Re: [PATCH] jfs: fix array-index-out-of-bounds in dbAdjTree
From: Manas Ghandat
Date: Mon Oct 23 2023 - 09:28:29 EST
Just a friendly remainder
On 17/10/23 17:33, Manas Ghandat wrote:
Currently there is a bound check missing in the dbAdjTree while
accessing the dmt_stree. To add the required check added the bool is_ctl
which is required to determine the size as suggest in the following
commit.
https://lore.kernel.org/linux-kernel-mentees/f9475918-2186-49b8-b801-6f0f9e75f4fa@xxxxxxxxxx/
Reported-by: syzbot+39ba34a099ac2e9bd3cb@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: https://syzkaller.appspot.com/bug?extid=39ba34a099ac2e9bd3cb
Signed-off-by: Manas Ghandat <ghandatmanas@xxxxxxxxx>
---
fs/jfs/jfs_dmap.c | 57 ++++++++++++++++++++++++++---------------------
1 file changed, 31 insertions(+), 26 deletions(-)
diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index 88afd108c2dd..57fba21994c3 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -63,10 +63,10 @@
*/
static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
int nblocks);
-static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval);
-static int dbBackSplit(dmtree_t * tp, int leafno);
-static int dbJoin(dmtree_t * tp, int leafno, int newval);
-static void dbAdjTree(dmtree_t * tp, int leafno, int newval);
+static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval, bool is_ctl);
+static int dbBackSplit(dmtree_t * tp, int leafno, bool is_ctl);
+static int dbJoin(dmtree_t * tp, int leafno, int newval, bool is_ctl);
+static void dbAdjTree(dmtree_t * tp, int leafno, int newval, bool is_ctl);
static int dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc,
int level);
static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results);
@@ -2096,7 +2096,7 @@ static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
* system.
*/
if (dp->tree.stree[word] == NOFREE)
- dbBackSplit((dmtree_t *) & dp->tree, word);
+ dbBackSplit((dmtree_t *) & dp->tree, word, false);
dbAllocBits(bmp, dp, blkno, nblocks);
}
@@ -2182,7 +2182,7 @@ static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
* the binary system of the leaves if need be.
*/
dbSplit(tp, word, BUDMIN,
- dbMaxBud((u8 *) & dp->wmap[word]));
+ dbMaxBud((u8 *) & dp->wmap[word]),false);
word += 1;
} else {
@@ -2222,7 +2222,7 @@ static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
* system of the leaves to reflect the current
* allocation (size).
*/
- dbSplit(tp, word, size, NOFREE);
+ dbSplit(tp, word, size, NOFREE, false);
/* get the number of dmap words handled */
nw = BUDSIZE(size, BUDMIN);
@@ -2329,7 +2329,7 @@ static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
/* update the leaf for this dmap word.
*/
rc = dbJoin(tp, word,
- dbMaxBud((u8 *) & dp->wmap[word]));
+ dbMaxBud((u8 *) & dp->wmap[word]),false);
if (rc)
return rc;
@@ -2362,7 +2362,7 @@ static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
/* update the leaf.
*/
- rc = dbJoin(tp, word, size);
+ rc = dbJoin(tp, word, size, false);
if (rc)
return rc;
@@ -2514,16 +2514,16 @@ dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, int level)
* that it is at the front of a binary buddy system.
*/
if (oldval == NOFREE) {
- rc = dbBackSplit((dmtree_t *) dcp, leafno);
+ rc = dbBackSplit((dmtree_t *) dcp, leafno, true);
if (rc) {
release_metapage(mp);
return rc;
}
oldval = dcp->stree[ti];
}
- dbSplit((dmtree_t *) dcp, leafno, dcp->budmin, newval);
+ dbSplit((dmtree_t *) dcp, leafno, dcp->budmin, newval, true);
} else {
- rc = dbJoin((dmtree_t *) dcp, leafno, newval);
+ rc = dbJoin((dmtree_t *) dcp, leafno, newval, true);
if (rc) {
release_metapage(mp);
return rc;
@@ -2554,7 +2554,7 @@ dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, int level)
*/
if (alloc) {
dbJoin((dmtree_t *) dcp, leafno,
- oldval);
+ oldval, true);
} else {
/* the dbJoin() above might have
* caused a larger binary buddy system
@@ -2564,9 +2564,9 @@ dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, int level)
*/
if (dcp->stree[ti] == NOFREE)
dbBackSplit((dmtree_t *)
- dcp, leafno);
+ dcp, leafno, true);
dbSplit((dmtree_t *) dcp, leafno,
- dcp->budmin, oldval);
+ dcp->budmin, oldval, true);
}
/* release the buffer and return the error.
