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

[Manas Ghandat <ghandatmanas@gmail.com>]

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@gmail.com>
> Reported-by: syzbot+0558d19c373e44da3c18@syzkaller.appspotmail.com
> 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);