syzbot ci has tested the following series
[v1] Add IP6IP6 flowtable SW acceleration https://lore.kernel.org/all/20251207-b4-flowtable-offload-ip6ip6-v1-0-18e3ab... * [PATCH nf-next 1/5] netfilter: Introduce tunnel metadata info in nf_flowtable_ctx struct * [PATCH nf-next 2/5] netfilter: Modify nf_flow_skb_encap_protocol() to return int intead of bool * [PATCH nf-next 3/5] netfilter: flowtable: Add IP6IP6 rx sw acceleration * [PATCH nf-next 4/5] netfilter: flowtable: Add IP6IP6 tx sw acceleration * [PATCH nf-next 5/5] selftests: netfilter: nft_flowtable.sh: Add IP6IP6 flowtable selftest
and found the following issues: * KASAN: slab-use-after-free Read in nf_flow_skb_encap_protocol * general protection fault in ipv6_frag_rcv * general protection fault in nf_flow_offload_ipv6_hook
Full report is available here: https://ci.syzbot.org/series/24632ec9-06ab-4e09-8015-19822d83c6a9
***
KASAN: slab-use-after-free Read in nf_flow_skb_encap_protocol
tree: nf-next URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netfilter/nf-next.g... base: ff736a286116d462a4067ba258fa351bc0b4ed80 arch: amd64 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 config: https://ci.syzbot.org/builds/833219cc-e7e2-437d-b31c-1eb3666c1e93/config C repro: https://ci.syzbot.org/findings/afcab565-801f-4cde-a1c5-b1d327537871/c_repro syz repro: https://ci.syzbot.org/findings/afcab565-801f-4cde-a1c5-b1d327537871/syz_repr...
================================================================== BUG: KASAN: slab-use-after-free in nf_flow_ip6_tunnel_proto net/netfilter/nf_flow_table_ip.c:388 [inline] BUG: KASAN: slab-use-after-free in nf_flow_skb_encap_protocol+0x13a2/0x1540 net/netfilter/nf_flow_table_ip.c:438 Read of size 2 at addr ffff888175605eb6 by task syz.1.20/6010
CPU: 1 UID: 0 PID: 6010 Comm: syz.1.20 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 nf_flow_ip6_tunnel_proto net/netfilter/nf_flow_table_ip.c:388 [inline] nf_flow_skb_encap_protocol+0x13a2/0x1540 net/netfilter/nf_flow_table_ip.c:438 nf_flow_offload_ipv6_lookup net/netfilter/nf_flow_table_ip.c:1074 [inline] nf_flow_offload_ipv6_hook+0x13c/0x32a0 net/netfilter/nf_flow_table_ip.c:1102 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook_ingress include/linux/netfilter_netdev.h:34 [inline] nf_ingress net/core/dev.c:5900 [inline] __netif_receive_skb_core+0x241c/0x2f90 net/core/dev.c:5996 __netif_receive_skb_one_core net/core/dev.c:6135 [inline] __netif_receive_skb+0x72/0x380 net/core/dev.c:6250 netif_receive_skb_internal net/core/dev.c:6336 [inline] netif_receive_skb+0x1cb/0x790 net/core/dev.c:6395 tun_rx_batched+0x1b9/0x730 drivers/net/tun.c:1485 tun_get_user+0x2b65/0x3e90 drivers/net/tun.c:1953 tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1999 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f53b9d8f7c9 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:00007f53babe6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f53b9fe6090 RCX: 00007f53b9d8f7c9 RDX: 000000000000fdef RSI: 0000200000000340 RDI: 0000000000000003 RBP: 00007f53b9df297f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f53b9fe6128 R14: 00007f53b9fe6090 R15: 00007ffc1b120a08 </TASK>
