Re: [syzbot] [bpf?] possible deadlock in kvfree_call_rcu

From: syzbot
Date: Fri Mar 29 2024 - 12:17:11 EST


Hello,

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

rd
[ 8.126582][ T1] usbcore: registered new interface driver dln2
[ 8.128975][ T1] usbcore: registered new interface driver pn533_usb
[ 8.136035][ T1] nfcsim 0.2 initialized
[ 8.137231][ T1] usbcore: registered new interface driver port100
[ 8.138748][ T1] usbcore: registered new interface driver nfcmrvl
[ 8.145859][ T1] Loading iSCSI transport class v2.0-870.
[ 8.163499][ T1] virtio_scsi virtio0: 1/0/0 default/read/poll queues
[ 8.175560][ T1] ------------[ cut here ]------------
[ 8.176754][ T1] refcount_t: decrement hit 0; leaking memory.
[ 8.178277][ T1] WARNING: CPU: 0 PID: 1 at lib/refcount.c:31 refcount_warn_saturate+0xfa/0x1d0
[ 8.179920][ T1] Modules linked in:
[ 8.180674][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.9.0-rc1-syzkaller-g317c7bc0ef03-dirty #0
[ 8.183676][ T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
[ 8.188610][ T1] RIP: 0010:refcount_warn_saturate+0xfa/0x1d0
[ 8.190118][ T1] Code: b2 00 00 00 e8 b7 d1 e9 fc 5b 5d c3 cc cc cc cc e8 ab d1 e9 fc c6 05 6e 76 e8 0a 01 90 48 c7 c7 e0 33 1f 8c e8 e7 6d ac fc 90 <0f> 0b 90 90 eb d9 e8 8b d1 e9 fc c6 05 4b 76 e8 0a 01 90 48 c7 c7
[ 8.193646][ T1] RSP: 0000:ffffc90000066e18 EFLAGS: 00010246
[ 8.195167][ T1] RAX: f6afc450a77aa400 RBX: ffff8880207ba75c RCX: ffff8880166d0000
[ 8.197227][ T1] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
[ 8.198422][ T1] RBP: 0000000000000004 R08: ffffffff815800c2 R09: fffffbfff1c396e0
[ 8.200207][ T1] R10: dffffc0000000000 R11: fffffbfff1c396e0 R12: ffffea000501edc0
[ 8.201595][ T1] R13: ffffea000501edc8 R14: 1ffffd4000a03db9 R15: 0000000000000000
[ 8.204095][ T1] FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
[ 8.206467][ T1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 8.207845][ T1] CR2: ffff88823ffff000 CR3: 000000000e132000 CR4: 00000000003506f0
[ 8.209685][ T1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 8.211033][ T1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 8.212686][ T1] Call Trace:
[ 8.213195][ T1] <TASK>
[ 8.213986][ T1] ? __warn+0x163/0x4e0
[ 8.215506][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 8.216913][ T1] ? report_bug+0x2b3/0x500
[ 8.218714][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 8.220709][ T1] ? handle_bug+0x3e/0x70
[ 8.222091][ T1] ? exc_invalid_op+0x1a/0x50
[ 8.223846][ T1] ? asm_exc_invalid_op+0x1a/0x20
[ 8.225196][ T1] ? __warn_printk+0x292/0x360
[ 8.226085][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 8.227407][ T1] ? refcount_warn_saturate+0xf9/0x1d0
[ 8.228175][ T1] __free_pages_ok+0xc60/0xd90
[ 8.229175][ T1] make_alloc_exact+0xa3/0xf0
[ 8.230474][ T1] vring_alloc_queue_split+0x20a/0x600
[ 8.231715][ T1] ? __pfx_vring_alloc_queue_split+0x10/0x10
[ 8.233617][ T1] ? vp_find_vqs+0x4c/0x4e0
[ 8.234631][ T1] ? virtscsi_probe+0x3ea/0xf60
[ 8.236180][ T1] ? virtio_dev_probe+0x991/0xaf0
[ 8.236983][ T1] ? really_probe+0x2b8/0xad0
[ 8.237853][ T1] ? driver_probe_device+0x50/0x430
[ 8.238614][ T1] vring_create_virtqueue_split+0xc6/0x310
[ 8.239928][ T1] ? ret_from_fork+0x4b/0x80
[ 8.242045][ T1] ? __pfx_vring_create_virtqueue_split+0x10/0x10
