffffffff8fbcf300
[   17.316002][    T1] RBP: 0000000000000023 R08: 0000000000000000 R09: 0000000000000000
[   17.316015][    T1] R10: dffffc0000000000 R11: fffffbfff1f63828 R12: dffffc0000000000
[   17.316031][    T1] R13: ffffffff8fbcf300 R14: ffff888025e6c040 R15: ffff888025e6c030
[   17.316047][    T1] FS:  0000000000000000(0000) GS:ffff888125be6000(0000) knlGS:0000000000000000
[   17.316065][    T1] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   17.316079][    T1] CR2: ffff88823ffff000 CR3: 000000000dfb0000 CR4: 00000000003526f0
[   17.316098][    T1] Call Trace:
[   17.316108][    T1]  <TASK>
[   17.316128][    T1]  ? debugfs_create_file_full+0x3f/0x60
[   17.316273][    T1]  drm_dev_register+0x7f/0xd80
[   17.316310][    T1]  vkms_create+0x40d/0x4f0
[   17.316337][    T1]  ? __pfx_vkms_init+0x10/0x10
[   17.316373][    T1]  vkms_init+0x57/0x80
[   17.316402][    T1]  do_one_initcall+0x250/0x870
[   17.316445][    T1]  ? __pfx_vkms_init+0x10/0x10
[   17.316473][    T1]  ? __pfx_do_one_initcall+0x10/0x10
[   17.316511][    T1]  ? kvm_clock_get_cycles+0x49/0x60
[   17.316543][    T1]  ? __pfx___schedule+0x10/0x10
[   17.316576][    T1]  ? clockevents_program_event+0x491/0x630
[   17.316607][    T1]  ? __hrtimer_rearm_deferred+0x99/0x4d0
[   17.318440][    T1]  ? irqentry_exit+0x218/0x910
[   17.318510][    T1]  ? lockdep_hardirqs_on+0x7b/0x110
[   17.318545][    T1]  ? irqentry_exit+0x218/0x910
[   17.318575][    T1]  ? trace_irq_disable+0x3b/0x140
[   17.318624][    T1]  ? next_arg+0x4a0/0x5e0
[   17.318660][    T1]  ? parameq+0x14d/0x170
[   17.318690][    T1]  ? parse_args+0x9c3/0xad0
[   17.318747][    T1]  ? rcu_is_watching+0x16/0xb0
[   17.318786][    T1]  do_initcall_level+0x10a/0x1a0
[   17.318830][    T1]  ? kernel_init+0x22/0x1d0
[   17.318867][    T1]  do_initcalls+0x59/0xa0
[   17.318908][    T1]  kernel_init_freeable+0x29d/0x3e0
[   17.318947][    T1]  ? __pfx_kernel_init+0x10/0x10
[   17.318987][    T1]  kernel_init+0x22/0x1d0
[   17.319029][    T1]  ? __pfx_kernel_init+0x10/0x10
[   17.319065][    T1]  ret_from_fork+0x514/0xb70
[   17.319106][    T1]  ? __pfx_ret_from_fork+0x10/0x10
[   17.321040][    T1]  ? __switch_to+0xc89/0x1420
[   17.321120][    T1]  ? __pfx_kernel_init+0x10/0x10
[   17.321163][    T1]  ret_from_fork_asm+0x1a/0x30
[   17.321202][    T1]  </TASK>
[   17.321228][    T1] Kernel panic - not syncing: kernel: panic_on_warn set ...
[   17.321250][    T1] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
[   17.321274][    T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
[   17.321288][    T1] Call Trace:
[   17.321298][    T1]  <TASK>
[   17.321307][    T1]  vpanic+0x56d/0xa60
[   17.321329][    T1]  ? __pfx__printk+0x10/0x10
[   17.321354][    T1]  ? __pfx_vpanic+0x10/0x10
[   17.321372][    T1]  ? is_bpf_text_address+0x292/0x2b0
[   17.321401][    T1]  ? is_bpf_text_address+0x26/0x2b0
[   17.321437][    T1]  panic+0xc5/0xd0
[   17.321457][    T1]  ? __pfx_panic+0x10/0x10
[   17.321487][    T1]  ? ret_from_fork_asm+0x1a/0x30
[   17.321513][    T1]  __warn+0x315/0x4c0
[   17.321532][    T1]  ? drm_mode_config_validate+0x1c6d/0x1e60
[   17.321568][    T1]  ? drm_mode_config_validate+0x1c6d/0x1e60
[   17.321596][    T1]  __report_bug+0x276/0x570
[   17.321625][    T1]  ? drm_mode_config_validate+0x1c6d/0x1e60
[   17.321656][    T1]  ? __pfx___report_bug+0x10/0x10
[   17.322207][    T1]  ? _raw_spin_unlock_irqrestore+0x30/0x80
[   17.322248][    T1]  ? rt_mutex_slowunlock+0x4ee/0xa30
[   17.322275][    T1]  report_bug_entry+0x19b/0x290
[   17.322306][    T1]  ? drm_mode_config_validate+0x1cae/0x1e60
[   17.322338][    T1]  ? drm_mode_config_validate+0x1cb3/0x1e60
[   17.322982][    T1]  handle_bug+0xce/0x200
[   17.323038][    T1]  exc_invalid_op+0x1a/0x50
[   17.323075][    T1]  asm_exc_invalid_op+0x1a/0x20
