================================================================== BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] BUG: KASAN: use-after-free in atomic_fetch_add_unless include/linux/atomic.h:575 [inline] BUG: KASAN: use-after-free in atomic_add_unless include/linux/atomic.h:597 [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+0xca/0x620 net/ipv6/route.c:1023 Read of size 4 at addr ffff88808fbf0d18 by task syz-executor5/1559 CPU: 0 PID: 1559 Comm: syz-executor5 Not tainted 5.0.0-rc3+ #24 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+0x1db/0x2d0 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:100 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] atomic_fetch_add_unless include/linux/atomic.h:575 [inline] atomic_add_unless include/linux/atomic.h:597 [inline] dst_hold_safe include/net/dst.h:308 [inline] ip6_hold_safe+0xca/0x620 net/ipv6/route.c:1023 rt6_get_pcpu_route net/ipv6/route.c:1243 [inline] ip6_pol_route+0x3a3/0x1490 net/ipv6/route.c:1892 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2068 fib6_rule_lookup+0x12f/0x870 net/ipv6/fib6_rules.c:118 ip6_route_output_flags+0x2c4/0x350 net/ipv6/route.c:2097 ip6_route_output include/net/ip6_route.h:88 [inline] ip6_dst_lookup_tail+0xe18/0x1d50 net/ipv6/ip6_output.c:958 ip6_dst_lookup_flow+0xca/0x270 net/ipv6/ip6_output.c:1086 ip6_sk_dst_lookup_flow net/ipv6/ip6_output.c:1124 [inline] ip6_sk_dst_lookup_flow+0x5d6/0xbf0 net/ipv6/ip6_output.c:1114 udpv6_sendmsg+0x211d/0x3570 net/ipv6/udp.c:1449 inet_sendmsg+0x1af/0x740 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xdd/0x130 net/socket.c:631 __sys_sendto+0x387/0x5f0 net/socket.c:1788 __do_sys_sendto net/socket.c:1800 [inline] __se_sys_sendto net/socket.c:1796 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1796 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458099 Code: 6d 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f5ade66fc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000458099 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 000000000073c040 R08: 0000000020000000 R09: 000000000000001c R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5ade6706d4 R13: 00000000004c5710 R14: 00000000004d94e0 R15: 00000000ffffffff Allocated by task 23892: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:496 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469 kasan_kmalloc mm/kasan/common.c:504 [inline] kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:411 kmem_cache_alloc+0x12d/0x710 mm/slab.c:3543 getname_flags fs/namei.c:140 [inline] getname_flags+0xd6/0x5b0 fs/namei.c:129 getname fs/namei.c:211 [inline] __do_sys_unlink fs/namei.c:4109 [inline] __se_sys_unlink fs/namei.c:4107 [inline] __x64_sys_unlink+0x35/0x50 fs/namei.c:4107 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 23892: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466 __cache_free mm/slab.c:3487 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3749 putname+0xef/0x130 fs/namei.c:261 do_unlinkat+0x215/0x9e0 fs/namei.c:4083 __do_sys_unlink fs/namei.c:4109 [inline] __se_sys_unlink fs/namei.c:4107 [inline] __x64_sys_unlink+0x42/0x50 fs/namei.c:4107 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88808fbf08c0 which belongs to the cache names_cache of size 4096 The buggy address is located 1112 bytes inside of 4096-byte region [ffff88808fbf08c0, ffff88808fbf18c0) The buggy address belongs to the page: page:ffffea00023efc00 count:1 mapcount:0 mapping:ffff88821bc45380 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea00026ddf08 ffffea0002153608 ffff88821bc45380 raw: 0000000000000000 ffff88808fbf08c0 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808fbf0c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808fbf0c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88808fbf0d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88808fbf0d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808fbf0e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================