Re: [PATCH] jfs : fs array-index-out-of-bounds in txCommit

From: Manas Ghandat
Date: Mon Oct 02 2023 - 00:36:32 EST


just a friendly ping

On 19/09/23 21:25, Manas Ghandat wrote:
Currently there is no check for out of bound access for xad in the
struct xtpage_t. Added the required check at various places for the same

Signed-off-by: Manas Ghandat <ghandatmanas@xxxxxxxxx>
Reported-by: syzbot+0558d19c373e44da3c18@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=0558d19c373e44da3c18
Fixes: df0cc57e057f
---
fs/jfs/jfs_txnmgr.c | 4 ++++
fs/jfs/jfs_xtree.c | 6 ++++++
2 files changed, 10 insertions(+)

diff --git a/fs/jfs/jfs_txnmgr.c b/fs/jfs/jfs_txnmgr.c
index ce4b4760fcb1..6c6640942bed 100644
--- a/fs/jfs/jfs_txnmgr.c
+++ b/fs/jfs/jfs_txnmgr.c
@@ -1722,6 +1722,10 @@ static void xtLog(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
jfs_err("xtLog: lwm > next");
goto out;
}
+ if (lwm >= XTROOTMAXSLOT) {
+ jfs_err("xtLog: lwm out of range");
+ goto out;
+ }
tlck->flag |= tlckUPDATEMAP;
xadlock->flag = mlckALLOCXADLIST;
xadlock->count = next - lwm;
diff --git a/fs/jfs/jfs_xtree.c b/fs/jfs/jfs_xtree.c
index 2d304cee884c..57569c52663e 100644
--- a/fs/jfs/jfs_xtree.c
+++ b/fs/jfs/jfs_xtree.c
@@ -357,6 +357,9 @@ static int xtSearch(struct inode *ip, s64 xoff, s64 *nextp,
for (base = XTENTRYSTART; lim; lim >>= 1) {
index = base + (lim >> 1);
+ if (index >= XTROOTMAXSLOT)
+ goto out;
+
XT_CMP(cmp, xoff, &p->xad[index], t64);
if (cmp == 0) {
/*
@@ -618,6 +621,9 @@ int xtInsert(tid_t tid, /* transaction id */
memmove(&p->xad[index + 1], &p->xad[index],
(nextindex - index) * sizeof(xad_t));
+ if (index >= XTROOTMAXSLOT)
+ goto out;
+
/* insert the new entry: mark the entry NEW */
xad = &p->xad[index];
XT_PUTENTRY(xad, xflag, xoff, xlen, xaddr);