[syzbot] [btrfs?] KASAN: slab-out-of-bounds Read in btrfs_qgroup_inherit

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2ab795141095 Merge tag 'cxl-fixes-6.10-rc3' of git://git.k..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=10a189ba980000
kernel config: https://syzkaller.appspot.com/x/.config?x=eb72437243175f22
dashboard link: https://syzkaller.appspot.com/bug?extid=a0d1f7e26910be4dc171
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12d4179a980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12e69a16980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ee6757748831/disk-2ab79514.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8169be68b124/vmlinux-2ab79514.xz
kernel image: https://storage.googleapis.com/syzbot-assets/023da2bf5a00/bzImage-2ab79514.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/ef7a34a3b3e5/mount_0.gz

The issue was bisected to:

commit b5357cb268c41b4e2b7383d2759fc562f5b58c33
Author: Qu Wenruo <w...@suse.com>
Date: Sat Apr 20 07:50:27 2024 +0000

btrfs: qgroup: do not check qgroup inherit if qgroup is disabled

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12e282ce980000
final oops: https://syzkaller.appspot.com/x/report.txt?x=11e282ce980000
console output: https://syzkaller.appspot.com/x/log.txt?x=16e282ce980000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a0d1f7...@syzkaller.appspotmail.com
Fixes: b5357cb268c4 ("btrfs: qgroup: do not check qgroup inherit if qgroup is disabled")

==================================================================
BUG: KASAN: slab-out-of-bounds in btrfs_qgroup_inherit+0x42e/0x2e20 fs/btrfs/qgroup.c:3277
Read of size 8 at addr ffff88814628ca50 by task syz-executor318/5171

CPU: 0 PID: 5171 Comm: syz-executor318 Not tainted 6.10.0-rc2-syzkaller-00010-g2ab795141095 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
print_address_description mm/kasan/report.c:377 [inline]
print_report+0x169/0x550 mm/kasan/report.c:488
kasan_report+0x143/0x180 mm/kasan/report.c:601
btrfs_qgroup_inherit+0x42e/0x2e20 fs/btrfs/qgroup.c:3277
create_pending_snapshot+0x1359/0x29b0 fs/btrfs/transaction.c:1854
create_pending_snapshots+0x195/0x1d0 fs/btrfs/transaction.c:1922
btrfs_commit_transaction+0xf20/0x3740 fs/btrfs/transaction.c:2382
create_snapshot+0x6a1/0x9e0 fs/btrfs/ioctl.c:875
btrfs_mksubvol+0x58f/0x710 fs/btrfs/ioctl.c:1029
btrfs_mksnapshot+0xb5/0xf0 fs/btrfs/ioctl.c:1075
__btrfs_ioctl_snap_create+0x387/0x4b0 fs/btrfs/ioctl.c:1340
btrfs_ioctl_snap_create_v2+0x1f2/0x3a0 fs/btrfs/ioctl.c:1422
btrfs_ioctl+0x99e/0xc60
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcbf1992509
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 18 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fcbf1928218 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fcbf1a1f618 RCX: 00007fcbf1992509
RDX: 0000000020000280 RSI: 0000000050009417 RDI: 0000000000000003
RBP: 00007fcbf1a1f610 R08: 00007ffea1298e97 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fcbf19eb660
R13: 00000000200002b8 R14: 00007fcbf19e60c0 R15: 0030656c69662f2e
</TASK>

Allocated by task 5171:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
__kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
kasan_kmalloc include/linux/kasan.h:211 [inline]
__do_kmalloc_node mm/slub.c:4121 [inline]
kmalloc_node_track_caller_noprof+0x225/0x440 mm/slub.c:4141
memdup_user+0x2b/0xc0 mm/util.c:214
btrfs_ioctl_snap_create_v2+0x2fd/0x3a0 fs/btrfs/ioctl.c:1411
btrfs_ioctl+0x99e/0xc60
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88814628ca00
which belongs to the cache kmalloc-96 of size 96
The buggy address is located 0 bytes to the right of
allocated 80-byte region [ffff88814628ca00, ffff88814628ca50)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14628c
flags: 0x57ff00000000000(node=1|zone=2|lastcpupid=0x7ff)
page_type: 0xffffefff(slab)
raw: 057ff00000000000 ffff888015041280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000080200020 00000001ffffefff 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 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 1, tgid 1 (swapper/0), ts 7530129564, free_ts 7138110092
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1468
prep_new_page mm/page_alloc.c:1476 [inline]
get_page_from_freelist+0x2e2d/0x2ee0 mm/page_alloc.c:3402
__alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4660
__alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
alloc_slab_page+0x5f/0x120 mm/slub.c:2264
allocate_slab+0x5a/0x2e0 mm/slub.c:2427
new_slab mm/slub.c:2480 [inline]
___slab_alloc+0xcd1/0x14b0 mm/slub.c:3666
__slab_alloc+0x58/0xa0 mm/slub.c:3756
__slab_alloc_node mm/slub.c:3809 [inline]
slab_alloc_node mm/slub.c:3988 [inline]
kmalloc_node_trace_noprof+0x20c/0x300 mm/slub.c:4160
kmalloc_node_noprof include/linux/slab.h:677 [inline]
alloc_node_nr_active kernel/workqueue.c:4833 [inline]
alloc_workqueue+0x847/0x2060 kernel/workqueue.c:5713
nvmet_init+0x8d/0x150 drivers/nvme/target/core.c:1698
do_one_initcall+0x248/0x880 init/main.c:1267
do_initcall_level+0x157/0x210 init/main.c:1329
do_initcalls+0x3f/0x80 init/main.c:1345
kernel_init_freeable+0x435/0x5d0 init/main.c:1578
kernel_init+0x1d/0x2b0 init/main.c:1467
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
page last free pid 1 tgid 1 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1088 [inline]
free_unref_page+0xd19/0xea0 mm/page_alloc.c:2565
vfree+0x186/0x2e0 mm/vmalloc.c:3346
free_partitions block/partitions/core.c:110 [inline]
check_partition block/partitions/core.c:169 [inline]
blk_add_partitions block/partitions/core.c:579 [inline]
bdev_disk_changed+0x80e/0x13d0 block/partitions/core.c:683
blkdev_get_whole+0x315/0x470 block/bdev.c:700
bdev_open+0x2e9/0xc60 block/bdev.c:909
bdev_file_open_by_dev+0x1b0/0x230 block/bdev.c:1011
disk_scan_partitions+0x1be/0x2b0 block/genhd.c:367
device_add_disk+0xca0/0xf90 block/genhd.c:510
add_disk include/linux/blkdev.h:715 [inline]
brd_alloc+0x503/0x770 drivers/block/brd.c:373
brd_init+0xfd/0x1d0 drivers/block/brd.c:435
do_one_initcall+0x248/0x880 init/main.c:1267
do_initcall_level+0x157/0x210 init/main.c:1329
do_initcalls+0x3f/0x80 init/main.c:1345
kernel_init_freeable+0x435/0x5d0 init/main.c:1578
kernel_init+0x1d/0x2b0 init/main.c:1467
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147

Memory state around the buggy address:
ffff88814628c900: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
ffff88814628c980: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff88814628ca00: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
^
ffff88814628ca80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
ffff88814628cb00: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
==================================================================


---
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