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 ffff88805ddf8030 by task syz.1.1800/15713

CPU: 1 PID: 15713 Comm: syz.1.1800 Not tainted 6.6.93-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xac/0x230 mm/kasan/report.c:475
 kasan_report+0x151/0x180 mm/kasan/report.c:588
 rose_get_neigh+0x391/0x990 net/rose/rose_route.c:692
 rose_connect+0x417/0x10a0 net/rose/af_rose.c:816
 __sys_connect_file net/socket.c:2057 [inline]
 __sys_connect+0x397/0x420 net/socket.c:2074
 __do_sys_connect net/socket.c:2084 [inline]
 __se_sys_connect net/socket.c:2081 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:2081
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f19c098e929
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:00007f19c1796038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007f19c0bb5fa0 RCX: 00007f19c098e929
RDX: 000000000000001c RSI: 0000200000000040 RDI: 0000000000000005
RBP: 00007f19c0a10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f19c0bb5fa0 R15: 00007ffdc6c69868
 </TASK>

Allocated by task 4477:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383
 kmalloc include/linux/slab.h:600 [inline]
 batadv_forw_packet_alloc+0x1e9/0x390 net/batman-adv/send.c:519
 batadv_iv_ogm_aggregate_new net/batman-adv/bat_iv_ogm.c:561 [inline]
 batadv_iv_ogm_queue_add+0x77b/0xcf0 net/batman-adv/bat_iv_ogm.c:669
 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:832 [inline]
 batadv_iv_ogm_schedule+0x815/0xe90 net/batman-adv/bat_iv_ogm.c:867
 batadv_iv_send_outstanding_bat_ogm_packet+0x731/0x840 net/batman-adv/bat_iv_ogm.c:1711
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
 insert_work+0x3d/0x310 kernel/workqueue.c:1651
 __queue_work+0xd2c/0x1020 kernel/workqueue.c:1804
 call_timer_fn+0x16e/0x530 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1746 [inline]
 __run_timers+0x558/0x7d0 kernel/time/timer.c:2022
 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035
 handle_softirqs+0x280/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687

Second to last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
 insert_work+0x3d/0x310 kernel/workqueue.c:1651
 __queue_work+0xc39/0x1020 kernel/workqueue.c:1800
 call_timer_fn+0x16e/0x530 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1746 [inline]
 __run_timers+0x558/0x7d0 kernel/time/timer.c:2022
 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035
 handle_softirqs+0x280/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0x56/0xc0 arch/x86/kernel/apic/apic.c:1088
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687

The buggy address belongs to the object at ffff88805ddf8000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 48 bytes inside of
 freed 512-byte region [ffff88805ddf8000, ffff88805ddf8200)

The buggy address belongs to the physical page:
page:ffffea0001777e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88805ddf9000 pfn:0x5ddf8
head:ffffea0001777e00 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017841c80 ffffea000069b810 ffffea00018b9e10
raw: ffff88805ddf9000 0000000000100009 00000001ffffffff 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 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 2115, tgid 2115 (kworker/u4:6), ts 90474312301, free_ts 26855930148
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
 prep_new_page mm/page_alloc.c:1561 [inline]
 get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
 alloc_slab_page+0x5d/0x170 mm/slub.c:1876
 allocate_slab mm/slub.c:2023 [inline]
 new_slab+0x87/0x2e0 mm/slub.c:2076
 ___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230
 __slab_alloc mm/slub.c:3329 [inline]
 __slab_alloc_node mm/slub.c:3382 [inline]
 slab_alloc_node mm/slub.c:3475 [inline]
 __kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3524
 __do_kmalloc_node mm/slab_common.c:1006 [inline]
 __kmalloc+0xa4/0x240 mm/slab_common.c:1020
 kmalloc include/linux/slab.h:604 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 fib6_info_alloc+0x32/0xe0 net/ipv6/ip6_fib.c:155
 ip6_route_info_create+0x44f/0x1200 net/ipv6/route.c:3793
 ip6_route_add+0x28/0x130 net/ipv6/route.c:3889
 addrconf_prefix_route net/ipv6/addrconf.c:2451 [inline]
 addrconf_add_linklocal+0x45c/0x6b0 net/ipv6/addrconf.c:3287
 addrconf_addr_gen+0x4ac/0x5a0 net/ipv6/addrconf.c:3416
 addrconf_init_auto_addrs+0x719/0xb40 net/ipv6/addrconf.c:-1
 addrconf_notify+0xb62/0x1010 net/ipv6/addrconf.c:3718
 notifier_call_chain+0x197/0x390 kernel/notifier.c:93
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1154 [inline]
 free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
 free_contig_range+0xa1/0x160 mm/page_alloc.c:6369
 destroy_args+0x87/0x770 mm/debug_vm_pgtable.c:1015
 debug_vm_pgtable+0x3cc/0x410 mm/debug_vm_pgtable.c:1395
 do_one_initcall+0x1fd/0x750 init/main.c:1238
 do_initcall_level+0x137/0x1f0 init/main.c:1300
 do_initcalls+0x69/0xd0 init/main.c:1316
 kernel_init_freeable+0x3d2/0x570 init/main.c:1553
 kernel_init+0x1d/0x1c0 init/main.c:1443
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293

Memory state around the buggy address:
 ffff88805ddf7f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805ddf7f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805ddf8000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff88805ddf8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805ddf8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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