@@ -2614,7 +2614,7 @@ dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, int level)
*
* serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
*/
-static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval)
+static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval, bool is_ctl)
{
int budsz;
int cursz;
@@ -2636,7 +2636,7 @@ static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval)
while (cursz >= splitsz) {
/* update the buddy's leaf with its new value.
*/
- dbAdjTree(tp, leafno ^ budsz, cursz);
+ dbAdjTree(tp, leafno ^ budsz, cursz, is_ctl);
/* on to the next size and buddy.
*/
@@ -2648,7 +2648,7 @@ static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval)
/* adjust the dmap tree to reflect the specified leaf's new
* value.
*/
- dbAdjTree(tp, leafno, newval);
+ dbAdjTree(tp, leafno, newval, is_ctl);
}
@@ -2679,7 +2679,7 @@ static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval)
*
* serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
*/
-static int dbBackSplit(dmtree_t * tp, int leafno)
+static int dbBackSplit(dmtree_t * tp, int leafno, bool is_ctl)
{
int budsz, bud, w, bsz, size;
int cursz;
@@ -2730,7 +2730,7 @@ static int dbBackSplit(dmtree_t * tp, int leafno)
* system in two.
*/
cursz = leaf[bud] - 1;
- dbSplit(tp, bud, cursz, cursz);
+ dbSplit(tp, bud, cursz, cursz, is_ctl);
break;
}
}
@@ -2758,7 +2758,7 @@ static int dbBackSplit(dmtree_t * tp, int leafno)
*
* RETURN VALUES: none
*/
-static int dbJoin(dmtree_t * tp, int leafno, int newval)
+static int dbJoin(dmtree_t * tp, int leafno, int newval, bool is_ctl)
{
int budsz, buddy;
s8 *leaf;
@@ -2813,12 +2813,12 @@ static int dbJoin(dmtree_t * tp, int leafno, int newval)
if (leafno < buddy) {
/* leafno is the left buddy.
*/
- dbAdjTree(tp, buddy, NOFREE);
+ dbAdjTree(tp, buddy, NOFREE, is_ctl);
} else {
/* buddy is the left buddy and becomes
* leafno.
*/
- dbAdjTree(tp, leafno, NOFREE);
+ dbAdjTree(tp, leafno, NOFREE, is_ctl);
leafno = buddy;
}
@@ -2831,7 +2831,7 @@ static int dbJoin(dmtree_t * tp, int leafno, int newval)
/* update the leaf value.
*/
- dbAdjTree(tp, leafno, newval);
+ dbAdjTree(tp, leafno, newval, is_ctl);
return 0;
}
@@ -2852,15 +2852,20 @@ static int dbJoin(dmtree_t * tp, int leafno, int newval)
*
* RETURN VALUES: none
*/
-static void dbAdjTree(dmtree_t * tp, int leafno, int newval)
+static void dbAdjTree(dmtree_t * tp, int leafno, int newval, bool is_ctl)
{
int lp, pp, k;
- int max;
+ int max, size;
+
+ size = is_ctl ? CTLTREESIZE : TREESIZE;
/* pick up the index of the leaf for this leafno.
*/
lp = leafno + le32_to_cpu(tp->dmt_leafidx);
+ if (lp > size || lp < 0)
+ return;
+
/* is the current value the same as the old value ? if so,
* there is nothing to do.
*/