[ 8.245917][ T1] vring_create_virtqueue+0xca/0x110
[ 8.247389][ T1] ? __pfx_vp_notify+0x10/0x10
[ 8.248236][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.250654][ T1] setup_vq+0xe9/0x2d0
[ 8.252034][ T1] ? __pfx_vp_notify+0x10/0x10
[ 8.254018][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.256278][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.258795][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.260398][ T1] vp_setup_vq+0xbf/0x330
[ 8.261387][ T1] ? __pfx_vp_config_changed+0x10/0x10
[ 8.262783][ T1] ? ioread16+0x2f/0x90
[ 8.265102][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.267083][ T1] vp_find_vqs_msix+0x8b2/0xc80
[ 8.268386][ T1] vp_find_vqs+0x4c/0x4e0
[ 8.270033][ T1] virtscsi_init+0x8db/0xd00
[ 8.272136][ T1] ? __pfx_virtscsi_init+0x10/0x10
[ 8.273670][ T1] ? __pfx_default_calc_sets+0x10/0x10
[ 8.275138][ T1] ? scsi_host_alloc+0xa57/0xea0
[ 8.276322][ T1] ? vp_get+0xfd/0x140
[ 8.277792][ T1] virtscsi_probe+0x3ea/0xf60
[ 8.278863][ T1] ? __pfx_virtscsi_probe+0x10/0x10
[ 8.280218][ T1] ? kernfs_add_one+0x156/0x8b0
[ 8.282404][ T1] ? virtio_no_restricted_mem_acc+0x9/0x10
[ 8.284631][ T1] ? virtio_features_ok+0x10c/0x270
[ 8.286348][ T1] virtio_dev_probe+0x991/0xaf0
[ 8.287773][ T1] ? __pfx_virtio_dev_probe+0x10/0x10
[ 8.288905][ T1] really_probe+0x2b8/0xad0
[ 8.290078][ T1] __driver_probe_device+0x1a2/0x390
[ 8.292149][ T1] driver_probe_device+0x50/0x430
[ 8.293916][ T1] __driver_attach+0x45f/0x710
[ 8.295546][ T1] ? __pfx___driver_attach+0x10/0x10
[ 8.296706][ T1] bus_for_each_dev+0x239/0x2b0
[ 8.297510][ T1] ? __pfx___driver_attach+0x10/0x10
[ 8.298632][ T1] ? __pfx_bus_for_each_dev+0x10/0x10
[ 8.299941][ T1] ? do_raw_spin_unlock+0x13c/0x8b0
[ 8.301483][ T1] bus_add_driver+0x347/0x620
[ 8.302606][ T1] driver_register+0x23a/0x320
[ 8.304274][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.305978][ T1] virtio_scsi_init+0x65/0xe0
[ 8.306774][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.307813][ T1] do_one_initcall+0x248/0x880
[ 8.309150][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.310617][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 8.313354][ T1] ? __pfx_do_one_initcall+0x10/0x10
[ 8.315007][ T1] ? __pfx_parse_args+0x10/0x10
[ 8.317331][ T1] ? do_initcalls+0x1c/0x80
[ 8.318887][ T1] ? rcu_is_watching+0x15/0xb0
[ 8.320094][ T1] do_initcall_level+0x157/0x210
[ 8.322194][ T1] do_initcalls+0x3f/0x80
[ 8.323354][ T1] kernel_init_freeable+0x435/0x5d0
[ 8.324941][ T1] ? __pfx_kernel_init_freeable+0x10/0x10
[ 8.326006][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 8.327488][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.329100][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.330857][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.332703][ T1] kernel_init+0x1d/0x2b0
[ 8.334765][ T1] ret_from_fork+0x4b/0x80
[ 8.335714][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.336933][ T1] ret_from_fork_asm+0x1a/0x30
[ 8.337933][ T1] </TASK>
[ 8.338682][ T1] Kernel panic - not syncing: kernel: panic_on_warn set ...
[ 8.341330][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.9.0-rc1-syzkaller-g317c7bc0ef03-dirty #0
[ 8.344143][ T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
[ 8.344784][ T1] Call Trace:
