================================================================== BUG: KASAN: slab-out-of-bounds in decode_session6+0x10e1/0x1950 net/xfrm/xfrm_policy.c:3460 Read of size 1 at addr ffff88802c2f10a6 by task syz-executor.2/28995 CPU: 1 PID: 28995 Comm: syz-executor.2 Not tainted 6.6.0-rc5-syzkaller-01543-gee2a35fedbc9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 decode_session6+0x10e1/0x1950 net/xfrm/xfrm_policy.c:3460 __xfrm_decode_session+0x54/0xb0 net/xfrm/xfrm_policy.c:3566 xfrm_decode_session_reverse include/net/xfrm.h:1223 [inline] icmpv6_route_lookup+0x397/0x550 net/ipv6/icmp.c:388 icmp6_send+0x123c/0x2740 net/ipv6/icmp.c:595 __icmpv6_send include/linux/icmpv6.h:28 [inline] icmpv6_send include/linux/icmpv6.h:49 [inline] ip6_link_failure+0x31/0x5a0 net/ipv6/route.c:2787 dst_link_failure include/net/dst.h:437 [inline] ip6_tnl_xmit+0x4f9/0x3920 net/ipv6/ip6_tunnel.c:1268 ipxip6_tnl_xmit net/ipv6/ip6_tunnel.c:1384 [inline] ip6_tnl_start_xmit+0x6ef/0x1750 net/ipv6/ip6_tunnel.c:1432 __netdev_start_xmit include/linux/netdevice.h:4891 [inline] netdev_start_xmit include/linux/netdevice.h:4905 [inline] xmit_one net/core/dev.c:3548 [inline] dev_hard_start_xmit+0x13d/0x6c0 net/core/dev.c:3564 sch_direct_xmit+0x1ac/0xc20 net/sched/sch_generic.c:342 qdisc_restart net/sched/sch_generic.c:407 [inline] __qdisc_run+0x540/0x19d0 net/sched/sch_generic.c:415 __dev_xmit_skb net/core/dev.c:3838 [inline] __dev_queue_xmit+0x24a0/0x3d10 net/core/dev.c:4315 dev_queue_xmit include/linux/netdevice.h:3085 [inline] neigh_connected_output+0x42c/0x5d0 net/core/neighbour.c:1583 neigh_output include/net/neighbour.h:542 [inline] ip6_finish_output2+0x584/0x1700 net/ipv6/ip6_output.c:135 __ip6_finish_output net/ipv6/ip6_output.c:196 [inline] ip6_finish_output+0x485/0x1250 net/ipv6/ip6_output.c:207 NF_HOOK_COND include/linux/netfilter.h:293 [inline] ip6_output+0x1e2/0x530 net/ipv6/ip6_output.c:228 dst_output include/net/dst.h:458 [inline] NF_HOOK include/linux/netfilter.h:304 [inline] NF_HOOK include/linux/netfilter.h:298 [inline] ip6_xmit+0x128d/0x1d40 net/ipv6/ip6_output.c:343 inet6_csk_xmit+0x3c7/0x740 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x1a40/0x3b20 net/ipv4/tcp_output.c:1408 tcp_transmit_skb net/ipv4/tcp_output.c:1426 [inline] tcp_send_syn_data net/ipv4/tcp_output.c:3892 [inline] tcp_connect+0x210a/0x5430 net/ipv4/tcp_output.c:3957 tcp_v6_connect+0x1483/0x2000 net/ipv6/tcp_ipv6.c:338 __inet_stream_connect+0x38b/0xe20 net/ipv4/af_inet.c:676 tcp_sendmsg_fastopen+0x3d2/0x700 net/ipv4/tcp.c:1021 tcp_sendmsg_locked+0x1ef0/0x3440 net/ipv4/tcp.c:1073 tcp_sendmsg+0x2e/0x40 net/ipv4/tcp.c:1336 inet6_sendmsg+0x9d/0xe0 net/ipv6/af_inet6.c:657 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xd5/0x180 net/socket.c:745 __sys_sendto+0x255/0x340 net/socket.c:2194 __do_sys_sendto net/socket.c:2206 [inline] __se_sys_sendto net/socket.c:2202 [inline] __x64_sys_sendto+0xe0/0x1b0 net/socket.c:2202 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7ff2a6c7cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff2a7a840c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007ff2a6d9bf80 RCX: 00007ff2a6c7cae9 RDX: 0000000000000001 RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00007ff2a6cc847a R08: 0000000020b63fe4 R09: 000000000000001b R10: 0000000020008845 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007ff2a6d9bf80 R15: 00007ffc11fe71f8 Allocated by task 7119: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1023 [inline] __kmalloc_node_track_caller+0x61/0x100 mm/slab_common.c:1043 kmalloc_reserve+0xef/0x260 net/core/skbuff.c:581 __alloc_skb+0x12b/0x330 net/core/skbuff.c:650 alloc_skb include/linux/skbuff.h:1286 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x29e/0xc70 drivers/net/netdevsim/dev.c:850 