loop6: detected capacity change from 0 to 1024
==================================================================
BUG: KASAN: slab-out-of-bounds in hfsplus_uni2asc+0x680/0x1270 fs/hfsplus/unicode.c:179
Read of size 2 at addr ffff88807807b40c by task syz.6.198/7616

CPU: 1 UID: 0 PID: 7616 Comm: syz.6.198 Not tainted 6.16.0-rc2-syzkaller-00162-g41687a5c6f8b #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xd2/0x2b0 mm/kasan/report.c:521
 kasan_report+0x118/0x150 mm/kasan/report.c:634
 hfsplus_uni2asc+0x680/0x1270 fs/hfsplus/unicode.c:179
 hfsplus_readdir+0x709/0xd60 fs/hfsplus/dir.c:207
 iterate_dir+0x5ac/0x770 fs/readdir.c:108
 __do_sys_getdents fs/readdir.c:326 [inline]
 __se_sys_getdents+0xe4/0x250 fs/readdir.c:312
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0b9778e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0b985c2038 EFLAGS: 00000246 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 00007f0b979b5fa0 RCX: 00007f0b9778e929
RDX: 00000000000000b8 RSI: 0000200000001fc0 RDI: 0000000000000004
RBP: 00007f0b97810b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f0b979b5fa0 R15: 00007ffd8a4daef8
 </TASK>

Allocated by task 7616:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4328 [inline]
 __kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4340
 kmalloc_noprof include/linux/slab.h:909 [inline]
 hfsplus_find_init+0x8c/0x1d0 fs/hfsplus/bfind.c:21
 hfsplus_readdir+0x1d4/0xd60 fs/hfsplus/dir.c:144
 iterate_dir+0x5ac/0x770 fs/readdir.c:108
 __do_sys_getdents fs/readdir.c:326 [inline]
 __se_sys_getdents+0xe4/0x250 fs/readdir.c:312
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88807807b000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 0 bytes to the right of
 allocated 1036-byte region [ffff88807807b000, ffff88807807b40c)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88807807f000 pfn:0x78078
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801a442000 0000000000000000 dead000000000001
raw: ffff88807807f000 0000000080080007 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801a442000 0000000000000000 dead000000000001
head: ffff88807807f000 0000000080080007 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0001e01e01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5840, tgid 5840 (syz-executor), ts 90779676663, free_ts 89330505838
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704
 prep_new_page mm/page_alloc.c:1712 [inline]
 get_page_from_freelist+0x21d5/0x22b0 mm/page_alloc.c:3669
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419
 alloc_slab_page mm/slub.c:2451 [inline]
 allocate_slab+0x8a/0x3b0 mm/slub.c:2619
 new_slab mm/slub.c:2673 [inline]
 ___slab_alloc+0xbfc/0x1480 mm/slub.c:3859
 __slab_alloc mm/slub.c:3949 [inline]
 __slab_alloc_node mm/slub.c:4024 [inline]
 slab_alloc_node mm/slub.c:4185 [inline]
 __do_kmalloc_node mm/slub.c:4327 [inline]
 __kmalloc_node_track_caller_noprof+0x2f8/0x4e0 mm/slub.c:4347
 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:601
 pskb_expand_head+0x18e/0x1150 net/core/skbuff.c:2241
 netlink_trim+0x1d5/0x2e0 net/netlink/af_netlink.c:1295
 netlink_broadcast_filtered+0x80/0x1140 net/netlink/af_netlink.c:1501
 nlmsg_multicast_filtered include/net/netlink.h:1151 [inline]
 nlmsg_multicast include/net/netlink.h:1170 [inline]
 nlmsg_notify+0xf0/0x1a0 net/netlink/af_netlink.c:2577
 rtnl_notify net/core/rtnetlink.c:958 [inline]
 rtmsg_ifinfo_send net/core/rtnetlink.c:4419 [inline]
 rtmsg_ifinfo_event net/core/rtnetlink.c:4435 [inline]
 rtnetlink_event+0x224/0x270 net/core/rtnetlink.c:7004
 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
 call_netdevice_notifiers net/core/dev.c:2282 [inline]
 netif_set_mac_address+0x37c/0x4c0 net/core/dev.c:9693
 do_setlink+0x88c/0x41c0 net/core/rtnetlink.c:3093
page last free pid 5912 tgid 5912 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1248 [inline]
 __free_frozen_pages+0xc65/0xe60 mm/page_alloc.c:2706
 discard_slab mm/slub.c:2717 [inline]
 __put_partials+0x161/0x1c0 mm/slub.c:3186
 put_cpu_partial+0x17c/0x250 mm/slub.c:3261
 __slab_free+0x2f7/0x400 mm/slub.c:4513
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4148 [inline]
 slab_alloc_node mm/slub.c:4197 [inline]
 __do_kmalloc_node mm/slub.c:4327 [inline]
 __kmalloc_node_track_caller_noprof+0x216/0x4e0 mm/slub.c:4347
 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:601
 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:670
 alloc_skb include/linux/skbuff.h:1336 [inline]
 mld_newpack+0x13c/0xc40 net/ipv6/mcast.c:1788
 add_grhead+0x5a/0x2a0 net/ipv6/mcast.c:1899
 add_grec+0x13b2/0x1670 net/ipv6/mcast.c:2037
 mld_send_cr net/ipv6/mcast.c:2163 [inline]
 mld_ifc_work+0x6e6/0xde0 net/ipv6/mcast.c:2702
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402

Memory state around the buggy address:
 ffff88807807b300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88807807b380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88807807b400: 00 04 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                      ^
 ffff88807807b480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807807b500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================