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From: Puranjay Mohan <puranjay12@gmail.com>
To: syzbot <syzbot+186522670e6722692d86@syzkaller.appspotmail.com>,
 akpm@linux-foundation.org, alexei.starovoitov@gmail.com,
 andrii.nakryiko@gmail.com, bpf@vger.kernel.org,
 linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
 linux-mm@kvack.org, linux@armlinux.org.uk, mark.rutland@arm.com,
 syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [mm?] BUG: unable to handle kernel paging request in
 copy_from_kernel_nofault (2)
In-Reply-To: <00000000000044fca50615a82595@google.com>
References: <00000000000044fca50615a82595@google.com>
Date: Tue, 09 Apr 2024 14:18:05 +0000
Message-ID: <mb61pwmp6hb6q.fsf@gmail.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain

syzbot <syzbot+186522670e6722692d86@syzkaller.appspotmail.com> writes:

> Hello,
>
> syzbot has tested the proposed patch but the reproducer is still triggering an issue:
> INFO: task hung in _vm_unmap_aliases
>
> INFO: task kworker/0:41:4201 blocked for more than 430 seconds.
>       Not tainted 6.9.0-rc1-syzkaller #0
> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> task:kworker/0:41    state:D stack:0     pid:4201  tgid:4201  ppid:2      flags:0x00000000
> Workqueue: events bpf_prog_free_deferred
> Call trace: 
> [<8189ad40>] (__schedule) from [<8189b97c>] (__schedule_loop kernel/sched/core.c:6823 [inline])
> [<8189ad40>] (__schedule) from [<8189b97c>] (schedule+0x2c/0xfc kernel/sched/core.c:6838)
>  r10:82c16005 r9:00000000 r8:82714be8 r7:00000002 r6:dfd0dd94 r5:84dd1800
>  r4:84dd1800
> [<8189b950>] (schedule) from [<8189bf8c>] (schedule_preempt_disabled+0x18/0x24 kernel/sched/core.c:6895)
>  r5:84dd1800 r4:82714be4
> [<8189bf74>] (schedule_preempt_disabled) from [<8189e86c>] (__mutex_lock_common kernel/locking/mutex.c:684 [inline])
> [<8189bf74>] (schedule_preempt_disabled) from [<8189e86c>] (__mutex_lock.constprop.0+0x2e8/0xae0 kernel/locking/mutex.c:752)
> [<8189e584>] (__mutex_lock.constprop.0) from [<8189f138>] (__mutex_lock_slowpath+0x14/0x18 kernel/locking/mutex.c:1040)
>  r10:82c16005 r9:dfd0de20 r8:00000000 r7:ffffffff r6:00000000 r5:84c7a680
>  r4:00000000
> [<8189f124>] (__mutex_lock_slowpath) from [<8189f178>] (mutex_lock+0x3c/0x40 kernel/locking/mutex.c:286)
> [<8189f13c>] (mutex_lock) from [<8049c624>] (_vm_unmap_aliases+0x60/0x2e8 mm/vmalloc.c:2788)
> [<8049c5c4>] (_vm_unmap_aliases) from [<804a04a8>] (vm_reset_perms mm/vmalloc.c:3235 [inline])
> [<8049c5c4>] (_vm_unmap_aliases) from [<804a04a8>] (vfree+0x170/0x1e4 mm/vmalloc.c:3314)
>  r10:82c16005 r9:00000001 r8:00000000 r7:ffffffff r6:00000000 r5:84c7a680
>  r4:00000000
> [<804a0338>] (vfree) from [<802edb08>] (module_memfree+0x30/0x50 kernel/module/main.c:1189)
>  r9:84dd1800 r8:00000080 r7:00000000 r6:82c16000 r5:00001000 r4:7f055000
> [<802edad8>] (module_memfree) from [<803916b0>] (bpf_jit_free_exec+0x10/0x14 kernel/bpf/core.c:1058)
>  r5:00001000 r4:dfe91000
> [<803916a0>] (bpf_jit_free_exec) from [<80391870>] (bpf_jit_binary_free kernel/bpf/core.c:1104 [inline])
> [<803916a0>] (bpf_jit_free_exec) from [<80391870>] (bpf_jit_free+0x68/0xe4 kernel/bpf/core.c:1228)
> [<80391808>] (bpf_jit_free) from [<80392958>] (bpf_prog_free_deferred+0x14c/0x164 kernel/bpf/core.c:2783)