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Freed by task 7119: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15b/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826 slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0xb8/0x2f0 mm/slub.c:3822 skb_kfree_head net/core/skbuff.c:949 [inline] skb_free_head+0x110/0x1b0 net/core/skbuff.c:961 skb_release_data+0x5ba/0x870 net/core/skbuff.c:991 skb_release_all net/core/skbuff.c:1057 [inline] __kfree_skb net/core/skbuff.c:1071 [inline] consume_skb net/core/skbuff.c:1287 [inline] consume_skb+0xd2/0x170 net/core/skbuff.c:1281 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x872/0xc70 drivers/net/netdevsim/dev.c:850 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 The buggy address belongs to the object at ffff88802c2f0000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 166 bytes to the right of allocated 4096-byte region [ffff88802c2f0000, ffff88802c2f1000) The buggy address belongs to the physical page: page:ffffea0000b0bc00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2c2f0 head:ffffea0000b0bc00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888012c42140 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 7119, tgid 7119 (kworker/0:10), ts 1673787341744, free_ts 1673766917646 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2cf/0x340 mm/page_alloc.c:1536 prep_new_page mm/page_alloc.c:1543 [inline] get_page_from_freelist+0xee0/0x2f20 mm/page_alloc.c:3170 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4426 alloc_pages+0x1a9/0x270 mm/mempolicy.c:2297 alloc_slab_page mm/slub.c:1870 [inline] allocate_slab+0x251/0x380 mm/slub.c:2017 new_slab mm/slub.c:2070 [inline] ___slab_alloc+0x8c7/0x1580 mm/slub.c:3223 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322 __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x131/0x340 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1022 [inline] __kmalloc_node_track_caller+0x50/0x100 mm/slab_common.c:1043 kmalloc_reserve+0xef/0x260 net/core/skbuff.c:581 __alloc_skb+0x12b/0x330 net/core/skbuff.c:650 alloc_skb include/linux/skbuff.h:1286 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x29e/0xc70 drivers/net/netdevsim/dev.c:850 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1136 [inline] free_unref_page_prepare+0x476/0xa40 mm/page_alloc.c:2312 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2405 __unfreeze_partials+0x21d/0x240 mm/slub.c:2655 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x18e/0x1d0 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x65/0x90 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook mm/slab.h:762 [inline] slab_alloc_node mm/slub.c:3478 [inline] slab_alloc mm/slub.c:3486 [inline] __kmem_cache_alloc_lru mm/slub.c:3493 [inline] kmem_cache_alloc+0x16c/0x3b0 mm/slub.c:3502 kmem_cache_zalloc include/linux/slab.h:710 [inline] alloc_buffer_head+0x21/0x140 fs/buffer.c:3023 folio_alloc_buffers+0x2e7/0x7f0 fs/buffer.c:935 folio_create_empty_buffers+0x36/0x470 fs/buffer.c:1648 ext4_block_write_begin+0xcc4/0xf10 fs/ext4/inode.c:1024 ext4_da_write_begin+0x40a/0x8c0 fs/ext4/inode.c:2890 generic_perform_write+0x278/0x600 mm/filemap.c:3969 ext4_buffered_write_iter+0x11f/0x3c0 fs/ext4/file.c:299 ext4_file_write_iter+0x7f7/0x1860 fs/ext4/file.c:717 call_write_iter include/linux/fs.h:1956 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x650/0xe40 fs/read_write.c:584 Memory state around the buggy address: ffff88802c2f0f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802c2f1000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88802c2f1080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88802c2f1100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802c2f1180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================