================================================================== BUG: KASAN: use-after-free in tipc_udp_xmit+0xa7d/0xc10 net/tipc/udp_media.c:200 Read of size 8 at addr ffff88804000eae0 by task syz-executor.4/20708 CPU: 1 PID: 20708 Comm: syz-executor.4 Not tainted 4.19.204-syzkaller #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+0x1fc/0x2ef lib/dump_stack.c:118 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354 kasan_report mm/kasan/report.c:412 [inline] __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433 tipc_udp_xmit+0xa7d/0xc10 net/tipc/udp_media.c:200 tipc_udp_send_msg+0x279/0x490 net/tipc/udp_media.c:248 tipc_bearer_xmit_skb+0x15b/0x330 net/tipc/bearer.c:518 tipc_disc_timeout+0x855/0xc90 net/tipc/discover.c:332 call_timer_fn+0x177/0x700 kernel/time/timer.c:1338 expire_timers+0x243/0x4e0 kernel/time/timer.c:1375 __run_timers kernel/time/timer.c:1696 [inline] run_timer_softirq+0x21c/0x670 kernel/time/timer.c:1709 __do_softirq+0x265/0x980 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x215/0x260 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1098 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline] RIP: 0010:kmem_cache_free+0x11c/0x260 mm/slab.c:3766 Code: 11 48 63 75 74 48 89 df e8 e1 1d df 01 e9 68 ff ff ff e8 07 89 cf ff 48 83 3d 67 55 59 08 00 0f 84 f8 00 00 00 4c 89 e7 57 9d <0f> 1f 44 00 00 eb 86 65 8b 05 b6 53 69 7e 83 f8 07 0f 87 e7 00 00 RSP: 0018:ffff88802fa27810 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000007 RBX: ffff8880abf80e70 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000282 RBP: ffff88813bfec040 R08: 0000000000400000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000282 R13: ffffffff812b4300 R14: ffffffffffffffff R15: 0000000000000001 pte_lock_deinit include/linux/mm.h:1910 [inline] pgtable_page_dtor include/linux/mm.h:1943 [inline] ___pte_free_tlb+0x40/0x190 arch/x86/mm/pgtable.c:64 __pte_free_tlb arch/x86/include/asm/pgalloc.h:73 [inline] free_pte_range mm/memory.c:457 [inline] free_pmd_range mm/memory.c:475 [inline] free_pud_range mm/memory.c:509 [inline] free_p4d_range mm/memory.c:543 [inline] free_pgd_range+0xa94/0x1020 mm/memory.c:623 free_pgtables+0x230/0x2f0 mm/memory.c:655 exit_mmap+0x2c8/0x530 mm/mmap.c:3094 __mmput kernel/fork.c:1015 [inline] mmput+0x14e/0x4a0 kernel/fork.c:1036 exit_mm kernel/exit.c:549 [inline] do_exit+0xaec/0x2be0 kernel/exit.c:857 do_group_exit+0x125/0x310 kernel/exit.c:967 get_signal+0x3f2/0x1f70 kernel/signal.c:2589 do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:799 exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe 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:00007f973dff5218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000056bf88 RCX: 00000000004665e9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056bf88 RBP: 000000000056bf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf8c R13: 00007ffe7ec7402f R14: 00007f973dff5300 R15: 0000000000022000 Allocated by task 20692: kmem_cache_alloc+0x122/0x370 mm/slab.c:3559 sock_alloc_inode+0x19/0x250 net/socket.c:244 alloc_inode+0x5d/0x180 fs/inode.c:211 new_inode_pseudo+0x14/0xe0 fs/inode.c:911 sock_alloc+0x3c/0x260 net/socket.c:567 __sock_create+0xba/0x740 net/socket.c:1327 udp_sock_create6+0xd1/0x550 net/ipv6/ip6_udp_tunnel.c:22 udp_sock_create include/net/udp_tunnel.h:61 [inline] tipc_udp_enable+0xb48/0x14d0 net/tipc/udp_media.c:734 tipc_enable_bearer+0x70f/0xbe0 net/tipc/bearer.c:317 __tipc_nl_bearer_enable+0x2e2/0x3d0 net/tipc/bearer.c:916 tipc_nl_bearer_enable+0x1e/0x30 net/tipc/bearer.c:925 genl_family_rcv_msg+0x642/0xc40 net/netlink/genetlink.c:602 genl_rcv_msg+0xbf/0x160 net/netlink/genetlink.c:627 netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2457 genl_rcv+0x24/0x40 net/netlink/genetlink.c:638 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x6bb/0xc40 net/netlink/af_netlink.c:1911 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:661 ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2225 __sys_sendmsg net/socket.c:2263 [inline] __do_sys_sendmsg net/socket.c:2272 [inline] __se_sys_sendmsg net/socket.c:2270 [inline] __x64_sys_sendmsg+0x132/0x220 net/socket.c:2270 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 15690: __cache_free mm/slab.c:3503 [inline] kmem_cache_free+0x7f/0x260 mm/slab.c:3765 destroy_inode+0xb9/0x110 fs/inode.c:268 iput_final fs/inode.c:1555 [inline] iput+0x4f1/0x860 fs/inode.c:1581 __sock_release net/socket.c:611 [inline] sock_release+0x174/0x1d0 net/socket.c:619 cleanup_bearer+0x1bb/0x280 net/tipc/udp_media.c:775 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 The buggy address belongs to the object at ffff88804000eac0 which belongs to the cache sock_inode_cache of size 992 The buggy address is located 32 bytes inside of 992-byte region [ffff88804000eac0, ffff88804000eea0) The buggy address belongs to the page: page:ffffea0001000380 count:1 mapcount:0 mapping:ffff8880b5b99780 index:0xffff88804000effd flags: 0xfff00000000100(slab) raw: 00fff00000000100 ffffea00022d6d88 ffffea00015b9c48 ffff8880b5b99780 raw: ffff88804000effd ffff88804000e1c0 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88804000e980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804000ea00: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc >ffff88804000ea80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff88804000eb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804000eb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 11 48 63 adc %ecx,0x63(%rax) 3: 75 74 jne 0x79 5: 48 89 df mov %rbx,%rdi 8: e8 e1 1d df 01 callq 0x1df1dee d: e9 68 ff ff ff jmpq 0xffffff7a 12: e8 07 89 cf ff callq 0xffcf891e 17: 48 83 3d 67 55 59 08 cmpq $0x0,0x8595567(%rip) # 0x8595586 1e: 00 1f: 0f 84 f8 00 00 00 je 0x11d 25: 4c 89 e7 mov %r12,%rdi 28: 57 push %rdi 29: 9d popfq 2a: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) <-- trapping instruction 2f: eb 86 jmp 0xffffffb7 31: 65 8b 05 b6 53 69 7e mov %gs:0x7e6953b6(%rip),%eax # 0x7e6953ee 38: 83 f8 07 cmp $0x7,%eax 3b: 0f .byte 0xf 3c: 87 e7 xchg %esp,%edi