Allocated by task 6010: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:342 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4978 [inline] slab_alloc_node mm/slub.c:5288 [inline] kmem_cache_alloc_node_noprof+0x433/0x710 mm/slub.c:5340 __alloc_skb+0x255/0x430 net/core/skbuff.c:679 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6712 sock_alloc_send_pskb+0x84d/0x980 net/core/sock.c:2995 tun_alloc_skb drivers/net/tun.c:1461 [inline] tun_get_user+0xa43/0x3e90 drivers/net/tun.c:1794 tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1999 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 6010: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2543 [inline] slab_free mm/slub.c:6642 [inline] kmem_cache_free+0x19b/0x690 mm/slub.c:6752 kfree_skb_reason include/linux/skbuff.h:1322 [inline] kfree_skb include/linux/skbuff.h:1331 [inline] dst_discard_out+0x1c/0x30 net/core/dst.c:32 nf_flow_ip6_tunnel_proto net/netfilter/nf_flow_table_ip.c:383 [inline] nf_flow_skb_encap_protocol+0x9c2/0x1540 net/netfilter/nf_flow_table_ip.c:438 nf_flow_offload_ipv6_lookup net/netfilter/nf_flow_table_ip.c:1074 [inline] nf_flow_offload_ipv6_hook+0x13c/0x32a0 net/netfilter/nf_flow_table_ip.c:1102 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook_ingress include/linux/netfilter_netdev.h:34 [inline] nf_ingress net/core/dev.c:5900 [inline] __netif_receive_skb_core+0x241c/0x2f90 net/core/dev.c:5996 __netif_receive_skb_one_core net/core/dev.c:6135 [inline] __netif_receive_skb+0x72/0x380 net/core/dev.c:6250 netif_receive_skb_internal net/core/dev.c:6336 [inline] netif_receive_skb+0x1cb/0x790 net/core/dev.c:6395 tun_rx_batched+0x1b9/0x730 drivers/net/tun.c:1485 tun_get_user+0x2b65/0x3e90 drivers/net/tun.c:1953 tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1999 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff888175605e00 which belongs to the cache skbuff_head_cache of size 240 The buggy address is located 182 bytes inside of freed 240-byte region [ffff888175605e00, ffff888175605ef0)
The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x175604 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 057ff00000000040 ffff8881036c4a00 dead000000000122 0000000000000000 raw: 0000000000000000 0000000080150015 00000000f5000000 0000000000000000 head: 057ff00000000040 ffff8881036c4a00 dead000000000122 0000000000000000 head: 0000000000000000 0000000080150015 00000000f5000000 0000000000000000 head: 057ff00000000001 ffffea0005d58101 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5922, tgid 5922 (syz-executor), ts 68256102142, free_ts 61484167308 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1845 prep_new_page mm/page_alloc.c:1853 [inline] get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3879 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5178 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3059 [inline] allocate_slab+0x96/0x350 mm/slub.c:3232 new_slab mm/slub.c:3286 [inline] ___slab_alloc+0xf56/0x1990 mm/slub.c:4655 __slab_alloc+0x65/0x100 mm/slub.c:4778 __slab_alloc_node mm/slub.c:4854 [inline] slab_alloc_node mm/slub.c:5276 [inline] kmem_cache_alloc_node_noprof+0x4c5/0x710 mm/slub.c:5340 __alloc_skb+0x255/0x430 net/core/skbuff.c:679 alloc_skb include/linux/skbuff.h:1383 [inline] nlmsg_new include/net/netlink.h:1055 [inline] inet_ifmcaddr_notify+0x7e/0x150 net/ipv4/igmp.c:1481 ____ip_mc_inc_group+0x9b8/0xde0 