>  r5:845b0754 r4:845b0400
> [<8039280c>] (bpf_prog_free_deferred) from [<8026678c>] (process_one_work+0x1b8/0x508 kernel/workqueue.c:3254)
>  r7:dddd00c0 r6:82c16000 r5:845b0754 r4:84d7cb00
> [<802665d4>] (process_one_work) from [<802674b0>] (process_scheduled_works kernel/workqueue.c:3335 [inline])
> [<802665d4>] (process_one_work) from [<802674b0>] (worker_thread+0x1ec/0x418 kernel/workqueue.c:3416)
>  r10:84dd1800 r9:84d7cb2c r8:61c88647 r7:dddd00e0 r6:82604d40 r5:dddd00c0
>  r4:84d7cb00
> [<802672c4>] (worker_thread) from [<802701c4>] (kthread+0x104/0x134 kernel/kthread.c:388)
>  r10:00000000 r9:dfa55e90 r8:845d8e80 r7:84d7cb00 r6:802672c4 r5:84dd1800
>  r4:84c66500
> [<802700c0>] (kthread) from [<80200104>] (ret_from_fork+0x14/0x30 arch/arm/kernel/entry-common.S:134)
> Exception stack(0xdfd0dfb0 to 0xdfd0dff8)
> dfa0:                                     00000000 00000000 00000000 00000000
> dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> dfe0: 00000000 00000000 00000000 00000000 00000013 00000000
>  r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:802700c0 r4:84c66500
> INFO: task kworker/1:55:4229 blocked for more than 430 seconds.
>       Not tainted 6.9.0-rc1-syzkaller #0
> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> task:kworker/1:55    state:D stack:0     pid:4229  tgid:4229  ppid:2      flags:0x00000000
> Workqueue: events bpf_prog_free_deferred
> Call trace: 
> [<8189ad40>] (__schedule) from [<8189b97c>] (__schedule_loop kernel/sched/core.c:6823 [inline])
> [<8189ad40>] (__schedule) from [<8189b97c>] (schedule+0x2c/0xfc kernel/sched/core.c:6838)
>  r10:82c16205 r9:00000000 r8:82714be8 r7:00000002 r6:dfe39d94 r5:84e83c00
>  r4:84e83c00
> [<8189b950>] (schedule) from [<8189bf8c>] (schedule_preempt_disabled+0x18/0x24 kernel/sched/core.c:6895)
>  r5:84e83c00 r4:82714be4
> [<8189bf74>] (schedule_preempt_disabled) from [<8189e86c>] (__mutex_lock_common kernel/locking/mutex.c:684 [inline])
> [<8189bf74>] (schedule_preempt_disabled) from [<8189e86c>] (__mutex_lock.constprop.0+0x2e8/0xae0 kernel/locking/mutex.c:752)
> [<8189e584>] (__mutex_lock.constprop.0) from [<8189f138>] (__mutex_lock_slowpath+0x14/0x18 kernel/locking/mutex.c:1040)
>  r10:82c16205 r9:dfe39e20 r8:00000000 r7:ffffffff r6:00000000 r5:84c7a240
>  r4:00000000
> [<8189f124>] (__mutex_lock_slowpath) from [<8189f178>] (mutex_lock+0x3c/0x40 kernel/locking/mutex.c:286)
> [<8189f13c>] (mutex_lock) from [<8049c624>] (_vm_unmap_aliases+0x60/0x2e8 mm/vmalloc.c:2788)
> [<8049c5c4>] (_vm_unmap_aliases) from [<804a04a8>] (vm_reset_perms mm/vmalloc.c:3235 [inline])
> [<8049c5c4>] (_vm_unmap_aliases) from [<804a04a8>] (vfree+0x170/0x1e4 mm/vmalloc.c:3314)
>  r10:82c16205 r9:00000001 r8:00000000 r7:ffffffff r6:00000000 r5:84c7a240
>  r4:00000000
> [<804a0338>] (vfree) from [<802edb08>] (module_memfree+0x30/0x50 kernel/module/main.c:1189)
>  r9:84e83c00 r8:00000180 r7:00000000 r6:82c16200 r5:00001000 r4:7f053000
> [<802edad8>] (module_memfree) from [<803916b0>] (bpf_jit_free_exec+0x10/0x14 kernel/bpf/core.c:1058)
>  r5:00001000 r4:dfe73000
> [<803916a0>] (bpf_jit_free_exec) from [<80391870>] (bpf_jit_binary_free kernel/bpf/core.c:1104 [inline])
