================================================================== BUG: KASAN: slab-use-after-free in hlist_add_head include/linux/list.h:1026 [inline] BUG: KASAN: slab-use-after-free in fib6_add+0xe5c/0x28b0 net/ipv6/ip6_fib.c:1490 Write of size 8 at addr ff60000032206040 by task syz-executor.0/7889 CPU: 1 PID: 7889 Comm: syz-executor.0 Not tainted 6.6.0-rc1-syzkaller-00011-g3fec323339a4 #0 Hardware name: riscv-virtio,qemu (DT) Call Trace: [] dump_backtrace+0x2e/0x3c arch/riscv/kernel/stacktrace.c:121 [] show_stack+0x34/0x40 arch/riscv/kernel/stacktrace.c:127 [] __dump_stack lib/dump_stack.c:88 [inline] [] dump_stack_lvl+0xe8/0x154 lib/dump_stack.c:106 [] print_address_description mm/kasan/report.c:364 [inline] [] print_report+0x1e4/0x4f4 mm/kasan/report.c:475 [] kasan_report+0xf0/0x1ba mm/kasan/report.c:588 [] check_region_inline mm/kasan/generic.c:181 [inline] [] __asan_store8+0x80/0xa8 mm/kasan/generic.c:260 [] hlist_add_head include/linux/list.h:1026 [inline] [] fib6_add+0xe5c/0x28b0 net/ipv6/ip6_fib.c:1490 [] __ip6_ins_rt net/ipv6/route.c:1303 [inline] [] ip6_route_add+0x72/0x148 net/ipv6/route.c:3847 [] rt6_add_dflt_router+0x1fe/0x3e8 net/ipv6/route.c:4375 [] ndisc_router_discovery+0x6b4/0x1f3c net/ipv6/ndisc.c:1384 [] ndisc_rcv+0x392/0x3f4 net/ipv6/ndisc.c:1856 [] icmpv6_rcv+0xc3c/0xea2 net/ipv6/icmp.c:979 [] ip6_protocol_deliver_rcu+0x13a/0xdf6 net/ipv6/ip6_input.c:438 [] ip6_input_finish+0xe6/0x28e net/ipv6/ip6_input.c:483 [] NF_HOOK include/linux/netfilter.h:304 [inline] [] NF_HOOK include/linux/netfilter.h:298 [inline] [] ip6_input+0xbc/0x422 net/ipv6/ip6_input.c:492 [] ip6_mc_input+0x3ee/0xbb4 net/ipv6/ip6_input.c:586 [] dst_input include/net/dst.h:468 [inline] [] ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline] [] NF_HOOK include/linux/netfilter.h:304 [inline] [] NF_HOOK include/linux/netfilter.h:298 [inline] [] ipv6_rcv+0x53c/0x5c2 net/ipv6/ip6_input.c:310 [] __netif_receive_skb_one_core+0xe8/0x132 net/core/dev.c:5523 [] __netif_receive_skb+0x2e/0xd0 net/core/dev.c:5637 [] netif_receive_skb_internal net/core/dev.c:5723 [inline] [] netif_receive_skb+0x174/0x7be net/core/dev.c:5782 [] tun_rx_batched+0x36c/0x43a drivers/net/tun.c:1555 [] tun_get_user+0x2056/0x2cd2 drivers/net/tun.c:2002 [] tun_chr_write_iter+0x96/0x15e drivers/net/tun.c:2048 [] call_write_iter include/linux/fs.h:1985 [inline] [] new_sync_write fs/read_write.c:491 [inline] [] vfs_write+0x3c8/0x5cc fs/read_write.c:584 [] ksys_write+0x104/0x226 fs/read_write.c:637 [] __do_sys_write fs/read_write.c:649 [inline] [] __se_sys_write fs/read_write.c:646 [inline] [] __riscv_sys_write+0x44/0x52 fs/read_write.c:646 [] syscall_handler+0x76/0xba arch/riscv/include/asm/syscall.h:90 [] do_trap_ecall_u+0x9c/0x9e arch/riscv/kernel/traps.c:320 [] ret_from_exception+0x0/0x64 arch/riscv/kernel/entry.S:102 Allocated by task 7885: stack_trace_save+0xa0/0xd2 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x6a mm/kasan/common.c:45 kasan_set_track+0x1a/0x26 mm/kasan/common.c:52 kasan_save_alloc_info+0x1a/0x24 mm/kasan/generic.c:511 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xa2/0xa8 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1023 [inline] __kmalloc+0x42/0xe6 mm/slab_common.c:1036 kmalloc include/linux/slab.h:603 [inline] kzalloc include/linux/slab.h:720 [inline] fib6_info_alloc+0x46/0xca net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x22e/0x112e net/ipv6/route.c:3749 ip6_route_add+0x2a/0x148 net/ipv6/route.c:3843 rt6_add_dflt_router+0x1fe/0x3e8 net/ipv6/route.c:4375 ndisc_router_discovery+0x6b4/0x1f3c net/ipv6/ndisc.c:1384 ndisc_rcv+0x392/0x3f4 net/ipv6/ndisc.c:1856 icmpv6_rcv+0xc3c/0xea2 net/ipv6/icmp.c:979 ip6_protocol_deliver_rcu+0x13a/0xdf6 net/ipv6/ip6_input.c:438 ip6_input_finish+0xe6/0x28e net/ipv6/ip6_input.c:483 NF_HOOK include/linux/netfilter.h:304 [inline] NF_HOOK include/linux/netfilter.h:298 [inline] ip6_input+0xbc/0x422 net/ipv6/ip6_input.c:492 ip6_mc_input+0x3ee/0xbb4 net/ipv6/ip6_input.c:586 dst_input include/net/dst.h:468 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline] NF_HOOK include/linux/netfilter.h:304 [inline] NF_HOOK include/linux/netfilter.h:298 [inline] ipv6_rcv+0x53c/0x5c2 net/ipv6/ip6_input.c:310 __netif_receive_skb_one_core+0xe8/0x132 net/core/dev.c:5523 __netif_receive_skb+0x2e/0xd0 net/core/dev.c:5637 netif_receive_skb_internal net/core/dev.c:5723 [inline] netif_receive_skb+0x174/0x7be net/core/dev.c:5782 tun_rx_batched+0x36c/0x43a drivers/net/tun.c:1555 tun_get_user+0x2056/0x2cd2 drivers/net/tun.c:2002 tun_chr_write_iter+0x96/0x15e drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:1985 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x3c8/0x5cc fs/read_write.c:584 ksys_write+0x104/0x226 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __riscv_sys_write+0x44/0x52 fs/read_write.c:646 syscall_handler+0x76/0xba arch/riscv/include/asm/syscall.h:90 do_trap_ecall_u+0x9c/0x9e arch/riscv/kernel/traps.c:320 ret_from_exception+0x0/0x64 arch/riscv/kernel/entry.S:102 Freed by task 7883: stack_trace_save+0xa0/0xd2 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x6a mm/kasan/common.c:45 kasan_set_track+0x1a/0x26 mm/kasan/common.c:52 kasan_save_free_info+0x28/0x46 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15e/0x20c mm/kasan/common.c:200 __kasan_slab_free+0x10/0x18 mm/kasan/common.c:244 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook+0xca/0x1b4 mm/slub.c:1826 slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0xa4/0x31a mm/slub.c:3822 kfree+0xa2/0x176 mm/slab_common.c:1072 fib6_info_destroy_rcu+0x150/0x1e6 net/ipv6/ip6_fib.c:180 rcu_do_batch kernel/rcu/tree.c:2139 [inline] rcu_core+0x608/0xf48 kernel/rcu/tree.c:2403 rcu_core_si+0xc/0x14 kernel/rcu/tree.c:2420 __do_softirq+0x2ee/0x8a2 kernel/softirq.c:553 Last potentially related work creation: stack_trace_save+0xa0/0xd2 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x6a mm/kasan/common.c:45 __kasan_record_aux_stack+0xf6/0x13e mm/kasan/generic.c:492 kasan_record_aux_stack_noalloc+0xe/0x16 mm/kasan/generic.c:502 __call_rcu_common.constprop.0+0x80/0x4d6 kernel/rcu/tree.c:2653 call_rcu+0xc/0x14 kernel/rcu/tree.c:2767 fib6_info_release include/net/ip6_fib.h:332 [inline] fib6_info_release include/net/ip6_fib.h:329 [inline] ndisc_router_discovery+0x1a24/0x1f3c net/ipv6/ndisc.c:1599 ndisc_rcv+0x392/0x3f4 net/ipv6/ndisc.c:1856 icmpv6_rcv+0xc3c/0xea2 net/ipv6/icmp.c:979 ip6_protocol_deliver_rcu+0x13a/0xdf6 net/ipv6/ip6_input.c:438 ip6_input_finish+0xe6/0x28e net/ipv6/ip6_input.c:483 