================================================================== 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:297 [inline] BUG: KASAN: use-after-free in ip6_hold_safe+0xad/0x380 net/ipv6/route.c:1050 Read of size 4 at addr ffff88808fe5f3ec by task syz-executor.0/13175 CPU: 1 PID: 13175 Comm: syz-executor.0 Not tainted 5.2.0-rc2+ #36 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:188 __kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 kasan_report+0x12/0x20 mm/kasan/common.c:614 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:94 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:297 [inline] ip6_hold_safe+0xad/0x380 net/ipv6/route.c:1050 rt6_get_pcpu_route net/ipv6/route.c:1277 [inline] ip6_pol_route+0x339/0x10f0 net/ipv6/route.c:1956 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2132 fib6_rule_lookup+0x133/0x5a0 net/ipv6/fib6_rules.c:116 ip6_route_output_flags+0x2c4/0x350 net/ipv6/route.c:2161 ip6_route_output include/net/ip6_route.h:89 [inline] ip6_dst_lookup_tail+0xd10/0x1b30 net/ipv6/ip6_output.c:966 ip6_dst_lookup_flow+0xa8/0x220 net/ipv6/ip6_output.c:1094 sctp_v6_get_dst+0x785/0x1d80 net/sctp/ipv6.c:278 sctp_transport_route+0x12d/0x360 net/sctp/transport.c:297 sctp_assoc_add_peer+0x53e/0xfc0 net/sctp/associola.c:663 sctp_process_param net/sctp/sm_make_chunk.c:2531 [inline] sctp_process_init+0x2491/0x2b10 net/sctp/sm_make_chunk.c:2344 sctp_sf_do_5_1B_init+0x8ba/0xe50 net/sctp/sm_statefuns.c:401 sctp_do_sm+0x121/0x50e0 net/sctp/sm_sideeffect.c:1147 sctp_endpoint_bh_rcv+0x451/0x950 net/sctp/endpointola.c:443 sctp_inq_push+0x1e4/0x280 net/sctp/inqueue.c:80 sctp_rcv+0x282e/0x35e0 net/sctp/input.c:256 sctp6_rcv+0x17/0x30 net/sctp/ipv6.c:1049 ip6_protocol_deliver_rcu+0x2fe/0x16c0 net/ipv6/ip6_input.c:401 ip6_input_finish+0x84/0x170 net/ipv6/ip6_input.c:442 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip6_input+0xe4/0x3f0 net/ipv6/ip6_input.c:451 dst_input include/net/dst.h:439 [inline] ip6_rcv_finish+0x1de/0x310 net/ipv6/ip6_input.c:80 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ipv6_rcv+0x10e/0x420 net/ipv6/ip6_input.c:276 __netif_receive_skb_one_core+0x113/0x1a0 net/core/dev.c:4985 __netif_receive_skb+0x2c/0x1d0 net/core/dev.c:5099 process_backlog+0x206/0x750 net/core/dev.c:5910 napi_poll net/core/dev.c:6333 [inline] net_rx_action+0x4f5/0x1070 net/core/dev.c:6399 __do_softirq+0x25c/0x94c kernel/softirq.c:293 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1040 do_softirq.part.0+0x11a/0x170 kernel/softirq.c:338 do_softirq kernel/softirq.c:330 [inline] __local_bh_enable_ip+0x211/0x270 kernel/softirq.c:190 local_bh_enable include/linux/bottom_half.h:32 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:684 [inline] ip6_finish_output2+0x10a0/0x2550 net/ipv6/ip6_output.c:121 ip6_finish_output+0x56d/0xc20 net/ipv6/ip6_output.c:154 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip6_output+0x235/0x7f0 net/ipv6/ip6_output.c:171 dst_output include/net/dst.h:433 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip6_xmit+0xe35/0x20b0 net/ipv6/ip6_output.c:275 sctp_v6_xmit+0x313/0x660 net/sctp/ipv6.c:217 sctp_packet_transmit+0x1bb8/0x36e0 net/sctp/output.c:626 sctp_packet_singleton net/sctp/outqueue.c:772 [inline] sctp_outq_flush_ctrl.constprop.0+0x73c/0xd30 net/sctp/outqueue.c:903 sctp_outq_flush+0xe8/0x2780 net/sctp/outqueue.c:1185 sctp_outq_uncork+0x6c/0x80 net/sctp/outqueue.c:757 