> [<803916a0>] (bpf_jit_free_exec) from [<80391870>] (bpf_jit_free+0x68/0xe4 kernel/bpf/core.c:1228)
> [<80391808>] (bpf_jit_free) from [<80392958>] (bpf_prog_free_deferred+0x14c/0x164 kernel/bpf/core.c:2783)
>  r5:845b2b54 r4:845b2800
> [<8039280c>] (bpf_prog_free_deferred) from [<8026678c>] (process_one_work+0x1b8/0x508 kernel/workqueue.c:3254)
>  r7:ddde40c0 r6:82c16200 r5:845b2b54 r4:845d9f80
> [<802665d4>] (process_one_work) from [<802674b0>] (process_scheduled_works kernel/workqueue.c:3335 [inline])
> [<802665d4>] (process_one_work) from [<802674b0>] (worker_thread+0x1ec/0x418 kernel/workqueue.c:3416)
>  r10:84e83c00 r9:845d9fac r8:61c88647 r7:ddde40e0 r6:82604d40 r5:ddde40c0
>  r4:845d9f80
> [<802672c4>] (worker_thread) from [<802701c4>] (kthread+0x104/0x134 kernel/kthread.c:388)
>  r10:00000000 r9:dfde5e90 r8:84640600 r7:845d9f80 r6:802672c4 r5:84e83c00
>  r4:84c66300
> [<802700c0>] (kthread) from [<80200104>] (ret_from_fork+0x14/0x30 arch/arm/kernel/entry-common.S:134)
> Exception stack(0xdfe39fb0 to 0xdfe39ff8)
> 9fa0:                                     00000000 00000000 00000000 00000000
> 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
>  r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:802700c0 r4:84c66300
> NMI backtrace for cpu 0
> CPU: 0 PID: 31 Comm: khungtaskd Not tainted 6.9.0-rc1-syzkaller #0
> Hardware name: ARM-Versatile Express
> Call trace: 
> [<818795bc>] (dump_backtrace) from [<818796b8>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:256)
>  r7:00000000 r6:00000113 r5:60000193 r4:81fc4768
> [<818796a0>] (show_stack) from [<81896e70>] (__dump_stack lib/dump_stack.c:88 [inline])
> [<818796a0>] (show_stack) from [<81896e70>] (dump_stack_lvl+0x70/0x7c lib/dump_stack.c:114)
> [<81896e00>] (dump_stack_lvl) from [<81896e94>] (dump_stack+0x18/0x1c lib/dump_stack.c:123)
>  r5:00000000 r4:00000001
> [<81896e7c>] (dump_stack) from [<81866994>] (nmi_cpu_backtrace+0x160/0x17c lib/nmi_backtrace.c:113)
> [<81866834>] (nmi_cpu_backtrace) from [<81866ae0>] (nmi_trigger_cpumask_backtrace+0x130/0x1d8 lib/nmi_backtrace.c:62)
>  r7:00000000 r6:8260c590 r5:8261a88c r4:ffffffff
> [<818669b0>] (nmi_trigger_cpumask_backtrace) from [<802105b4>] (arch_trigger_cpumask_backtrace+0x18/0x1c arch/arm/kernel/smp.c:851)
>  r9:8260c6f4 r8:00007b4d r7:8289dfe0 r6:00007d59 r5:8500ee04 r4:850d4b24
> [<8021059c>] (arch_trigger_cpumask_backtrace) from [<8034ec48>] (trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline])
> [<8021059c>] (arch_trigger_cpumask_backtrace) from [<8034ec48>] (check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline])
> [<8021059c>] (arch_trigger_cpumask_backtrace) from [<8034ec48>] (watchdog+0x480/0x594 kernel/hung_task.c:380)
> [<8034e7c8>] (watchdog) from [<802701c4>] (kthread+0x104/0x134 kernel/kthread.c:388)
>  r10:00000000 r9:df819e58 r8:82e98440 r7:00000000 r6:8034e7c8 r5:82ee8c00
>  r4:82f42100
> [<802700c0>] (kthread) from [<80200104>] (ret_from_fork+0x14/0x30 arch/arm/kernel/entry-common.S:134)
> Exception stack(0xdf8ddfb0 to 0xdf8ddff8)
> dfa0:                                     00000000 00000000 00000000 00000000
> dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> dfe0: 00000000 00000000 00000000 00000000 00000013 00000000