net/ipv4/igmp.c:1564 __ip_mc_inc_group net/ipv4/igmp.c:1573 [inline] ip_mc_inc_group net/ipv4/igmp.c:1579 [inline] ip_mc_up+0x125/0x300 net/ipv4/igmp.c:1880 inetdev_event+0xfb3/0x15b0 net/ipv4/devinet.c:1630 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:9802 page last free pid 5811 tgid 5811 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2901 __slab_free+0x2e7/0x390 mm/slub.c:5970 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4978 [inline] slab_alloc_node mm/slub.c:5288 [inline] kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5295 ptlock_alloc+0x20/0x70 mm/memory.c:7302 ptlock_init include/linux/mm.h:3059 [inline] pagetable_pte_ctor include/linux/mm.h:3113 [inline] __pte_alloc_one_noprof include/asm-generic/pgalloc.h:78 [inline] pte_alloc_one+0x7a/0x310 arch/x86/mm/pgtable.c:18 __do_fault+0xd1/0x390 mm/memory.c:5276 do_shared_fault mm/memory.c:5780 [inline] do_fault mm/memory.c:5854 [inline] do_pte_missing mm/memory.c:4362 [inline] handle_pte_fault mm/memory.c:6195 [inline] __handle_mm_fault+0x1847/0x5400 mm/memory.c:6336 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6505 do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
Memory state around the buggy address: ffff888175605d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888175605e00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888175605e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
^ ffff888175605f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888175605f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================
***
general protection fault in ipv6_frag_rcv
tree: nf-next URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netfilter/nf-next.g... base: ff736a286116d462a4067ba258fa351bc0b4ed80 arch: amd64 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 config: https://ci.syzbot.org/builds/833219cc-e7e2-437d-b31c-1eb3666c1e93/config C repro: https://ci.syzbot.org/findings/bac8a298-33d8-4b3a-9f63-a0a2373aaab2/c_repro syz repro: https://ci.syzbot.org/findings/bac8a298-33d8-4b3a-9f63-a0a2373aaab2/syz_repr...
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 UID: 0 PID: 5982 Comm: syz.1.20 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:dst_dev include/net/dst.h:571 [inline] RIP: 0010:skb_dst_dev include/net/dst.h:586 [inline] RIP: 0010:skb_dst_dev_net include/net/dst.h:596 [inline] RIP: 0010:ipv6_frag_rcv+0x19c/0x2a20 net/ipv6/reassembly.c:328 Code: 5c 24 08 4c 89 74 24 10 48 8b 44 24 60 42 80 3c 28 00 74 08 48 89 df e8 42 15 21 f8 48 8b 03 49 89 c6 49 83 e6 fe 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 f7 e8 25 15 21 f8 bb 08 01 00 00 49 03 RSP: 0018:ffffc90003776d20 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88816d87a1d8 RCX: ffff88816bf65700 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90003776f08 R08: ffffea0006d29400 R09: 0000000b00007ff5 R10: ffffea0006d29400 R11: ffffffff8a04b090 R12: 0000000000000040 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff888173607480 FS: 00007fa70abdd6c0(0000) GS:ffff8882a9f2e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000010000 CR3: 0000000112fa8000 CR4: 00000000000006f0 Call Trace: <TASK> nf_flow_ip6_tunnel_proto net/netfilter/nf_flow_table_ip.c:383 [inline] nf_flow_skb_encap_protocol+0x9c2/0x1540 