================================================================== BUG: KASAN: use-after-free in ax25_release+0x5ca/0x870 net/ax25/af_ax25.c:1061 Read of size 8 at addr ffff888029c63208 by task syz.3.632/6371 CPU: 1 PID: 6371 Comm: syz.3.632 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x168/0x230 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_release+0x5ca/0x870 net/ax25/af_ax25.c:1061 __sock_release net/socket.c:649 [inline] sock_close+0xd5/0x240 net/socket.c:1336 __fput+0x234/0x930 fs/file_table.c:311 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 RIP: 0033:0x7f894fd69ec9 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:00007fff7d37e9b8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 000000000004d7ca RCX: 00007f894fd69ec9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f894ffc2da0 R08: 0000000000000001 R09: 0000001a7d37ecaf R10: 0000001b31520000 R11: 0000000000000246 R12: 00007f894ffc0fac R13: 00007f894ffc0fa0 R14: ffffffffffffffff R15: 00007fff7d37ead0 Allocated by task 6377: 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:604 [inline] kzalloc include/linux/slab.h:735 [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+0x178/0x2d0 net/core/dev.c:-1 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8929 dev_ifsioc+0x147/0xe70 net/core/dev_ioctl.c:324 dev_ioctl+0x55f/0xe50 net/core/dev_ioctl.c:587 sock_do_ioctl+0x222/0x2f0 net/socket.c:1154 sock_ioctl+0x4ed/0x6e0 net/socket.c:1257 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 6374: 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_device_event+0x4b4/0x4f0 net/ax25/af_ax25.c:144 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+0x178/0x2d0 net/core/dev.c:-1 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8929 dev_ifsioc+0x147/0xe70 net/core/dev_ioctl.c:324 dev_ioctl+0x55f/0xe50 net/core/dev_ioctl.c:587 sock_do_ioctl+0x222/0x2f0 net/socket.c:1154 sock_ioctl+0x4ed/0x6e0 net/socket.c:1257 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 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+0x11d/0x1d0 kernel/workqueue.c:1559 snd_rawmidi_output_trigger sound/core/rawmidi.c:186 [inline] snd_rawmidi_kernel_write1+0x4a4/0x590 sound/core/rawmidi.c:1502 snd_rawmidi_write+0x5e2/0xbc0 sound/core/rawmidi.c:1555 do_loop_readv_writev fs/read_write.c:-1 [inline] do_iter_write+0x3e4/0x7b0 fs/read_write.c:857 vfs_writev fs/read_write.c:928 [inline] do_writev+0x254/0x410 fs/read_write.c:971 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 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+0x11d/0x1d0 kernel/workqueue.c:1559 snd_rawmidi_output_trigger sound/core/rawmidi.c:186 [inline] snd_rawmidi_kernel_write1+0x4a4/0x590 sound/core/rawmidi.c:1502 snd_rawmidi_write+0x5e2/0xbc0 sound/core/rawmidi.c:1555 do_loop_readv_writev fs/read_write.c:-1 [inline] do_iter_write+0x3e4/0x7b0 fs/read_write.c:857 vfs_writev fs/read_write.c:928 [inline] do_writev+0x254/0x410 fs/read_write.c:971 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 The buggy address belongs to the object at ffff888029c63200 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 8 bytes inside of 192-byte region [ffff888029c63200, ffff888029c632c0) The buggy address belongs to the page: page:ffffea0000a718c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x29c63 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea0000a45dc0 0000000500000005 ffff888016841a00 raw: 0000000000000000 0000000080100010 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 18433983911, free_ts 18425084008 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2031 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+0x81e/0xdf0 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:604 [inline] kzalloc include/linux/slab.h:735 [inline] call_usermodehelper_setup+0x8a/0x260 kernel/umh.c:365 kobject_uevent_env+0x65e/0x890 lib/kobject_uevent.c:629 device_add+0x91c/0xfb0 drivers/base/core.c:3393 __video_register_device+0x38e1/0x4670 drivers/media/v4l2-core/v4l2-dev.c:1042 video_register_device include/media/v4l2-dev.h:384 [inline] register_instance+0x274/0x350 drivers/media/test-drivers/vicodec/vicodec-core.c:2061 vicodec_probe+0x206/0x500 drivers/media/test-drivers/vicodec/vicodec-core.c:2123 platform_probe+0x137/0x1c0 drivers/base/platform.c:1391 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x284/0xc80 drivers/base/dd.c:595 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785 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+0x94/0x280 mm/page_alloc.c:3396 mm_free_pgd kernel/fork.c:653 [inline] __mmdrop+0xaa/0x3e0 kernel/fork.c:704 free_bprm+0x141/0x300 fs/exec.c:1494 kernel_execve+0x380/0x900 fs/exec.c:2015 call_usermodehelper_exec_async+0x207/0x350 kernel/umh.c:112 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Memory state around the buggy address: ffff888029c63100: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888029c63180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff888029c63200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888029c63280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888029c63300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================