Re: Kunit: BUG: KASAN: null-ptr-deref in __fpga_bridge_get+0x88/0x100 [fpga_bridge]

From: Marco Pagani
Date: Mon Oct 09 2023 - 09:45:17 EST



On 2023-10-08 08:29, Naresh Kamboju wrote:
> Following kernel bug and warning noticed while running fpga_bridge on
> arm64 Juno-r2 device running Linux next 6.6.0-rc4-next-20231006 tag.
>
> Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>

Hi Naresh, and thanks for reporting. This issue has been already fixed:

https://lore.kernel.org/linux-fpga/20230929152057.85047-1-marpagan@xxxxxxxxxx/

>
> KUNIT_TEST_MODULE=snd-hda-cirrus-scodec-test.ko
> [ 239.069569] KTAP version 1
> [ 239.072540] 1..1
> [ 239.074962] KTAP version 1
> [ 239.078060] # Subtest: fpga_bridge
> [ 239.081928] # module: fpga_bridge_test
> [ 239.082011] 1..3
> [ 239.100750] ==================================================================
> [ 239.108037] BUG: KASAN: null-ptr-deref in
> __fpga_bridge_get+0x88/0x100 [fpga_bridge]
> [ 239.115958] Read of size 8 at addr 0000000000000010 by task
> kunit_try_catch/2052
> [ 239.123410]
> [ 239.124932] CPU: 3 PID: 2052 Comm: kunit_try_catch Tainted: G B
> N 6.6.0-rc4-next-20231006 #1
> [ 239.134660] Hardware name: ARM Juno development board (r2) (DT)
> [ 239.140624] Call trace:
> [ 239.143097] dump_backtrace+0x9c/0x128
> [ 239.146913] show_stack+0x20/0x38
> [ 239.150278] dump_stack_lvl+0x60/0xb0
> [ 239.154005] print_report+0x2f0/0x5d8
> [ 239.157729] kasan_report+0xc8/0x118
> [ 239.161362] __asan_load8+0x68/0xc0
> [ 239.164911] __fpga_bridge_get+0x88/0x100 [fpga_bridge]
> [ 239.170290] fpga_bridge_get+0x48/0x78 [fpga_bridge]
> [ 239.175405] fpga_bridge_test_get+0xa0/0x1a8 [fpga_bridge_test]
> [ 239.181469] kunit_try_run_case+0x84/0x110
> [ 239.185633] kunit_generic_run_threadfn_adapter+0x38/0x60
> [ 239.191109] kthread+0x18c/0x1a8
> [ 239.194385] ret_from_fork+0x10/0x20
> [ 239.198017] ==================================================================
> [ 239.205450] Unable to handle kernel NULL pointer dereference at
> virtual address 0000000000000010
> [ 239.214507] Mem abort info:
> [ 239.217327] ESR = 0x0000000096000004
> [ 239.221158] EC = 0x25: DABT (current EL), IL = 32 bits
> [ 239.226533] SET = 0, FnV = 0
> [ 239.229608] EA = 0, S1PTW = 0
> [ 239.233339] FSC = 0x04: level 0 translation fault
> [ 239.238263] Data abort info:
> [ 239.241181] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
> [ 239.246716] CM = 0, WnR = 0, TnD = 0, TagAccess = 0
> [ 239.251820] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> [ 239.257179] user pgtable: 4k pages, 48-bit VAs, pgdp=00000008ac6ec000
> [ 239.263670] [0000000000000010] pgd=0000000000000000, p4d=0000000000000000
> [ 239.270544] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
> [ 239.276840] Modules linked in: fpga_bridge_test(+) fpga_bridge
> tda998x hdlcd onboard_usb_hub cec crct10dif_ce drm_dma_helper