net/netfilter/nf_flow_table_ip.c:438 nf_flow_offload_ipv6_lookup net/netfilter/nf_flow_table_ip.c:1074 [inline] nf_flow_offload_ipv6_hook+0x13c/0x32a0 net/netfilter/nf_flow_table_ip.c:1102 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook_ingress include/linux/netfilter_netdev.h:34 [inline] nf_ingress net/core/dev.c:5900 [inline] __netif_receive_skb_core+0x241c/0x2f90 net/core/dev.c:5996 __netif_receive_skb_one_core net/core/dev.c:6135 [inline] __netif_receive_skb+0x72/0x380 net/core/dev.c:6250 netif_receive_skb_internal net/core/dev.c:6336 [inline] netif_receive_skb+0x1cb/0x790 net/core/dev.c:6395 tun_rx_batched+0x1b9/0x730 drivers/net/tun.c:1485 tun_get_user+0x2b65/0x3e90 drivers/net/tun.c:1953 tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1999 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa70b58f7c9 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:00007fa70abdd038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fa70b7e6090 RCX: 00007fa70b58f7c9 RDX: 000000000000fdef RSI: 0000200000000340 RDI: 0000000000000003 RBP: 00007fa70b5f297f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa70b7e6128 R14: 00007fa70b7e6090 R15: 00007ffcd9538b88 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:dst_dev include/net/dst.h:571 [inline] RIP: 0010:skb_dst_dev include/net/dst.h:586 [inline] RIP: 0010:skb_dst_dev_net include/net/dst.h:596 [inline] RIP: 0010:ipv6_frag_rcv+0x19c/0x2a20 net/ipv6/reassembly.c:328 Code: 5c 24 08 4c 89 74 24 10 48 8b 44 24 60 42 80 3c 28 00 74 08 48 89 df e8 42 15 21 f8 48 8b 03 49 89 c6 49 83 e6 fe 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 f7 e8 25 15 21 f8 bb 08 01 00 00 49 03 RSP: 0018:ffffc90003776d20 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88816d87a1d8 RCX: ffff88816bf65700 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90003776f08 R08: ffffea0006d29400 R09: 0000000b00007ff5 R10: ffffea0006d29400 R11: ffffffff8a04b090 R12: 0000000000000040 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff888173607480 FS: 00007fa70abdd6c0(0000) GS:ffff8882a9f2e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000010000 CR3: 0000000112fa8000 CR4: 00000000000006f0 ---------------- Code disassembly (best guess): 0: 5c pop %rsp 1: 24 08 and $0x8,%al 3: 4c 89 74 24 10 mov %r14,0x10(%rsp) 8: 48 8b 44 24 60 mov 0x60(%rsp),%rax d: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) 12: 74 08 je 0x1c 14: 48 89 df mov %rbx,%rdi 17: e8 42 15 21 f8 call 0xf821155e 1c: 48 8b 03 mov (%rbx),%rax 1f: 49 89 c6 mov %rax,%r14 22: 49 83 e6 fe and $0xfffffffffffffffe,%r14 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 4c 89 f7 mov %r14,%rdi 34: e8 25 15 21 f8 call 0xf821155e 39: bb 08 01 00 00 mov $0x108,%ebx 3e: 49 rex.WB 3f: 03 .byte 0x3
***
general protection fault in nf_flow_offload_ipv6_hook
tree: nf-next URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netfilter/nf-next.g... base: ff736a286116d462a4067ba258fa351bc0b4ed80 arch: amd64 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 config: https://ci.syzbot.org/builds/833219cc-e7e2-437d-b31c-1eb3666c1e93/config C repro: https://ci.syzbot.org/findings/bee4a66a-8f79-4936-9f6e-7f9e229693c9/c_repro syz repro: https://ci.syzbot.org/findings/bee4a66a-8f79-4936-9f6e-7f9e229693c9/syz_repr...
