[PATCH] jfs: replace hardcoded magic number with DTPAGEMAXSLOT constant

From: Zheng Yu
Date: Tue Jul 29 2025 - 14:29:38 EST


Replace hardcoded value 127 with DTPAGEMAXSLOT constant in boundary
checks within jfs_readdir() and dtReadFirst(). This improves code
maintainability and ensures consistency with the defined maximum
slot value.

Fixes: ca84a2c9be48 ("jfs: array-index-out-of-bounds fix in dtReadFirst")
Fixes: 839f102efb16 ("jfs: fix array-index-out-of-bounds in jfs_readdir")
Signed-off-by: Zheng Yu <zheng.yu@xxxxxxxxxxxxxxxx>
---
fs/jfs/jfs_dtree.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/jfs/jfs_dtree.c b/fs/jfs/jfs_dtree.c
index ab11849cf9cc..0ab83bb7bbdf 100644
--- a/fs/jfs/jfs_dtree.c
+++ b/fs/jfs/jfs_dtree.c
@@ -2903,7 +2903,7 @@ int jfs_readdir(struct file *file, struct dir_context *ctx)
stbl = DT_GETSTBL(p);

for (i = index; i < p->header.nextindex; i++) {
- if (stbl[i] < 0 || stbl[i] > 127) {
+ if (stbl[i] < 0 || stbl[i] >= DTPAGEMAXSLOT) {
jfs_err("JFS: Invalid stbl[%d] = %d for inode %ld, block = %lld",
i, stbl[i], (long)ip->i_ino, (long long)bn);
free_page(dirent_buf);
@@ -3108,7 +3108,7 @@ static int dtReadFirst(struct inode *ip, struct btstack * btstack)
/* get the leftmost entry */
stbl = DT_GETSTBL(p);

- if (stbl[0] < 0 || stbl[0] > 127) {
+ if (stbl[0] < 0 || stbl[0] >= DTPAGEMAXSLOT) {
DT_PUTPAGE(mp);
jfs_error(ip->i_sb, "stbl[0] out of bound\n");
return -EIO;
--
2.43.0