> drm_kms_helper drm fuse backlight dm_mod ip_tables x_tables
> [ 239.293440] CPU: 1 PID: 2052 Comm: kunit_try_catch Tainted: G B
> N 6.6.0-rc4-next-20231006 #1
> [ 239.303135] Hardware name: ARM Juno development board (r2) (DT)
> [ 239.309076] pstate: 40000005 (nZcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> [ 239.316066] pc : __fpga_bridge_get+0x88/0x100 [fpga_bridge]
> [ 239.321710] lr : __fpga_bridge_get+0x88/0x100 [fpga_bridge]
> [ 239.327341] sp : ffff800089237d00
> [ 239.330666] x29: ffff800089237d00 x28: 0000000000000000 x27: 0000000000000000
> [ 239.337849] x26: ffff000800a6c600 x25: ffff8000892673e8 x24: ffff8000809cc528
> [ 239.345031] x23: ffff000800a6c108 x22: 0000000000000000 x21: ffff000828683000
> [ 239.352215] x20: ffff000828683300 x19: ffff000828683008 x18: 0000000000000000
> [ 239.359400] x17: 3d3d3d3d3d3d3d3d x16: 3d3d3d3d3d3d3d3d x15: 3d3d3d3d3d3d3d3d
> [ 239.366585] x14: 3d3d3d3d3d3d3d3d x13: 3d3d3d3d3d3d3d3d x12: ffff700010eb79f1
> [ 239.373765] x11: 1ffff00010eb79f0 x10: ffff700010eb79f0 x9 : dfff800000000000
> [ 239.380948] x8 : 00008fffef148610 x7 : ffff8000875bcf87 x6 : 0000000000000001
> [ 239.388130] x5 : ffff8000875bcf80 x4 : ffff700010eb79f1 x3 : 0000000000000000
> [ 239.395309] x2 : 0000000000040020 x1 : ffff00082d182300 x0 : 0000000000000001
> [ 239.402488] Call trace:
> [ 239.404943] __fpga_bridge_get+0x88/0x100 [fpga_bridge]
> [ 239.410232] fpga_bridge_get+0x48/0x78 [fpga_bridge]
> [ 239.415254] fpga_bridge_test_get+0xa0/0x1a8 [fpga_bridge_test]
> [ 239.421230] kunit_try_run_case+0x84/0x110
> [ 239.425362] kunit_generic_run_threadfn_adapter+0x38/0x60
> [ 239.430799] kthread+0x18c/0x1a8
> [ 239.434047] ret_from_fork+0x10/0x20
> [ 239.437656] Code: 9431930e f94036d6 910042c0 9431930b (f9400ac0)
> [ 239.443769] ---[ end trace 0000000000000000 ]---
> [ 545.778709] # fpga_bridge_test_get: try timed out
> [ 545.783886] ------------[ cut here ]------------
> [ 545.788568] refcount_t: addition on 0; use-after-free.
> [ 545.793835] WARNING: CPU: 1 PID: 2051 at lib/refcount.c:25
> refcount_warn_saturate+0x14c/0x178
> [ 545.802410] Modules linked in: fpga_bridge_test(+) fpga_bridge
> tda998x hdlcd onboard_usb_hub cec crct10dif_ce drm_dma_helper
> drm_kms_helper drm fuse backlight dm_mod ip_tables x_tables
> [ 545.819009] CPU: 1 PID: 2051 Comm: modprobe Tainted: G B D
> N 6.6.0-rc4-next-20231006 #1
> [ 545.828090] Hardware name: ARM Juno development board (r2) (DT)
> [ 545.834028] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> [ 545.841017] pc : refcount_warn_saturate+0x14c/0x178
> [ 545.845919] lr : refcount_warn_saturate+0x14c/0x178
> [ 545.850819] sp : ffff8000892670c0
> [ 545.854145] x29: ffff8000892670c0 x28: ffff8000820cdf40 x27: ffff80007f8d7480
> [ 545.861328] x26: ffff8000892673f8 x25: ffff00082d182300 x24: ffff8000892673d0
> [ 545.868510] x23: ffff800089267410 x22: ffff00082ea86e00 x21: ffff00082d182328
