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BUG: KASAN: use-after-free in decode_session6 net/xfrm/xfrm_policy.c:3390 [inline]
BUG: KASAN: use-after-free in __xfrm_decode_session+0x1af8/0x26c0 net/xfrm/xfrm_policy.c:3482
Read of size 1 at addr ffff88809492d44d by task syz-executor.4/15113

CPU: 0 PID: 15113 Comm: syz-executor.4 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fb/0x318 lib/dump_stack.c:118
 print_address_description+0x75/0x5c0 mm/kasan/report.c:374
 __kasan_report+0x14b/0x1c0 mm/kasan/report.c:506
 kasan_report+0x26/0x50 mm/kasan/common.c:634
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/generic_report.c:129
 decode_session6 net/xfrm/xfrm_policy.c:3390 [inline]
 __xfrm_decode_session+0x1af8/0x26c0 net/xfrm/xfrm_policy.c:3482
 vti6_tnl_xmit+0x3ee/0x1710 net/ipv6/ip6_vti.c:531
 __netdev_start_xmit include/linux/netdevice.h:4413 [inline]
 netdev_start_xmit include/linux/netdevice.h:4427 [inline]
 xmit_one net/core/dev.c:3199 [inline]
 dev_hard_start_xmit+0x1c1/0x3f0 net/core/dev.c:3215
 sch_direct_xmit+0x1e5/0xd50 net/sched/sch_generic.c:313
 qdisc_restart net/sched/sch_generic.c:376 [inline]
 __qdisc_run+0xa7f/0x1b80 net/sched/sch_generic.c:384
 __dev_xmit_skb net/core/dev.c:3456 [inline]
 __dev_queue_xmit+0x1248/0x3010 net/core/dev.c:3761
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3825
 packet_snd net/packet/af_packet.c:2959 [inline]
 packet_sendmsg+0x4b77/0x63b0 net/packet/af_packet.c:2984
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg net/socket.c:657 [inline]
 ___sys_sendmsg+0x60d/0x910 net/socket.c:2311
 __sys_sendmmsg+0x239/0x470 net/socket.c:2413
 __do_sys_sendmmsg net/socket.c:2442 [inline]
 __se_sys_sendmmsg net/socket.c:2439 [inline]
 __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2439
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a219
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f2b7a546c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045a219
RDX: 00000000040001c0 RSI: 0000000020002b00 RDI: 0000000000000007
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2b7a5476d4
R13: 00000000004c7fb3 R14: 00000000004de3f8 R15: 00000000ffffffff

Allocated by task 13733:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc+0x11c/0x1b0 mm/kasan/common.c:510
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:524
 __do_kmalloc mm/slab.c:3655 [inline]
 __kmalloc_track_caller+0x253/0x340 mm/slab.c:3670
 kstrdup+0x34/0x70 mm/util.c:60
 smack_inode_init_security+0x3cf/0x490 security/smack/smack_lsm.c:1014
 security_inode_init_security+0xfe/0x310 security/security.c:985
 ext4_init_security+0x34/0x40 fs/ext4/xattr_security.c:57
 __ext4_new_inode+0x446c/0x5650 fs/ext4/ialloc.c:1160
 ext4_symlink+0x536/0xed0 fs/ext4/namei.c:3262
 vfs_symlink+0x36f/0x4f0 fs/namei.c:4119
 do_symlinkat+0x187/0x3f0 fs/namei.c:4146
 __do_sys_symlink fs/namei.c:4165 [inline]
 __se_sys_symlink fs/namei.c:4163 [inline]
 __x64_sys_symlink+0x60/0x70 fs/namei.c:4163
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 13733:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 kasan_set_free_info mm/kasan/common.c:332 [inline]
 __kasan_slab_free+0x12a/0x1e0 mm/kasan/common.c:471
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:480
 __cache_free mm/slab.c:3425 [inline]
 kfree+0x115/0x200 mm/slab.c:3756
 security_inode_init_security+0x281/0x310 security/security.c:999
 ext4_init_security+0x34/0x40 fs/ext4/xattr_security.c:57
 __ext4_new_inode+0x446c/0x5650 fs/ext4/ialloc.c:1160
 ext4_symlink+0x536/0xed0 fs/ext4/namei.c:3262
 vfs_symlink+0x36f/0x4f0 fs/namei.c:4119
 do_symlinkat+0x187/0x3f0 fs/namei.c:4146
 __do_sys_symlink fs/namei.c:4165 [inline]
 __se_sys_symlink fs/namei.c:4163 [inline]
 __x64_sys_symlink+0x60/0x70 fs/namei.c:4163
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88809492d440
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 13 bytes inside of
 32-byte region [ffff88809492d440, ffff88809492d460)
The buggy address belongs to the page:
page:ffffea0002524b40 refcount:1 mapcount:0 mapping:ffff8880aa4001c0 index:0xffff88809492dfc1
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea0002a16388 ffffea000150fd48 ffff8880aa4001c0
raw: ffff88809492dfc1 ffff88809492d000 000000010000003d 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809492d300: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff88809492d380: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff88809492d400: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
                                              ^
 ffff88809492d480: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff88809492d500: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
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