[moderation/CI] Re: configfs: fix slab-UAF Write in config_item_put

[syzbot ci <syzbot+ci93000cdc57c52911@syzkaller.appspotmail.com>]

syzbot ci has tested the following series

[v3] configfs: fix slab-UAF Write in config_item_put
https://lore.kernel.org/all/20261105165055.362-1-drifabdelmalekmohamedsaid@gmail.com
* [PATCH v3] configfs: fix slab-UAF Write in config_item_put

and found the following issues:
* KASAN: slab-use-after-free Write in config_item_get
* kernel BUG in config_item_get
* kernel BUG in configfs_symlink

Full report is available here:
https://ci.syzbot.org/series/6e7e3ace-c083-43ff-9d6c-4b65ef15bd2f

***

KASAN: slab-use-after-free Write in config_item_get

tree:      vfs
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/vfs/vfs.git
base:      691edd89507f8977eb8831892c3b460edc79d73c
arch:      amd64
compiler:  Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/b34863a5-8646-4b81-a3b6-8d7c722db7f8/config
syz repro: https://ci.syzbot.org/findings/4586cba9-fdc4-48a1-bbe4-43b477a6d2cf/syz_repro

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:112 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:283 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:366 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:383 [inline]
BUG: KASAN: slab-use-after-free in kref_get include/linux/kref.h:45 [inline]
BUG: KASAN: slab-use-after-free in config_item_get+0x26/0x90 fs/configfs/item.c:104
Write of size 4 at addr ffff8881191a501c by task syz.1.22/5911

CPU: 0 UID: 0 PID: 5911 Comm: syz.1.22 Not tainted syzkaller #0 PREEMPT(full) 
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_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200
 instrument_atomic_read_write include/linux/instrumented.h:112 [inline]
 atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
 __refcount_add include/linux/refcount.h:283 [inline]
 __refcount_inc include/linux/refcount.h:366 [inline]
 refcount_inc include/linux/refcount.h:383 [inline]
 kref_get include/linux/kref.h:45 [inline]
 config_item_get+0x26/0x90 fs/configfs/item.c:104
 configfs_get_config_item fs/configfs/configfs_internal.h:127 [inline]
 configfs_symlink+0x17d/0xa60 fs/configfs/symlink.c:167
 vfs_symlink+0x18e/0x370 fs/namei.c:5812
 filename_symlinkat+0x1a5/0x430 fs/namei.c:5837
 __do_sys_symlinkat fs/namei.c:5857 [inline]
 __se_sys_symlinkat+0x4e/0x2b0 fs/namei.c:5852
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffbd0f9fb19
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffbd1dfb028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007ffbd1225fa0 RCX: 00007ffbd0f9fb19
RDX: 0000200000000780 RSI: ffffffffffffff9c RDI: 0000200000000740
RBP: 00007ffbd1037b70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffbd1226038 R14: 00007ffbd1225fa0 R15: 00007ffeea8f6108
 </TASK>