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1776 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1179 [inline] sctp_do_sm+0x504/0x50e0 net/sctp/sm_sideeffect.c:1150 sctp_primitive_ASSOCIATE+0x9d/0xd0 net/sctp/primitive.c:73 __sctp_connect+0x8c3/0xcd0 net/sctp/socket.c:1211 __sctp_setsockopt_connectx+0x133/0x1a0 net/sctp/socket.c:1334 sctp_setsockopt_connectx_old net/sctp/socket.c:1350 [inline] sctp_setsockopt net/sctp/socket.c:4644 [inline] sctp_setsockopt+0x22c0/0x6d10 net/sctp/socket.c:4608 sock_common_setsockopt+0x94/0xd0 net/core/sock.c:3130 __sys_setsockopt+0x17a/0x280 net/socket.c:2078 __do_sys_setsockopt net/socket.c:2089 [inline] __se_sys_setsockopt net/socket.c:2086 [inline] __x64_sys_setsockopt+0xbe/0x150 net/socket.c:2086 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459279 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:00007f9749c7ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000459279 RDX: 000000000000006b RSI: 0000000000000084 RDI: 0000000000000004 RBP: 000000000075bfc0 R08: 000000000000001c R09: 0000000000000000 R10: 000000002055bfe4 R11: 0000000000000246 R12: 00007f9749c7f6d4 R13: 00000000004cea80 R14: 00000000004dced0 R15: 00000000ffffffff Allocated by task 8978: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:503 __do_kmalloc mm/slab.c:3660 [inline] __kmalloc+0x15c/0x740 mm/slab.c:3669 kmalloc include/linux/slab.h:552 [inline] tomoyo_realpath_from_path+0xcd/0x7a0 security/tomoyo/realpath.c:277 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x230/0x430 security/tomoyo/file.c:822 tomoyo_inode_getattr+0x1d/0x30 security/tomoyo/tomoyo.c:129 security_inode_getattr+0xf2/0x150 security/security.c:1183 vfs_getattr+0x25/0x70 fs/stat.c:115 vfs_statx+0x157/0x200 fs/stat.c:191 vfs_stat include/linux/fs.h:3193 [inline] __do_sys_newstat+0xa4/0x130 fs/stat.c:341 __se_sys_newstat fs/stat.c:337 [inline] __x64_sys_newstat+0x54/0x80 fs/stat.c:337 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 8978: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459 __cache_free mm/slab.c:3432 [inline] kfree+0xcf/0x220 mm/slab.c:3755 tomoyo_realpath_from_path+0x1de/0x7a0 security/tomoyo/realpath.c:319 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x230/0x430 security/tomoyo/file.c:822 tomoyo_inode_getattr+0x1d/0x30 security/tomoyo/tomoyo.c:129 security_inode_getattr+0xf2/0x150 security/security.c:1183 vfs_getattr+0x25/0x70 fs/stat.c:115 vfs_statx+0x157/0x200 fs/stat.c:191 vfs_stat include/linux/fs.h:3193 [inline] __do_sys_newstat+0xa4/0x130 fs/stat.c:341 __se_sys_newstat fs/stat.c:337 [inline] __x64_sys_newstat+0x54/0x80 fs/stat.c:337 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88808fe5e580 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 3692 bytes inside of 4096-byte region [ffff88808fe5e580, ffff88808fe5f580) The buggy address belongs to the page: page:ffffea00023f9780 refcount:1 mapcount:0 mapping:ffff8880aa400dc0 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0002671a08 ffffea0002653b08 ffff8880aa400dc0 raw: 0000000000000000 ffff88808fe5e580 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808fe5f280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808fe5f300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88808fe5f380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88808fe5f400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808fe5f480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================