inode->i_rwsem should be locked when writing file. But the lock
is missing when writing zeros to the file in exfat_file_mmap().
Fixes: 11a347fb6cef ("exfat: change to get file size from DataLength")
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@xxxxxxxx>
---
fs/exfat/file.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/fs/exfat/file.c b/fs/exfat/file.c
index d25a96a148af..473c1641d50d 100644
--- a/fs/exfat/file.c
+++ b/fs/exfat/file.c
@@ -613,7 +613,11 @@ static int exfat_file_mmap(struct file *file, struct vm_area_struct *vma)
start + vma->vm_end - vma->vm_start);
if ((vma->vm_flags & VM_WRITE) && ei->valid_size < end) {
+ if (!inode_trylock(inode))
+ return -EAGAIN;
+
ret = exfat_file_zeroed_range(file, ei->valid_size, end);
+ inode_unlock(inode);
if (ret < 0) {
exfat_err(inode->i_sb,
"mmap: fail to zero from %llu to %llu(%d)",
--
2.34.1
Attachment:
0001-exfat-fix-file-not-locking-when-writing-zeros-in-exf.patch
Description: 0001-exfat-fix-file-not-locking-when-writing-zeros-in-exf.patch
