[syzbot] [ntfs3?] KASAN: stack-out-of-bounds Read in filemap_get_read_batch

syzbot
2023-01-10T17:21:43Z

Hello,

syzbot found the following issue on:

HEAD commit: 41c03ba9beea Merge tag 'for_linus' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1042b176480000
kernel config: https://syzkaller.appspot.com/x/.config?x=9babfdc3dd4772d0
dashboard link: https://syzkaller.appspot.com/bug?extid=9d9efb38bb1425ff6283
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1187a762480000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/041403c21ee3/disk-41c03ba9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/579dec11b65a/vmlinux-41c03ba9.xz
kernel image: https://storage.googleapis.com/syzbot-assets/dcb6cfc03c78/bzImage-41c03ba9.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/8d89f17a9699/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9d9efb38bb1425ff6283@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: stack-out-of-bounds in native_save_fl arch/x86/include/asm/irqflags.h:35 [inline]
BUG: KASAN: stack-out-of-bounds in arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
BUG: KASAN: stack-out-of-bounds in arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline]
BUG: KASAN: stack-out-of-bounds in lock_acquire+0x1c3/0x3c0 kernel/locking/lockdep.c:5671
Read of size 8 at addr ffffc9000473727f by task syz-executor.0/5208

CPU: 0 PID: 5208 Comm: syz-executor.0 Not tainted 6.2.0-rc2-syzkaller-00057-g41c03ba9beea #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106
print_address_description+0x74/0x340 mm/kasan/report.c:306
print_report+0x107/0x1f0 mm/kasan/report.c:417
kasan_report+0xcd/0x100 mm/kasan/report.c:517
native_save_fl arch/x86/include/asm/irqflags.h:35 [inline]
arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline]
lock_acquire+0x1c3/0x3c0 kernel/locking/lockdep.c:5671
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:325
rcu_read_lock include/linux/rcupdate.h:764 [inline]
filemap_get_read_batch+0x15a/0xe00 mm/filemap.c:2379
filemap_get_pages+0x47c/0x10d0 mm/filemap.c:2602
filemap_read+0x3cf/0xea0 mm/filemap.c:2694
call_read_iter include/linux/fs.h:2180 [inline]
generic_file_splice_read+0x1ff/0x5d0 fs/splice.c:309
do_splice_to fs/splice.c:793 [inline]
splice_direct_to_actor+0x41b/0xc00 fs/splice.c:865
do_splice_direct+0x279/0x3d0 fs/splice.c:974
do_sendfile+0x5fb/0xf80 fs/read_write.c:1255
__do_sys_sendfile64 fs/read_write.c:1323 [inline]
__se_sys_sendfile64+0x14f/0x1b0 fs/read_write.c:1309
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fa9e708c0c9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa9e7dcd168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fa9e71abf80 RCX: 00007fa9e708c0c9
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004
RBP: 00007fa9e70e7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 00008400fffffffa R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe3f108fdf R14: 00007fa9e7dcd300 R15: 0000000000022000
</TASK>

The buggy address belongs to stack of task syz-executor.0/5208
and is located at offset 31 in frame:
lock_acquire+0x0/0x3c0 kernel/locking/lockdep.c:5623

This frame has 3 objects:
[32, 40) 'flags.i.i.i87'
[64, 72) 'flags.i.i.i'
[96, 136) 'hlock'

The buggy address belongs to the virtual mapping at
[ffffc90004730000, ffffc90004739000) created by:
dup_task_struct+0x8b/0x490 kernel/fork.c:987

The buggy address belongs to the physical page:
page:ffffea0001dcdb40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7736d
memcg:ffff8880200d6682
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff ffff8880200d6682
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO), pid 5195, tgid 5195 (syz-executor.1), ts 61000027517, free_ts 60960682032
prep_new_page mm/page_alloc.c:2531 [inline]
get_page_from_freelist+0x742/0x7c0 mm/page_alloc.c:4283
__alloc_pages+0x259/0x560 mm/page_alloc.c:5549
vm_area_alloc_pages mm/vmalloc.c:2989 [inline]
__vmalloc_area_node mm/vmalloc.c:3057 [inline]
__vmalloc_node_range+0x9b2/0x1400 mm/vmalloc.c:3227
alloc_thread_stack_node+0x307/0x500 kernel/fork.c:311
dup_task_struct+0x8b/0x490 kernel/fork.c:987
copy_process+0x53c/0x3f00 kernel/fork.c:2097
kernel_clone+0x21b/0x630 kernel/fork.c:2681
__do_sys_clone kernel/fork.c:2822 [inline]
__se_sys_clone kernel/fork.c:2806 [inline]
__x64_sys_clone+0x228/0x290 kernel/fork.c:2806
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1446 [inline]
free_pcp_prepare+0x751/0x780 mm/page_alloc.c:1496
free_unref_page_prepare mm/page_alloc.c:3369 [inline]
free_unref_page_list+0xb2/0x830 mm/page_alloc.c:3510
release_pages+0x233e/0x25e0 mm/swap.c:1076
__pagevec_release+0x7d/0xf0 mm/swap.c:1096
pagevec_release include/linux/pagevec.h:71 [inline]
folio_batch_release include/linux/pagevec.h:135 [inline]
truncate_inode_pages_range+0x452/0x1690 mm/truncate.c:372
kill_bdev block/bdev.c:76 [inline]
blkdev_flush_mapping+0x153/0x2c0 block/bdev.c:662
blkdev_put_whole block/bdev.c:693 [inline]
blkdev_put+0x4a5/0x730 block/bdev.c:953
deactivate_locked_super+0xa7/0xf0 fs/super.c:332
cleanup_mnt+0x494/0x520 fs/namespace.c:1291
task_work_run+0x243/0x300 kernel/task_work.c:179
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0x124/0x150 kernel/entry/common.c:171
exit_to_user_mode_prepare+0xb2/0x140 kernel/entry/common.c:203
__syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:296
do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
ffffc90004737100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffffc90004737180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc90004737200: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
^
ffffc90004737280: 00 f2 f2 f2 00 f2 f2 f2 00 00 00 00 00 f3 f3 f3
ffffc90004737300: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

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