*** Guest State *** CR0: actual=0x0000000000000020, shadow=0x0000000000000000, gh_mask=fffffffffffffff7 ================================================================== BUG: KASAN: use-after-free in memset include/linux/string.h:337 [inline] BUG: KASAN: use-after-free in __ext4_expand_extra_isize+0x16c/0x240 fs/ext4/inode.c:5931 Write of size 27643 at addr ffff88807eb5b085 by task syz-executor2/18416 CPU: 0 PID: 18416 Comm: syz-executor2 Not tainted 4.20.0-rc7-next-20181224 #1 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 EXT4-fs error (device sda1): ext4_xattr_ibody_find:2188: inode #16769: comm syz-executor1: corrupted in-inode xattr 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 memset+0x24/0x40 mm/kasan/common.c:113 memset include/linux/string.h:337 [inline] __ext4_expand_extra_isize+0x16c/0x240 fs/ext4/inode.c:5931 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5983 [inline] ext4_mark_inode_dirty+0x827/0xb80 fs/ext4/inode.c:6059 ext4_dirty_inode+0x8f/0xc0 fs/ext4/inode.c:6093 __mark_inode_dirty+0xab5/0x1590 fs/fs-writeback.c:2122 generic_update_time+0x268/0x440 fs/inode.c:1654 update_time fs/inode.c:1670 [inline] file_update_time+0x392/0x650 fs/inode.c:1880 __generic_file_write_iter+0x1cf/0x630 mm/filemap.c:3338 ext4_file_write_iter+0x381/0x1400 fs/ext4/file.c:266 call_write_iter include/linux/fs.h:1862 [inline] do_iter_readv_writev+0x902/0xbc0 fs/read_write.c:680 do_iter_write fs/read_write.c:959 [inline] do_iter_write+0x184/0x610 fs/read_write.c:940 vfs_iter_write+0x77/0xb0 fs/read_write.c:972 iter_file_splice_write+0x885/0xfc0 fs/splice.c:749 do_splice_from fs/splice.c:851 [inline] direct_splice_actor+0x126/0x1a0 fs/splice.c:1023 splice_direct_to_actor+0x3be/0x9d0 fs/splice.c:978 do_splice_direct+0x2c7/0x420 fs/splice.c:1066 do_sendfile+0x61a/0xe60 fs/read_write.c:1439 __do_sys_sendfile64 fs/read_write.c:1494 [inline] __se_sys_sendfile64 fs/read_write.c:1486 [inline] __x64_sys_sendfile64+0x15a/0x240 fs/read_write.c:1486 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 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:00007f40766d3c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457ec9 RDX: 0000000020000000 RSI: 0000000000000007 RDI: 0000000000000007 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 00008080fffffffe R11: 0000000000000246 R12: 00007f40766d46d4 R13: 00000000004c4b6b R14: 00000000004d8278 R15: 00000000ffffffff The buggy address belongs to the page: page:ffffea0001fad6c0 count:2 mapcount:0 mapping:ffff8880a6b3b498 index:0x448 def_blk_aops flags: 0x1fffc000000203a(referenced|dirty|lru|active|private) raw: 01fffc000000203a ffffea0001d1fd48 ffffea0001fa1548 ffff8880a6b3b498 raw: 0000000000000448 ffff8880485270a8 00000002ffffffff ffff8880563a6180 page dumped because: kasan: bad access detected page->mem_cgroup:ffff8880563a6180 Memory state around the buggy address: ffff88807eb5bf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88807eb5bf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88807eb5c000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88807eb5c080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88807eb5c100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================