================================================================== 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+0x460/0x660 net/ax25/af_ax25.c:495 Read of size 4 at addr ffff88805e212938 by task syz.4.108/4604 CPU: 1 PID: 4604 Comm: syz.4.108 Not tainted 5.15.180-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 print_address_description+0x63/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x16b/0x1c0 mm/kasan/report.c:451 ax25_fillin_cb_from_dev net/ax25/af_ax25.c:468 [inline] ax25_fillin_cb+0x460/0x660 net/ax25/af_ax25.c:495 ax25_setsockopt+0xab7/0xe70 net/ax25/af_ax25.c:690 __sys_setsockopt+0x57e/0x990 net/socket.c:2203 __do_sys_setsockopt net/socket.c:2214 [inline] __se_sys_setsockopt net/socket.c:2211 [inline] __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2211 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f2b08803169 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:00007f2b0666c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f2b08a1bfa0 RCX: 00007f2b08803169 RDX: 0000000000000019 RSI: 0000000000000101 RDI: 0000000000000007 RBP: 00007f2b08884990 R08: 0000000000000010 R09: 0000000000000000 R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f2b08a1bfa0 R15: 00007ffeb8f18e28 Allocated by task 4515: 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+0xba/0xf0 mm/kasan/common.c:513 kasan_kmalloc include/linux/kasan.h:264 [inline] kmem_cache_alloc_trace+0x143/0x290 mm/slub.c:3247 kmalloc include/linux/slab.h:604 [inline] kzalloc include/linux/slab.h:735 [inline] ax25_dev_device_up+0x51/0x5a0 net/ax25/ax25_dev.c:55 ax25_device_event+0x4a0/0x510 net/ax25/af_ax25.c:139 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:391 __dev_notify_flags+0x1fd/0x3f0 net/core/dev.c:-1 dev_change_flags+0xe7/0x190 net/core/dev.c:8928 dev_ifsioc+0x147/0x10c0 net/core/dev_ioctl.c:324 dev_ioctl+0x504/0xf60 net/core/dev_ioctl.c:587 sock_do_ioctl+0x34f/0x5a0 net/socket.c:1154 sock_ioctl+0x484/0x770 net/socket.c:1257 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 4593: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x80 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kfree+0xf1/0x270 mm/slub.c:4559 ax25_dev_put include/net/ax25.h:302 [inline] ax25_release+0x3b3/0x840 net/ax25/af_ax25.c:1062 __sock_release net/socket.c:649 [inline] sock_close+0xcd/0x230 net/socket.c:1336 __fput+0x3fe/0x8e0 fs/file_table.c:311 task_work_run+0x129/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Last potentially related work creation: kasan_save_stack+0x36/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xba/0x100 mm/kasan/generic.c:348 insert_work+0x54/0x3e0 kernel/workqueue.c:1366 __queue_work+0x963/0xd00 kernel/workqueue.c:1532 queue_work_on+0x14b/0x250 kernel/workqueue.c:1559 snd_rawmidi_output_trigger sound/core/rawmidi.c:186 [inline] snd_rawmidi_kernel_write1+0x4f1/0x5e0 sound/core/rawmidi.c:1502 snd_rawmidi_write+0x59e/0xb50 sound/core/rawmidi.c:1555 do_loop_readv_writev fs/read_write.c:-1 [inline] do_iter_write+0x39c/0x760 fs/read_write.c:857 vfs_writev fs/read_write.c:928 [inline] do_writev+0x281/0x470 fs/read_write.c:971 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Second to last potentially related work creation: kasan_save_stack+0x36/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xba/0x100 mm/kasan/generic.c:348 insert_work+0x54/0x3e0 kernel/workqueue.c:1366 __queue_work+0x963/0xd00 kernel/workqueue.c:1532 queue_work_on+0x14b/0x250 kernel/workqueue.c:1559 snd_rawmidi_output_trigger sound/core/rawmidi.c:186 [inline] snd_rawmidi_kernel_write1+0x4f1/0x5e0 sound/core/rawmidi.c:1502 snd_rawmidi_write+0x59e/0xb50 sound/core/rawmidi.c:1555 do_loop_readv_writev fs/read_write.c:-1 [inline] do_iter_write+0x39c/0x760 fs/read_write.c:857 vfs_writev fs/read_write.c:928 [inline] do_writev+0x281/0x470 fs/read_write.c:971 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff88805e212900 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 56 bytes inside of 192-byte region [ffff88805e212900, ffff88805e2129c0) The buggy address belongs to the page: page:ffffea0001788480 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5e212 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea0001771f40 0000000900000007 ffff888017441a00 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 3546, ts 69693717995, free_ts 18260766817 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x3b78/0x3d40 mm/page_alloc.c:4192 __alloc_pages+0x272/0x700 mm/page_alloc.c:5466 __alloc_pages_node include/linux/gfp.h:570 [inline] alloc_slab_page mm/slub.c:1777 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xb1/0x4b0 mm/slub.c:1975 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] __kmalloc_node+0x1fa/0x390 mm/slub.c:4451 kmalloc_array_node include/linux/slab.h:697 [inline] kcalloc_node include/linux/slab.h:702 [inline] memcg_alloc_page_obj_cgroups+0x7e/0x120 mm/memcontrol.c:2841 account_slab_page mm/slab.h:424 [inline] allocate_slab mm/slub.c:1928 [inline] new_slab+0xfb/0x4b0 mm/slub.c:1975 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0x18e/0x280 mm/slub.c:3233 shmem_alloc_inode+0x16/0x30 mm/shmem.c:3789 alloc_inode fs/inode.c:261 [inline] new_inode_pseudo+0x60/0x210 fs/inode.c:1001 new_inode+0x25/0x1d0 fs/inode.c:1030 shmem_get_inode+0x327/0xad0 mm/shmem.c:2290 shmem_mknod+0x54/0x1b0 mm/shmem.c:2850 lookup_open fs/namei.c:3462 [inline] open_last_lookups fs/namei.c:3532 [inline] path_openat+0x130a/0x2f20 fs/namei.c:3739 do_filp_open+0x21c/0x460 fs/namei.c:3769 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+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396 free_contig_range+0x95/0xf0 mm/page_alloc.c:9385 destroy_args+0xfe/0x980 mm/debug_vm_pgtable.c:1018 debug_vm_pgtable+0x40d/0x470 mm/debug_vm_pgtable.c:1331 do_one_initcall+0x22b/0x7a0 init/main.c:1302 do_initcall_level+0x157/0x210 init/main.c:1375 do_initcalls+0x49/0x90 init/main.c:1391 kernel_init_freeable+0x425/0x5c0 init/main.c:1615 kernel_init+0x19/0x290 init/main.c:1506 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Memory state around the buggy address: ffff88805e212800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88805e212880: 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88805e212900: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805e212980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88805e212a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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