==================================================================
BUG: KASAN: use-after-free in ax25_fillin_cb_from_dev net/ax25/af_ax25.c:468 [inline]
BUG: KASAN: use-after-free in ax25_fillin_cb+0x459/0x640 net/ax25/af_ax25.c:495
Read of size 4 at addr ffff888017a6f238 by task syz.1.1465/8745

CPU: 1 PID: 8745 Comm: syz.1.1465 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 ax25_fillin_cb_from_dev net/ax25/af_ax25.c:468 [inline]
 ax25_fillin_cb+0x459/0x640 net/ax25/af_ax25.c:495
 ax25_setsockopt+0x8c9/0xa60 net/ax25/af_ax25.c:690
 __sys_setsockopt+0x2bf/0x3d0 net/socket.c:2212
 __do_sys_setsockopt net/socket.c:2223 [inline]
 __se_sys_setsockopt net/socket.c:2220 [inline]
 __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2220
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f6c04cc9cb9
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:00007f6c02ee3028 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f6c04f45180 RCX: 00007f6c04cc9cb9
RDX: 0000000000000019 RSI: 0000000000000101 RDI: 000000000000000c
RBP: 00007f6c04d37bf7 R08: 0000000000000010 R09: 0000000000000000
R10: 0000200000000240 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6c04f45218 R14: 00007f6c04f45180 R15: 00007ffeae0b1dd8
 </TASK>

