================================================================== BUG: KASAN: use-after-free in tipc_recvmsg+0xf77/0xf90 net/tipc/socket.c:1979 Read of size 4 at addr ffff88802a676540 by task syz-executor.0/11914 CPU: 1 PID: 11914 Comm: syz-executor.0 Not tainted 5.14.0-rc2-next-20210723-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: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 net/socket.c:957 [inline] ____sys_recvmsg+0x2c4/0x600 net/socket.c:2611 ___sys_recvmsg+0x127/0x200 net/socket.c:2653 __sys_recvmsg+0xe2/0x1a0 net/socket.c:2683 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:00007f2a7b8f2188 EFLAGS: 00000246 ORIG_RAX: 000000000000002f RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9 RDX: 0000000000000000 RSI: 0000000020007100 RDI: 0000000000000004 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffc385d606f R14: 00007f2a7b8f2300 R15: 0000000000022000 Allocated by task 11918: 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_reverse+0x1ee/0x970 net/tipc/msg.c:647 tipc_sk_respond+0x1f0/0x560 net/tipc/socket.c:291 __tipc_shutdown+0x9c5/0xe90 net/tipc/socket.c:588 tipc_release+0x13f/0x1a80 net/tipc/socket.c:640 __sock_release+0xcd/0x280 net/socket.c:648 sock_close+0x18/0x20 net/socket.c:1300 __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 11914: 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 net/socket.c:957 [inline] ____sys_recvmsg+0x2c4/0x600 net/socket.c:2611 ___sys_recvmsg+0x127/0x200 net/socket.c:2653 __sys_recvmsg+0xe2/0x1a0 net/socket.c:2683 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 ffff88802a676500 which belongs to the cache skbuff_fclone_cache of size 472 The buggy address is located 64 bytes inside of 472-byte region [ffff88802a676500, ffff88802a6766d8) The buggy address belongs to the page: page:ffffea0000a99d80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2a676 head:ffffea0000a99d80 order:1 compound_mapcount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0000de4000 0000000500000005 ffff888144181140 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 8446, ts 64057088914, free_ts 62820661257 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 tcp_sendmsg_locked+0xc78/0x2f10 net/ipv4/tcp.c:1309 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1461 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:821 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 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] kmem_cache_alloc+0x285/0x4a0 mm/slub.c:2971 proc_reg_open+0x1d5/0x570 fs/proc/inode.c:515 do_dentry_open+0x4c8/0x11d0 fs/open.c:826 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 entry_SYSCALL_64_after_hwframe+0x44/0xae Memory state around the buggy address: ffff88802a676400: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc ffff88802a676480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88802a676500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802a676580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802a676600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================