[syzbot] [hams?] KASAN: slab-use-after-free Read in ax25_release

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 4099a71718b0 Merge tag 'sched-urgent-2024-12-29' of git://..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=133e70b0580000
kernel config: https://syzkaller.appspot.com/x/.config?x=aa8dc22aa6de51f5
dashboard link: https://syzkaller.appspot.com/bug?extid=a5716c7fb89dcd7205d8
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-4099a717.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b05c8741aa90/vmlinux-4099a717.xz
kernel image: https://storage.googleapis.com/syzbot-assets/406102cf22f0/bzImage-4099a717.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a5716c...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in ax25_release+0x99a/0xa10 net/ax25/af_ax25.c:1062
Read of size 1 at addr ffff88804c0f9ccc by task syz.0.352/7238

CPU: 3 UID: 0 PID: 7238 Comm: syz.0.352 Not tainted 6.13.0-rc4-syzkaller-00110-g4099a71718b0 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
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
ax25_release+0x99a/0xa10 net/ax25/af_ax25.c:1062
__sock_release+0xb0/0x270 net/socket.c:640
sock_close+0x1c/0x30 net/socket.c:1408
__fput+0x3f8/0xb60 fs/file_table.c:450
task_work_run+0x14e/0x250 kernel/task_work.c:239
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:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218
do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8962185d29
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:00007ffdad15cf68 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00000000000106e8 RCX: 00007f8962185d29
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f8962377ba0 R08: 0000000000000001 R09: 00007ffdad15d25f
R10: 00007f8962000000 R11: 0000000000000246 R12: 0000000000010730
R13: 00007f8962375fa0 R14: 0000000000000032 R15: ffffffffffffffff
</TASK>

Allocated by task 7239:
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
kmalloc_noprof include/linux/slab.h:901 [inline]
kzalloc_noprof include/linux/slab.h:1037 [inline]
ax25_dev_device_up+0x47/0x690 net/ax25/ax25_dev.c:57
ax25_device_event+0x485/0x610 net/ax25/af_ax25.c:143
notifier_call_chain+0xb7/0x410 kernel/notifier.c:85
call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1996
call_netdevice_notifiers_extack net/core/dev.c:2034 [inline]
call_netdevice_notifiers net/core/dev.c:2048 [inline]
__dev_notify_flags+0x12d/0x2e0 net/core/dev.c:8988
dev_change_flags+0x10c/0x160 net/core/dev.c:9026
dev_ifsioc+0x9c8/0x10b0 net/core/dev_ioctl.c:526
dev_ioctl+0x224/0x10c0 net/core/dev_ioctl.c:783
sock_do_ioctl+0x19e/0x280 net/socket.c:1223
sock_ioctl+0x228/0x6c0 net/socket.c:1328
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl fs/ioctl.c:892 [inline]
__x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892
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 7239:
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
ax25_dev_put include/net/ax25.h:294 [inline]
ax25_dev_device_down+0x341/0x400 net/ax25/ax25_dev.c:131
ax25_device_event+0x4b5/0x610 net/ax25/af_ax25.c:148
notifier_call_chain+0xb7/0x410 kernel/notifier.c:85
call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1996
call_netdevice_notifiers_extack net/core/dev.c:2034 [inline]
call_netdevice_notifiers net/core/dev.c:2048 [inline]
dev_close_many+0x333/0x6a0 net/core/dev.c:1589
dev_close net/core/dev.c:1611 [inline]
dev_close+0x181/0x230 net/core/dev.c:1605
bpq_device_event+0x820/0xaf0 drivers/net/hamradio/bpqether.c:547
notifier_call_chain+0xb7/0x410 kernel/notifier.c:85
call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1996
call_netdevice_notifiers_extack net/core/dev.c:2034 [inline]
call_netdevice_notifiers net/core/dev.c:2048 [inline]
dev_close_many+0x333/0x6a0 net/core/dev.c:1589
dev_close net/core/dev.c:1611 [inline]
dev_close+0x181/0x230 net/core/dev.c:1605
bond_setup_by_slave drivers/net/bonding/bond_main.c:1631 [inline]
bond_enslave+0x1f67/0x6040 drivers/net/bonding/bond_main.c:2043
bond_do_ioctl+0x60e/0x6d0 drivers/net/bonding/bond_main.c:4685
dev_siocbond net/core/dev_ioctl.c:471 [inline]
dev_ifsioc+0x1ea/0x10b0 net/core/dev_ioctl.c:613
dev_ioctl+0x224/0x10c0 net/core/dev_ioctl.c:783
sock_do_ioctl+0x19e/0x280 net/socket.c:1223
sock_ioctl+0x228/0x6c0 net/socket.c:1328
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl fs/ioctl.c:892 [inline]
__x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892
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

