KASAN: out-of-bounds Read in leaf_paste

KASAN: out-of-bounds Read in leaf_paste_entries (2)
Status: moderation: reported on 2021/11/12 19:19
Reported-by: syzbot+ef8359d6478091124f23@syzkaller.appspotmail.com
First crash: 24d, last: 4d15h

similar bugs (3):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-4.19	KASAN: out-of-bounds Read in leaf_paste_entries	C		error	7	15d	387d	0/1	upstream: reported C repro on 2020/11/14 23:23
linux-4.14	KASAN: out-of-bounds Read in leaf_paste_entries	C			9	3d17h	427d	0/1	upstream: reported C repro on 2020/10/05 14:11
upstream	KASAN: out-of-bounds Read in leaf_paste_entries	C	inconclusive		8	58d	289d	22/22	fixed on 2021/11/10 00:50

Sample crash report:

REISERFS (device loop2): Using rupasov hash to sort names
==================================================================
BUG: KASAN: out-of-bounds in memmove include/linux/fortify-string.h:241 [inline]
BUG: KASAN: out-of-bounds in leaf_paste_entries+0x449/0x910 fs/reiserfs/lbalance.c:1377
Read of size 18446744073709551584 at addr ffff888191d7efa4 by task syz-executor.2/2393

CPU: 0 PID: 2393 Comm: syz-executor.2 Not tainted 5.16.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description.constprop.0.cold+0x8d/0x2ed mm/kasan/report.c:247
 __kasan_report mm/kasan/report.c:433 [inline]
 kasan_report.cold+0x83/0xdf mm/kasan/report.c:450
 check_region_inline mm/kasan/generic.c:183 [inline]
 kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
 memmove+0x20/0x60 mm/kasan/shadow.c:54
 memmove include/linux/fortify-string.h:241 [inline]
 leaf_paste_entries+0x449/0x910 fs/reiserfs/lbalance.c:1377
 balance_leaf_finish_node_paste_dirent fs/reiserfs/do_balan.c:1295 [inline]
 balance_leaf_finish_node_paste fs/reiserfs/do_balan.c:1321 [inline]
 balance_leaf_finish_node fs/reiserfs/do_balan.c:1364 [inline]
 balance_leaf+0x951e/0xd8b0 fs/reiserfs/do_balan.c:1452
 do_balance+0x315/0x810 fs/reiserfs/do_balan.c:1888
 reiserfs_paste_into_item+0x762/0x8e0 fs/reiserfs/stree.c:2159
 reiserfs_add_entry+0x8cb/0xcf0 fs/reiserfs/namei.c:567
 reiserfs_mkdir+0x675/0x980 fs/reiserfs/namei.c:860
 create_privroot fs/reiserfs/xattr.c:889 [inline]
 reiserfs_xattr_init+0x4de/0xb60 fs/reiserfs/xattr.c:1012
 reiserfs_fill_super+0x21ea/0x2f80 fs/reiserfs/super.c:2175
 mount_bdev+0x34d/0x410 fs/super.c:1370
 legacy_get_tree+0x105/0x220 fs/fs_context.c:610
 vfs_get_tree+0x89/0x2f0 fs/super.c:1500
 do_new_mount fs/namespace.c:2988 [inline]
 path_mount+0x1320/0x1fa0 fs/namespace.c:3318
 do_mount fs/namespace.c:3331 [inline]
 __do_sys_mount fs/namespace.c:3539 [inline]
 __se_sys_mount fs/namespace.c:3516 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3516
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f4fc0c8e01a
Code: 48 c7 c2 bc ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4fbe201fa8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00007f4fc0c8e01a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f4fbe202000
RBP: 00007f4fbe202040 R08: 00007f4fbe202040 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000000
R13: 0000000020000100 R14: 00007f4fbe202000 R15: 0000000020011500
 </TASK>

The buggy address belongs to the page:
page:ffffea0006475f80 refcount:3 mapcount:0 mapping:ffff8881460b1b40 index:0x3d97 pfn:0x191d7e
memcg:ffff8880114d4000
aops:def_blk_aops ino:700002
flags: 0x57ff00000002022(referenced|active|private|node=1|zone=2|lastcpupid=0x7ff)
raw: 057ff00000002022 0000000000000000 dead000000000122 ffff8881460b1b40
raw: 0000000000003d97 ffff88806d414570 00000003ffffffff ffff8880114d4000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Movable, gfp_mask 0x148c48(GFP_NOFS|__GFP_NOFAIL|__GFP_COMP|__GFP_HARDWALL|__GFP_MOVABLE), pid 2393, ts 2267257248348, free_ts 0
 prep_new_page mm/page_alloc.c:2418 [inline]
 get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4149
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5369
 alloc_pages+0x1a7/0x300 mm/mempolicy.c:2191
 folio_alloc+0x1c/0x70 mm/mempolicy.c:2201
 filemap_alloc_folio mm/filemap.c:1036 [inline]
 __filemap_get_folio+0x5f2/0xd60 mm/filemap.c:1951
 pagecache_get_page+0x2c/0x1a0 mm/folio-compat.c:125
 find_or_create_page include/linux/pagemap.h:489 [inline]
 grow_dev_page fs/buffer.c:949 [inline]
 grow_buffers fs/buffer.c:1014 [inline]
 __getblk_slow+0x1ed/0xae0 fs/buffer.c:1041
 __getblk_gfp+0x6e/0x80 fs/buffer.c:1334
 sb_getblk include/linux/buffer_head.h:327 [inline]
 search_by_key+0x3a5/0x3cc0 fs/reiserfs/stree.c:672
 reiserfs_read_locked_inode+0x154/0x2160 fs/reiserfs/inode.c:1557
 reiserfs_fill_super+0x1350/0x2f80 fs/reiserfs/super.c:2071
 mount_bdev+0x34d/0x410 fs/super.c:1370
 legacy_get_tree+0x105/0x220 fs/fs_context.c:610
 vfs_get_tree+0x89/0x2f0 fs/super.c:1500
 do_new_mount fs/namespace.c:2988 [inline]
 path_mount+0x1320/0x1fa0 fs/namespace.c:3318
 do_mount fs/namespace.c:3331 [inline]
 __do_sys_mount fs/namespace.c:3539 [inline]
 __se_sys_mount fs/namespace.c:3516 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3516
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888191d7ee80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888191d7ef00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888191d7ef80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                               ^
 ffff888191d7f000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888191d7f080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (3):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci-upstream-kasan-gce-selinux-root	2021/12/02 12:20	upstream	58e1100fdc59	61f86278	.config	log	report	info	KASAN: out-of-bounds Read in leaf_paste_entries
ci-upstream-kasan-gce-root	2021/11/18 19:34	upstream	42eb8fdac2fc	31a30fc0	.config	log	report	info	KASAN: out-of-bounds Read in leaf_paste_entries
ci-qemu-upstream-386	2021/11/12 06:32	upstream	5833291ab6de	75b04091	.config	log	report	info	KASAN: out-of-bounds Read in leaf_paste_entries