Allocated by task 5903:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:426
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x31c/0x600 mm/slub.c:5680
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 config_desc_make+0x23e/0x620 drivers/usb/gadget/configfs.c:730
 configfs_mkdir+0x4f6/0x9e0 fs/configfs/dir.c:1369
 vfs_mkdir+0x411/0x660 fs/namei.c:5428
 filename_mkdirat+0x284/0x550 fs/namei.c:5461
 __do_sys_mkdirat fs/namei.c:5482 [inline]
 __se_sys_mkdirat+0x35/0x150 fs/namei.c:5479
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5908:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:264 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:296
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2780 [inline]
 slab_free mm/slub.c:6630 [inline]
 kfree+0x1c5/0x650 mm/slub.c:6923
 config_item_cleanup fs/configfs/item.c:128 [inline]
 config_item_release+0x13a/0x2d0 fs/configfs/item.c:137
 configfs_symlink+0x7b4/0xa60 fs/configfs/symlink.c:240
 vfs_symlink+0x18e/0x370 fs/namei.c:5812
 filename_symlinkat+0x1a5/0x430 fs/namei.c:5837
 __do_sys_symlinkat fs/namei.c:5857 [inline]
 __se_sys_symlinkat+0x4e/0x2b0 fs/namei.c:5852
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8881191a5000
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 28 bytes inside of
 freed 1024-byte region [ffff8881191a5000, ffff8881191a5400)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1191a0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x17ff00000000040(head|node=0|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 017ff00000000040 ffff888100041dc0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 017ff00000000040 ffff888100041dc0 dead000000000100 dead000000000122
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 017ff00000000003 fffffffffffffe01 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5697, tgid 5697 (kworker/u8:3), ts 73161807282
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1856
 prep_new_page mm/page_alloc.c:1864 [inline]
 get_page_from_freelist+0x220f/0x2280 mm/page_alloc.c:3935
 __alloc_frozen_pages_noprof+0x1fe/0x410 mm/page_alloc.c:5444
 alloc_slab_page mm/slub.c:3384 [inline]
 allocate_slab+0x7d/0x5e0 mm/slub.c:3499
 new_slab mm/slub.c:3550 [inline]
 refill_objects+0x2d5/0x350 mm/slub.c:7539
 refill_sheaf mm/slub.c:2917 [inline]
 __pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4811
 alloc_from_pcs mm/slub.c:4887 [inline]
 slab_alloc_node mm/slub.c:5021 [inline]
 __do_kmalloc_node mm/slub.c:5530 [inline]
 __kmalloc_noprof+0x476/0x710 mm/slub.c:5556
 _kmalloc_noprof include/linux/slab.h:995 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 neigh_alloc net/core/neighbour.c:525 [inline]
 ___neigh_create+0x6da/0x21f0 net/core/neighbour.c:659
 ip6_finish_output2+0xe06/0x1460 net/ipv6/ip6_output.c:130
 NF_HOOK_COND include/linux/netfilter.h:314 [inline]
 ip6_output+0x337/0x540 net/ipv6/ip6_output.c:248
 dst_output include/net/dst.h:472 [inline]
 NF_HOOK include/linux/netfilter.h:325 [inline]
 ndisc_send_skb+0xcb2/0x1650 net/ipv6/ndisc.c:513
 ndisc_send_ns+0xd7/0x160 net/ipv6/ndisc.c:672
 addrconf_dad_work+0xa8d/0x15c0 net/ipv6/addrconf.c:4343
 process_one_work kernel/workqueue.c:3495 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
 kthread+0x38b/0x480 kernel/kthread.c:436
page last free pid 5696 tgid 5696 ts 63917357465 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1403 [inline]
 __free_frozen_pages+0xc97/0xd90 mm/page_alloc.c:2954
 __slab_free+0x269/0x2c0 mm/slub.c:5926
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:361
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4720 [inline]
 slab_alloc_node mm/slub.c:5033 [inline]
 kmem_cache_alloc_noprof+0x2b4/0x600 mm/slub.c:5047
 __proc_create+0x55d/0xad0 fs/proc/generic.c:462
 proc_create_reg fs/proc/generic.c:606 [inline]
 proc_create_data+0xa5/0x190 fs/proc/generic.c:620
 nfs_net_init+0x1a7/0x290 fs/nfs/inode.c:2777
 ops_init+0x35d/0x5d0 net/core/net_namespace.c:137
 setup_net+0x118/0x350 net/core/net_namespace.c:443
 copy_net_ns+0x536/0x770 net/core/net_namespace.c:584
 create_new_namespaces+0x3f0/0x6b0 kernel/nsproxy.c:132
 unshare_nsproxy_namespaces+0x144/0x190 kernel/nsproxy.c:234
 ksys_unshare+0x532/0x890 kernel/fork.c:3320
 __do_sys_unshare kernel/fork.c:3386 [inline]
 __se_sys_unshare kernel/fork.c:3384 [inline]
 __x64_sys_unshare+0x38/0x50 kernel/fork.c:3384

