From 6e589291f4b1b700ca12baec5930592a0d51e63c Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso@mit.edu>
Date: Mon, 11 Feb 2019 01:07:10 -0500
Subject: [PATCH] ext4: disallow files with EXT4_JOURNAL_DATA_FL from
EXT4_IOC_SWAP_BOOT
A malicious/clueless root user can use EXT4_IOC_SWAP_BOOT to force a
corner casew which can lead to the file system getting corrupted.
There's no usefulness to allowing this, so just prohibit this case.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
fs/ext4/ioctl.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 2e76fb55d94ac..eb8ca8d80885a 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -132,6 +132,7 @@ static long swap_inode_boot_loader(struct super_block *sb,
if (inode->i_nlink != 1 || !S_ISREG(inode->i_mode) ||
IS_SWAPFILE(inode) || IS_ENCRYPTED(inode) ||
+ (EXT4_I(inode)->i_flags & EXT4_JOURNAL_DATA_FL) ||
ext4_has_inline_data(inode)) {
err = -EINVAL;
goto journal_err_out;
--
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