================================================================== BUG: KASAN: use-after-free in ifname_compare_aligned include/linux/netfilter/x_tables.h:369 [inline] BUG: KASAN: use-after-free in ip6_packet_match net/ipv6/netfilter/ip6_tables.c:89 [inline] BUG: KASAN: use-after-free in ip6t_do_table+0x14e2/0x17e0 net/ipv6/netfilter/ip6_tables.c:333 Read of size 8 at addr ffff8801c683c000 by task syz-executor.4/8800 CPU: 1 PID: 8800 Comm: syz-executor.4 Not tainted 4.9.141+ #23 ffff8801d86e7010 ffffffff81b42e79 ffffea00071a0f00 ffff8801c683c000 0000000000000000 ffff8801c683c000 dffffc0000000000 ffff8801d86e7048 ffffffff815009b8 ffff8801c683c000 0000000000000008 0000000000000000 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] print_address_description+0x6c/0x234 mm/kasan/report.c:256 [] kasan_report_error mm/kasan/report.c:355 [inline] [] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412 [] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 [] ifname_compare_aligned include/linux/netfilter/x_tables.h:369 [inline] [] ip6_packet_match net/ipv6/netfilter/ip6_tables.c:89 [inline] [] ip6t_do_table+0x14e2/0x17e0 net/ipv6/netfilter/ip6_tables.c:333 [] ip6t_mangle_out net/ipv6/netfilter/ip6table_mangle.c:63 [inline] [] ip6table_mangle_hook+0x2d7/0x660 net/ipv6/netfilter/ip6table_mangle.c:85 [] nf_iterate+0x126/0x310 net/netfilter/core.c:324 [] nf_hook_slow+0x114/0x1e0 net/netfilter/core.c:355 [] nf_hook_thresh include/linux/netfilter.h:191 [inline] [] nf_hook include/linux/netfilter.h:203 [inline] [] __ip6_local_out+0x484/0x620 net/ipv6/output_core.c:164 [] ip6_local_out+0x29/0x180 net/ipv6/output_core.c:174 [] ip6_send_skb+0xa1/0x340 net/ipv6/ip6_output.c:1751 [] udp_v6_send_skb+0x429/0xe70 net/ipv6/udp.c:974 [] udp_v6_push_pending_frames+0x22d/0x340 net/ipv6/udp.c:1007 [] udpv6_sendmsg+0x1dc1/0x2430 net/ipv6/udp.c:1273 [] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:770 [] sock_sendmsg_nosec net/socket.c:648 [inline] [] sock_sendmsg+0xbb/0x110 net/socket.c:658 [] ___sys_sendmsg+0x47a/0x840 net/socket.c:1982 [] __sys_sendmmsg+0x23c/0x3d0 net/socket.c:2065 [] C_SYSC_sendmmsg net/compat.c:742 [inline] [] compat_SyS_sendmmsg+0x32/0x40 net/compat.c:739 [] do_syscall_32_irqs_on arch/x86/entry/common.c:328 [inline] [] do_fast_syscall_32+0x2f1/0xa10 arch/x86/entry/common.c:390 [] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137 Allocated by task 2126: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack mm/kasan/kasan.c:505 [inline] set_track mm/kasan/kasan.c:517 [inline] kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:609 kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:594 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:547 slab_post_alloc_hook mm/slab.h:417 [inline] slab_alloc_node mm/slub.c:2715 [inline] slab_alloc mm/slub.c:2723 [inline] kmem_cache_alloc+0xd5/0x2b0 mm/slub.c:2728 dup_fd+0x85/0xb10 fs/file.c:298 copy_files kernel/fork.c:1260 [inline] copy_process.part.8+0x17e7/0x6a10 kernel/fork.c:1680 copy_process kernel/fork.c:1505 [inline] _do_fork+0x1b2/0xd30 kernel/fork.c:1972 kernel_thread+0x34/0x40 kernel/fork.c:2036 call_usermodehelper_exec_sync kernel/kmod.c:275 [inline] call_usermodehelper_exec_work+0xb0/0x250 kernel/kmod.c:327 process_one_work+0x831/0x15f0 kernel/workqueue.c:2092 worker_thread+0xd6/0x1140 kernel/workqueue.c:2226 kthread+0x26d/0x300 kernel/kthread.c:211 ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 Freed by task 8814: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack mm/kasan/kasan.c:505 [inline] set_track mm/kasan/kasan.c:517 [inline] kasan_slab_free+0xac/0x190 mm/kasan/kasan.c:582 slab_free_hook mm/slub.c:1355 [inline] slab_free_freelist_hook mm/slub.c:1377 [inline] slab_free mm/slub.c:2958 [inline] kmem_cache_free+0xbe/0x310 mm/slub.c:2980 put_files_struct+0x1f0/0x250 fs/file.c:439 exit_files+0x83/0xb0 fs/file.c:463 do_exit+0x75f/0x2a50 kernel/exit.c:828 do_group_exit+0x111/0x300 kernel/exit.c:937 SYSC_exit_group kernel/exit.c:948 [inline] SyS_exit_group+0x1d/0x20 kernel/exit.c:946 do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285 entry_SYSCALL_64_after_swapgs+0x5d/0xdb The buggy address belongs to the object at ffff8801c683c000 which belongs to the cache files_cache of size 832 The buggy address is located 0 bytes inside of 832-byte region [ffff8801c683c000, ffff8801c683c340) The buggy address belongs to the page: page:ffffea00071a0f00 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x4000000000004080(slab|head) page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c683bf00: fb fb fb fb fb fb fc fc fc fc fb fb fb fb fb fb ffff8801c683bf80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801c683c000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801c683c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c683c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================