Re: [syzbot] [ext4?] KASAN: slab-use-after-free Read in fsnotify

From: syzbot
Date: Fri Apr 12 2024 - 10:30:14 EST


Hello,

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

viperboard
[ 7.815991][ T1] usbcore: registered new interface driver dln2
[ 7.818221][ T1] usbcore: registered new interface driver pn533_usb
[ 7.823865][ T1] nfcsim 0.2 initialized
[ 7.825314][ T1] usbcore: registered new interface driver port100
[ 7.828562][ T1] usbcore: registered new interface driver nfcmrvl
[ 7.837679][ T1] Loading iSCSI transport class v2.0-870.
[ 7.856316][ T1] virtio_scsi virtio0: 1/0/0 default/read/poll queues
[ 7.867881][ T1] ------------[ cut here ]------------
[ 7.869240][ T1] refcount_t: decrement hit 0; leaking memory.
[ 7.870647][ T1] WARNING: CPU: 0 PID: 1 at lib/refcount.c:31 refcount_warn_saturate+0xfa/0x1d0
[ 7.872673][ T1] Modules linked in:
[ 7.873450][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.9.0-rc3-syzkaller-00222-ga4170c0055a4 #0
[ 7.875073][ T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
[ 7.876781][ T1] RIP: 0010:refcount_warn_saturate+0xfa/0x1d0
[ 7.877963][ T1] Code: b2 00 00 00 e8 e7 63 e7 fc 5b 5d c3 cc cc cc cc e8 db 63 e7 fc c6 05 6c d2 e4 0a 01 90 48 c7 c7 c0 30 1f 8c e8 77 e1 a9 fc 90 <0f> 0b 90 90 eb d9 e8 bb 63 e7 fc c6 05 49 d2 e4 0a 01 90 48 c7 c7
[ 7.881853][ T1] RSP: 0000:ffffc90000066e18 EFLAGS: 00010246
[ 7.883056][ T1] RAX: 7664671302135400 RBX: ffff8880202afc6c RCX: ffff8880166d0000
[ 7.885276][ T1] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 7.887369][ T1] RBP: 0000000000000004 R08: ffffffff815880a2 R09: fffffbfff1c39b48
[ 7.888750][ T1] R10: dffffc0000000000 R11: fffffbfff1c39b48 R12: ffffea000502ddc0
[ 7.890131][ T1] R13: ffffea000502ddc8 R14: 1ffffd4000a05bb9 R15: 0000000000000000
[ 7.891813][ T1] FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
[ 7.893900][ T1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 7.895917][ T1] CR2: ffff88823ffff000 CR3: 000000000e134000 CR4: 00000000003506f0
[ 7.897448][ T1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 7.898766][ T1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 7.900462][ T1] Call Trace:
[ 7.901245][ T1] <TASK>
[ 7.901998][ T1] ? __warn+0x163/0x4e0
[ 7.902783][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 7.904160][ T1] ? report_bug+0x2b3/0x500
[ 7.905119][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 7.906474][ T1] ? handle_bug+0x3e/0x70
[ 7.907513][ T1] ? exc_invalid_op+0x1a/0x50
[ 7.908463][ T1] ? asm_exc_invalid_op+0x1a/0x20
[ 7.909468][ T1] ? __warn_printk+0x292/0x360
[ 7.910957][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 7.912558][ T1] ? refcount_warn_saturate+0xf9/0x1d0
[ 7.913803][ T1] __free_pages_ok+0xc60/0xd90
[ 7.914583][ T1] make_alloc_exact+0xa3/0xf0
[ 7.915425][ T1] vring_alloc_queue_split+0x20a/0x600
[ 7.916903][ T1] ? __pfx_vring_alloc_queue_split+0x10/0x10
[ 7.917937][ T1] ? vp_find_vqs+0x4c/0x4e0
[ 7.918930][ T1] ? virtscsi_probe+0x3ea/0xf60
[ 7.919998][ T1] ? virtio_dev_probe+0x991/0xaf0
[ 7.921234][ T1] ? really_probe+0x2b8/0xad0
[ 7.921893][ T1] ? driver_probe_device+0x50/0x430
[ 7.922882][ T1] vring_create_virtqueue_split+0xc6/0x310
[ 7.924087][ T1] ? ret_from_fork+0x4b/0x80
[ 7.924906][ T1] ? __pfx_vring_create_virtqueue_split+0x10/0x10
[ 7.926406][ T1] vring_create_virtqueue+0xca/0x110
[ 7.927871][ T1] ? __pfx_vp_notify+0x10/0x10
[ 7.929037][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.929986][ T1] setup_vq+0xe9/0x2d0
[ 7.930782][ T1] ? __pfx_vp_notify+0x10/0x10
[ 7.931882][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.932643][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.933619][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.934781][ T1] vp_setup_vq+0xbf/0x330
[ 7.935911][ T1] ? __pfx_vp_config_changed+0x10/0x10
[ 7.937334][ T1] ? ioread16+0x2f/0x90
[ 7.938489][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.939978][ T1] vp_find_vqs_msix+0x8b2/0xc80
