From a53046291020ec41e09181396c1e829287b48d47 Mon Sep 17 00:00:00 2001 From: Haimin Zhang Date: Tue, 22 Mar 2022 21:59:17 +0800 Subject: [PATCH] jfs: prevent NULL deref in diFree Add validation check for JFS_IP(ipimap)->i_imap to prevent a NULL deref in diFree since diFree uses it without do any validations. When function jfs_mount calls diMount to initialize fileset inode allocation map, it can fail and JFS_IP(ipimap)->i_imap won't be initialized. Then it calls diFreeSpecial to close fileset inode allocation map inode and it will flow into jfs_evict_inode. Function jfs_evict_inode just validates JFS_SBI(inode->i_sb)->ipimap, then calls diFree. diFree use JFS_IP(ipimap)->i_imap directly, then it will cause a NULL deref. Reported-by: TCS Robot Signed-off-by: Haimin Zhang Signed-off-by: Dave Kleikamp --- fs/jfs/inode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/jfs/inode.c b/fs/jfs/inode.c index 57ab424c05ff..072821b50ab9 100644 --- a/fs/jfs/inode.c +++ b/fs/jfs/inode.c @@ -146,12 +146,13 @@ void jfs_evict_inode(struct inode *inode) dquot_initialize(inode); if (JFS_IP(inode)->fileset == FILESYSTEM_I) { + struct inode *ipimap = JFS_SBI(inode->i_sb)->ipimap; truncate_inode_pages_final(&inode->i_data); if (test_cflag(COMMIT_Freewmap, inode)) jfs_free_zero_link(inode); - if (JFS_SBI(inode->i_sb)->ipimap) + if (ipimap && JFS_IP(ipimap)->i_imap) diFree(inode); /*