[moderation] [hfs?] KASAN: slab-use-after-free Read in hfs_bnode_unhash (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2ef5971ff345 Merge tag 'vfs-6.10-rc4.fixes' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14e471ca980000
kernel config: https://syzkaller.appspot.com/x/.config?x=81c0d76ceef02b39
dashboard link: https://syzkaller.appspot.com/bug?extid=adeb387cede15eb11607
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386
CC: [linux-...@vger.kernel.org linux-...@vger.kernel.org]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-2ef5971f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/85722ebc781d/vmlinux-2ef5971f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/27fd8bd02a1e/bzImage-2ef5971f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+adeb38...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in hfs_bnode_unhash+0x1d9/0x1f0 fs/hfs/bnode.c:312
Read of size 8 at addr ffff888026ca6c20 by task kswapd0/111

CPU: 1 PID: 111 Comm: kswapd0 Not tainted 6.10.0-rc3-syzkaller-00021-g2ef5971ff345 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
print_address_description mm/kasan/report.c:377 [inline]
print_report+0xc3/0x620 mm/kasan/report.c:488
kasan_report+0xd9/0x110 mm/kasan/report.c:601
hfs_bnode_unhash+0x1d9/0x1f0 fs/hfs/bnode.c:312
hfs_release_folio+0x42d/0x570 fs/hfs/inode.c:117
filemap_release_folio+0x1ed/0x280 mm/filemap.c:4173
shrink_folio_list+0x254a/0x4150 mm/vmscan.c:1394
evict_folios+0x6e6/0x1bf0 mm/vmscan.c:4553
try_to_shrink_lruvec+0x618/0x9b0 mm/vmscan.c:4749
shrink_one+0x3f8/0x7c0 mm/vmscan.c:4788
shrink_many mm/vmscan.c:4851 [inline]
lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4951
shrink_node mm/vmscan.c:5910 [inline]
kswapd_shrink_node mm/vmscan.c:6720 [inline]
balance_pgdat+0x1105/0x1970 mm/vmscan.c:6911
kswapd+0x5ea/0xbf0 mm/vmscan.c:7180
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>

Allocated by task 7986:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:387
kasan_kmalloc include/linux/kasan.h:211 [inline]
__do_kmalloc_node mm/slub.c:4122 [inline]
__kmalloc_noprof+0x1ec/0x420 mm/slub.c:4135
kmalloc_noprof include/linux/slab.h:664 [inline]
kzalloc_noprof include/linux/slab.h:778 [inline]
__hfs_bnode_create+0x108/0x860 fs/hfs/bnode.c:259
hfs_bnode_find+0x2d1/0xc50 fs/hfs/bnode.c:335
hfs_brec_find+0x2af/0x510 fs/hfs/bfind.c:126
hfs_cat_create+0x3e8/0xb40 fs/hfs/catalog.c:112
hfs_create+0x6b/0xf0 fs/hfs/dir.c:202
lookup_open.isra.0+0x10a1/0x13c0 fs/namei.c:3505
open_last_lookups fs/namei.c:3574 [inline]
path_openat+0x92f/0x29f0 fs/namei.c:3804
do_filp_open+0x1dc/0x430 fs/namei.c:3834
do_sys_openat2+0x17a/0x1e0 fs/open.c:1405
do_sys_open fs/open.c:1420 [inline]
__do_compat_sys_openat fs/open.c:1480 [inline]
__se_compat_sys_openat fs/open.c:1478 [inline]
__ia32_compat_sys_openat+0x16e/0x210 fs/open.c:1478
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Freed by task 7679:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
poison_slab_object+0xf7/0x160 mm/kasan/common.c:240
__kasan_slab_free+0x32/0x50 mm/kasan/common.c:256
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2196 [inline]
slab_free mm/slub.c:4437 [inline]
kfree+0x12a/0x3b0 mm/slub.c:4558
hfs_btree_close+0xac/0x390 fs/hfs/btree.c:154
hfs_mdb_put+0xbf/0x380 fs/hfs/mdb.c:360
generic_shutdown_super+0x159/0x3d0 fs/super.c:642
kill_block_super+0x3b/0x90 fs/super.c:1676
deactivate_locked_super+0xbe/0x1a0 fs/super.c:473
deactivate_super+0xde/0x100 fs/super.c:506
cleanup_mnt+0x222/0x450 fs/namespace.c:1267
task_work_run+0x14e/0x250 kernel/task_work.c:180
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
__do_fast_syscall_32+0x80/0x120 arch/x86/entry/common.c:389
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e

