2024-05-28 12:47:30

by syzbot

[permalink] [raw]
Subject: [syzbot] [arm?] BUG: unable to handle kernel paging request in task_h_load

Hello,

syzbot found the following issue on:

HEAD commit: 6d69b6c12fce Merge tag 'nfs-for-6.10-1' of git://git.linux..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=164ce7f0980000
kernel config: https://syzkaller.appspot.com/x/.config?x=21de3d423116c304
dashboard link: https://syzkaller.appspot.com/bug?extid=8336c747d79a4c3a0944
compiler: aarch64-linux-gnu-gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=119fbe58980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13a8443c980000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/384ffdcca292/non_bootable_disk-6d69b6c1.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9fa4d7c3665d/vmlinux-6d69b6c1.xz
kernel image: https://storage.googleapis.com/syzbot-assets/131ac291917c/Image-6d69b6c1.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]

Unable to handle kernel paging request at virtual address 007000000621a118
Mem abort info:
ESR = 0x0000000096000004
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x04: level 0 translation fault
Data abort info:
ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[007000000621a118] address between user and kernel address ranges
Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 3189 Comm: syz-executor371 Not tainted 6.9.0-syzkaller-12124-g6d69b6c12fce #0
Hardware name: linux,dummy-virt (DT)
pstate: 204000c9 (nzCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : cfs_rq_of kernel/sched/sched.h:1468 [inline]
pc : update_cfs_rq_h_load kernel/sched/fair.c:9441 [inline]
pc : task_h_load+0x40/0xb8 kernel/sched/fair.c:9466
lr : detach_tasks kernel/sched/fair.c:9181 [inline]
lr : sched_balance_rq+0x80c/0xc94 kernel/sched/fair.c:11375
sp : ffff80008000bd50
x29: ffff80008000bd50 x28: f8f0000004c62538 x27: ffff8000825e3308
x26: 0000000000000001 x25: fff000007f8d6de0 x24: ffff80008000bf14
x23: fff000007f8d6340 x22: fff000007f8d6340 x21: fff000007f8d6d40
x20: ffff80008000be78 x19: f8f0000004c62480 x18: ffffffffffffffff
x17: fff07ffffd331000 x16: ffff800080008000 x15: 0000000000000001
x14: 000000000000000a x13: 0000000000000000 x12: 0000000000000011
x11: 0000000000000001 x10: 0000000000000001 x9 : 0000000000000da8
x8 : fff000007f8d6440 x7 : f4f000000621a200 x6 : 0000000000000001
x5 : 00000000ffffbd09 x4 : ffff80008000be78 x3 : f5f000000602ff40
x2 : f87000000621a080 x1 : 00000000ffffa6e9 x0 : f8f0000004c62480
Call trace:
update_cfs_rq_h_load kernel/sched/fair.c:9440 [inline]
task_h_load+0x40/0xb8 kernel/sched/fair.c:9466
sched_balance_domains+0x270/0x3ac kernel/sched/fair.c:11798
sched_balance_softirq+0x50/0x74 kernel/sched/fair.c:12503
handle_softirqs+0x10c/0x240 kernel/softirq.c:554
__do_softirq+0x14/0x20 kernel/softirq.c:588
____do_softirq+0x10/0x1c arch/arm64/kernel/irq.c:81
call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:889
do_softirq_own_stack+0x1c/0x28 arch/arm64/kernel/irq.c:86
invoke_softirq kernel/softirq.c:435 [inline]
__irq_exit_rcu kernel/softirq.c:637 [inline]
irq_exit_rcu+0xbc/0xd8 kernel/softirq.c:649
__el1_irq arch/arm64/kernel/entry-common.c:537 [inline]
el1_interrupt+0x38/0x64 arch/arm64/kernel/entry-common.c:551
el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:556
el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:594
__pte_offset_map+0x2c/0x100 mm/pgtable-generic.c:292
pte_offset_map_nolock+0x38/0xb0 mm/pgtable-generic.c:314
handle_pte_fault mm/memory.c:5366 [inline]
__handle_mm_fault+0x2e8/0xc20 mm/memory.c:5523
handle_mm_fault+0x68/0x27c mm/memory.c:5688
do_page_fault+0xf8/0x480 arch/arm64/mm/fault.c:578
do_translation_fault+0xac/0xbc arch/arm64/mm/fault.c:690
do_mem_abort+0x44/0x94 arch/arm64/mm/fault.c:826
el0_ia+0xa4/0x118 arch/arm64/kernel/entry-common.c:598
el0t_64_sync_handler+0xd0/0x12c arch/arm64/kernel/entry-common.c:736
el0t_64_sync+0x19c/0x1a0 arch/arm64/kernel/entry.S:598
Code: b5000082 1400001c f9404842 b4000382 (f9404c41)
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
0: b5000082 cbnz x2, 0x10
4: 1400001c b 0x74
8: f9404842 ldr x2, [x2, #144]
c: b4000382 cbz x2, 0x7c
* 10: f9404c41 ldr x1, [x2, #152] <-- trapping instruction


---
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2024-06-04 11:01:33

by Will Deacon

[permalink] [raw]
Subject: Re: [syzbot] [arm?] BUG: unable to handle kernel paging request in task_h_load

Hello Syzbot,

On Tue, May 28, 2024 at 05:47:22AM -0700, syzbot wrote:
> syzbot found the following issue on:
>
> HEAD commit: 6d69b6c12fce Merge tag 'nfs-for-6.10-1' of git://git.linux..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=164ce7f0980000
> kernel config: https://syzkaller.appspot.com/x/.config?x=21de3d423116c304
> dashboard link: https://syzkaller.appspot.com/bug?extid=8336c747d79a4c3a0944
> compiler: aarch64-linux-gnu-gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> userspace arch: arm64
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=119fbe58980000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13a8443c980000
>
> Downloadable assets:
> disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/384ffdcca292/non_bootable_disk-6d69b6c1.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/9fa4d7c3665d/vmlinux-6d69b6c1.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/131ac291917c/Image-6d69b6c1.gz.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: [email protected]
>
> Unable to handle kernel paging request at virtual address 007000000621a118
> Mem abort info:
> ESR = 0x0000000096000004
> EC = 0x25: DABT (current EL), IL = 32 bits
> SET = 0, FnV = 0
> EA = 0, S1PTW = 0
> FSC = 0x04: level 0 translation fault
> Data abort info:
> ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
> CM = 0, WnR = 0, TnD = 0, TagAccess = 0
> GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> [007000000621a118] address between user and kernel address ranges
> Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
> Modules linked in:
> CPU: 1 PID: 3189 Comm: syz-executor371 Not tainted 6.9.0-syzkaller-12124-g6d69b6c12fce #0
> Hardware name: linux,dummy-virt (DT)
> pstate: 204000c9 (nzCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> pc : cfs_rq_of kernel/sched/sched.h:1468 [inline]
> pc : update_cfs_rq_h_load kernel/sched/fair.c:9441 [inline]
> pc : task_h_load+0x40/0xb8 kernel/sched/fair.c:9466
> lr : detach_tasks kernel/sched/fair.c:9181 [inline]
> lr : sched_balance_rq+0x80c/0xc94 kernel/sched/fair.c:11375

Mark and I were looking at this today and we believe it should be fixed
by:

https://lore.kernel.org/all/[email protected]/T/#u

which is queued in -next via the mm tree and will hopefully land in -rc3.

Will