[ 8.344784][ T1] <TASK>
[ 8.344784][ T1] dump_stack_lvl+0x241/0x360
[ 8.344784][ T1] ? __pfx_dump_stack_lvl+0x10/0x10
[ 8.344784][ T1] ? __pfx__printk+0x10/0x10
[ 8.344784][ T1] ? _printk+0xd5/0x120
[ 8.344784][ T1] ? vscnprintf+0x5d/0x90
[ 8.354884][ T1] panic+0x349/0x860
[ 8.354884][ T1] ? __warn+0x172/0x4e0
[ 8.354884][ T1] ? __pfx_panic+0x10/0x10
[ 8.354884][ T1] ? show_trace_log_lvl+0x4e6/0x520
[ 8.354884][ T1] ? ret_from_fork_asm+0x1a/0x30
[ 8.354884][ T1] __warn+0x346/0x4e0
[ 8.354884][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 8.354884][ T1] report_bug+0x2b3/0x500
[ 8.364918][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 8.364918][ T1] handle_bug+0x3e/0x70
[ 8.364918][ T1] exc_invalid_op+0x1a/0x50
[ 8.364918][ T1] asm_exc_invalid_op+0x1a/0x20
[ 8.364918][ T1] RIP: 0010:refcount_warn_saturate+0xfa/0x1d0
[ 8.364918][ T1] Code: b2 00 00 00 e8 b7 d1 e9 fc 5b 5d c3 cc cc cc cc e8 ab d1 e9 fc c6 05 6e 76 e8 0a 01 90 48 c7 c7 e0 33 1f 8c e8 e7 6d ac fc 90 <0f> 0b 90 90 eb d9 e8 8b d1 e9 fc c6 05 4b 76 e8 0a 01 90 48 c7 c7
[ 8.374911][ T1] RSP: 0000:ffffc90000066e18 EFLAGS: 00010246
[ 8.374911][ T1] RAX: f6afc450a77aa400 RBX: ffff8880207ba75c RCX: ffff8880166d0000
[ 8.374911][ T1] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
[ 8.374911][ T1] RBP: 0000000000000004 R08: ffffffff815800c2 R09: fffffbfff1c396e0
[ 8.384883][ T1] R10: dffffc0000000000 R11: fffffbfff1c396e0 R12: ffffea000501edc0
[ 8.384883][ T1] R13: ffffea000501edc8 R14: 1ffffd4000a03db9 R15: 0000000000000000
[ 8.384883][ T1] ? __warn_printk+0x292/0x360
[ 8.384883][ T1] ? refcount_warn_saturate+0xf9/0x1d0
[ 8.384883][ T1] __free_pages_ok+0xc60/0xd90
[ 8.394940][ T1] make_alloc_exact+0xa3/0xf0
[ 8.394940][ T1] vring_alloc_queue_split+0x20a/0x600
[ 8.394940][ T1] ? __pfx_vring_alloc_queue_split+0x10/0x10
[ 8.394940][ T1] ? vp_find_vqs+0x4c/0x4e0
[ 8.394940][ T1] ? virtscsi_probe+0x3ea/0xf60
[ 8.404787][ T1] ? virtio_dev_probe+0x991/0xaf0
[ 8.404787][ T1] ? really_probe+0x2b8/0xad0
[ 8.404787][ T1] ? driver_probe_device+0x50/0x430
[ 8.404787][ T1] vring_create_virtqueue_split+0xc6/0x310
[ 8.404787][ T1] ? ret_from_fork+0x4b/0x80
[ 8.404787][ T1] ? __pfx_vring_create_virtqueue_split+0x10/0x10
[ 8.404787][ T1] vring_create_virtqueue+0xca/0x110
[ 8.414898][ T1] ? __pfx_vp_notify+0x10/0x10
[ 8.414898][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.414898][ T1] setup_vq+0xe9/0x2d0
[ 8.414898][ T1] ? __pfx_vp_notify+0x10/0x10
[ 8.414898][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.414898][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.414898][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.424822][ T1] vp_setup_vq+0xbf/0x330
[ 8.424822][ T1] ? __pfx_vp_config_changed+0x10/0x10
[ 8.424822][ T1] ? ioread16+0x2f/0x90
[ 8.424822][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.424822][ T1] vp_find_vqs_msix+0x8b2/0xc80
[ 8.424822][ T1] vp_find_vqs+0x4c/0x4e0
[ 8.424822][ T1] virtscsi_init+0x8db/0xd00
[ 8.434924][ T1] ? __pfx_virtscsi_init+0x10/0x10
[ 8.434924][ T1] ? __pfx_default_calc_sets+0x10/0x10
[ 8.434924][ T1] ? scsi_host_alloc+0xa57/0xea0
[ 8.434924][ T1] ? vp_get+0xfd/0x140
[ 8.434924][ T1] virtscsi_probe+0x3ea/0xf60
[ 8.434924][ T1] ? __pfx_virtscsi_probe+0x10/0x10
[ 8.434924][ T1] ? kernfs_add_one+0x156/0x8b0