Memory state around the buggy address:
 ffff8881191a4f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881191a4f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8881191a5000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff8881191a5080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881191a5100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


***

kernel BUG in config_item_get

tree:      vfs
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/vfs/vfs.git
base:      691edd89507f8977eb8831892c3b460edc79d73c
arch:      amd64
compiler:  Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/b34863a5-8646-4b81-a3b6-8d7c722db7f8/config
syz repro: https://ci.syzbot.org/findings/1475de5c-5602-4f7c-97d8-fa318d3969f7/syz_repro

refcount_t: addition on 0; use-after-free.
------------[ cut here ]------------
kernel BUG at lib/refcount.c:34!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 5904 Comm: syz.1.18 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:refcount_warn_saturate+0xf0/0x110 lib/refcount.c:34
Code: 80 c1 03 38 c1 0f 8c 6a ff ff ff 4c 89 f7 e8 a7 10 51 fd e9 5d ff ff ff e8 fd c2 d9 fc 48 c7 c7 a0 98 8c 8c e8 e1 73 38 fc 90 <0f> 0b e8 e9 c2 d9 fc 48 c7 c7 20 99 8c 8c e8 cd 73 38 fc 90 0f 0b
RSP: 0018:ffffc900030bfc68 EFLAGS: 00010246
RAX: 000000000000002a RBX: 0000000000000002 RCX: ca30be1f7752be00
RDX: 0000000000000000 RSI: 8000000000000001 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffc900030bf9e7 R09: 1ffff92000617f3c
R10: dffffc0000000000 R11: fffff52000617f3d R12: 1ffff1102365c80a
R13: ffff88811776d218 R14: ffff888117f184b4 R15: ffff8881ba75a598
FS:  00007fcbbc6696c0(0000) GS:ffff88818be0d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcbbb6716a0 CR3: 0000000117a68000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __refcount_add include/linux/refcount.h:-1 [inline]
 __refcount_inc include/linux/refcount.h:366 [inline]
 refcount_inc include/linux/refcount.h:383 [inline]
 kref_get include/linux/kref.h:45 [inline]
 config_item_get+0x88/0x90 fs/configfs/item.c:104
 configfs_get_config_item fs/configfs/configfs_internal.h:127 [inline]
 configfs_symlink+0x17d/0xa60 fs/configfs/symlink.c:167
 vfs_symlink+0x18e/0x370 fs/namei.c:5812
 filename_symlinkat+0x1a5/0x430 fs/namei.c:5837
 __do_sys_symlinkat fs/namei.c:5857 [inline]
 __se_sys_symlinkat+0x4e/0x2b0 fs/namei.c:5852
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcbbb79fb19
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fcbbc669028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007fcbbba25fa0 RCX: 00007fcbbb79fb19
RDX: 0000200000000840 RSI: ffffffffffffff9c RDI: 0000200000000800
RBP: 00007fcbbb837b70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcbbba26038 R14: 00007fcbbba25fa0 R15: 00007ffd984fbca8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:refcount_warn_saturate+0xf0/0x110 lib/refcount.c:34
Code: 80 c1 03 38 c1 0f 8c 6a ff ff ff 4c 89 f7 e8 a7 10 51 fd e9 5d ff ff ff e8 fd c2 d9 fc 48 c7 c7 a0 98 8c 8c e8 e1 73 38 fc 90 <0f> 0b e8 e9 c2 d9 fc 48 c7 c7 20 99 8c 8c e8 cd 73 38 fc 90 0f 0b
RSP: 0018:ffffc900030bfc68 EFLAGS: 00010246
RAX: 000000000000002a RBX: 0000000000000002 RCX: ca30be1f7752be00
RDX: 0000000000000000 RSI: 8000000000000001 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffc900030bf9e7 R09: 1ffff92000617f3c
R10: dffffc0000000000 R11: fffff52000617f3d R12: 1ffff1102365c80a
R13: ffff88811776d218 R14: ffff888117f184b4 R15: ffff8881ba75a598
FS:  00007fcbbc6696c0(0000) GS:ffff88818be0d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcbbb6716a0 CR3: 0000000117a68000 CR4: 00000000000006f0


