================================================================== BUG: KASAN: use-after-free in tipc_recvmsg+0xf77/0xf90 net/tipc/socket.c:1979 Read of size 4 at addr ffff88802b347440 by task kworker/u4:1/10 CPU: 1 PID: 10 Comm: kworker/u4:1 Not tainted 5.14.0-rc2-next-20210723-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: tipc_rcv tipc_conn_recv_work 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:256 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 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+0xca/0x110 net/socket.c:957 tipc_conn_rcv_from_sock+0x162/0x2f0 net/tipc/topsrv.c:398 tipc_conn_recv_work+0xeb/0x190 net/tipc/topsrv.c:421 process_one_work+0x98d/0x1630 kernel/workqueue.c:2276 worker_thread+0x658/0x11f0 kernel/workqueue.c:2422 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Allocated by task 17410: 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:2958 [inline] kmem_cache_alloc_node+0x266/0x3e0 mm/slub.c:2994 __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_build+0xf7/0x10a0 net/tipc/msg.c:386 __tipc_sendstream+0x6d0/0x1150 net/tipc/socket.c:1610 tipc_sendstream+0x4c/0x70 net/tipc/socket.c:1541 sock_sendmsg_nosec net/socket.c:703 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:723 sock_write_iter+0x289/0x3c0 net/socket.c:1056 call_write_iter include/linux/fs.h:2152 [inline] new_sync_write+0x426/0x650 fs/read_write.c:518 vfs_write+0x75a/0xa40 fs/read_write.c:605 ksys_write+0x1ee/0x250 fs/read_write.c:658 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 Freed by task 10: 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:1627 [inline] slab_free_freelist_hook+0xdf/0x240 mm/slub.c:1652 slab_free mm/slub.c:3212 [inline] kmem_cache_free+0x8e/0x5a0 mm/slub.c:3228 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+0xca/0x110 net/socket.c:957 tipc_conn_rcv_from_sock+0x162/0x2f0 net/tipc/topsrv.c:398 tipc_conn_recv_work+0xeb/0x190 net/tipc/topsrv.c:421 process_one_work+0x98d/0x1630 kernel/workqueue.c:2276 worker_thread+0x658/0x11f0 kernel/workqueue.c:2422 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff88802b347400 which belongs to the cache skbuff_fclone_cache of size 472 The buggy address is located 64 bytes inside of 472-byte region [ffff88802b347400, ffff88802b3475d8) The buggy address belongs to the page: page:ffffea0000acd180 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2b346 head:ffffea0000acd180 order:1 compound_mapcount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0000adb300 0000000a0000000a ffff88814017a780 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 0x52a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 14351, ts 356614737339, free_ts 338594507509 prep_new_page mm/page_alloc.c:2424 [inline] get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4152 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5374 alloc_pages+0x1a3/0x2d0 mm/mempolicy.c:2278 alloc_slab_page mm/slub.c:1690 [inline] allocate_slab+0x32e/0x4b0 mm/slub.c:1830 new_slab mm/slub.c:1893 [inline] new_slab_objects mm/slub.c:2639 [inline] ___slab_alloc+0x4ba/0x820 mm/slub.c:2802 __slab_alloc.constprop.0+0xa7/0xf0 mm/slub.c:2842 slab_alloc_node mm/slub.c:2924 [inline] kmem_cache_alloc_node+0x12c/0x3e0 mm/slub.c:2994 __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 tso_fragment net/ipv4/tcp_output.c:2126 [inline] tcp_write_xmit+0x1ccd/0x6030 net/ipv4/tcp_output.c:2676 __tcp_push_pending_frames+0xaa/0x390 net/ipv4/tcp_output.c:2874 tcp_push_pending_frames include/net/tcp.h:1880 [inline] tcp_data_snd_check net/ipv4/tcp_input.c:5425 [inline] tcp_rcv_established+0x935/0x2130 net/ipv4/tcp_input.c:5920 tcp_v4_do_rcv+0x5d4/0x880 net/ipv4/tcp_ipv4.c:1694 sk_backlog_rcv include/net/sock.h:1023 [inline] __release_sock+0x134/0x3b0 net/core/sock.c:2655 release_sock+0x54/0x1b0 net/core/sock.c:3179 sk_stream_wait_memory+0x604/0xed0 net/core/stream.c:145 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1338 [inline] free_pcp_prepare+0x373/0x860 mm/page_alloc.c:1389 free_unref_page_prepare mm/page_alloc.c:3315 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3394 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:2958 [inline] slab_alloc mm/slub.c:2966 [inline] __kmalloc+0x1f4/0x330 mm/slub.c:4102 kmalloc include/linux/slab.h:596 [inline] tomoyo_realpath_from_path+0xc3/0x620 security/tomoyo/realpath.c:254 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x272/0x380 security/tomoyo/file.c:771 tomoyo_file_open security/tomoyo/tomoyo.c:311 [inline] tomoyo_file_open+0xa3/0xd0 security/tomoyo/tomoyo.c:306 security_file_open+0x52/0x4f0 security/security.c:1633 do_dentry_open+0x353/0x11d0 fs/open.c:813 do_open fs/namei.c:3374 [inline] path_openat+0x1c23/0x27f0 fs/namei.c:3507 do_filp_open+0x1aa/0x400 fs/namei.c:3534 do_sys_openat2+0x16d/0x420 fs/open.c:1204 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 Memory state around the buggy address: ffff88802b347300: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc ffff88802b347380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88802b347400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802b347480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802b347500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================