>  r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:802700c0 r4:82f42100
> Sending NMI from CPU 0 to CPUs 1:
> NMI backtrace for cpu 1
> CPU: 1 PID: 5655 Comm: kworker/1:259 Not tainted 6.9.0-rc1-syzkaller #0
> Hardware name: ARM-Versatile Express
> Workqueue: wg-crypt-wg0 wg_packet_encrypt_worker
> PC is at poly1305_final_arch+0x0/0x80 arch/arm/crypto/poly1305-glue.c:189
> LR is at poly1305_final include/crypto/poly1305.h:94 [inline]
> LR is at chacha20poly1305_crypt_sg_inplace+0x43c/0x4b4 lib/crypto/chacha20poly1305.c:320
> pc : [<80232f80>]    lr : [<807fa0e4>]    psr: 60000113
> sp : eafa1990  ip : eafa1990  fp : eafa1bb4
> r10: 00000000  r9 : 00000000  r8 : 00000000
> r7 : eafa19e0  r6 : 00000000  r5 : 00000000  r4 : eafa19f0
> r3 : 00000000  r2 : 00000000  r1 : eafa19f0  r0 : eafa1a68
> Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
> Control: 30c5387d  Table: 8461dec0  DAC: 00000000
> Call trace: 
> [<807f9ca8>] (chacha20poly1305_crypt_sg_inplace) from [<807fa188>] (chacha20poly1305_encrypt_sg_inplace+0x2c/0x34 lib/crypto/chacha20poly1305.c:338)
>  r10:00000000 r9:00000000 r8:00000074 r7:00000001 r6:84dca018 r5:00000000
>  r4:00000074
> [<807fa15c>] (chacha20poly1305_encrypt_sg_inplace) from [<80bfb0f8>] (encrypt_packet+0x194/0x230 drivers/net/wireguard/send.c:216)
>  r5:00000000 r4:00000074
> [<80bfaf64>] (encrypt_packet) from [<80bfb8d0>] (wg_packet_encrypt_worker+0xbc/0x270 drivers/net/wireguard/send.c:297)
>  r10:846c86e8 r9:82f2a540 r8:00000000 r7:846c86a0 r6:8260eea8 r5:00000000
>  r4:82f2a540
> [<80bfb814>] (wg_packet_encrypt_worker) from [<8026678c>] (process_one_work+0x1b8/0x508 kernel/workqueue.c:3254)
>  r10:84032e05 r9:85156000 r8:00000180 r7:ddde40c0 r6:84032e00 r5:ff7ffcf4
>  r4:8505ff00
> [<802665d4>] (process_one_work) from [<802674b0>] (process_scheduled_works kernel/workqueue.c:3335 [inline])
> [<802665d4>] (process_one_work) from [<802674b0>] (worker_thread+0x1ec/0x418 kernel/workqueue.c:3416)
>  r10:85156000 r9:8505ff2c r8:61c88647 r7:ddde40e0 r6:82604d40 r5:ddde40c0
>  r4:8505ff00
> [<802672c4>] (worker_thread) from [<802701c4>] (kthread+0x104/0x134 kernel/kthread.c:388)
>  r10:00000000 r9:eaeb1e90 r8:84ed1a40 r7:8505ff00 r6:802672c4 r5:85156000
>  r4:847e7040
> [<802700c0>] (kthread) from [<80200104>] (ret_from_fork+0x14/0x30 arch/arm/kernel/entry-common.S:134)
> Exception stack(0xeafa1fb0 to 0xeafa1ff8)
> 1fa0:                                     00000000 00000000 00000000 00000000
> 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000
>  r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:802700c0 r4:847e7040
>
>
> Tested on:
>
> commit:         7deb8d88 arm32, bpf: Fix sign-extension mov instruction
> git tree:       https://github.com/puranjaymohan/linux.git arm32_movsx_fix
> console output: https://syzkaller.appspot.com/x/log.txt?x=175200cb180000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=43f1e0cbdb852271
> dashboard link: https://syzkaller.appspot.com/bug?extid=186522670e6722692d86
> compiler:       arm-linux-gnueabi-gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> userspace arch: arm
>
> Note: no patches were applied.

I am not able to reproduce the above locally. I don't think it is
related to the change.

Thanks,
Puranjay