================================================================== BUG: KASAN: slab-out-of-bounds in pskb_expand_head+0x1c4/0x1064 net/core/skbuff.c:1714 Write of size 48 at addr ffff0000c0fdfdc0 by task kworker/1:3/3549 CPU: 1 PID: 3549 Comm: kworker/1:3 Not tainted 5.15.111-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Workqueue: mld mld_ifc_work Call trace: dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 print_address_description+0x7c/0x3f0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x174/0x1e4 mm/kasan/report.c:451 kasan_check_range+0x274/0x2b4 mm/kasan/generic.c:189 memcpy+0xb4/0xe8 mm/kasan/shadow.c:66 pskb_expand_head+0x1c4/0x1064 net/core/skbuff.c:1714 __skb_cow include/linux/skbuff.h:3365 [inline] skb_cow_head include/linux/skbuff.h:3399 [inline] batadv_skb_head_push+0x158/0x1e8 net/batman-adv/soft-interface.c:73 batadv_interface_tx+0xb74/0x12d8 net/batman-adv/soft-interface.c:330 __netdev_start_xmit include/linux/netdevice.h:5019 [inline] netdev_start_xmit include/linux/netdevice.h:5033 [inline] xmit_one net/core/dev.c:3592 [inline] dev_hard_start_xmit+0x2bc/0x92c net/core/dev.c:3608 __dev_queue_xmit+0x13a8/0x2a6c net/core/dev.c:4223 dev_queue_xmit+0x24/0x34 net/core/dev.c:4256 neigh_hh_output include/net/neighbour.h:500 [inline] neigh_output include/net/neighbour.h:514 [inline] ip6_finish_output2+0x1310/0x1c48 net/ipv6/ip6_output.c:126 __ip6_finish_output+0x518/0x67c net/ipv6/ip6_output.c:191 ip6_finish_output+0x40/0x218 net/ipv6/ip6_output.c:201 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x270/0x594 net/ipv6/ip6_output.c:224 dst_output include/net/dst.h:449 [inline] NF_HOOK+0x160/0x4ec include/linux/netfilter.h:307 mld_sendpack+0x828/0x1264 net/ipv6/mcast.c:1820 mld_send_cr net/ipv6/mcast.c:2121 [inline] mld_ifc_work+0x85c/0xb9c net/ipv6/mcast.c:2653 process_one_work+0x790/0x11b8 kernel/workqueue.c:2307 worker_thread+0x910/0x1034 kernel/workqueue.c:2454 kthread+0x37c/0x45c kernel/kthread.c:319 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 Allocated by task 3549: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc+0xbc/0xfc mm/kasan/common.c:513 __kasan_kmalloc+0x10/0x1c mm/kasan/common.c:522 kasan_kmalloc include/linux/kasan.h:264 [inline] __kmalloc_node_track_caller+0x234/0x448 mm/slub.c:4963 kmalloc_reserve+0xe8/0x270 net/core/skbuff.c:356 __alloc_skb+0x1a4/0x584 net/core/skbuff.c:427 alloc_skb include/linux/skbuff.h:1167 [inline] alloc_skb_with_frags+0xb4/0x58c net/core/skbuff.c:6119 sock_alloc_send_pskb+0x7a8/0x8c0 net/core/sock.c:2497 sock_alloc_send_skb+0x44/0x58 net/core/sock.c:2514 mld_newpack+0x170/0x820 net/ipv6/mcast.c:1748 add_grhead net/ipv6/mcast.c:1851 [inline] add_grec+0x1164/0x1528 net/ipv6/mcast.c:1989 mld_send_cr net/ipv6/mcast.c:2115 [inline] mld_ifc_work+0x710/0xb9c net/ipv6/mcast.c:2653 process_one_work+0x790/0x11b8 kernel/workqueue.c:2307 worker_thread+0x910/0x1034 kernel/workqueue.c:2454 kthread+0x37c/0x45c kernel/kthread.c:319 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 Last potentially related work creation: kasan_save_stack+0x38/0x68 mm/kasan/common.c:38 kasan_record_aux_stack+0xd4/0x11c mm/kasan/generic.c:348 kvfree_call_rcu+0xb8/0x684 kernel/rcu/tree.c:3560 drop_sysctl_table+0x274/0x3a0 fs/proc/proc_sysctl.c:1680 drop_sysctl_table+0x284/0x3a0 fs/proc/proc_sysctl.c:1683 unregister_sysctl_table+0x94/0x130 fs/proc/proc_sysctl.c:1718 unregister_net_sysctl_table+0x20/0x30 net/sysctl_net.c:175 mpls_dev_sysctl_unregister+0x88/0xc0 net/mpls/af_mpls.c:1445 mpls_dev_notify+0x538/0x770 net/mpls/af_mpls.c:1663 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:391 call_netdevice_notifiers_info net/core/dev.c:1998 [inline] call_netdevice_notifiers_extack net/core/dev.c:2010 [inline] call_netdevice_notifiers net/core/dev.c:2024 [inline] unregister_netdevice_many+0xec4/0x189c net/core/dev.c:11065 ip6_tnl_exit_batch_net+0x57c/0x5cc net/ipv6/ip6_tunnel.c:2312 ops_exit_list net/core/net_namespace.c:174 [inline] cleanup_net+0x5e0/0x9bc net/core/net_namespace.c:596 process_one_work+0x790/0x11b8 kernel/workqueue.c:2307 worker_thread+0x910/0x1034 kernel/workqueue.c:2454 kthread+0x37c/0x45c kernel/kthread.c:319 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 