[   17.323101][    T1] RIP: 0010:drm_mode_config_validate+0x1cae/0x1e60
[   17.323142][    T1] Code: 0f 85 ae 00 00 00 4d 8d 77 10 8b 6d 00 4c 89 f0 48 c1 e8 03 80 3c 18 00 74 08 4c 89 f7 e8 5a d7 af fc 49 8b 16 4c 89 ef 89 ee <67> 48 0f b9 3a eb 05 e8 56 4a 44 fc 49 bd 00 00 00 00 00 fc ff df
[   17.323163][    T1] RSP: 0000:ffffc90000067810 EFLAGS: 00010246
[   17.323186][    T1] RAX: 1ffff11004bcd808 RBX: dffffc0000000000 RCX: ffff88801c6b5dc0
[   17.323205][    T1] RDX: ffff888025a56980 RSI: 0000000000000023 RDI: ffffffff8fbcf300
[   17.323222][    T1] RBP: 0000000000000023 R08: 0000000000000000 R09: 0000000000000000
[   17.323237][    T1] R10: dffffc0000000000 R11: fffffbfff1f63828 R12: dffffc0000000000
[   17.323388][    T1] R13: ffffffff8fbcf300 R14: ffff888025e6c040 R15: ffff888025e6c030
[   17.323437][    T1]  ? debugfs_create_file_full+0x3f/0x60
[   17.323476][    T1]  drm_dev_register+0x7f/0xd80
[   17.323517][    T1]  vkms_create+0x40d/0x4f0
[   17.323548][    T1]  ? __pfx_vkms_init+0x10/0x10
[   17.323582][    T1]  vkms_init+0x57/0x80
[   17.323617][    T1]  do_one_initcall+0x250/0x870
[   17.323655][    T1]  ? __pfx_vkms_init+0x10/0x10
[   17.323687][    T1]  ? __pfx_do_one_initcall+0x10/0x10
[   17.323731][    T1]  ? kvm_clock_get_cycles+0x49/0x60
[   17.324961][    T1]  ? __pfx___schedule+0x10/0x10
[   17.325015][    T1]  ? clockevents_program_event+0x491/0x630
[   17.325058][    T1]  ? __hrtimer_rearm_deferred+0x99/0x4d0
[   17.325107][    T1]  ? irqentry_exit+0x218/0x910
[   17.325950][    T1]  ? lockdep_hardirqs_on+0x7b/0x110
[   17.325977][    T1]  ? irqentry_exit+0x218/0x910
[   17.325999][    T1]  ? trace_irq_disable+0x3b/0x140
[   17.326037][    T1]  ? next_arg+0x4a0/0x5e0
[   17.326399][    T1]  ? parameq+0x14d/0x170
[   17.326436][    T1]  ? parse_args+0x9c3/0xad0
[   17.326488][    T1]  ? rcu_is_watching+0x16/0xb0
[   17.326530][    T1]  do_initcall_level+0x10a/0x1a0
[   17.326576][    T1]  ? kernel_init+0x22/0x1d0
[   17.326615][    T1]  do_initcalls+0x59/0xa0
[   17.326656][    T1]  kernel_init_freeable+0x29d/0x3e0
[   17.326695][    T1]  ? __pfx_kernel_init+0x10/0x10
[   17.326972][    T1]  kernel_init+0x22/0x1d0
[   17.327019][    T1]  ? __pfx_kernel_init+0x10/0x10
[   17.327052][    T1]  ret_from_fork+0x514/0xb70
[   17.327090][    T1]  ? __pfx_ret_from_fork+0x10/0x10
[   17.327123][    T1]  ? __switch_to+0xc89/0x1420
[   17.327166][    T1]  ? __pfx_kernel_init+0x10/0x10
[   17.327206][    T1]  ret_from_fork_asm+0x1a/0x30
[   17.327246][    T1]  </TASK>
[   17.327972][    T1] Kernel Offset: disabled


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-build3418809368=/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='go1.26.0'
GOWORK=''
PKG_CONFIG='pkg-config'

git status (err=<nil>)
HEAD detached at d4abbeacd53
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=d4abbeacd53add822a563e66a8ca9e64929b96ab -X github.com/google/syzkaller/prog.gitRevisionDate=20260804-103143"  ./sys/syz-sysgen | grep -q false || go install -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=d4abbeacd53add822a563e66a8ca9e64929b96ab -X github.com/google/syzkaller/prog.gitRevisionDate=20260804-103143"  ./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=d4abbeacd53add822a563e66a8ca9e64929b96ab -X github.com/google/syzkaller/prog.gitRevisionDate=20260804-103143"  -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=\"d4abbeacd53add822a563e66a8ca9e64929b96ab\"
/usr/bin/ld: /tmp/ccSFcTDt.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=12f43549580000


Tested on:

commit:         4352b8ae Merge tag 'i3c/for-7.3' of git://git.kernel.o..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=c01bf1b5895f71b2
dashboard link: https://syzkaller.appspot.com/bug?extid=9cb1ac7fce4944ba9165
compiler:       Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=10c13179580000