[ 7.940989][ T1] vp_find_vqs+0x4c/0x4e0
[ 7.941655][ T1] virtscsi_init+0x8db/0xd00
[ 7.942427][ T1] ? __pfx_virtscsi_init+0x10/0x10
[ 7.943724][ T1] ? __pfx_default_calc_sets+0x10/0x10
[ 7.944616][ T1] ? scsi_host_alloc+0xa57/0xea0
[ 7.946041][ T1] ? vp_get+0xfd/0x140
[ 7.946895][ T1] virtscsi_probe+0x3ea/0xf60
[ 7.947740][ T1] ? __pfx_virtscsi_probe+0x10/0x10
[ 7.948718][ T1] ? kernfs_add_one+0x156/0x8b0
[ 7.949578][ T1] ? virtio_no_restricted_mem_acc+0x9/0x10
[ 7.950761][ T1] ? virtio_features_ok+0x10c/0x270
[ 7.951946][ T1] virtio_dev_probe+0x991/0xaf0
[ 7.953286][ T1] ? __pfx_virtio_dev_probe+0x10/0x10
[ 7.954435][ T1] really_probe+0x2b8/0xad0
[ 7.955311][ T1] __driver_probe_device+0x1a2/0x390
[ 7.956686][ T1] driver_probe_device+0x50/0x430
[ 7.957771][ T1] __driver_attach+0x45f/0x710
[ 7.958769][ T1] ? __pfx___driver_attach+0x10/0x10
[ 7.959612][ T1] bus_for_each_dev+0x239/0x2b0
[ 7.960946][ T1] ? __pfx___driver_attach+0x10/0x10
[ 7.962251][ T1] ? __pfx_bus_for_each_dev+0x10/0x10
[ 7.964315][ T1] ? do_raw_spin_unlock+0x13c/0x8b0
[ 7.966148][ T1] bus_add_driver+0x347/0x620
[ 7.967112][ T1] driver_register+0x23a/0x320
[ 7.968628][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 7.969941][ T1] virtio_scsi_init+0x65/0xe0
[ 7.970833][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 7.972203][ T1] do_one_initcall+0x248/0x880
[ 7.973355][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 7.974515][ T1] ? __pfx_do_one_initcall+0x10/0x10
[ 7.975602][ T1] ? lockdep_hardirqs_on_prepare+0x43d/0x780
[ 7.977269][ T1] ? __pfx_parse_args+0x10/0x10
[ 7.978148][ T1] ? do_initcalls+0x1c/0x80
[ 7.979254][ T1] ? rcu_is_watching+0x15/0xb0
[ 7.980350][ T1] do_initcall_level+0x157/0x210
[ 7.981349][ T1] do_initcalls+0x3f/0x80
[ 7.982742][ T1] kernel_init_freeable+0x435/0x5d0
[ 7.984461][ T1] ? __pfx_kernel_init_freeable+0x10/0x10
[ 7.986325][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 7.987513][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.988803][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.990065][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.991335][ T1] kernel_init+0x1d/0x2b0
[ 7.992855][ T1] ret_from_fork+0x4b/0x80
[ 7.994528][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.996074][ T1] ret_from_fork_asm+0x1a/0x30
[ 7.997423][ T1] </TASK>
[ 7.998234][ T1] Kernel panic - not syncing: kernel: panic_on_warn set ...
[ 7.999604][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.9.0-rc3-syzkaller-00222-ga4170c0055a4 #0
[ 8.001827][ T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
[ 8.004098][ T1] Call Trace:
[ 8.005064][ T1] <TASK>
[ 8.005501][ T1] dump_stack_lvl+0x241/0x360
[ 8.006050][ T1] ? __pfx_dump_stack_lvl+0x10/0x10
[ 8.006050][ T1] ? __pfx__printk+0x10/0x10
[ 8.006050][ T1] ? _printk+0xd5/0x120
[ 8.006050][ T1] ? vscnprintf+0x5d/0x90
[ 8.006050][ T1] panic+0x349/0x860
[ 8.006050][ T1] ? __warn+0x172/0x4e0
[ 8.006050][ T1] ? __pfx_panic+0x10/0x10
[ 8.006050][ T1] ? show_trace_log_lvl+0x4e6/0x520
[ 8.006050][ T1] ? ret_from_fork_asm+0x1a/0x30
[ 8.006050][ T1] __warn+0x346/0x4e0
[ 8.006050][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 8.006050][ T1] report_bug+0x2b3/0x500
[ 8.006050][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 8.006050][ T1] handle_bug+0x3e/0x70
[ 8.006050][ T1] exc_invalid_op+0x1a/0x50
[ 8.006050][ T1] asm_exc_invalid_op+0x1a/0x20
[ 8.006050][ T1] RIP: 0010:refcount_warn_saturate+0xfa/0x1d0
[ 8.006050][ T1] Code: b2 00 00 00 e8 e7 63 e7 fc 5b 5d c3 cc cc cc cc e8 db 63 e7 fc c6 05 6c d2 e4 0a 01 90 48 c7 c7 c0 30 1f 8c e8 77 e1 a9 fc 90 <0f> 0b 90 90 eb d9 e8 bb 63 e7 fc c6 05 49 d2 e4 0a 01 90 48 c7 c7
[ 8.006050][ T1] RSP: 0000:ffffc90000066e18 EFLAGS: 00010246
[ 8.006050][ T1] RAX: 7664671302135400 RBX: ffff8880202afc6c RCX: ffff8880166d0000
[ 8.006050][ T1] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 8.006050][ T1] RBP: 0000000000000004 R08: ffffffff815880a2 R09: fffffbfff1c39b48
