syzbot

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BUG: KASAN: slab-use-after-free in rose_get_neigh+0x391/0x990 net/rose/rose_route.c:692
Read of size 1 at addr ffff88806f497830 by task syz-executor945/6023

CPU: 1 UID: 0 PID: 6023 Comm: syz-executor945 Not tainted 6.15.0-syzkaller-10402-g4cb6c8af8591 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xd2/0x2b0 mm/kasan/report.c:521
 kasan_report+0x118/0x150 mm/kasan/report.c:634
 rose_get_neigh+0x391/0x990 net/rose/rose_route.c:692
 rose_connect+0x416/0x10a0 net/rose/af_rose.c:816
 __sys_connect_file net/socket.c:2038 [inline]
 __sys_connect+0x313/0x440 net/socket.c:2057
 __do_sys_connect net/socket.c:2063 [inline]
 __se_sys_connect net/socket.c:2060 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:2060
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7f2155bec9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 1e 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7f20d05218 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007f7f215e51e8 RCX: 00007f7f2155bec9
RDX: 000000000000001c RSI: 0000200000000040 RDI: 0000000000000008
RBP: 00007f7f215e51e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7f215ab84c
R13: 000020000000004d R14: 0000200000000046 R15: 0000200000000040
 </TASK>

Allocated by task 5886:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4358
 kmalloc_noprof include/linux/slab.h:905 [inline]
 rose_add_node+0x23a/0xde0 net/rose/rose_route.c:85
 rose_rt_ioctl+0xa48/0xfb0 net/rose/rose_route.c:747
 rose_ioctl+0x3ce/0x8b0 net/rose/af_rose.c:1380
 sock_do_ioctl+0xd9/0x300 net/socket.c:1190
 sock_ioctl+0x576/0x790 net/socket.c:1311
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6012:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2380 [inline]
 slab_free mm/slub.c:4642 [inline]
 kfree+0x18e/0x440 mm/slub.c:4841
 rose_rt_device_down+0x66d/0x6c0 net/rose/rose_route.c:522
 rose_device_event+0x603/0x6a0 net/rose/af_rose.c:248
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
 call_netdevice_notifiers net/core/dev.c:2282 [inline]
 __dev_notify_flags+0x18d/0x2e0 net/core/dev.c:-1
 netif_change_flags+0xe8/0x1a0 net/core/dev.c:9526
 dev_change_flags+0x130/0x260 net/core/dev_api.c:68
 dev_ioctl+0x7b4/0x1150 net/core/dev_ioctl.c:823
 sock_do_ioctl+0x22c/0x300 net/socket.c:1204
 sock_ioctl+0x576/0x790 net/socket.c:1311
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88806f497800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 48 bytes inside of
 freed 512-byte region [ffff88806f497800, ffff88806f497a00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6f494
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801a441c80 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801a441c80 dead000000000122 0000000000000000
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0001bd2501 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5817, tgid 5817 (syz-executor945), ts 96431662937, free_ts 96422040266
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1710
 prep_new_page mm/page_alloc.c:1718 [inline]
 get_page_from_freelist+0x21d1/0x22b0 mm/page_alloc.c:3680
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4970
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2450 [inline]
 allocate_slab+0x8a/0x3b0 mm/slub.c:2618
 new_slab mm/slub.c:2672 [inline]
 ___slab_alloc+0xbfc/0x1480 mm/slub.c:3858
 __slab_alloc mm/slub.c:3948 [inline]
 __slab_alloc_node mm/slub.c:4023 [inline]
 slab_alloc_node mm/slub.c:4184 [inline]
 __do_kmalloc_node mm/slub.c:4326 [inline]
 __kmalloc_noprof+0x305/0x4f0 mm/slub.c:4339
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 fib6_info_alloc+0x30/0xf0 net/ipv6/ip6_fib.c:155
 ip6_route_info_create+0x142/0x860 net/ipv6/route.c:3764
 addrconf_f6i_alloc+0x1d2/0x450 net/ipv6/route.c:4679
 fixup_permanent_addr net/ipv6/addrconf.c:3587 [inline]
 addrconf_permanent_addr+0x274/0x9d0 net/ipv6/addrconf.c:3626
 addrconf_notify+0x887/0x1010 net/ipv6/addrconf.c:3698
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
 call_netdevice_notifiers net/core/dev.c:2282 [inline]
 __dev_notify_flags+0x18d/0x2e0 net/core/dev.c:-1
 netif_change_flags+0xe8/0x1a0 net/core/dev.c:9526
 do_setlink+0xc55/0x41c0 net/core/rtnetlink.c:3141
page last free pid 5886 tgid 5885 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1254 [inline]
 __free_frozen_pages+0xc65/0xe50 mm/page_alloc.c:2717
 stack_depot_save_flags+0x445/0x900 lib/stackdepot.c:678
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_save_track+0x4f/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4147 [inline]
 slab_alloc_node mm/slub.c:4196 [inline]
 kmem_cache_alloc_lru_noprof+0x1c6/0x3d0 mm/slub.c:4215
 xas_alloc lib/xarray.c:378 [inline]
 xas_create+0x116b/0x1b90 lib/xarray.c:685
 xas_store+0x95/0x1880 lib/xarray.c:795
 memcg_list_lru_alloc+0x58d/0x7e0 mm/list_lru.c:547
 __memcg_slab_post_alloc_hook+0x149/0x8c0 mm/memcontrol.c:3058
 memcg_slab_post_alloc_hook mm/slub.c:2179 [inline]
 slab_post_alloc_hook mm/slub.c:4157 [inline]
 slab_alloc_node mm/slub.c:4196 [inline]
 kmem_cache_alloc_lru_noprof+0x2c7/0x3d0 mm/slub.c:4215
 pidfs_alloc_inode+0x28/0x90 fs/pidfs.c:654
 alloc_inode+0x6a/0x1b0 fs/inode.c:346
 new_inode_pseudo include/linux/fs.h:3335 [inline]
 prepare_anon_dentry fs/libfs.c:2145 [inline]
 path_from_stashed+0x299/0x8f0 fs/libfs.c:2232
 pidfs_register_pid+0x108/0x1b0 fs/pidfs.c:956
 prepare_peercred net/unix/af_unix.c:754 [inline]
 unix_socketpair+0xdc/0x6f0 net/unix/af_unix.c:1782
 __sys_socketpair+0x2b8/0x560 net/socket.c:1763

Memory state around the buggy address:
 ffff88806f497700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88806f497780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88806f497800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff88806f497880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88806f497900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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