From: Gou Hao <gouhao@uniontech.com>
Date: Wed, 6 Sep 2023 01:33:41 +0000 (+0800)
Subject: ext4: move 'ix' sanity check to corrent position
X-Git-Tag: v4.14.330~26
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=131e2763562da001abf666501e5823468a51c35b;p=thirdparty%2Fkernel%2Fstable.git

ext4: move 'ix' sanity check to corrent position

[ Upstream commit af90a8f4a09ec4a3de20142e37f37205d4687f28 ]

Check 'ix' before it is used.

Fixes: 80e675f906db ("ext4: optimize memmmove lengths in extent/index insertions")
Signed-off-by: Gou Hao <gouhao@uniontech.com>
Link: https://lore.kernel.org/r/20230906013341.7199-1-gouhao@uniontech.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 652d16f90beb7..c8cce6bb02765 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -1002,6 +1002,11 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
 		ix = curp->p_idx;
 	}
 
+	if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
+		EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
+		return -EFSCORRUPTED;
+	}
+
 	len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
 	BUG_ON(len < 0);
 	if (len > 0) {
@@ -1011,11 +1016,6 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
 		memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
 	}
 
-	if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
-		EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
-		return -EFSCORRUPTED;
-	}
-
 	ix->ei_block = cpu_to_le32(logical);
 	ext4_idx_store_pblock(ix, ptr);
 	le16_add_cpu(&curp->p_hdr->eh_entries, 1);