***

kernel BUG in configfs_symlink

tree:      vfs
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/vfs/vfs.git
base:      691edd89507f8977eb8831892c3b460edc79d73c
arch:      amd64
compiler:  Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/b34863a5-8646-4b81-a3b6-8d7c722db7f8/config
AI triage: https://ci.syzbot.org/findings/124f4628-8711-4fab-bb9a-b0f7ba1656ba/triage_trajectory

refcount_t: underflow; use-after-free.
------------[ cut here ]------------
kernel BUG at lib/refcount.c:37!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 5815 Comm: syz.2.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:refcount_warn_saturate+0x104/0x110
Code: 5d ff ff ff e8 fd c2 d9 fc 48 c7 c7 a0 98 8c 8c e8 e1 73 38 fc 90 0f 0b e8 e9 c2 d9 fc 48 c7 c7 20 99 8c 8c e8 cd 73 38 fc 90 <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90006787c88 EFLAGS: 00010246
RAX: 0000000000000026 RBX: 0000000000000003 RCX: 7d2d66e1f00cde00
RDX: 0000000000000000 RSI: 8000000000000000 RDI: 0000000000000000
RBP: ffffc90006787d88 R08: ffffc90006787a07 R09: 1ffff92000cf0f40
R10: dffffc0000000000 R11: fffff52000cf0f41 R12: 1ffff110228fe2e2
R13: 00000000fffffffe R14: ffff88816f8584b4 R15: 1ffff92000cf0fa0
FS:  00007f3b9041d6c0(0000) GS:ffff8882a780d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007feda95bb440 CR3: 0000000110044000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 configfs_symlink+0x7b4/0xa60
 vfs_symlink+0x18e/0x370
 filename_symlinkat+0x1a5/0x430
 __se_sys_symlinkat+0x4e/0x2b0
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3b8f59fb19
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3b9041d028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007f3b8f826090 RCX: 00007f3b8f59fb19
RDX: 0000200000000840 RSI: ffffffffffffff9c RDI: 0000200000000800
RBP: 00007f3b8f637b70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3b8f826128 R14: 00007f3b8f826090 R15: 00007ffcd3b51e38
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:refcount_warn_saturate+0x104/0x110
Code: 5d ff ff ff e8 fd c2 d9 fc 48 c7 c7 a0 98 8c 8c e8 e1 73 38 fc 90 0f 0b e8 e9 c2 d9 fc 48 c7 c7 20 99 8c 8c e8 cd 73 38 fc 90 <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90006787c88 EFLAGS: 00010246
RAX: 0000000000000026 RBX: 0000000000000003 RCX: 7d2d66e1f00cde00
RDX: 0000000000000000 RSI: 8000000000000000 RDI: 0000000000000000
RBP: ffffc90006787d88 R08: ffffc90006787a07 R09: 1ffff92000cf0f40
R10: dffffc0000000000 R11: fffff52000cf0f41 R12: 1ffff110228fe2e2
R13: 00000000fffffffe R14: ffff88816f8584b4 R15: 1ffff92000cf0fa0
FS:  00007f3b9041d6c0(0000) GS:ffff88818be0d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd9936587f0 CR3: 0000000110044000 CR4: 00000000000006f0


***

If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
  Tested-by: syzbot@syzkaller.appspotmail.com

---
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- Arguments like custom git repos and branches are not supported.

The email will later be sent to:
[a.hindborg@kernel.org brauner@kernel.org drifabdelmalekmohamedsaid@gmail.com jack@suse.cz leitao@debian.org linux-fsdevel@vger.kernel.org linux-kernel@vger.kernel.org ranhongyun1@huawei.com syzbot@syzkaller.appspotmail.com syzkaller-bugs@googlegroups.com viro@zeniv.linux.org.uk]

If the report looks fine to you, reply with:
#syz upstream

If the report is a false positive, reply with
#syz invalid