================================================================== BUG: KASAN: slab-out-of-bounds in decode_session6 net/xfrm/xfrm_policy.c:3413 [inline] BUG: KASAN: slab-out-of-bounds in __xfrm_decode_session+0x17ae/0x1fa0 net/xfrm/xfrm_policy.c:3520 Read of size 1 at addr ffff888024625ea9 by task syz.3.1181/9554 CPU: 0 PID: 9554 Comm: syz.3.1181 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 decode_session6 net/xfrm/xfrm_policy.c:3413 [inline] __xfrm_decode_session+0x17ae/0x1fa0 net/xfrm/xfrm_policy.c:3520 xfrm_decode_session_reverse include/net/xfrm.h:1170 [inline] icmpv6_route_lookup+0x3ea/0x5a0 net/ipv6/icmp.c:394 icmp6_send+0xff2/0x1990 net/ipv6/icmp.c:601 __icmpv6_send include/linux/icmpv6.h:28 [inline] icmpv6_send include/linux/icmpv6.h:49 [inline] ip6_link_failure+0x35/0x490 net/ipv6/route.c:2789 dst_link_failure include/net/dst.h:422 [inline] ip6_tnl_xmit+0x671/0x23e0 net/ipv6/ip6_tunnel.c:1279 ipxip6_tnl_xmit net/ipv6/ip6_tunnel.c:1395 [inline] ip6_tnl_start_xmit+0xd27/0x12d0 net/ipv6/ip6_tunnel.c:1444 __netdev_start_xmit include/linux/netdevice.h:5036 [inline] netdev_start_xmit include/linux/netdevice.h:5050 [inline] xmit_one net/core/dev.c:3662 [inline] dev_hard_start_xmit+0x2a5/0x7e0 net/core/dev.c:3678 sch_direct_xmit+0x25a/0x4b0 net/sched/sch_generic.c:345 qdisc_restart net/sched/sch_generic.c:410 [inline] __qdisc_run+0xa7e/0x1490 net/sched/sch_generic.c:418 __dev_xmit_skb net/core/dev.c:3955 [inline] __dev_queue_xmit+0xe3d/0x2f80 net/core/dev.c:4266 neigh_output include/net/neighbour.h:509 [inline] ip6_finish_output2+0x108c/0x1510 net/ipv6/ip6_output.c:130 ip6_fragment+0x133d/0x1ee0 net/ipv6/ip6_output.c:998 dst_output include/net/dst.h:452 [inline] NF_HOOK include/linux/netfilter.h:302 [inline] ip6_xmit+0x109b/0x16d0 net/ipv6/ip6_output.c:338 sctp_v6_xmit+0x985/0x11b0 net/sctp/ipv6.c:250 sctp_packet_transmit+0x239c/0x2910 net/sctp/output.c:652 sctp_packet_singleton+0x231/0x330 net/sctp/outqueue.c:780 sctp_outq_flush_ctrl net/sctp/outqueue.c:911 [inline] sctp_outq_flush+0x4ac/0x3100 net/sctp/outqueue.c:1209 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:-1 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline] sctp_do_sm+0x4ee2/0x55f0 net/sctp/sm_sideeffect.c:1170 sctp_primitive_ASSOCIATE+0x91/0xc0 net/sctp/primitive.c:73 __sctp_connect+0x94b/0xd80 net/sctp/socket.c:1232 __sctp_setsockopt_connectx net/sctp/socket.c:1334 [inline] sctp_getsockopt_connectx3+0x2ee/0x470 net/sctp/socket.c:1419 sctp_getsockopt+0x3ab/0x8a0 net/sctp/socket.c:8132 __sys_getsockopt+0x1b0/0x230 net/socket.c:2256 __do_sys_getsockopt net/socket.c:2271 [inline] __se_sys_getsockopt net/socket.c:2268 [inline] __x64_sys_getsockopt+0xb1/0xc0 net/socket.c:2268 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fa96b317e59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa969571028 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 00007fa96b590fa0 RCX: 00007fa96b317e59 RDX: 000000000000006f RSI: 0000000000000084 RDI: 0000000000000005 RBP: 00007fa96b3add6f R08: 0000200000000040 R09: 0000000000000000 R10: 0000200000000280 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa96b591038 R14: 00007fa96b590fa0 R15: 00007ffdf8481e98 Allocated by task 3560: 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 mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:612 [inline] tomoyo_realpath_from_path+0x118/0x610 security/tomoyo/realpath.c:254 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x1eb/0x410 security/tomoyo/file.c:771 security_file_open+0x5e/0xa0 security/security.c:1669 do_dentry_open+0x322/0xf80 fs/open.c:813 do_open fs/namei.c:3616 [inline] path_openat+0x26f5/0x2fa0 fs/namei.c:3750 do_filp_open+0x1e2/0x410 fs/namei.c:3777 do_sys_openat2+0x150/0x4b0 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 3560: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 tomoyo_realpath_from_path+0x5d8/0x610 security/tomoyo/realpath.c:291 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x1eb/0x410 security/tomoyo/file.c:771 security_file_open+0x5e/0xa0 security/security.c:1669 do_dentry_open+0x322/0xf80 fs/open.c:813 do_open fs/namei.c:3616 [inline] path_openat+0x26f5/0x2fa0 fs/namei.c:3750 do_filp_open+0x1e2/0x410 fs/namei.c:3777 do_sys_openat2+0x150/0x4b0 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff888024624000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 3753 bytes to the right of 4096-byte region [ffff888024624000, ffff888024625000) The buggy address belongs to the page: page:ffffea0000918800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x24620 head:ffffea0000918800 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 0000000200000001 ffff888016c42140 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 0x1d2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4179, ts 148340372600, free_ts 148247916099 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x80a/0xdd0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] slab_alloc mm/slub.c:3233 [inline] __kmalloc+0x1cd/0x330 mm/slub.c:4408 kmalloc include/linux/slab.h:612 [inline] tomoyo_realpath_from_path+0x118/0x610 security/tomoyo/realpath.c:254 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path2_perm+0x2a0/0x840 security/tomoyo/file.c:923 tomoyo_path_rename+0xfd/0x150 security/tomoyo/tomoyo.c:278 security_path_rename+0x1dc/0x280 security/security.c:1206 do_renameat2+0x69b/0xf60 fs/namei.c:4980 __do_sys_rename fs/namei.c:5039 [inline] __se_sys_rename fs/namei.c:5037 [inline] __x64_sys_rename+0x82/0x90 fs/namei.c:5037 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396 free_slab mm/slub.c:2020 [inline] discard_slab mm/slub.c:2026 [inline] __unfreeze_partials+0x1a5/0x200 mm/slub.c:2512 put_cpu_partial+0x12d/0x190 mm/slub.c:2592 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] __kmalloc_track_caller+0x125/0x330 mm/slub.c:4930 kmemdup+0x22/0x50 mm/util.c:128 shmem_symlink+0x155/0x6c0 mm/shmem.c:3096 vfs_symlink+0x247/0x3d0 fs/namei.c:4437 do_symlinkat+0x1ab/0x6b0 fs/namei.c:4466 __do_sys_symlinkat fs/namei.c:4483 [inline] __se_sys_symlinkat fs/namei.c:4480 [inline] __x64_sys_symlinkat+0x95/0xa0 fs/namei.c:4480 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff888024625d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888024625e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888024625e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888024625f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888024625f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================