[syzbot] [fs?] KASAN: slab-use-after-free Read in debugfs_u32_get

[syzbot <syzbot+d59601b9136ebc356300@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    a0e3919a2df2 Merge tag 'usb-6.13-rc3' of git://git.kernel...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=151714f8580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=99a5586995ec03b2
dashboard link: https://syzkaller.appspot.com/bug?extid=d59601b9136ebc356300
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14954344580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/669aa1e15c11/disk-a0e3919a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ee966f8b50ac/vmlinux-a0e3919a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e872e1d072f1/bzImage-a0e3919a.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d59601b9136ebc356300@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in debugfs_u32_get+0x65/0x80 fs/debugfs/file.c:641
Read of size 4 at addr ffff88802e925580 by task syz.1.16833/9478

CPU: 0 UID: 0 PID: 9478 Comm: syz.1.16833 Not tainted 6.13.0-rc2-syzkaller-00333-ga0e3919a2df2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:489
 kasan_report+0xd9/0x110 mm/kasan/report.c:602
 debugfs_u32_get+0x65/0x80 fs/debugfs/file.c:641
 simple_attr_read+0x169/0x300 fs/libfs.c:1341
 debugfs_attr_read+0x74/0xa0 fs/debugfs/file.c:507
 vfs_read+0x1df/0xbe0 fs/read_write.c:563
 ksys_read+0x12b/0x250 fs/read_write.c:708
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f12bab85d19
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:00007f12bb9e1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f12bad75fa0 RCX: 00007f12bab85d19
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f12bac01a20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f12bad75fa0 R15: 00007ffe5afa9ff8
 </TASK>

Allocated by task 4097:
 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:377 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4298 [inline]
 __kmalloc_node_noprof+0x21f/0x520 mm/slub.c:4304
 __kvmalloc_node_noprof+0x6f/0x1a0 mm/util.c:650
 alloc_netdev_mqs+0xc9/0x1320 net/core/dev.c:11209
 nsim_create+0x98/0xb20 drivers/net/netdevsim/netdev.c:777
 __nsim_dev_port_add+0x3bf/0x700 drivers/net/netdevsim/dev.c:1393
 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:1449 [inline]
 nsim_drv_probe+0xdbf/0x1490 drivers/net/netdevsim/dev.c:1607
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:658
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:958
 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:459
 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1030
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:534
 device_add+0x114b/0x1a70 drivers/base/core.c:3665
 nsim_bus_dev_new drivers/net/netdevsim/bus.c:442 [inline]
 new_device_store+0x41d/0x730 drivers/net/netdevsim/bus.c:173
 bus_attr_store+0x71/0xb0 drivers/base/bus.c:172
 sysfs_kf_write+0x117/0x170 fs/sysfs/file.c:139
 kernfs_fop_write_iter+0x33d/0x500 fs/kernfs/file.c:334
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0x5ae/0x1150 fs/read_write.c:679
 ksys_write+0x12b/0x250 fs/read_write.c:731
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 11:
 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:582
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4613 [inline]
 kfree+0x14f/0x4b0 mm/slub.c:4761
 kvfree+0x47/0x50 mm/util.c:693
 device_release+0xa1/0x240 drivers/base/core.c:2567
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1e4/0x5a0 lib/kobject.c:737
 put_device+0x1f/0x30 drivers/base/core.c:3773
 free_netdev+0x4f1/0x6c0 net/core/dev.c:11378
 __nsim_dev_port_del+0x189/0x240 drivers/net/netdevsim/dev.c:1428
 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline]
 nsim_dev_reload_destroy+0x108/0x4d0 drivers/net/netdevsim/dev.c:1661
 nsim_dev_reload_down+0x6e/0xd0 drivers/net/netdevsim/dev.c:968
 devlink_reload+0x17f/0x760 net/devlink/dev.c:461
 devlink_pernet_pre_exit+0x1a1/0x2b0 net/devlink/core.c:509
 ops_pre_exit_list net/core/net_namespace.c:162 [inline]
 cleanup_net+0x488/0xbd0 net/core/net_namespace.c:628
 process_one_work+0x958/0x1b30 kernel/workqueue.c:3229
 process_scheduled_works kernel/workqueue.c:3310 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
 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

The buggy address belongs to the object at ffff88802e924000
 which belongs to the cache kmalloc-cg-8k of size 8192
The buggy address is located 5504 bytes inside of
 freed 8192-byte region [ffff88802e924000, ffff88802e926000)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2e920
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888027164121
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801ac4f640 ffffea000178f800 dead000000000002
raw: 0000000000000000 0000000000020002 00000001f5000000 ffff888027164121
head: 00fff00000000040 ffff88801ac4f640 ffffea000178f800 dead000000000002
head: 0000000000000000 0000000000020002 00000001f5000000 ffff888027164121
head: 00fff00000000003 ffffea0000ba4801 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd60c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5924, tgid 5924 (syz-executor), ts 75639968784, free_ts 75606128640
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1556
 prep_new_page mm/page_alloc.c:1564 [inline]
 get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3474
 __alloc_pages_noprof+0x223/0x25b0 mm/page_alloc.c:4751
 alloc_pages_mpol_noprof+0x2c9/0x610 mm/mempolicy.c:2269
 alloc_slab_page mm/slub.c:2423 [inline]
 allocate_slab mm/slub.c:2589 [inline]
 new_slab+0x2c9/0x410 mm/slub.c:2642
 ___slab_alloc+0xce2/0x1650 mm/slub.c:3830
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3920
 __slab_alloc_node mm/slub.c:3995 [inline]
 slab_alloc_node mm/slub.c:4156 [inline]
 __do_kmalloc_node mm/slub.c:4297 [inline]
 __kmalloc_node_noprof+0x2f0/0x520 mm/slub.c:4304
 __kvmalloc_node_noprof+0x6f/0x1a0 mm/util.c:650
 alloc_netdev_mqs+0xc9/0x1320 net/core/dev.c:11209
 nsim_create+0x98/0xb20 drivers/net/netdevsim/netdev.c:777
 __nsim_dev_port_add+0x3bf/0x700 drivers/net/netdevsim/dev.c:1393
 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:1449 [inline]
 nsim_drv_probe+0xdbf/0x1490 drivers/net/netdevsim/dev.c:1607
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:658
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830
page last free pid 5930 tgid 5930 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_page+0x661/0x1080 mm/page_alloc.c:2657
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4119 [inline]
 slab_alloc_node mm/slub.c:4168 [inline]
 kmem_cache_alloc_node_noprof+0x1ca/0x3b0 mm/slub.c:4220
 __alloc_skb+0x2b3/0x380 net/core/skbuff.c:668
 alloc_skb include/linux/skbuff.h:1323 [inline]
 nlmsg_new include/net/netlink.h:1018 [inline]
 netlink_ack+0x164/0xb20 net/netlink/af_netlink.c:2479
 netlink_rcv_skb+0x327/0x410 net/netlink/af_netlink.c:2548
 netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline]
 netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1347
 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1891
 sock_sendmsg_nosec net/socket.c:711 [inline]
 __sock_sendmsg net/socket.c:726 [inline]
 __sys_sendto+0x488/0x4f0 net/socket.c:2197
 __do_sys_sendto net/socket.c:2204 [inline]
 __se_sys_sendto net/socket.c:2200 [inline]
 __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2200
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88802e925480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802e925500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802e925580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88802e925600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802e925680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
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