[syzbot] usb-testing boot error: KASAN: out-of-bounds Read in __schedule

From: syzbot
Date: Sun Aug 21 2022 - 16:00:37 EST


Hello,

syzbot found the following issue on:

HEAD commit: 568035b01cfb Linux 6.0-rc1
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
console output: https://syzkaller.appspot.com/x/log.txt?x=10c0a92d080000
kernel config: https://syzkaller.appspot.com/x/.config?x=3cb39b084894e9a5
dashboard link: https://syzkaller.appspot.com/bug?extid=dc34dd8e1a7a138b88ac
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+dc34dd8e1a7a138b88ac@xxxxxxxxxxxxxxxxxxxxxxxxx

==================================================================
BUG: KASAN: out-of-bounds in schedule_debug kernel/sched/core.c:5736 [inline]
BUG: KASAN: out-of-bounds in __schedule+0x2114/0x26f0 kernel/sched/core.c:6388
Read of size 8 at addr ffffc900015f8000 by task kworker/u4:1/237

CPU: 1 PID: 237 Comm: kworker/u4:1 Not tainted 6.0.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:317 [inline]
print_report.cold+0x59/0x719 mm/kasan/report.c:433
kasan_report+0xb1/0x1e0 mm/kasan/report.c:495
schedule_debug kernel/sched/core.c:5736 [inline]
__schedule+0x2114/0x26f0 kernel/sched/core.c:6388
preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6663
__cond_resched+0x13/0x20 kernel/sched/core.c:8299
might_resched include/linux/kernel.h:110 [inline]
might_alloc include/linux/sched/mm.h:274 [inline]
slab_pre_alloc_hook mm/slab.h:700 [inline]
slab_alloc_node mm/slub.c:3157 [inline]
slab_alloc mm/slub.c:3251 [inline]
__kmem_cache_alloc_lru mm/slub.c:3258 [inline]
kmem_cache_alloc+0x2fe/0x4a0 mm/slub.c:3268
prepare_kernel_cred+0x27/0x890 kernel/cred.c:717
call_usermodehelper_exec_async+0x10e/0x580 kernel/umh.c:91
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
</TASK>

The buggy address belongs to stack of task kworker/u4:1/237

The buggy address belongs to the virtual mapping at
[ffffc900015f8000, ffffc90001601000) created by:
kernel_clone+0xe7/0xab0 kernel/fork.c:2673

The buggy address belongs to the physical page:
page:ffffea0004396940 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10e5a5
flags: 0x200000000000000(node=0|zone=2)
raw: 0200000000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2dc2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_NOWARN|__GFP_ZERO), pid 26, tgid 26 (kworker/u4:1), ts 6964925972, free_ts 0
prep_new_page mm/page_alloc.c:2532 [inline]
get_page_from_freelist+0x11cc/0x2a20 mm/page_alloc.c:4283
__alloc_pages+0x1c7/0x510 mm/page_alloc.c:5515
__alloc_pages_bulk+0x9a1/0x1400 mm/page_alloc.c:5463
alloc_pages_bulk_array_mempolicy+0x1b3/0x360 mm/mempolicy.c:2365
vm_area_alloc_pages mm/vmalloc.c:2930 [inline]
__vmalloc_area_node mm/vmalloc.c:3026 [inline]
__vmalloc_node_range+0x576/0x13a0 mm/vmalloc.c:3196
alloc_thread_stack_node kernel/fork.c:312 [inline]
dup_task_struct kernel/fork.c:977 [inline]
copy_process+0x13c0/0x6de0 kernel/fork.c:2087
kernel_clone+0xe7/0xab0 kernel/fork.c:2673
user_mode_thread+0xad/0xe0 kernel/fork.c:2742
call_usermodehelper_exec_work kernel/umh.c:174 [inline]
call_usermodehelper_exec_work+0xcc/0x180 kernel/umh.c:160
process_one_work+0x991/0x1610 kernel/workqueue.c:2289
worker_thread+0x665/0x1080 kernel/workqueue.c:2436
kthread+0x2ea/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
page_owner free stack trace missing

Memory state around the buggy address:
ffffc900015f7f00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
ffffc900015f7f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>ffffc900015f8000: 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
^
ffffc900015f8080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffffc900015f8100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


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