Oops: general protection fault, probably for non-canonical address 0xdffffc000000000c: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000060-0x0000000000000067] CPU: 1 UID: 0 PID: 5978 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:nf_flow_offload_ipv6_forward net/netfilter/nf_flow_table_ip.c:1027 [inline] RIP: 0010:nf_flow_offload_ipv6_hook+0x2f3/0x32a0 net/netfilter/nf_flow_table_ip.c:1106 Code: 85 c6 03 00 00 e8 6d f0 31 f8 41 bc 14 00 00 00 e9 af 02 00 00 48 8d 4b 60 48 89 4c 24 18 48 c1 e9 03 48 89 8c 24 90 00 00 00 <42> 0f b6 04 21 84 c0 0f 85 de 23 00 00 44 0f b7 73 60 41 83 e6 03 RSP: 0018:ffffc900031d6fe0 EFLAGS: 00010206 RAX: ffffffff898e1101 RBX: 0000000000000002 RCX: 000000000000000c RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000 RBP: ffffc900031d73e0 R08: ffffffff8f7d1e77 R09: 1ffffffff1efa3ce R10: dffffc0000000000 R11: fffffbfff1efa3cf R12: dffffc0000000000 R13: 1ffff9200063ae1c R14: ffff88816cfc5680 R15: ffffc900031d72e0 FS: 00007fd7653a06c0(0000) GS:ffff8882a9f2e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000010000 CR3: 000000011342a000 CR4: 00000000000006f0 Call Trace: <TASK> nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook_ingress include/linux/netfilter_netdev.h:34 [inline] nf_ingress net/core/dev.c:5900 [inline] __netif_receive_skb_core+0x241c/0x2f90 net/core/dev.c:5996 __netif_receive_skb_one_core net/core/dev.c:6135 [inline] __netif_receive_skb+0x72/0x380 net/core/dev.c:6250 netif_receive_skb_internal net/core/dev.c:6336 [inline] netif_receive_skb+0x1cb/0x790 net/core/dev.c:6395 tun_rx_batched+0x1b9/0x730 drivers/net/tun.c:1485 tun_get_user+0x2b65/0x3e90 drivers/net/tun.c:1953 tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1999 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd76458f7c9 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:00007fd7653a0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fd7647e6090 RCX: 00007fd76458f7c9 RDX: 000000000000fdef RSI: 0000200000000380 RDI: 0000000000000003 RBP: 00007fd7645f297f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd7647e6128 R14: 00007fd7647e6090 R15: 00007ffde1f0b2b8 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:nf_flow_offload_ipv6_forward net/netfilter/nf_flow_table_ip.c:1027 [inline] RIP: 0010:nf_flow_offload_ipv6_hook+0x2f3/0x32a0 net/netfilter/nf_flow_table_ip.c:1106 Code: 85 c6 03 00 00 e8 6d f0 31 f8 41 bc 14 00 00 00 e9 af 02 00 00 48 8d 4b 60 48 89 4c 24 18 48 c1 e9 03 48 89 8c 24 90 00 00 00 <42> 0f b6 04 21 84 c0 0f 85 de 23 00 00 44 0f b7 73 60 41 83 e6 03 RSP: 0018:ffffc900031d6fe0 EFLAGS: 00010206 RAX: ffffffff898e1101 RBX: 0000000000000002 RCX: 000000000000000c RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000 RBP: ffffc900031d73e0 R08: ffffffff8f7d1e77 R09: 1ffffffff1efa3ce R10: dffffc0000000000 R11: fffffbfff1efa3cf R12: dffffc0000000000 R13: 1ffff9200063ae1c R14: ffff88816cfc5680 R15: ffffc900031d72e0 FS: 00007fd7653a06c0(0000) GS:ffff8882a9f2e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000010000 CR3: 000000011342a000 CR4: 00000000000006f0 ---------------- Code disassembly (best guess): 0: 85 c6 test %eax,%esi 2: 03 00 add (%rax),%eax 4: 00 e8 add %ch,%al 6: 6d insl (%dx),%es:(%rdi) 7: f0 31 f8 lock xor %edi,%eax a: 41 bc 14 00 00 00 mov $0x14,%r12d 10: e9 af 02 00 00 jmp 0x2c4 15: 48 8d 4b 60 lea 0x60(%rbx),%rcx 19: 48 89 4c 24 18 mov %rcx,0x18(%rsp) 1e: 48 c1 e9 03 shr $0x3,%rcx 22: 48 89 8c 24 90 00 00 mov %rcx,0x90(%rsp) 29: 00 * 2a: 42 0f b6 04 21 movzbl (%rcx,%r12,1),%eax <-- trapping instruction 2f: 84 c0 test %al,%al 31: 0f 85 de 23 00 00 jne 0x2415 37: 44 0f b7 73 60 movzwl 0x60(%rbx),%r14d 3c: 41 83 e6 03 and $0x3,%r14d
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