The buggy address belongs to the object at ffff0000c0fdfc00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 192 bytes to the right of 256-byte region [ffff0000c0fdfc00, ffff0000c0fdfd00) The buggy address belongs to the page: page:0000000027784579 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x100fde head:0000000027784579 order:1 compound_mapcount:0 flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000010200 fffffc0003080c80 0000000300000003 ffff0000c0002480 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000c0fdfc80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000c0fdfd00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff0000c0fdfd80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff0000c0fdfe00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000c0fdfe80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== Unable to handle kernel paging request at virtual address dfff800000000000 Mem abort info: ESR = 0x0000000096000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x06: level 2 translation fault Data abort info: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 [dfff800000000000] address between user and kernel address ranges Internal error: Oops: 96000006 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 3549 Comm: kworker/1:3 Tainted: G B 5.15.111-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Workqueue: mld mld_ifc_work pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : _compound_head include/linux/page-flags.h:196 [inline] pc : put_page+0x2c/0x21c include/linux/mm.h:1233 lr : put_page+0x24/0x21c include/linux/mm.h:1232 sp : ffff80001f737060 x29: ffff80001f737060 x28: ffff0001c0fdfdf0 x27: 1fffe0001924014f x26: dfff800000000000 x25: ffffffffffffffff x24: 1fffe000381fbfb8 x23: ffff0001c0fdfdf0 x22: 0000000000000000 x21: dfff800000000000 x20: 0000000000000007 x19: ffffffffffffffff x18: 0000000000000402 x17: ff80800008334714 x16: ffff800011942c14 x15: ffff800008334714 x14: 00000000ffffffff x13: ffffffffffffffff x12: 0000000000000000 x11: ff8080000fd21128 x10: 0000000000000000 x9 : ffff80000fd21128 x8 : 0000000000000000 x7 : 0000000000000000 x6 : ffff80000fd15534 x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff80000fd0c0d4 x2 : 0000000000000001 x1 : 0000000000000000 x0 : ffffffffffffffff Call trace: _compound_head include/linux/page-flags.h:196 [inline] put_page+0x2c/0x21c include/linux/mm.h:1233 __skb_frag_unref include/linux/skbuff.h:3219 [inline] skb_release_data+0x2e4/0x5fc net/core/skbuff.c:672 skb_release_all net/core/skbuff.c:742 [inline] __kfree_skb net/core/skbuff.c:756 [inline] consume_skb+0x138/0x40c net/core/skbuff.c:914 batadv_send_bcast_packet+0x44/0x58 net/batman-adv/send.c:999 batadv_interface_tx+0xcec/0x12d8 net/batman-adv/soft-interface.c:351 __netdev_start_xmit include/linux/netdevice.h:5019 [inline] netdev_start_xmit include/linux/netdevice.h:5033 [inline] xmit_one net/core/dev.c:3592 [inline] dev_hard_start_xmit+0x2bc/0x92c net/core/dev.c:3608 __dev_queue_xmit+0x13a8/0x2a6c net/core/dev.c:4223 dev_queue_xmit+0x24/0x34 net/core/dev.c:4256 neigh_hh_output include/net/neighbour.h:500 [inline] neigh_output include/net/neighbour.h:514 [inline] ip6_finish_output2+0x1310/0x1c48 net/ipv6/ip6_output.c:126 __ip6_finish_output+0x518/0x67c net/ipv6/ip6_output.c:191 ip6_finish_output+0x40/0x218 net/ipv6/ip6_output.c:201 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x270/0x594 net/ipv6/ip6_output.c:224 dst_output include/net/dst.h:449 [inline] NF_HOOK+0x160/0x4ec include/linux/netfilter.h:307 mld_sendpack+0x828/0x1264 net/ipv6/mcast.c:1820 mld_send_cr net/ipv6/mcast.c:2121 [inline] mld_ifc_work+0x85c/0xb9c net/ipv6/mcast.c:2653 process_one_work+0x790/0x11b8 kernel/workqueue.c:2307 worker_thread+0x910/0x1034 kernel/workqueue.c:2454 kthread+0x37c/0x45c kernel/kthread.c:319 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 Code: f2fbfff5 961e7d13 91002274 d343fe88 (38756908) ---[ end trace 62ea86ad67171d3b ]--- ---------------- Code disassembly (best guess): 0: f2fbfff5 movk x21, #0xdfff, lsl #48 4: 961e7d13 bl 0xfffffffff879f450 8: 91002274 add x20, x19, #0x8 c: d343fe88 lsr x8, x20, #3 * 10: 38756908 ldrb w8, [x8, x21] <-- trapping instruction