================================================================== BUG: KASAN: use-after-free in tipc_recvmsg+0xf77/0xf90 net/tipc/socket.c:1979 Read of size 4 at addr ffff888021405440 by task syz-executor.2/12888 CPU: 0 PID: 12888 Comm: syz-executor.2 Not tainted 5.14.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105 print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:233 __kasan_report mm/kasan/report.c:419 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:436 tipc_recvmsg+0xf77/0xf90 net/tipc/socket.c:1979 sock_recvmsg_nosec net/socket.c:943 [inline] sock_recvmsg net/socket.c:961 [inline] sock_recvmsg net/socket.c:957 [inline] ____sys_recvmsg+0x2c4/0x600 net/socket.c:2606 ___sys_recvmsg+0x127/0x200 net/socket.c:2648 do_recvmmsg+0x24d/0x6d0 net/socket.c:2742 __sys_recvmmsg net/socket.c:2823 [inline] __do_sys_recvmmsg net/socket.c:2844 [inline] __se_sys_recvmmsg net/socket.c:2837 [inline] __x64_sys_recvmmsg+0x17d/0x260 net/socket.c:2837 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665e9 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7da87d7188 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9 RDX: 0000000000000009 RSI: 0000000020003240 RDI: 0000000000000004 RBP: 00000000004bfcc4 R08: 0000000020003480 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffe84f23c9f R14: 00007f7da87d7300 R15: 0000000000022000 Allocated by task 12870: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x84/0xa0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook mm/slab.h:519 [inline] slab_alloc_node mm/slub.c:2956 [inline] kmem_cache_alloc_node+0x266/0x3e0 mm/slub.c:2992 __alloc_skb+0x20b/0x340 net/core/skbuff.c:414 alloc_skb_fclone include/linux/skbuff.h:1162 [inline] tipc_buf_acquire+0x25/0xe0 net/tipc/msg.c:72 tipc_msg_create+0x32/0x1f0 net/tipc/msg.c:104 __tipc_shutdown+0xb7f/0xe90 net/tipc/socket.c:591 tipc_release+0x13f/0x1a80 net/tipc/socket.c:640 __sock_release+0xcd/0x280 net/socket.c:648 sock_close+0x18/0x20 net/socket.c:1295 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 12888: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xfb/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1625 [inline] slab_free_freelist_hook+0xdf/0x240 mm/slub.c:1650 slab_free mm/slub.c:3210 [inline] kmem_cache_free+0x8e/0x5a0 mm/slub.c:3226 kfree_skbmem+0x166/0x1b0 net/core/skbuff.c:720 __kfree_skb net/core/skbuff.c:756 [inline] kfree_skb net/core/skbuff.c:773 [inline] kfree_skb+0x140/0x3f0 net/core/skbuff.c:767 tipc_recvmsg+0x70d/0xf90 net/tipc/socket.c:1977 sock_recvmsg_nosec net/socket.c:943 [inline] sock_recvmsg net/socket.c:961 [inline] sock_recvmsg net/socket.c:957 [inline] ____sys_recvmsg+0x2c4/0x600 net/socket.c:2606 ___sys_recvmsg+0x127/0x200 net/socket.c:2648 do_recvmmsg+0x24d/0x6d0 net/socket.c:2742 __sys_recvmmsg net/socket.c:2823 [inline] __do_sys_recvmmsg net/socket.c:2844 [inline] __se_sys_recvmmsg net/socket.c:2837 [inline] __x64_sys_recvmmsg+0x17d/0x260 net/socket.c:2837 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff888021405400 which belongs to the cache skbuff_fclone_cache of size 472 The buggy address is located 64 bytes inside of 472-byte region [ffff888021405400, ffff8880214055d8) The buggy address belongs to the page: page:ffffea0000850100 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21404 head:ffffea0000850100 order:1 compound_mapcount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0000c96c80 0000000800000008 ffff888015ba3280 raw: 0000000000000000 00000000800c000c 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 0x52a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 10763, ts 185338500271, free_ts 183481528513 prep_new_page mm/page_alloc.c:2433 [inline] get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4166 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5388 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2244 alloc_slab_page mm/slub.c:1688 [inline] allocate_slab+0x32e/0x4b0 mm/slub.c:1828 new_slab mm/slub.c:1891 [inline] new_slab_objects mm/slub.c:2637 [inline] ___slab_alloc+0x4ba/0x820 mm/slub.c:2800 __slab_alloc.constprop.0+0xa7/0xf0 mm/slub.c:2840 slab_alloc_node mm/slub.c:2922 [inline] kmem_cache_alloc_node+0x12c/0x3e0 mm/slub.c:2992 __alloc_skb+0x20b/0x340 net/core/skbuff.c:414 alloc_skb_fclone include/linux/skbuff.h:1162 [inline] sk_stream_alloc_skb+0x109/0xc30 net/ipv4/tcp.c:887 tcp_fragment+0x1c8/0x15f0 net/ipv4/tcp_output.c:1569 __tcp_retransmit_skb+0x351/0x2a50 net/ipv4/tcp_output.c:3183 tcp_retransmit_skb+0x2a/0x360 net/ipv4/tcp_output.c:3257 tcp_xmit_retransmit_queue.part.0+0x3fa/0x990 net/ipv4/tcp_output.c:3339 tcp_xmit_retransmit_queue+0x57/0x70 net/ipv4/tcp_output.c:3293 tcp_xmit_recovery net/ipv4/tcp_input.c:3699 [inline] tcp_xmit_recovery+0x86/0x180 net/ipv4/tcp_input.c:3685 tcp_ack+0x26cf/0x59e0 net/ipv4/tcp_input.c:3873 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1343 [inline] free_pcp_prepare+0x2c5/0x780 mm/page_alloc.c:1394 free_unref_page_prepare mm/page_alloc.c:3329 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3408 qlink_free mm/kasan/quarantine.c:146 [inline] qlist_free_all+0x5a/0xc0 mm/kasan/quarantine.c:165 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272 __kasan_slab_alloc+0x8e/0xa0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook mm/slab.h:519 [inline] slab_alloc_node mm/slub.c:2956 [inline] slab_alloc mm/slub.c:2964 [inline] kmem_cache_alloc+0x285/0x4a0 mm/slub.c:2969 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138 getname_flags include/linux/audit.h:319 [inline] getname+0x8e/0xd0 fs/namei.c:209 do_sys_openat2+0xf5/0x420 fs/open.c:1198 do_sys_open fs/open.c:1220 [inline] __do_sys_open fs/open.c:1228 [inline] __se_sys_open fs/open.c:1224 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1224 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Memory state around the buggy address: ffff888021405300: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc ffff888021405380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888021405400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888021405480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888021405500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================