The buggy address belongs to the object at ffff888026ca6c00
which belongs to the cache kmalloc-192 of size 192
The buggy address is located 32 bytes inside of
freed 192-byte region [ffff888026ca6c00, ffff888026ca6cc0)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x26ca6
anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffefff(slab)
raw: 00fff00000000000 ffff8880154423c0 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000100010 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 0x152cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 7777, tgid 7777 (syz-executor.3), ts 170862842329, free_ts 170815776235
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1468
prep_new_page mm/page_alloc.c:1476 [inline]
get_page_from_freelist+0x136a/0x2e50 mm/page_alloc.c:3420
__alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4678
__alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
alloc_slab_page+0x56/0x110 mm/slub.c:2265
allocate_slab mm/slub.c:2428 [inline]
new_slab+0x84/0x260 mm/slub.c:2481
___slab_alloc+0xdac/0x1870 mm/slub.c:3667
__slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3757
__slab_alloc_node mm/slub.c:3810 [inline]
slab_alloc_node mm/slub.c:3989 [inline]
__do_kmalloc_node mm/slub.c:4121 [inline]
kmalloc_node_track_caller_noprof+0x365/0x440 mm/slub.c:4142
kmemdup_noprof+0x29/0x60 mm/util.c:131
neigh_parms_alloc+0x82/0x5d0 net/core/neighbour.c:1718
inetdev_init+0x142/0x580 net/ipv4/devinet.c:281
inetdev_event+0xb17/0x1800 net/ipv4/devinet.c:1565
notifier_call_chain+0xb9/0x410 kernel/notifier.c:93
call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1992
call_netdevice_notifiers_extack net/core/dev.c:2030 [inline]
call_netdevice_notifiers net/core/dev.c:2044 [inline]
register_netdevice+0x1583/0x1c40 net/core/dev.c:10408
register_netdev+0x2f/0x50 net/core/dev.c:10512
page last free pid 7777 tgid 7777 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1088 [inline]
free_unref_page+0x64a/0xe40 mm/page_alloc.c:2583
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:322
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slub.c:3941 [inline]
slab_alloc_node mm/slub.c:4001 [inline]
kmalloc_trace_noprof+0x11e/0x310 mm/slub.c:4148
kmalloc_noprof include/linux/slab.h:660 [inline]
kzalloc_noprof include/linux/slab.h:778 [inline]
ref_tracker_alloc+0x17c/0x5b0 lib/ref_tracker.c:203
__netdev_tracker_alloc include/linux/netdevice.h:4038 [inline]
netdev_hold include/linux/netdevice.h:4067 [inline]
netdev_hold include/linux/netdevice.h:4062 [inline]
rx_queue_add_kobject net/core/net-sysfs.c:1102 [inline]
net_rx_queue_update_kobjects+0x284/0x5f0 net/core/net-sysfs.c:1160
register_queue_kobjects net/core/net-sysfs.c:1895 [inline]
netdev_register_kobject+0x26d/0x3f0 net/core/net-sysfs.c:2140
register_netdevice+0x12ce/0x1c40 net/core/dev.c:10375
__ip_tunnel_create+0x37b/0x4c0 net/ipv4/ip_tunnel.c:266
ip_tunnel_init_net+0x1c2/0x6e0 net/ipv4/ip_tunnel.c:1160
ops_init+0xb9/0x650 net/core/net_namespace.c:139
setup_net+0x5fc/0xd60 net/core/net_namespace.c:343
copy_net_ns+0x4ae/0x880 net/core/net_namespace.c:508
create_new_namespaces+0x3ea/0xb10 kernel/nsproxy.c:110
unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:228

Memory state around the buggy address:
ffff888026ca6b00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888026ca6b80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff888026ca6c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888026ca6c80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff888026ca6d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


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