================================================================== BUG: KASAN: use-after-free in memcpy include/linux/string.h:406 [inline] BUG: KASAN: use-after-free in scr_memcpyw include/linux/vt_buffer.h:49 [inline] BUG: KASAN: use-after-free in vc_do_resize+0x9d6/0x13f0 drivers/tty/vt/vt.c:1286 Read of size 2 at addr ffff888095442cc2 by task syz-executor.2/3120 CPU: 0 PID: 3120 Comm: syz-executor.2 Not tainted 5.8.0-syzkaller #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+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x436 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 check_memory_region_inline mm/kasan/generic.c:186 [inline] check_memory_region+0x13d/0x180 mm/kasan/generic.c:192 memcpy+0x20/0x60 mm/kasan/common.c:105 memcpy include/linux/string.h:406 [inline] scr_memcpyw include/linux/vt_buffer.h:49 [inline] vc_do_resize+0x9d6/0x13f0 drivers/tty/vt/vt.c:1286 fbcon_modechanged+0x36c/0x710 drivers/video/fbdev/core/fbcon.c:2990 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:3048 fb_set_var+0xae8/0xd60 drivers/video/fbdev/core/fbmem.c:1056 do_fb_ioctl+0x33f/0x6c0 drivers/video/fbdev/core/fbmem.c:1109 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:48 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:753 __do_sys_ioctl fs/ioctl.c:762 [inline] __se_sys_ioctl fs/ioctl.c:760 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45cce9 Code: 2d b6 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 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0f9628cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000000d540 RCX: 000000000045cce9 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000003 RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007ffd03c5f39f R14: 00007f0f9628d9c0 R15: 000000000078bf0c Allocated by task 7146: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494 kmalloc_node include/linux/slab.h:578 [inline] __vmalloc_area_node+0x589/0x7a0 mm/vmalloc.c:2459 __vmalloc_node_range mm/vmalloc.c:2541 [inline] __vmalloc_node mm/vmalloc.c:2584 [inline] vzalloc+0x116/0x1a0 mm/vmalloc.c:2637 do_ipt_get_ctl+0x4f3/0x8e0 net/ipv4/netfilter/ip_tables.c:800 nf_sockopt net/netfilter/nf_sockopt.c:104 [inline] nf_getsockopt+0x72/0xd0 net/netfilter/nf_sockopt.c:122 ip_getsockopt net/ipv4/ip_sockglue.c:1749 [inline] ip_getsockopt+0x167/0x1c0 net/ipv4/ip_sockglue.c:1729 tcp_getsockopt+0x86/0xd0 net/ipv4/tcp.c:3893 __sys_getsockopt+0x14b/0x2e0 net/socket.c:2172 __do_sys_getsockopt net/socket.c:2187 [inline] __se_sys_getsockopt net/socket.c:2184 [inline] __x64_sys_getsockopt+0xba/0x150 net/socket.c:2184 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 7146: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0xf5/0x140 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x103/0x2c0 mm/slab.c:3757 kvfree+0x42/0x50 mm/util.c:603 __vunmap+0x88a/0xac0 mm/vmalloc.c:2306 __vfree mm/vmalloc.c:2350 [inline] vfree+0x88/0x140 mm/vmalloc.c:2380 copy_entries_to_user net/ipv4/netfilter/ip_tables.c:867 [inline] get_entries net/ipv4/netfilter/ip_tables.c:1024 [inline] do_ipt_get_ctl+0x6ee/0x8e0 net/ipv4/netfilter/ip_tables.c:1700 nf_sockopt net/netfilter/nf_sockopt.c:104 [inline] nf_getsockopt+0x72/0xd0 net/netfilter/nf_sockopt.c:122 ip_getsockopt net/ipv4/ip_sockglue.c:1749 [inline] ip_getsockopt+0x167/0x1c0 net/ipv4/ip_sockglue.c:1729 tcp_getsockopt+0x86/0xd0 net/ipv4/tcp.c:3893 __sys_getsockopt+0x14b/0x2e0 net/socket.c:2172 __do_sys_getsockopt net/socket.c:2187 [inline] __se_sys_getsockopt net/socket.c:2184 [inline] __x64_sys_getsockopt+0xba/0x150 net/socket.c:2184 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff888095442cc0 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 2 bytes inside of 32-byte region [ffff888095442cc0, ffff888095442ce0) The buggy address belongs to the page: page:ffffea0002551080 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888095442fc1 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002772f48 ffffea0002997f88 ffff8880aa0001c0 raw: ffff888095442fc1 ffff888095442000 000000010000003f 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888095442b80: 00 00 00 fc fc fc fc fc 05 fc fc fc fc fc fc fc ffff888095442c00: 05 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc >ffff888095442c80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ^ ffff888095442d00: 05 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc ffff888095442d80: 00 fc fc fc fc fc fc fc 00 00 fc fc fc fc fc fc ==================================================================