> [ 545.875690] x20: ffff00082d182328 x19: 0000000000000002 x18: 0000000000000000
> [ 545.882869] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
> [ 545.890047] x14: 0000000000000000 x13: 2e656572662d7265 x12: ffff70001124cdb9
> [ 545.897225] x11: 1ffff0001124cdb8 x10: ffff70001124cdb8 x9 : ffff8000801a10b8
> [ 545.904405] x8 : 00008fffeedb3248 x7 : ffff800089266dc7 x6 : 0000000000000001
> [ 545.911583] x5 : ffff800089266dc0 x4 : ffff70001124cdb9 x3 : dfff800000000000
> [ 545.918762] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff00082d9e3480
> [ 545.925940] Call trace:
> [ 545.928394] refcount_warn_saturate+0x14c/0x178
> [ 545.932947] kthread_stop+0x230/0x318
> [ 545.936629] kunit_try_catch_run+0x248/0x2a8
> [ 545.940927] kunit_run_case_catch_errors+0xdc/0x1b0
> [ 545.945831] kunit_run_tests+0x6d8/0x860
> [ 545.949776] __kunit_test_suites_init+0x9c/0xf0
> [ 545.954332] kunit_exec_run_tests+0x9c/0xb8
> [ 545.958539] kunit_module_notify+0x2f0/0x318
> [ 545.962832] notifier_call_chain+0x90/0x1c8
> [ 545.967038] blocking_notifier_call_chain_robust+0xc8/0x148
> [ 545.972637] load_module+0x296c/0x2d50
> [ 545.976408] init_module_from_file+0xdc/0x138
> [ 545.980789] __arm64_sys_finit_module+0x23c/0x458
> [ 545.985517] invoke_syscall+0x68/0x198
> [ 545.989290] el0_svc_common.constprop.0+0x80/0x150
> [ 545.994108] do_el0_svc+0x38/0x50
> [ 545.997438] el0_svc+0x3c/0x80
> [ 546.000516] el0t_64_sync_handler+0x120/0x130
> [ 546.004897] el0t_64_sync+0x190/0x198
> [ 546.008577] ---[ end trace 0000000000000000 ]---
> [ 546.013383] Unable to handle kernel NULL pointer dereference at
> virtual address 0000000000000000
> [ 546.022243] Mem abort info:
> [ 546.025101] ESR = 0x0000000096000004
> [ 546.028922] EC = 0x25: DABT (current EL), IL = 32 bits
> [ 546.034303] SET = 0, FnV = 0
> [ 546.037422] EA = 0, S1PTW = 0
> [ 546.040622] FSC = 0x04: level 0 translation fault
> [ 546.045556] Data abort info:
> [ 546.048477] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
> [ 546.054019] CM = 0, WnR = 0, TnD = 0, TagAccess = 0
> [ 546.059128] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> [ 546.064501] user pgtable: 4k pages, 48-bit VAs, pgdp=00000008b2af1000
> [ 546.071027] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000
> [ 546.077909] Internal error: Oops: 0000000096000004 [#2] PREEMPT SMP
> [ 546.084206] Modules linked in: fpga_bridge_test(+) fpga_bridge
> tda998x hdlcd onboard_usb_hub cec crct10dif_ce drm_dma_helper
> drm_kms_helper drm fuse backlight dm_mod ip_tables x_tables
> [ 546.100801] CPU: 1 PID: 2051 Comm: modprobe Tainted: G B D W
> N 6.6.0-rc4-next-20231006 #1
> [ 546.109884] Hardware name: ARM Juno development board (r2) (DT)
> [ 546.115823] pstate: 40000005 (nZcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> [ 546.122811] pc : kthread_stop+0x1f4/0x318
> [ 546.126846] lr : kthread_stop+0x78/0x318
> [ 546.130788] sp : ffff8000892670e0
