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BUG: KASAN: slab-use-after-free in rose_get_neigh+0x1b6/0x6f0 net/rose/rose_route.c:692
Read of size 1 at addr ffff8880611ad830 by task syz.3.349/6532

CPU: 1 UID: 0 PID: 6532 Comm: syz.3.349 Not tainted 6.11.0-rc2-syzkaller-00354-g0a3e6939d4b3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 rose_get_neigh+0x1b6/0x6f0 net/rose/rose_route.c:692
 rose_connect+0x45a/0x1170 net/rose/af_rose.c:808
 __sys_connect_file net/socket.c:2061 [inline]
 __sys_connect+0x2df/0x310 net/socket.c:2078
 __do_sys_connect net/socket.c:2088 [inline]
 __se_sys_connect net/socket.c:2085 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:2085
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1dc97799f9
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:00007f1dca61e038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007f1dc9915f80 RCX: 00007f1dc97799f9
RDX: 000000000000001c RSI: 00000000200002c0 RDI: 000000000000000d
RBP: 00007f1dc97e78ee R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f1dc9915f80 R15: 00007ffefe1adb28
 </TASK>

Allocated by task 5902:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 __kmalloc_cache_noprof+0x19c/0x2c0 mm/slub.c:4189
 kmalloc_noprof include/linux/slab.h:681 [inline]
 rose_add_node+0x209/0xda0 net/rose/rose_route.c:85
 rose_rt_ioctl+0xa6f/0xed0 net/rose/rose_route.c:747
 rose_ioctl+0x3cb/0x9d0 net/rose/af_rose.c:1372
 sock_do_ioctl+0x158/0x460 net/socket.c:1222
 sock_ioctl+0x629/0x8e0 net/socket.c:1341
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6485:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240
 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2252 [inline]
 slab_free mm/slub.c:4473 [inline]
 kfree+0x149/0x360 mm/slub.c:4594
 rose_rt_device_down+0x6e5/0x740 net/rose/rose_route.c:522
 rose_device_event+0x601/0x6a0 net/rose/af_rose.c:248
 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
 call_netdevice_notifiers_extack net/core/dev.c:2032 [inline]
 call_netdevice_notifiers net/core/dev.c:2046 [inline]
 dev_close_many+0x33c/0x4c0 net/core/dev.c:1587
 dev_close+0x1c0/0x2c0 net/core/dev.c:1609
 bpq_device_event+0x372/0x8b0 drivers/net/hamradio/bpqether.c:547
 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
 __dev_notify_flags+0x207/0x400
 dev_change_flags+0xf0/0x1a0 net/core/dev.c:8915
 dev_ifsioc+0x7c8/0xe70 net/core/dev_ioctl.c:527
 dev_ioctl+0x719/0x1340 net/core/dev_ioctl.c:784
 sock_do_ioctl+0x240/0x460 net/socket.c:1236
 sock_ioctl+0x629/0x8e0 net/socket.c:1341
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880611ad800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 48 bytes inside of
 freed 512-byte region [ffff8880611ad800, ffff8880611ada00)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880611ae400 pfn:0x611ac
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xfdffffff(slab)
raw: 00fff00000000240 ffff888015841c80 ffffea0000490410 ffffea000090c110
raw: ffff8880611ae400 000000000010000f 00000001fdffffff 0000000000000000
head: 00fff00000000240 ffff888015841c80 ffffea0000490410 ffffea000090c110
head: ffff8880611ae400 000000000010000f 00000001fdffffff 0000000000000000
head: 00fff00000000002 ffffea0001846b01 ffffffffffffffff 0000000000000000
head: 0000000000000004 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5363, tgid 5361 (syz.0.16), ts 79017156624, free_ts 79016485295
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1493
 prep_new_page mm/page_alloc.c:1501 [inline]
 get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3442
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4700
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x5f/0x120 mm/slub.c:2321
 allocate_slab+0x5a/0x2f0 mm/slub.c:2484
 new_slab mm/slub.c:2537 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3723
 __slab_alloc+0x58/0xa0 mm/slub.c:3813
 __slab_alloc_node mm/slub.c:3866 [inline]
 slab_alloc_node mm/slub.c:4025 [inline]
 __kmalloc_cache_noprof+0x1d5/0x2c0 mm/slub.c:4184
 kmalloc_noprof include/linux/slab.h:681 [inline]
 kzalloc_noprof include/linux/slab.h:807 [inline]
 fib6_net_init+0x374/0x880 net/ipv6/ip6_fib.c:2447
 ops_init+0x31e/0x590 net/core/net_namespace.c:139
 setup_net+0x287/0x9e0 net/core/net_namespace.c:356
 copy_net_ns+0x33f/0x560 net/core/net_namespace.c:494
 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
 ksys_unshare+0x619/0xc10 kernel/fork.c:3309
 __do_sys_unshare kernel/fork.c:3380 [inline]
 __se_sys_unshare kernel/fork.c:3378 [inline]
 __x64_sys_unshare+0x38/0x40 kernel/fork.c:3378
page last free pid 5358 tgid 5358 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1094 [inline]
 free_unref_page+0xd22/0xea0 mm/page_alloc.c:2612
 stack_depot_save_flags+0x6f6/0x830 lib/stackdepot.c:666
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_save_track+0x51/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:312 [inline]
 __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3988 [inline]
 slab_alloc_node mm/slub.c:4037 [inline]
 kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4044
 fill_pool lib/debugobjects.c:169 [inline]
 debug_objects_fill_pool+0x67e/0x9b0 lib/debugobjects.c:616
 debug_object_activate+0x135/0x510 lib/debugobjects.c:705
 debug_hrtimer_activate kernel/time/hrtimer.c:423 [inline]
 debug_activate kernel/time/hrtimer.c:478 [inline]
 enqueue_hrtimer+0x30/0x3c0 kernel/time/hrtimer.c:1085
 __hrtimer_start_range_ns kernel/time/hrtimer.c:1260 [inline]
 hrtimer_start_range_ns+0xac8/0xca0 kernel/time/hrtimer.c:1302
 futex_wait_queue+0xb0/0x1d0 kernel/futex/waitwake.c:357
 __futex_wait+0x17f/0x320 kernel/futex/waitwake.c:669
 futex_wait+0x101/0x360 kernel/futex/waitwake.c:697
 do_futex+0x33b/0x560 kernel/futex/syscalls.c:102
 __do_sys_futex kernel/futex/syscalls.c:179 [inline]
 __se_sys_futex+0x3f9/0x480 kernel/futex/syscalls.c:160
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff8880611ad700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880611ad780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880611ad800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff8880611ad880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880611ad900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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