Allocated by task 8457:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522
 kmalloc include/linux/slab.h:607 [inline]
 kzalloc include/linux/slab.h:738 [inline]
 ax25_dev_device_up+0x50/0x580 net/ax25/ax25_dev.c:55
 ax25_device_event+0x483/0x4f0 net/ax25/af_ax25.c:139
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391
 call_netdevice_notifiers_extack net/core/dev.c:2061 [inline]
 call_netdevice_notifiers net/core/dev.c:2075 [inline]
 __dev_notify_flags+0x194/0x300 net/core/dev.c:8891
 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8929
 dev_ifsioc+0x130/0xd50 net/core/dev_ioctl.c:324
 dev_ioctl+0x545/0xe30 net/core/dev_ioctl.c:572
 sock_do_ioctl+0x245/0x320 net/socket.c:1161
 sock_ioctl+0x4d2/0x710 net/socket.c:1266
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Freed by task 8680:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1710 [inline]
 slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kfree+0xef/0x2a0 mm/slub.c:4564
 ax25_dev_put include/net/ax25.h:302 [inline]
 ax25_release+0x661/0x870 net/ax25/af_ax25.c:1062
 __sock_release net/socket.c:651 [inline]
 sock_close+0xd5/0x240 net/socket.c:1345
 __fput+0x234/0x930 fs/file_table.c:311
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0x626/0x20c0 kernel/exit.c:883
 do_group_exit+0x12e/0x300 kernel/exit.c:997
 get_signal+0x6ca/0x12c0 kernel/signal.c:2900
 arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Last potentially related work creation:
 kasan_save_stack+0x35/0x60 mm/kasan/common.c:38
 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
 insert_work+0x54/0x3d0 kernel/workqueue.c:1366
 __queue_work+0x9c5/0xd50 kernel/workqueue.c:1532
 queue_work_on+0x124/0x1f0 kernel/workqueue.c:1559
 queue_work include/linux/workqueue.h:512 [inline]
 loop_queue_work drivers/block/loop.c:1068 [inline]
 loop_queue_rq+0x9d8/0xac0 drivers/block/loop.c:2202
 blk_mq_dispatch_rq_list+0xa7e/0x1d40 block/blk-mq.c:1387
 __blk_mq_sched_dispatch_requests+0x30e/0x410 block/blk-mq-sched.c:333
 blk_mq_sched_dispatch_requests+0xf4/0x1b0 block/blk-mq-sched.c:366
 __blk_mq_run_hw_queue+0xbb/0x100 block/blk-mq.c:1512
 __blk_mq_delay_run_hw_queue+0x137/0x610 block/blk-mq.c:1589
 blk_mq_run_hw_queues+0x2f9/0x4a0 block/blk-mq.c:1704
 blk_mq_requeue_work+0x642/0x690 block/blk-mq.c:808
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Second to last potentially related work creation:
 kasan_save_stack+0x35/0x60 mm/kasan/common.c:38
 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
 insert_work+0x54/0x3d0 kernel/workqueue.c:1366
 __queue_work+0x9c5/0xd50 kernel/workqueue.c:1532
 queue_work_on+0x124/0x1f0 kernel/workqueue.c:1559
 queue_work include/linux/workqueue.h:512 [inline]
 loop_queue_work drivers/block/loop.c:1068 [inline]
 loop_queue_rq+0x9d8/0xac0 drivers/block/loop.c:2202
 __blk_mq_issue_directly block/blk-mq.c:2015 [inline]
 __blk_mq_try_issue_directly+0x497/0x820 block/blk-mq.c:2071
 blk_mq_request_issue_directly block/blk-mq.c:2119 [inline]
 blk_mq_try_issue_list_directly+0x1a1/0x530 block/blk-mq.c:2137
 blk_mq_sched_insert_requests+0x2d6/0x5c0 block/blk-mq-sched.c:512
 blk_mq_flush_plug_list+0x59b/0x690 block/blk-mq.c:1972
 blk_flush_plug_list+0x404/0x450 block/blk-core.c:1734
 blk_finish_plug+0x59/0x80 block/blk-core.c:1751
 generic_writepages+0x10f/0x170 mm/page-writeback.c:2369
 do_writepages+0x476/0x6e0 mm/page-writeback.c:2386
 filemap_fdatawrite_wbc+0x1eb/0x240 mm/filemap.c:400
 __filemap_fdatawrite_range mm/filemap.c:433 [inline]
 __filemap_fdatawrite mm/filemap.c:439 [inline]
 filemap_flush+0xd4/0x130 mm/filemap.c:466
 sync_filesystem+0x141/0x220 fs/sync.c:60
 generic_shutdown_super+0x6b/0x300 fs/super.c:448
 kill_block_super+0x7c/0xe0 fs/super.c:1427
 deactivate_locked_super+0x93/0xf0 fs/super.c:335
 cleanup_mnt+0x42d/0x4e0 fs/namespace.c:1148
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff888017a6f200
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 56 bytes inside of
 192-byte region [ffff888017a6f200, ffff888017a6f2c0)
The buggy address belongs to the page:
page:ffffea00005e9bc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x17a6f
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea0001e86d80 0000000300000003 ffff888016c41a00
raw: 0000000000000000 0000000000100010 00000001ffffffff 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 0x112a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 4189, ts 73636160533, free_ts 73592283906
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5487
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x80a/0xdd0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc_trace+0x1a5/0x2a0 mm/slub.c:3250
 kmalloc include/linux/slab.h:607 [inline]
 addr_event+0xc3/0x460 drivers/infiniband/core/roce_gid_mgmt.c:840
 inetaddr_event+0xec/0x150 drivers/infiniband/core/roce_gid_mgmt.c:869
 notifier_call_chain kernel/notifier.c:83 [inline]
 blocking_notifier_call_chain+0x103/0x1b0 kernel/notifier.c:318
 __inet_insert_ifa+0x9f7/0xbe0 net/ipv4/devinet.c:567
 inet_rtm_newaddr+0x99a/0x1890 net/ipv4/devinet.c:966
 rtnetlink_rcv_msg+0x844/0xf30 net/core/rtnetlink.c:5684
 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 __sys_sendto+0x46d/0x620 net/socket.c:2072
 __do_sys_sendto net/socket.c:2084 [inline]
 __se_sys_sendto net/socket.c:2080 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2080
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396
 free_slab mm/slub.c:2020 [inline]
 discard_slab mm/slub.c:2026 [inline]
 __unfreeze_partials+0x1a5/0x200 mm/slub.c:2512
 put_cpu_partial+0x12d/0x190 mm/slub.c:2592
 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 kmem_cache_alloc_node+0x12d/0x2d0 mm/slub.c:3261
 __alloc_skb+0xf4/0x750 net/core/skbuff.c:415
 alloc_skb include/linux/skbuff.h:1162 [inline]
 mld_newpack+0x12f/0xb90 net/ipv6/mcast.c:1745
 add_grhead+0x5a/0x240 net/ipv6/mcast.c:1856
 add_grec+0x1341/0x15d0 net/ipv6/mcast.c:1994
 mld_send_cr net/ipv6/mcast.c:2120 [inline]
 mld_ifc_work+0x6e7/0xb40 net/ipv6/mcast.c:2658
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457

Memory state around the buggy address:
 ffff888017a6f100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888017a6f180: 04 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888017a6f200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff888017a6f280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888017a6f300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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