From: Edward Adam Davis eadavis@qq.com

stable inclusion from stable-v5.10.227 commit 2451e5917c56be45d4add786e2a059dd9c2c37c4 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYRAK CVE: CVE-2024-49902

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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[ Upstream commit d64ff0d2306713ff084d4b09f84ed1a8c75ecc32 ]

syzbot report a out of bounds in dbSplit, it because dmt_leafidx greater than num leaves per dmap tree, add a checking for dmt_leafidx in dbFindLeaf.

Shaggy: Modified sanity check to apply to control pages as well as leaf pages.

Reported-and-tested-by: syzbot+dca05492eff41f604890@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=dca05492eff41f604890 Signed-off-by: Edward Adam Davis eadavis@qq.com Signed-off-by: Dave Kleikamp dave.kleikamp@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yifan Qiao qiaoyifan4@huawei.com --- fs/jfs/jfs_dmap.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c index 2bbdae936076..fa12fc979799 100644 --- a/fs/jfs/jfs_dmap.c +++ b/fs/jfs/jfs_dmap.c @@ -3011,9 +3011,10 @@ static void dbAdjTree(dmtree_t *tp, int leafno, int newval, bool is_ctl) static int dbFindLeaf(dmtree_t *tp, int l2nb, int *leafidx, bool is_ctl) { int ti, n = 0, k, x = 0; - int max_size; + int max_size, max_idx;

max_size = is_ctl ? CTLTREESIZE : TREESIZE; + max_idx = is_ctl ? LPERCTL : LPERDMAP;

/* first check the root of the tree to see if there is * sufficient free space. @@ -3045,6 +3046,8 @@ static int dbFindLeaf(dmtree_t *tp, int l2nb, int *leafidx, bool is_ctl) */ assert(n < 4); } + if (le32_to_cpu(tp->dmt_leafidx) >= max_idx) + return -ENOSPC;

/* set the return to the leftmost leaf describing sufficient * free space.