From: Haimin Zhang tcs_kernel@tencent.com
[ Upstream commit a53046291020ec41e09181396c1e829287b48d47 ]
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 tcs_robot@tencent.com Signed-off-by: Haimin Zhang tcs_kernel@tencent.com Signed-off-by: Dave Kleikamp dave.kleikamp@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 87b41edc800d..68779cc3609a 100644 --- a/fs/jfs/inode.c +++ b/fs/jfs/inode.c @@ -156,12 +156,13 @@ 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);
/*