syzbot


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

Status: upstream: reported on 2022/08/21 20:00
Reported-by: syzbot+dc34dd8e1a7a138b88ac@syzkaller.appspotmail.com
First crash: 101d, last: 101d

Sample crash report:
==================================================================
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
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-usb 2022/08/17 19:56 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 568035b01cfb a9409d47 .config log report usb-testing boot error: KASAN: out-of-bounds Read in __schedule
* Struck through repros no longer work on HEAD.