================================================================== BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] BUG: KASAN: use-after-free in atomic_fetch_add_unless include/linux/atomic-fallback.h:1086 [inline] BUG: KASAN: use-after-free in atomic_add_unless include/linux/atomic-fallback.h:1111 [inline] BUG: KASAN: use-after-free in atomic_inc_not_zero include/linux/atomic-fallback.h:1127 [inline] BUG: KASAN: use-after-free in dst_hold_safe include/net/dst.h:308 [inline] BUG: KASAN: use-after-free in ip6_hold_safe+0xb3/0x3a0 net/ipv6/route.c:1023 Read of size 4 at addr ffff8880914a7300 by task syz-executor.2/7196 CPU: 1 PID: 7196 Comm: syz-executor.2 Not tainted 5.0.0+ #103 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+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x123/0x190 mm/kasan/generic.c:191 kasan_check_read+0x11/0x20 mm/kasan/common.c:102 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] atomic_fetch_add_unless include/linux/atomic-fallback.h:1086 [inline] atomic_add_unless include/linux/atomic-fallback.h:1111 [inline] atomic_inc_not_zero include/linux/atomic-fallback.h:1127 [inline] dst_hold_safe include/net/dst.h:308 [inline] ip6_hold_safe+0xb3/0x3a0 net/ipv6/route.c:1023 rt6_get_pcpu_route net/ipv6/route.c:1243 [inline] ip6_pol_route+0x348/0x1040 net/ipv6/route.c:1904 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2080 __fib6_rule_action net/ipv6/fib6_rules.c:233 [inline] fib6_rule_action+0x3d0/0xaa0 net/ipv6/fib6_rules.c:264 fib_rules_lookup+0x351/0xa90 net/core/fib_rules.c:304 fib6_rule_lookup+0x340/0x560 net/ipv6/fib6_rules.c:110 ip6_route_output_flags+0x2c4/0x350 net/ipv6/route.c:2109 ip6_route_output include/net/ip6_route.h:88 [inline] ip6_dst_lookup_tail+0xd10/0x1b30 net/ipv6/ip6_output.c:964 ip6_dst_lookup_flow+0xa8/0x220 net/ipv6/ip6_output.c:1092 ip6_datagram_dst_update+0x5d8/0xc20 net/ipv6/datagram.c:91 __ip6_datagram_connect+0x5e9/0x1390 net/ipv6/datagram.c:250 ip6_datagram_connect+0x30/0x50 net/ipv6/datagram.c:273 ip6_datagram_connect_v6_only+0x69/0x90 net/ipv6/datagram.c:285 inet_dgram_connect+0x150/0x2e0 net/ipv4/af_inet.c:571 __sys_connect+0x266/0x330 net/socket.c:1808 __do_sys_connect net/socket.c:1819 [inline] __se_sys_connect net/socket.c:1816 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1816 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458079 Code: ad b8 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 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ff5660e5c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458079 RDX: 000000000000001c RSI: 0000000020000000 RDI: 0000000000000003 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff5660e66d4 R13: 00000000004be3fb R14: 00000000004cebc8 R15: 00000000ffffffff Allocated by task 4219: save_stack+0x45/0xd0 mm/kasan/common.c:75 set_track mm/kasan/common.c:87 [inline] __kasan_kmalloc mm/kasan/common.c:497 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:505 slab_post_alloc_hook mm/slab.h:436 [inline] slab_alloc mm/slab.c:3392 [inline] kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3554 kmem_cache_zalloc include/linux/slab.h:730 [inline] __proc_create+0x2c9/0x860 fs/proc/generic.c:408 proc_mkdir_data+0xbc/0x240 fs/proc/generic.c:469 proc_net_mkdir include/linux/proc_fs.h:124 [inline] rxrpc_init_net+0xa14/0xe30 net/rxrpc/net_ns.c:96 ops_init+0xb6/0x410 net/core/net_namespace.c:129 setup_net+0x2c5/0x730 net/core/net_namespace.c:314 copy_net_ns+0x1d9/0x340 net/core/net_namespace.c:437 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:206 ksys_unshare+0x440/0x980 kernel/fork.c:2549 __do_sys_unshare kernel/fork.c:2617 [inline] __se_sys_unshare kernel/fork.c:2615 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2615 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 4219: save_stack+0x45/0xd0 mm/kasan/common.c:75 set_track mm/kasan/common.c:87 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:459 kasan_slab_free+0xe/0x10 mm/kasan/common.c:467 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3764 pde_free+0xb5/0x110 fs/proc/generic.c:42 pde_put fs/proc/generic.c:647 [inline] pde_put+0x87/0xa0 fs/proc/generic.c:643 remove_proc_subtree+0x277/0x310 fs/proc/generic.c:730 proc_remove fs/proc/generic.c:745 [inline] proc_remove+0x6a/0x90 fs/proc/generic.c:742 rxrpc_exit_net+0x1f5/0x310 net/rxrpc/net_ns.c:129 ops_exit_list.isra.0+0xb0/0x160 net/core/net_namespace.c:153 setup_net+0x3f2/0x730 net/core/net_namespace.c:331 copy_net_ns+0x1d9/0x340 net/core/net_namespace.c:437 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:206 ksys_unshare+0x440/0x980 kernel/fork.c:2549 __do_sys_unshare kernel/fork.c:2617 [inline] __se_sys_unshare kernel/fork.c:2615 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2615 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880914a7280 which belongs to the cache proc_dir_entry of size 256 The buggy address is located 128 bytes inside of 256-byte region [ffff8880914a7280, ffff8880914a7380) The buggy address belongs to the page: page:ffffea00024529c0 count:1 mapcount:0 mapping:ffff88821bc45b00 index:0xffff8880914a7000 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea0001adc208 ffffea0001ba94c8 ffff88821bc45b00 raw: ffff8880914a7000 ffff8880914a7000 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880914a7200: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8880914a7280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880914a7300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880914a7380: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8880914a7400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================