NF_HOOK include/linux/netfilter.h:304 [inline] NF_HOOK include/linux/netfilter.h:298 [inline] ip6_input+0xbc/0x422 net/ipv6/ip6_input.c:492 ip6_mc_input+0x3ee/0xbb4 net/ipv6/ip6_input.c:586 dst_input include/net/dst.h:468 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline] NF_HOOK include/linux/netfilter.h:304 [inline] NF_HOOK include/linux/netfilter.h:298 [inline] ipv6_rcv+0x53c/0x5c2 net/ipv6/ip6_input.c:310 __netif_receive_skb_one_core+0xe8/0x132 net/core/dev.c:5523 __netif_receive_skb+0x2e/0xd0 net/core/dev.c:5637 netif_receive_skb_internal net/core/dev.c:5723 [inline] netif_receive_skb+0x174/0x7be net/core/dev.c:5782 tun_rx_batched+0x36c/0x43a drivers/net/tun.c:1555 tun_get_user+0x2056/0x2cd2 drivers/net/tun.c:2002 tun_chr_write_iter+0x96/0x15e drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:1985 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x3c8/0x5cc fs/read_write.c:584 ksys_write+0x104/0x226 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __riscv_sys_write+0x44/0x52 fs/read_write.c:646 syscall_handler+0x76/0xba arch/riscv/include/asm/syscall.h:90 do_trap_ecall_u+0x9c/0x9e arch/riscv/kernel/traps.c:320 ret_from_exception+0x0/0x64 arch/riscv/kernel/entry.S:102 Second to last potentially related work creation: stack_trace_save+0xa0/0xd2 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x6a mm/kasan/common.c:45 __kasan_record_aux_stack+0xf6/0x13e mm/kasan/generic.c:492 kasan_record_aux_stack_noalloc+0xe/0x16 mm/kasan/generic.c:502 __call_rcu_common.constprop.0+0x80/0x4d6 kernel/rcu/tree.c:2653 call_rcu+0xc/0x14 kernel/rcu/tree.c:2767 fib6_info_release include/net/ip6_fib.h:332 [inline] fib6_info_release include/net/ip6_fib.h:329 [inline] ndisc_router_discovery+0x1a24/0x1f3c net/ipv6/ndisc.c:1599 ndisc_rcv+0x392/0x3f4 net/ipv6/ndisc.c:1856 icmpv6_rcv+0xc3c/0xea2 net/ipv6/icmp.c:979 ip6_protocol_deliver_rcu+0x13a/0xdf6 net/ipv6/ip6_input.c:438 ip6_input_finish+0xe6/0x28e net/ipv6/ip6_input.c:483 NF_HOOK include/linux/netfilter.h:304 [inline] NF_HOOK include/linux/netfilter.h:298 [inline] ip6_input+0xbc/0x422 net/ipv6/ip6_input.c:492 ip6_mc_input+0x3ee/0xbb4 net/ipv6/ip6_input.c:586 dst_input include/net/dst.h:468 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline] NF_HOOK include/linux/netfilter.h:304 [inline] NF_HOOK include/linux/netfilter.h:298 [inline] ipv6_rcv+0x53c/0x5c2 net/ipv6/ip6_input.c:310 __netif_receive_skb_one_core+0xe8/0x132 net/core/dev.c:5523 __netif_receive_skb+0x2e/0xd0 net/core/dev.c:5637 netif_receive_skb_internal net/core/dev.c:5723 [inline] netif_receive_skb+0x174/0x7be net/core/dev.c:5782 tun_rx_batched+0x36c/0x43a drivers/net/tun.c:1555 tun_get_user+0x2056/0x2cd2 drivers/net/tun.c:2002 tun_chr_write_iter+0x96/0x15e drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:1985 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x3c8/0x5cc fs/read_write.c:584 ksys_write+0x104/0x226 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __riscv_sys_write+0x44/0x52 fs/read_write.c:646 syscall_handler+0x76/0xba arch/riscv/include/asm/syscall.h:90 do_trap_ecall_u+0x9c/0x9e arch/riscv/kernel/traps.c:320 ret_from_exception+0x0/0x64 arch/riscv/kernel/entry.S:102 The buggy address belongs to the object at