[ 8.006050][ T1] R10: dffffc0000000000 R11: fffffbfff1c39b48 R12: ffffea000502ddc0
[ 8.006050][ T1] R13: ffffea000502ddc8 R14: 1ffffd4000a05bb9 R15: 0000000000000000
[ 8.006050][ T1] ? __warn_printk+0x292/0x360
[ 8.006050][ T1] ? refcount_warn_saturate+0xf9/0x1d0
[ 8.006050][ T1] __free_pages_ok+0xc60/0xd90
[ 8.006050][ T1] make_alloc_exact+0xa3/0xf0
[ 8.006050][ T1] vring_alloc_queue_split+0x20a/0x600
[ 8.006050][ T1] ? __pfx_vring_alloc_queue_split+0x10/0x10
[ 8.006050][ T1] ? vp_find_vqs+0x4c/0x4e0
[ 8.006050][ T1] ? virtscsi_probe+0x3ea/0xf60
[ 8.006050][ T1] ? virtio_dev_probe+0x991/0xaf0
[ 8.006050][ T1] ? really_probe+0x2b8/0xad0
[ 8.006050][ T1] ? driver_probe_device+0x50/0x430
[ 8.006050][ T1] vring_create_virtqueue_split+0xc6/0x310
[ 8.006050][ T1] ? ret_from_fork+0x4b/0x80
[ 8.055954][ T1] ? __pfx_vring_create_virtqueue_split+0x10/0x10
[ 8.055954][ T1] vring_create_virtqueue+0xca/0x110
[ 8.055954][ T1] ? __pfx_vp_notify+0x10/0x10
[ 8.055954][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.055954][ T1] setup_vq+0xe9/0x2d0
[ 8.055954][ T1] ? __pfx_vp_notify+0x10/0x10
[ 8.055954][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.055954][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.055954][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.055954][ T1] vp_setup_vq+0xbf/0x330
[ 8.055954][ T1] ? __pfx_vp_config_changed+0x10/0x10
[ 8.055954][ T1] ? ioread16+0x2f/0x90
[ 8.055954][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.055954][ T1] vp_find_vqs_msix+0x8b2/0xc80
[ 8.055954][ T1] vp_find_vqs+0x4c/0x4e0
[ 8.055954][ T1] virtscsi_init+0x8db/0xd00
[ 8.055954][ T1] ? __pfx_virtscsi_init+0x10/0x10
[ 8.055954][ T1] ? __pfx_default_calc_sets+0x10/0x10
[ 8.055954][ T1] ? scsi_host_alloc+0xa57/0xea0
[ 8.055954][ T1] ? vp_get+0xfd/0x140
[ 8.055954][ T1] virtscsi_probe+0x3ea/0xf60
[ 8.055954][ T1] ? __pfx_virtscsi_probe+0x10/0x10
[ 8.055954][ T1] ? kernfs_add_one+0x156/0x8b0
[ 8.055954][ T1] ? virtio_no_restricted_mem_acc+0x9/0x10
[ 8.055954][ T1] ? virtio_features_ok+0x10c/0x270
[ 8.055954][ T1] virtio_dev_probe+0x991/0xaf0
[ 8.055954][ T1] ? __pfx_virtio_dev_probe+0x10/0x10
[ 8.055954][ T1] really_probe+0x2b8/0xad0
[ 8.055954][ T1] __driver_probe_device+0x1a2/0x390
[ 8.055954][ T1] driver_probe_device+0x50/0x430
[ 8.055954][ T1] __driver_attach+0x45f/0x710
[ 8.055954][ T1] ? __pfx___driver_attach+0x10/0x10
[ 8.055954][ T1] bus_for_each_dev+0x239/0x2b0
[ 8.055954][ T1] ? __pfx___driver_attach+0x10/0x10
[ 8.055954][ T1] ? __pfx_bus_for_each_dev+0x10/0x10
[ 8.055954][ T1] ? do_raw_spin_unlock+0x13c/0x8b0
[ 8.055954][ T1] bus_add_driver+0x347/0x620
[ 8.055954][ T1] driver_register+0x23a/0x320
[ 8.055954][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.055954][ T1] virtio_scsi_init+0x65/0xe0
[ 8.055954][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.055954][ T1] do_one_initcall+0x248/0x880
[ 8.055954][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.055954][ T1] ? __pfx_do_one_initcall+0x10/0x10
[ 8.105903][ T1] ? lockdep_hardirqs_on_prepare+0x43d/0x780
[ 8.105903][ T1] ? __pfx_parse_args+0x10/0x10
[ 8.105903][ T1] ? do_initcalls+0x1c/0x80
[ 8.105903][ T1] ? rcu_is_watching+0x15/0xb0
[ 8.105903][ T1] do_initcall_level+0x157/0x210
[ 8.105903][ T1] do_initcalls+0x3f/0x80
[ 8.105903][ T1] kernel_init_freeable+0x435/0x5d0
[ 8.105903][ T1] ? __pfx_kernel_init_freeable+0x10/0x10
[ 8.105903][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 8.105903][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.105903][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.105903][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.105903][ T1] kernel_init+0x1d/0x2b0
[ 8.105903][ T1] ret_from_fork+0x4b/0x80
[ 8.105903][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.105903][ T1] ret_from_fork_asm+0x1a/0x30
[ 8.105903][ T1] </TASK>
[ 8.105903][ T1] Kernel Offset: disabled
[ 8.105903][ T1] Rebooting in 86400 seconds..


