================================================================== BUG: KASAN: slab-out-of-bounds in hlist_add_head include/linux/list.h:814 [inline] BUG: KASAN: slab-out-of-bounds in enqueue_timer+0xb7/0x300 kernel/time/timer.c:541 Write of size 8 at addr ffff8881e1a371c8 by task syz.2.850/2795 CPU: 0 PID: 2795 Comm: syz.2.850 Not tainted 5.4.276-syzkaller-00021-g58de09405d1e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d8/0x241 lib/dump_stack.c:118 print_address_description+0x8c/0x600 mm/kasan/report.c:384 __kasan_report+0xf3/0x120 mm/kasan/report.c:516 kasan_report+0x30/0x60 mm/kasan/common.c:653 hlist_add_head include/linux/list.h:814 [inline] enqueue_timer+0xb7/0x300 kernel/time/timer.c:541 __internal_add_timer kernel/time/timer.c:554 [inline] internal_add_timer+0x240/0x430 kernel/time/timer.c:604 __mod_timer+0x6f1/0x13e0 kernel/time/timer.c:1065 can_pernet_init+0x1de/0x2e0 net/can/af_can.c:810 ops_init+0x1d4/0x4a0 net/core/net_namespace.c:141 setup_net+0x214/0x990 net/core/net_namespace.c:348 copy_net_ns+0x30d/0x510 net/core/net_namespace.c:489 create_new_namespaces+0x47a/0x570 kernel/nsproxy.c:103 copy_namespaces+0x169/0x1b0 kernel/nsproxy.c:161 copy_process+0x12da/0x3230 kernel/fork.c:2055 _do_fork+0x197/0x900 kernel/fork.c:2399 __do_sys_clone kernel/fork.c:2557 [inline] __se_sys_clone kernel/fork.c:2538 [inline] __x64_sys_clone+0x26b/0x2c0 kernel/fork.c:2538 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f1cbe60eb99 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:00007f1cbd88fff8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f1cbe79cf60 RCX: 00007f1cbe60eb99 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000630c1000 RBP: 00007f1cbe67da7a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 000000000000000b R14: 00007f1cbe79cf60 R15: 00007ffe4c9bc328 Allocated by task 429: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] __kasan_kmalloc+0x171/0x210 mm/kasan/common.c:529 kmalloc include/linux/slab.h:561 [inline] kzalloc include/linux/slab.h:690 [inline] neigh_alloc net/core/neighbour.c:439 [inline] ___neigh_create+0x6d2/0x1ae0 net/core/neighbour.c:592 ip6_finish_output2+0x965/0x18e0 net/ipv6/ip6_output.c:141 NF_HOOK_COND include/linux/netfilter.h:292 [inline] ip6_output+0x1b3/0x430 net/ipv6/ip6_output.c:248 dst_output include/net/dst.h:438 [inline] NF_HOOK include/linux/netfilter.h:303 [inline] mld_sendpack+0x606/0xb50 net/ipv6/mcast.c:1679 mld_send_cr net/ipv6/mcast.c:1975 [inline] mld_ifc_timer_expire+0x814/0xc10 net/ipv6/mcast.c:2474 call_timer_fn+0x36/0x390 kernel/time/timer.c:1448 expire_timers kernel/time/timer.c:1493 [inline] __run_timers+0x879/0xbe0 kernel/time/timer.c:1817 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1830 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292 Freed by task 0: (stack is not available) The buggy address belongs to the object at ffff8881e1a37000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 456 bytes inside of 512-byte region [ffff8881e1a37000, ffff8881e1a37200) The buggy address belongs to the page: page:ffffea0007868d00 refcount:1 mapcount:0 mapping:ffff8881f5c02500 index:0x0 compound_mapcount: 0 flags: 0x8000000000010200(slab|head) raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5c02500 raw: 0000000000000000 0000000000100010 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL) set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook mm/page_alloc.c:2165 [inline] prep_new_page+0x18f/0x370 mm/page_alloc.c:2171 get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794 __alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4893 alloc_slab_page+0x39/0x3c0 mm/slub.c:343 allocate_slab mm/slub.c:1683 [inline] new_slab+0x97/0x440 mm/slub.c:1749 new_slab_objects mm/slub.c:2505 [inline] ___slab_alloc+0x2fe/0x490 mm/slub.c:2667 __slab_alloc+0x62/0xa0 mm/slub.c:2707 slab_alloc_node mm/slub.c:2792 [inline] slab_alloc mm/slub.c:2837 [inline] __kmalloc+0x19b/0x2e0 mm/slub.c:3909 kmalloc include/linux/slab.h:561 [inline] kzalloc include/linux/slab.h:690 [inline] fib6_info_alloc+0x2c/0xd0 net/ipv6/ip6_fib.c:154 ip6_route_info_create+0x459/0x1420 net/ipv6/route.c:3663 addrconf_f6i_alloc+0x215/0x4c0 net/ipv6/route.c:4447 ipv6_add_addr+0x44e/0xd40 net/ipv6/addrconf.c:1114 addrconf_add_linklocal+0x318/0x9e0 net/ipv6/addrconf.c:3246 addrconf_addr_gen+0x572/0xd00 net/ipv6/addrconf.c:3377 addrconf_notify+0x9d2/0xe50 net/ipv6/addrconf.c:3659 notifier_call_chain kernel/notifier.c:98 [inline] __raw_notifier_call_chain kernel/notifier.c:399 [inline] raw_notifier_call_chain+0x95/0x110 kernel/notifier.c:406 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1176 [inline] __free_pages_ok+0x847/0x950 mm/page_alloc.c:1438 free_the_page mm/page_alloc.c:4955 [inline] __free_pages+0x91/0x140 mm/page_alloc.c:4961 bpf_check+0x8aaa/0xb340 kernel/bpf/verifier.c:9731 bpf_prog_load kernel/bpf/syscall.c:1724 [inline] __do_sys_bpf kernel/bpf/syscall.c:2891 [inline] __se_sys_bpf+0x8139/0xbcb0 kernel/bpf/syscall.c:2849 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Memory state around the buggy address: ffff8881e1a37080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8881e1a37100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8881e1a37180: 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8881e1a37200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8881e1a37280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================