The buggy address belongs to the object at ffff88804c0f9c00
which belongs to the cache kmalloc-256 of size 256
The buggy address is located 204 bytes inside of
freed 256-byte region [ffff88804c0f9c00, ffff88804c0f9d00)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4c0f8
head: order:1 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 ffff88801b042b40 0000000000000000 dead000000000001
raw: 0000000000000000 0000000080100010 00000001f5000000 0000000000000000
head: 00fff00000000040 ffff88801b042b40 0000000000000000 dead000000000001
head: 0000000000000000 0000000080100010 00000001f5000000 0000000000000000
head: 00fff00000000001 ffffea0001303e01 ffffffffffffffff 0000000000000000
head: 0000000000000002 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5931, tgid 5931 (syz-executor), ts 45493664183, free_ts 45397637475
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1558
prep_new_page mm/page_alloc.c:1566 [inline]
get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3476
__alloc_pages_noprof+0x223/0x25b0 mm/page_alloc.c:4753
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+0xd7d/0x17a0 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_noprof+0x2ec/0x510 mm/slub.c:4310
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1037 [inline]
fib_create_info+0x8c1/0x5080 net/ipv4/fib_semantics.c:1435
fib_table_insert+0x1d7/0x1d70 net/ipv4/fib_trie.c:1231
fib_magic+0x4d6/0x5c0 net/ipv4/fib_frontend.c:1112
fib_add_ifaddr+0x174/0x560 net/ipv4/fib_frontend.c:1134
fib_netdev_event+0x38a/0x710 net/ipv4/fib_frontend.c:1494
notifier_call_chain+0xb7/0x410 kernel/notifier.c:85
call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1996
call_netdevice_notifiers_extack net/core/dev.c:2034 [inline]
call_netdevice_notifiers net/core/dev.c:2048 [inline]
__dev_notify_flags+0x12d/0x2e0 net/core/dev.c:8988
page last free pid 5933 tgid 5933 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:2659
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_lru_noprof+0x226/0x3d0 mm/slub.c:4187
__d_alloc+0x31/0xaa0 fs/dcache.c:1646
d_alloc+0x4a/0x1e0 fs/dcache.c:1726
d_alloc_parallel+0xe9/0x12b0 fs/dcache.c:2490
__lookup_slow+0x194/0x460 fs/namei.c:1776
lookup_one_len+0x181/0x1b0 fs/namei.c:2905
start_creating.part.0+0x12f/0x3a0 fs/debugfs/inode.c:378
start_creating fs/debugfs/inode.c:351 [inline]
__debugfs_create_file+0xa5/0x660 fs/debugfs/inode.c:423
debugfs_create_file_short+0x74/0xa0 fs/debugfs/inode.c:478
add_common_files net/mac80211/debugfs_netdev.c:830 [inline]
add_files net/mac80211/debugfs_netdev.c:947 [inline]
ieee80211_debugfs_add_netdev net/mac80211/debugfs_netdev.c:1011 [inline]
ieee80211_debugfs_recreate_netdev+0x584/0x1700 net/mac80211/debugfs_netdev.c:1044
ieee80211_if_add+0x9a9/0x18d0 net/mac80211/iface.c:2190
ieee80211_register_hw+0x382c/0x41a0 net/mac80211/main.c:1594

Memory state around the buggy address:
ffff88804c0f9b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88804c0f9c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88804c0f9c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88804c0f9d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88804c0f9d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


---
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