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KCSAN: data-race in copy_page_to_iter / ext4_fill_raw_inode

Status: auto-closed as invalid on 2022/01/07 12:09
Subsystems: ext4
[Documentation on labels]
First crash: 874d, last: 874d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in copy_page_to_iter / ext4_fill_raw_inode

write to 0xffff888128a32008 of 4 bytes by task 10149 on cpu 1:
 ext4_fill_raw_inode+0x562/0xea0
 ext4_do_update_inode fs/ext4/inode.c:5094 [inline]
 ext4_mark_iloc_dirty+0x364/0x890 fs/ext4/inode.c:5694
 __ext4_mark_inode_dirty+0x4ec/0x5f0 fs/ext4/inode.c:5890
 ext4_write_end+0x331/0x710 fs/ext4/inode.c:1316
 ext4_da_write_end+0x6d/0x630 fs/ext4/inode.c:3026
 generic_perform_write+0x261/0x400 mm/filemap.c:3767
 ext4_buffered_write_iter+0x25b/0x380 fs/ext4/file.c:269
 ext4_file_write_iter+0x2e7/0x1200
 call_write_iter include/linux/fs.h:2162 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0x7f5/0x950 fs/read_write.c:590
 ksys_write+0xd9/0x190 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:652
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888128a32000 of 512 bytes by task 4284 on cpu 0:
 instrument_copy_to_user include/linux/instrumented.h:119 [inline]
 copyout lib/iov_iter.c:156 [inline]
 copy_page_to_iter_iovec lib/iov_iter.c:228 [inline]
 __copy_page_to_iter lib/iov_iter.c:852 [inline]
 copy_page_to_iter+0x2cb/0x950 lib/iov_iter.c:880
 filemap_read+0x138b/0x16d0 mm/filemap.c:2697
 generic_file_read_iter+0x72/0x2a0 mm/filemap.c:2792
 blkdev_read_iter+0x96/0x140 block/fops.c:583
 call_read_iter include/linux/fs.h:2156 [inline]
 new_sync_read fs/read_write.c:400 [inline]
 vfs_read+0x66c/0x750 fs/read_write.c:481
 ksys_read+0xd9/0x190 fs/read_write.c:619
 __do_sys_read fs/read_write.c:629 [inline]
 __se_sys_read fs/read_write.c:627 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:627
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 4284 Comm: udevd Tainted: G        W         5.16.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/12/03 12:02 upstream 5f58da2befa5 c7c20675 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in copy_page_to_iter / ext4_fill_raw_inode
* Struck through repros no longer work on HEAD.