syzkaller build log:
go env (err=<nil>)
GO111MODULE='auto'
GOARCH='amd64'
GOBIN=''
GOCACHE='/syzkaller/.cache/go-build'
GOENV='/syzkaller/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
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'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.21.4'
GCCGO='gccgo'
GOAMD64='v1'
AR='ar'
CC='gcc'
CXX='g++'
CGO_ENABLED='1'
GOMOD='/syzkaller/jobs-2/linux/gopath/src/github.com/google/syzkaller/go.mod'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build1668308411=/tmp/go-build -gno-record-gcc-switches'

git status (err=<nil>)
HEAD detached at 56086b24b
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}}' ./sys/syz-sysgen | grep -q false || go install ./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=56086b24bdfd822d3b227edb3064db443cd8c971 -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240409-083312'" "-tags=syz_target syz_os_linux syz_arch_amd64 " -o ./bin/linux_amd64/syz-fuzzer github.com/google/syzkaller/syz-fuzzer
GOOS=linux GOARCH=amd64 go build "-ldflags=-s -w -X github.com/google/syzkaller/prog.GitRevision=56086b24bdfd822d3b227edb3064db443cd8c971 -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240409-083312'" "-tags=syz_target syz_os_linux syz_arch_amd64 " -o ./bin/linux_amd64/syz-execprog github.com/google/syzkaller/tools/syz-execprog
GOOS=linux GOARCH=amd64 go build "-ldflags=-s -w -X github.com/google/syzkaller/prog.GitRevision=56086b24bdfd822d3b227edb3064db443cd8c971 -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240409-083312'" "-tags=syz_target syz_os_linux syz_arch_amd64 " -o ./bin/linux_amd64/syz-stress github.com/google/syzkaller/tools/syz-stress
mkdir -p ./bin/linux_amd64
gcc -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 -fpermissive -w -DGOOS_linux=1 -DGOARCH_amd64=1 \
-DHOSTGOOS_linux=1 -DGIT_REVISION=\"56086b24bdfd822d3b227edb3064db443cd8c971\"


Error text is too large and was truncated, full error text is at:
https://syzkaller.appspot.com/x/error.txt?x=122f8f97180000


Tested on:

commit: a4170c00 fsnotify: do not handle events on a shutting ..
git tree: https://github.com/amir73il/linux fsnotify-fixes
kernel config: https://syzkaller.appspot.com/x/.config?x=9995779c8305f57e
dashboard link: https://syzkaller.appspot.com/bug?extid=5e3f9b2a67b45f16d4e6
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Note: no patches were applied.