> [ 546.134118] x29: ffff8000892670e0 x28: ffff8000820cdf40 x27: ffff80007f8d7480
> [ 546.141300] x26: ffff8000892673f8 x25: ffff00082d182300 x24: ffff8000892673d0
> [ 546.148480] x23: ffff800089267410 x22: ffff00082ea86e00 x21: ffff00082d182328
> [ 546.155661] x20: 0000000000000000 x19: ffff00082d182300 x18: 0000000000000000
> [ 546.162840] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
> [ 546.170017] x14: 0000000000000000 x13: 2e656572662d7265 x12: ffff70001124cdb9
> [ 546.177196] x11: 1ffff0001124cdb8 x10: ffff70001124cdb8 x9 : ffff8000801a10b8
> [ 546.184375] x8 : ffff8000892670c0 x7 : 0000000000000000 x6 : 0000000000000001
> [ 546.191559] x5 : 0000000000000000 x4 : ffff00082d9e3480 x3 : 0000000000000000
> [ 546.198737] x2 : 0000000000000001 x1 : ffff80008760bd60 x0 : 0000000000000001
> [ 546.205920] Call trace:
> [ 546.208373] kthread_stop+0x1f4/0x318
> [ 546.212056] kunit_try_catch_run+0x248/0x2a8
> [ 546.216354] kunit_run_case_catch_errors+0xdc/0x1b0
> [ 546.221259] kunit_run_tests+0x6d8/0x860
> [ 546.225207] __kunit_test_suites_init+0x9c/0xf0
> [ 546.229762] kunit_exec_run_tests+0x9c/0xb8
> [ 546.233970] kunit_module_notify+0x2f0/0x318
> [ 546.238263] notifier_call_chain+0x90/0x1c8
> [ 546.242467] blocking_notifier_call_chain_robust+0xc8/0x148
> [ 546.248069] load_module+0x296c/0x2d50
> [ 546.251841] init_module_from_file+0xdc/0x138
> [ 546.256222] __arm64_sys_finit_module+0x23c/0x458
> [ 546.260954] invoke_syscall+0x68/0x198
> [ 546.264730] el0_svc_common.constprop.0+0x80/0x150
> [ 546.269548] do_el0_svc+0x38/0x50
> [ 546.272878] el0_svc+0x3c/0x80
> [ 546.275954] el0t_64_sync_handler+0x120/0x130
> [ 546.280336] el0t_64_sync+0x190/0x198
> [ 546.284024] Code: c8017e60 35ffffa1 17ffffae f9800291 (c85f7e80)
> [ 546.290138] ---[ end trace 0000000000000000 ]---
> Segmentation fault
> modprobe-fpga-bridge-test fail
>
> Links:
> - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20231006/testrun/20279429/suite/log-parser-test/test/check-kernel-bug/log
> - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20231006/testrun/20279429/suite/log-parser-test/tests/
> - https://tuxapi.tuxsuite.com/v1/groups/linaro/projects/lkft/tests/2WO7UKXuHh4Z2jX19cmUhNchbyq
> - https://storage.tuxsuite.com/public/linaro/lkft/builds/2WO7RQfyDFoIvCa0HgqR2mRxOu8/
> - https://storage.tuxsuite.com/public/linaro/lkft/builds/2WO7RQfyDFoIvCa0HgqR2mRxOu8/config
> - https://storage.tuxsuite.com/public/linaro/lkft/builds/2WO7RQfyDFoIvCa0HgqR2mRxOu8/vmlinux.xz
> - https://storage.tuxsuite.com/public/linaro/lkft/builds/2WO7RQfyDFoIvCa0HgqR2mRxOu8/System.map
>
> Step to reproduce:
> - https://storage.tuxsuite.com/public/linaro/lkft/builds/2WO7RQfyDFoIvCa0HgqR2mRxOu8/tuxmake_reproducer.sh
> - https://tuxapi.tuxsuite.com/v1/groups/linaro/projects/lkft/tests/2WO7UKXuHh4Z2jX19cmUhNchbyq/reproducer
>
>
>
> --
> Linaro LKFT
> https://lkft.linaro.org
>