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authorJuntong Deng <juntong.deng@outlook.com>2023-10-02 12:56:58 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-11-28 20:19:43 +0300
commit1a7c53fdea1d189087544d9a606d249e93c4934b (patch)
treec8b2b7aed7965411fab3e064001e1a5016d5274e /fs/jfs
parent8bbe784c2ff28d56ca0c548aaf3e584edc77052d (diff)
downloadlinux-1a7c53fdea1d189087544d9a606d249e93c4934b.tar.xz
fs/jfs: Add check for negative db_l2nbperpage
[ Upstream commit 525b861a008143048535011f3816d407940f4bfa ] l2nbperpage is log2(number of blks per page), and the minimum legal value should be 0, not negative. In the case of l2nbperpage being negative, an error will occur when subsequently used as shift exponent. Syzbot reported this bug: UBSAN: shift-out-of-bounds in fs/jfs/jfs_dmap.c:799:12 shift exponent -16777216 is negative Reported-by: syzbot+debee9ab7ae2b34b0307@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=debee9ab7ae2b34b0307 Signed-off-by: Juntong Deng <juntong.deng@outlook.com> Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/jfs')
-rw-r--r--fs/jfs/jfs_dmap.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index 88afd108c2dd..3a1842348112 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -180,7 +180,8 @@ int dbMount(struct inode *ipbmap)
bmp->db_nfree = le64_to_cpu(dbmp_le->dn_nfree);
bmp->db_l2nbperpage = le32_to_cpu(dbmp_le->dn_l2nbperpage);
- if (bmp->db_l2nbperpage > L2PSIZE - L2MINBLOCKSIZE) {
+ if (bmp->db_l2nbperpage > L2PSIZE - L2MINBLOCKSIZE ||
+ bmp->db_l2nbperpage < 0) {
err = -EINVAL;
goto err_release_metapage;
}