[ 8.444785][ T1] ? virtio_no_restricted_mem_acc+0x9/0x10
[ 8.444785][ T1] ? virtio_features_ok+0x10c/0x270
[ 8.444785][ T1] virtio_dev_probe+0x991/0xaf0
[ 8.444785][ T1] ? __pfx_virtio_dev_probe+0x10/0x10
[ 8.454872][ T1] really_probe+0x2b8/0xad0
[ 8.454872][ T1] __driver_probe_device+0x1a2/0x390
[ 8.454872][ T1] driver_probe_device+0x50/0x430
[ 8.454872][ T1] __driver_attach+0x45f/0x710
[ 8.454872][ T1] ? __pfx___driver_attach+0x10/0x10
[ 8.454872][ T1] bus_for_each_dev+0x239/0x2b0
[ 8.454872][ T1] ? __pfx___driver_attach+0x10/0x10
[ 8.464890][ T1] ? __pfx_bus_for_each_dev+0x10/0x10
[ 8.464890][ T1] ? do_raw_spin_unlock+0x13c/0x8b0
[ 8.464890][ T1] bus_add_driver+0x347/0x620
[ 8.464890][ T1] driver_register+0x23a/0x320
[ 8.464890][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.464890][ T1] virtio_scsi_init+0x65/0xe0
[ 8.464890][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.464890][ T1] do_one_initcall+0x248/0x880
[ 8.474920][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.474920][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 8.474920][ T1] ? __pfx_do_one_initcall+0x10/0x10
[ 8.474920][ T1] ? __pfx_parse_args+0x10/0x10
[ 8.474920][ T1] ? do_initcalls+0x1c/0x80
[ 8.474920][ T1] ? rcu_is_watching+0x15/0xb0
[ 8.474920][ T1] do_initcall_level+0x157/0x210
[ 8.474920][ T1] do_initcalls+0x3f/0x80
[ 8.474920][ T1] kernel_init_freeable+0x435/0x5d0
[ 8.474920][ T1] ? __pfx_kernel_init_freeable+0x10/0x10
[ 8.484767][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 8.484767][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.484767][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.484767][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.484767][ T1] kernel_init+0x1d/0x2b0
[ 8.484767][ T1] ret_from_fork+0x4b/0x80
[ 8.484767][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.484767][ T1] ret_from_fork_asm+0x1a/0x30
[ 8.484767][ T1] </TASK>
[ 8.484767][ T1] Kernel Offset: disabled
[ 8.484767][ 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-build3987916201=/tmp/go-build -gno-record-gcc-switches'

git status (err=<nil>)
HEAD detached at 454571b6a
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=454571b6a16598f5a6e015b9fb1a04932bce7ab9 -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240326-163935'" "-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=454571b6a16598f5a6e015b9fb1a04932bce7ab9 -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240326-163935'" "-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=454571b6a16598f5a6e015b9fb1a04932bce7ab9 -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240326-163935'" "-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=\"454571b6a16598f5a6e015b9fb1a04932bce7ab9\"


Error text is too large and was truncated, full error text is at:
https://syzkaller.appspot.com/x/error.txt?x=17e67d0d180000


Tested on:

commit: 317c7bc0 Merge tag 'mmc-v6.9-rc1' of git://git.kernel...
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
kernel config: https://syzkaller.appspot.com/x/.config?x=7b667bc37450fdcd
dashboard link: https://syzkaller.appspot.com/bug?extid=1fa663a2100308ab6eab
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch: https://syzkaller.appspot.com/x/patch.diff?x=144ea745180000