ff60000032206000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 64 bytes inside of freed 512-byte region [ff60000032206000, ff60000032206200) The buggy address belongs to the physical page: page:ff1c000002c88100 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xb2204 head:ff1c000002c88100 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0 ksm flags: 0xffe000000000840(slab|head|node=0|zone=0|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 0ffe000000000840 ff60000008401780 ff1c000002403500 0000000000000003 raw: 0000000000000000 0000000080100010 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), pid 27946, tgid 27946 (kworker/u6:5), ts 5195984574200, free_ts 4944762724900 __set_page_owner+0x32/0x18a mm/page_owner.c:192 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x8c/0xe2 mm/page_alloc.c:1536 prep_new_page mm/page_alloc.c:1543 [inline] get_page_from_freelist+0x84a/0x121e mm/page_alloc.c:3170 __alloc_pages+0x19c/0x142e mm/page_alloc.c:4426 alloc_pages+0x126/0x252 mm/mempolicy.c:2298 alloc_slab_page mm/slub.c:1870 [inline] allocate_slab mm/slub.c:2017 [inline] new_slab+0x272/0x382 mm/slub.c:2070 ___slab_alloc+0x5b6/0xa92 mm/slub.c:3223 __slab_alloc.constprop.0+0x58/0x94 mm/slub.c:3322 __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0xf0/0x2e0 mm/slub.c:3517 kmalloc_trace+0x24/0x56 mm/slab_common.c:1114 kmalloc include/linux/slab.h:599 [inline] kzalloc include/linux/slab.h:720 [inline] alloc_bprm+0x4c/0x61e fs/exec.c:1514 kernel_execve+0x7e/0x2e8 fs/exec.c:1989 call_usermodehelper_exec_async+0x17e/0x27a kernel/umh.c:110 ret_from_fork+0xa/0x1c arch/riscv/kernel/entry.S:264 page last free stack trace: __reset_page_owner+0x4c/0xf8 mm/page_owner.c:149 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1136 [inline] free_unref_page_prepare+0x224/0x592 mm/page_alloc.c:2312 free_unref_page+0x5a/0x234 mm/page_alloc.c:2405 free_the_page mm/page_alloc.c:562 [inline] __free_pages+0x104/0x126 mm/page_alloc.c:4516 vfree+0x14c/0x68e mm/vmalloc.c:2842 snd_dma_vmalloc_free+0x2a/0x34 sound/core/memalloc.c:355 snd_dma_free_pages+0x44/0x58 sound/core/memalloc.c:126 do_free_pages sound/core/pcm_memory.c:93 [inline] do_free_pages sound/core/pcm_memory.c:88 [inline] snd_pcm_lib_free_pages+0xde/0x18c sound/core/pcm_memory.c:499 do_hw_free sound/core/pcm_native.c:876 [inline] snd_pcm_release_substream.part.0+0x1ca/0x1cc sound/core/pcm_native.c:2709 snd_pcm_release_substream+0x4c/0x60 sound/core/pcm_native.c:2703 snd_pcm_oss_release_file sound/core/oss/pcm_oss.c:2413 [inline] snd_pcm_oss_release_file sound/core/oss/pcm_oss.c:2405 [inline] snd_pcm_oss_release+0xee/0x1ac sound/core/oss/pcm_oss.c:2592 __fput+0x252/0x594 fs/file_table.c:384 ____fput+0x1a/0x24 fs/file_table.c:412 task_work_run+0x154/0x1ea kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x736/0x1770 kernel/exit.c:874 do_group_exit+0x8e/0x15e kernel/exit.c:1024 Memory state around the buggy address: ff60000032205f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ff60000032205f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ff60000032206000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ff60000032206080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ff60000032206100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================