================================================================== BUG: KASAN: slab-use-after-free in decode_session6+0x10e1/0x1950 net/xfrm/xfrm_policy.c:3460 Read of size 1 at addr ffff88804144d025 by task syz-executor.1/20897 CPU: 0 PID: 20897 Comm: syz-executor.1 Not tainted 6.6.0-rc3-syzkaller-00146-g9f3ebbef746f #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+0x11b2/0x2710 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:4889 [inline] netdev_start_xmit include/linux/netdevice.h:4903 [inline] xmit_one net/core/dev.c:3544 [inline] dev_hard_start_xmit+0x13d/0x6c0 net/core/dev.c:3560 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:3834 [inline] __dev_queue_xmit+0x24db/0x3d60 net/core/dev.c:4306 dev_queue_xmit include/linux/netdevice.h:3082 [inline] neigh_connected_output+0x42c/0x5d0 net/core/neighbour.c:1581 neigh_output include/net/neighbour.h:542 [inline] ip6_finish_output2+0x581/0x1700 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] rawv6_send_hdrinc net/ipv6/raw.c:655 [inline] rawv6_sendmsg+0x23a5/0x4100 net/ipv6/raw.c:908 inet_sendmsg+0x9d/0xe0 net/ipv4/af_inet.c:840 sock_sendmsg_nosec net/socket.c:730 [inline] sock_sendmsg+0xd9/0x180 net/socket.c:753 ____sys_sendmsg+0x2ac/0x940 net/socket.c:2541 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2595 __sys_sendmmsg+0x2a5/0x450 net/socket.c:2674 __compat_sys_sendmmsg net/compat.c:360 [inline] __do_compat_sys_sendmmsg net/compat.c:367 [inline] __se_compat_sys_sendmmsg net/compat.c:364 [inline] __ia32_compat_sys_sendmmsg+0x9d/0x100 net/compat.c:364 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 RIP: 0023:0xf7f65579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f7f605ac EFLAGS: 00000292 ORIG_RAX: 0000000000000159 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020002bc0 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 5195: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x81/0x90 mm/kasan/common.c:328 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] kmem_cache_alloc_node+0x180/0x3f0 mm/slub.c:3523 __alloc_skb+0x287/0x330 net/core/skbuff.c:640 alloc_skb_fclone include/linux/skbuff.h:1336 [inline] tcp_stream_alloc_skb+0x34/0x560 net/ipv4/tcp.c:869 tcp_sendmsg_locked+0xeae/0x3440 net/ipv4/tcp.c:1150 tcp_sendmsg+0x2e/0x40 net/ipv4/tcp.c:1336 inet_sendmsg+0x9d/0xe0 net/ipv4/af_inet.c:840 sock_sendmsg_nosec net/socket.c:730 [inline] sock_sendmsg+0xd9/0x180 net/socket.c:753 sock_write_iter+0x29b/0x3d0 net/socket.c:1141 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 ksys_write+0x1f0/0x250 fs/read_write.c:637 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 Freed by task 8097: 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+0xf0/0x480 mm/slub.c:3831 kfree_skbmem+0x166/0x1b0 net/core/skbuff.c:1031 __kfree_skb net/core/skbuff.c:1068 [inline] napi_consume_skb net/core/skbuff.c:1357 [inline] napi_consume_skb+0x1cc/0x2b0 net/core/skbuff.c:1339 free_old_xmit_skbs+0xf0/0x3d0 drivers/net/virtio_net.c:761 virtnet_poll_tx+0x268/0x630 drivers/net/virtio_net.c:2249 __napi_poll.constprop.0+0xb4/0x530 net/core/dev.c:6527 napi_poll net/core/dev.c:6594 [inline] net_rx_action+0x956/0xe90 net/core/dev.c:6727 __do_softirq+0x218/0x965 kernel/softirq.c:553 The buggy address belongs to the object at ffff88804144cf00 which belongs to the cache skbuff_fclone_cache of size 488 The buggy address is located 293 bytes inside of freed 488-byte region [ffff88804144cf00, ffff88804144d0e8) The buggy address belongs to the physical page: page:ffffea0001051300 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4144c head:ffffea0001051300 order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888019e4d780 ffffea0001e7e380 0000000000000008 raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5195, tgid 5037 (syz-fuzzer), ts 1122569616042, free_ts 1122016337209 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:2298 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+0x132/0x3f0 mm/slub.c:3523 __alloc_skb+0x287/0x330 net/core/skbuff.c:640 alloc_skb_fclone include/linux/skbuff.h:1336 [inline] tcp_stream_alloc_skb+0x34/0x560 net/ipv4/tcp.c:869 tcp_sendmsg_locked+0xeae/0x3440 net/ipv4/tcp.c:1150 tcp_sendmsg+0x2e/0x40 net/ipv4/tcp.c:1336 inet_sendmsg+0x9d/0xe0 net/ipv4/af_inet.c:840 sock_sendmsg_nosec net/socket.c:730 [inline] sock_sendmsg+0xd9/0x180 net/socket.c:753 sock_write_iter+0x29b/0x3d0 net/socket.c:1141 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 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 vm_area_dup+0x21/0x2f0 kernel/fork.c:500 dup_mmap+0x93c/0x1d80 kernel/fork.c:710 dup_mm kernel/fork.c:1686 [inline] copy_mm kernel/fork.c:1735 [inline] copy_process+0x6bff/0x73f0 kernel/fork.c:2501 kernel_clone+0xfd/0x920 kernel/fork.c:2909 __do_compat_sys_ia32_clone+0xb7/0xf0 arch/x86/kernel/sys_ia32.c:254 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Memory state around the buggy address: ffff88804144cf00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804144cf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88804144d000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804144d080: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff88804144d100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi