IPVS: ftp: loaded support on port[0] = 21 ================================================================== BUG: KASAN: use-after-free in vcs_read_buf drivers/tty/vt/vc_screen.c:357 [inline] BUG: KASAN: use-after-free in vcs_read+0xaa7/0xb40 drivers/tty/vt/vc_screen.c:449 Write of size 2 at addr ffff8880a0b68000 by task syz-executor825/6836 CPU: 0 PID: 6836 Comm: syz-executor825 Not tainted 5.9.0-rc1-next-20200821-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/0x497 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 vcs_read_buf drivers/tty/vt/vc_screen.c:357 [inline] vcs_read+0xaa7/0xb40 drivers/tty/vt/vc_screen.c:449 do_loop_readv_writev fs/read_write.c:734 [inline] do_loop_readv_writev fs/read_write.c:721 [inline] do_iter_read+0x48e/0x6e0 fs/read_write.c:955 vfs_readv+0xe5/0x150 fs/read_write.c:1073 do_preadv fs/read_write.c:1165 [inline] __do_sys_preadv fs/read_write.c:1215 [inline] __se_sys_preadv fs/read_write.c:1210 [inline] __x64_sys_preadv+0x231/0x310 fs/read_write.c:1210 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x440af9 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 0f fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffc361d17f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000440af9 RDX: 0000000000000006 RSI: 0000000020001b00 RDI: 0000000000000003 RBP: 00007ffc361d1800 R08: 0000000000000000 R09: 0000000120080522 R10: 0000000000000003 R11: 0000000000000246 R12: 00000000004a2290 R13: 0000000000402010 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 6756: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 kmem_cache_alloc_trace+0x16e/0x2c0 mm/slab.c:3550 kmalloc include/linux/slab.h:554 [inline] tomoyo_print_header security/tomoyo/audit.c:156 [inline] tomoyo_init_log+0x18a/0x1e50 security/tomoyo/audit.c:255 tomoyo_supervisor+0x32f/0xeb0 security/tomoyo/common.c:2097 tomoyo_audit_path_log security/tomoyo/file.c:168 [inline] tomoyo_path_permission security/tomoyo/file.c:587 [inline] tomoyo_path_permission+0x25c/0x360 security/tomoyo/file.c:573 tomoyo_path_perm+0x2e7/0x3f0 security/tomoyo/file.c:838 security_inode_getattr+0xcf/0x140 security/security.c:1278 vfs_getattr fs/stat.c:121 [inline] vfs_statx_fd+0x70/0xf0 fs/stat.c:151 vfs_fstat include/linux/fs.h:3186 [inline] __do_sys_newfstat+0x88/0x100 fs/stat.c:398 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 6756: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422 __cache_free mm/slab.c:3418 [inline] kfree+0x103/0x2c0 mm/slab.c:3756 tomoyo_init_log+0x14b6/0x1e50 security/tomoyo/audit.c:294 tomoyo_supervisor+0x32f/0xeb0 security/tomoyo/common.c:2097 tomoyo_audit_path_log security/tomoyo/file.c:168 [inline] tomoyo_path_permission security/tomoyo/file.c:587 [inline] tomoyo_path_permission+0x25c/0x360 security/tomoyo/file.c:573 tomoyo_path_perm+0x2e7/0x3f0 security/tomoyo/file.c:838 security_inode_getattr+0xcf/0x140 security/security.c:1278 vfs_getattr fs/stat.c:121 [inline] vfs_statx_fd+0x70/0xf0 fs/stat.c:151 vfs_fstat include/linux/fs.h:3186 [inline] __do_sys_newfstat+0x88/0x100 fs/stat.c:398 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff8880a0b68000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 0 bytes inside of 4096-byte region [ffff8880a0b68000, ffff8880a0b69000) The buggy address belongs to the page: page:00000000829a4ea3 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xa0b68 head:00000000829a4ea3 order:1 compound_mapcount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea0002a24688 ffffea0002a2aa88 ffff8880aa040900 raw: 0000000000000000 ffff8880a0b68000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a0b67f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880a0b67f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880a0b68000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a0b68080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a0b68100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================