================================================================== BUG: KASAN: slab-out-of-bounds in fib6_nh_get_excptn_bucket+0x198/0x1b0 net/ipv6/route.c:1591 Read of size 8 at addr ffff88805d6ce8f8 by task syz-executor.2/2812 CPU: 1 PID: 2812 Comm: syz-executor.2 Not tainted 5.3.0-rc8+ #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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0xd4/0x306 mm/kasan/report.c:351 __kasan_report.cold+0x1b/0x36 mm/kasan/report.c:482 kasan_report+0x12/0x17 mm/kasan/common.c:618 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 fib6_nh_get_excptn_bucket+0x198/0x1b0 net/ipv6/route.c:1591 fib6_nh_flush_exceptions+0x37/0x2d0 net/ipv6/route.c:1719 fib6_nh_release+0x84/0x3a0 net/ipv6/route.c:3503 fib6_info_destroy_rcu+0x11e/0x150 net/ipv6/ip6_fib.c:174 __rcu_reclaim kernel/rcu/rcu.h:222 [inline] rcu_do_batch kernel/rcu/tree.c:2114 [inline] rcu_core+0x67f/0x1580 kernel/rcu/tree.c:2314 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2323 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:537 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1137 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:compound_head include/linux/page-flags.h:176 [inline] RIP: 0010:PageSwapCache include/linux/page-flags.h:383 [inline] RIP: 0010:free_swap_cache mm/swap_state.c:267 [inline] RIP: 0010:free_pages_and_swap_cache+0xa9/0x3f0 mm/swap_state.c:295 Code: 3c 18 00 0f 85 e6 02 00 00 48 8b 45 d0 4c 8b 28 49 8d 45 08 48 89 45 a8 48 c1 e8 03 80 3c 18 00 0f 85 e5 02 00 00 4d 8b 75 08 <31> ff 4d 89 ec 4c 89 f6 83 e6 01 48 89 75 c8 e8 03 b7 cc ff 48 8b RSP: 0018:ffff888068f0f668 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 1ffffd4000467bc1 RBX: dffffc0000000000 RCX: ffffffff81a5cf43 RDX: 0000000000000000 RSI: ffffffff81a5cf56 RDI: 0000000000000004 RBP: ffff888068f0f6c8 R08: ffff88808ff44380 R09: fffff94000501039 R10: fffff94000501038 R11: ffffea00028081c7 R12: ffffea00028081c0 R13: ffffea000233de00 R14: dead000000000100 R15: 0000000000000121 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:184 [inline] tlb_flush_mmu+0x89/0x630 mm/mmu_gather.c:191 zap_pte_range mm/memory.c:1126 [inline] zap_pmd_range mm/memory.c:1161 [inline] zap_pud_range mm/memory.c:1190 [inline] zap_p4d_range mm/memory.c:1211 [inline] unmap_page_range+0x181f/0x2170 mm/memory.c:1232 unmap_single_vma+0x19d/0x300 mm/memory.c:1277 unmap_vmas+0x135/0x280 mm/memory.c:1309 exit_mmap+0x2ba/0x530 mm/mmap.c:3145 __mmput kernel/fork.c:1064 [inline] mmput+0x179/0x4d0 kernel/fork.c:1085 exit_mm kernel/exit.c:547 [inline] do_exit+0x84e/0x2e50 kernel/exit.c:866 do_group_exit+0x135/0x360 kernel/exit.c:983 get_signal+0x47c/0x2500 kernel/signal.c:2734 do_signal+0x87/0x1700 arch/x86/kernel/signal.c:815 exit_to_usermode_loop+0x286/0x380 arch/x86/entry/common.c:159 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x5a9/0x6a0 arch/x86/entry/common.c:299 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4598e9 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe479905cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000000 RBX: 000000000075bf28 RCX: 00000000004598e9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000075bf28 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000075bf2c R13: 00007ffd19b51bef R14: 00007fe4799069c0 R15: 000000000075bf2c Allocated by task 2812: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc mm/kasan/common.c:493 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:466 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:507 kmem_cache_alloc_trace+0x158/0x790 mm/slab.c:3550 kmalloc include/linux/slab.h:552 [inline] kzalloc include/linux/slab.h:748 [inline] fib6_info_alloc+0xb6/0x1b0 net/ipv6/ip6_fib.c:154 ip6_route_info_create+0x2fe/0x1530 net/ipv6/route.c:3605 ip6_route_add+0x27/0xc0 net/ipv6/route.c:3697 inet6_rtm_newroute+0x16c/0x180 net/ipv6/route.c:5265 rtnetlink_rcv_msg+0x463/0xb00 net/core/rtnetlink.c:5223 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5241 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x531/0x710 net/netlink/af_netlink.c:1328 netlink_sendmsg+0x8a5/0xd60 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:657 ___sys_sendmsg+0x803/0x920 net/socket.c:2311 __sys_sendmsg+0x105/0x1d0 net/socket.c:2356 __do_sys_sendmsg net/socket.c:2365 [inline] __se_sys_sendmsg net/socket.c:2363 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2363 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 1971: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:455 kasan_slab_free+0xe/0x10 mm/kasan/common.c:463 __cache_free mm/slab.c:3425 [inline] kfree+0x10a/0x2c0 mm/slab.c:3756 free_mnt_ns+0xe2/0x160 fs/namespace.c:3134 put_mnt_ns fs/namespace.c:3752 [inline] put_mnt_ns+0x72/0x90 fs/namespace.c:3747 free_nsproxy+0x48/0x230 kernel/nsproxy.c:172 switch_task_namespaces+0xb3/0xd0 kernel/nsproxy.c:225 exit_task_namespaces+0x18/0x20 kernel/nsproxy.c:230 do_exit+0x92a/0x2e50 kernel/exit.c:878 do_group_exit+0x135/0x360 kernel/exit.c:983 get_signal+0x47c/0x2500 kernel/signal.c:2734 do_signal+0x87/0x1700 arch/x86/kernel/signal.c:815 exit_to_usermode_loop+0x286/0x380 arch/x86/entry/common.c:159 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x5a9/0x6a0 arch/x86/entry/common.c:299 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88805d6ce800 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 56 bytes to the right of 192-byte region [ffff88805d6ce800, ffff88805d6ce8c0) The buggy address belongs to the page: page:ffffea000175b380 refcount:1 mapcount:0 mapping:ffff8880aa400000 index:0xffff88805d6ce500 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea0001c12e48 ffffea00028075c8 ffff8880aa400000 raw: ffff88805d6ce500 ffff88805d6ce000 000000010000000c 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88805d6ce780: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc ffff88805d6ce800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88805d6ce880: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88805d6ce900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88805d6ce980: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================