From ebc180048b61a257bb91cc9bbad789c2e28f51a8 Mon Sep 17 00:00:00 2001
From: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Date: Mon, 18 Nov 2024 10:26:50 +0800
Subject: [PATCH] fs/ntfs3: Additional check in ntfs_file_release
[ Upstream commit 031d6f608290c847ba6378322d0986d08d1a645a ]
Reported-by: syzbot+8c652f14a0fde76ff11d@syzkaller.appspotmail.com
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Signed-off-by: Bin Lan <bin.lan.cn@windriver.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/ntfs3/file.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/fs/ntfs3/file.c b/fs/ntfs3/file.c
index aedd4f5f459e6..70b38465aee36 100644
--- a/fs/ntfs3/file.c
+++ b/fs/ntfs3/file.c
@@ -1214,8 +1214,16 @@ static int ntfs_file_release(struct inode *inode, struct file *file)
int err = 0;
/* If we are last writer on the inode, drop the block reservation. */
- if (sbi->options->prealloc && ((file->f_mode & FMODE_WRITE) &&
- atomic_read(&inode->i_writecount) == 1)) {
+ if (sbi->options->prealloc &&
+ ((file->f_mode & FMODE_WRITE) &&
+ atomic_read(&inode->i_writecount) == 1)
+ /*
+ * The only file when inode->i_fop = &ntfs_file_operations and
+ * init_rwsem(&ni->file.run_lock) is not called explicitly is MFT.
+ *
+ * Add additional check here.
+ */
+ && inode->i_ino != MFT_REC_MFT) {
ni_lock(ni);
down_write(&ni->file.run_lock);
--
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