[v5.15] KASAN: use-after-free Read in reiserfs_get_unused_objectid

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: b0ece631f84a Linux 5.15.111
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=10d42cba280000
kernel config: https://syzkaller.appspot.com/x/.config?x=5e93479ceb1e500
dashboard link: https://syzkaller.appspot.com/bug?extid=8ea7d81ab26fd6524edf
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=137268fc280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1374226e280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/4dbb092b5601/disk-b0ece631.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5fe7e3edcf9b/vmlinux-b0ece631.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1b2e75f47bfb/bzImage-b0ece631.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/37eb1ac07dc8/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8ea7d8...@syzkaller.appspotmail.com

REISERFS (device loop0): using ordered data mode
reiserfs: using flush barriers
REISERFS (device loop0): journal params: device loop0, size 512, journal first block 18, max trans len 256, max batch 225, max commit age 30, max trans age 30
REISERFS (device loop0): checking transaction log (loop0)
REISERFS (device loop0): Using r5 hash to sort names
==================================================================
BUG: KASAN: use-after-free in reiserfs_get_unused_objectid+0x22d/0x480 fs/reiserfs/objectid.c:87
Read of size 250888 at addr ffff8880708c8058 by task syz-executor834/3499

CPU: 0 PID: 3499 Comm: syz-executor834 Not tainted 5.15.111-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
print_address_description+0x63/0x3b0 mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:434 [inline]
kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
kasan_check_range+0x27e/0x290 mm/kasan/generic.c:189
memmove+0x25/0x60 mm/kasan/shadow.c:54
reiserfs_get_unused_objectid+0x22d/0x480 fs/reiserfs/objectid.c:87
reiserfs_new_inode+0x2b8/0x1d90 fs/reiserfs/inode.c:1952
reiserfs_mkdir+0x5ac/0x8f0 fs/reiserfs/namei.c:845
xattr_mkdir fs/reiserfs/xattr.c:76 [inline]
create_privroot fs/reiserfs/xattr.c:889 [inline]
reiserfs_xattr_init+0x348/0x730 fs/reiserfs/xattr.c:1012
reiserfs_fill_super+0x226a/0x2690 fs/reiserfs/super.c:2179
mount_bdev+0x26d/0x3a0 fs/super.c:1378
legacy_get_tree+0xeb/0x180 fs/fs_context.c:610
vfs_get_tree+0x88/0x270 fs/super.c:1508
do_new_mount+0x28b/0xad0 fs/namespace.c:2994
do_mount fs/namespace.c:3337 [inline]
__do_sys_mount fs/namespace.c:3545 [inline]
__se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3522
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+0x61/0xcb
RIP: 0033:0x7fa5438775fa
Code: 48 c7 c2 c0 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 a8 00 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd668e6c98 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fa5438775fa
RDX: 0000000020000080 RSI: 0000000020000040 RDI: 00007ffd668e6cb0
RBP: 00007ffd668e6cb0 R08: 00007ffd668e6cf0 R09: 0000000000000000
R10: 0000000000008008 R11: 0000000000000286 R12: 0000000000000004
R13: 00005555565e62c0 R14: 0000000000008008 R15: 00007ffd668e6cf0
</TASK>

The buggy address belongs to the page:
page:ffffea0001c23200 refcount:3 mapcount:0 mapping:ffff88801ac37270 index:0x10 pfn:0x708c8
memcg:ffff8881407a4000
aops:def_blk_aops ino:700000
flags: 0xfff00000002022(referenced|active|private|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002022 0000000000000000 dead000000000122 ffff88801ac37270
raw: 0000000000000010 ffff88807437a000 00000003ffffffff ffff8881407a4000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Movable, gfp_mask 0x108c48(GFP_NOFS|__GFP_NOFAIL|__GFP_HARDWALL|__GFP_MOVABLE), pid 3499, ts 56897973903, free_ts 56885936708
prep_new_page mm/page_alloc.c:2426 [inline]
get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159
__alloc_pages+0x272/0x700 mm/page_alloc.c:5421
__page_cache_alloc+0xd4/0x4a0 mm/filemap.c:1022
pagecache_get_page+0xa91/0x1010 mm/filemap.c:1940
find_or_create_page include/linux/pagemap.h:420 [inline]
grow_dev_page fs/buffer.c:949 [inline]
grow_buffers fs/buffer.c:1014 [inline]
__getblk_slow fs/buffer.c:1041 [inline]
__getblk_gfp+0x22a/0xaf0 fs/buffer.c:1336
__bread_gfp+0x2a/0x390 fs/buffer.c:1381
sb_bread include/linux/buffer_head.h:337 [inline]
read_super_block+0x91/0x7e0 fs/reiserfs/super.c:1606
reiserfs_fill_super+0x90a/0x2690 fs/reiserfs/super.c:1968
mount_bdev+0x26d/0x3a0 fs/super.c:1378
legacy_get_tree+0xeb/0x180 fs/fs_context.c:610
vfs_get_tree+0x88/0x270 fs/super.c:1508
do_new_mount+0x28b/0xad0 fs/namespace.c:2994
do_mount fs/namespace.c:3337 [inline]
__do_sys_mount fs/namespace.c:3545 [inline]
__se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3522
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+0x61/0xcb
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1340 [inline]
free_pcp_prepare mm/page_alloc.c:1391 [inline]
free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317
free_unref_page_list+0x1f7/0x8e0 mm/page_alloc.c:3433
release_pages+0x1bb9/0x1f40 mm/swap.c:963
tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:240 [inline]
tlb_flush_mmu mm/mmu_gather.c:247 [inline]
tlb_finish_mmu+0x177/0x320 mm/mmu_gather.c:338
unmap_region+0x304/0x350 mm/mmap.c:2668
__do_munmap+0x12db/0x1740 mm/mmap.c:2899
__vm_munmap+0x134/0x230 mm/mmap.c:2922
__do_sys_munmap mm/mmap.c:2948 [inline]
__se_sys_munmap mm/mmap.c:2944 [inline]
__x64_sys_munmap+0x67/0x70 mm/mmap.c:2944
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+0x61/0xcb

Memory state around the buggy address:
ffff8880708ccf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8880708ccf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880708cd000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff8880708cd080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff8880708cd100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================


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