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authorJuntong Deng <juntong.deng@outlook.com>2023-10-02 17:56:58 +0800
committerDave Kleikamp <dave.kleikamp@oracle.com>2023-10-03 18:26:59 -0500
commit525b861a008143048535011f3816d407940f4bfa (patch)
treec31a9cf4a97ab842d6fd3e19c4a746f133b9fff9 /fs/jfs
parent5e62ed3b1c8a397185af53d6b94f04b9ff21ec7d (diff)
fs/jfs: Add check for negative db_l2nbperpage
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>
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;
}