From 2abb7d3b12d007c30193f48bebed781009bebdd2 Mon Sep 17 00:00:00 2001 From: Jia-Ju Bai Date: Sun, 6 Oct 2019 17:57:57 -0700 Subject: [PATCH] fs: ocfs2: fix a possible null-pointer dereference in ocfs2_info_scan_inode_alloc() In ocfs2_info_scan_inode_alloc(), there is an if statement on line 283 to check whether inode_alloc is NULL: if (inode_alloc) When inode_alloc is NULL, it is used on line 287: ocfs2_inode_lock(inode_alloc, &bh, 0); ocfs2_inode_lock_full_nested(inode, ...) struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); Thus, a possible null-pointer dereference may occur. To fix this bug, inode_alloc is checked on line 286. This bug is found by a static analysis tool STCheck written by us. Link: http://lkml.kernel.org/r/20190726033717.32359-1-baijiaju1990@gmail.com Signed-off-by: Jia-Ju Bai Reviewed-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Gang He Cc: Jun Piao Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ocfs2/ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ocfs2/ioctl.c b/fs/ocfs2/ioctl.c index d6f7b299eb23..efeea208fdeb 100644 --- a/fs/ocfs2/ioctl.c +++ b/fs/ocfs2/ioctl.c @@ -283,7 +283,7 @@ static int ocfs2_info_scan_inode_alloc(struct ocfs2_super *osb, if (inode_alloc) inode_lock(inode_alloc); - if (o2info_coherent(&fi->ifi_req)) { + if (inode_alloc && o2info_coherent(&fi->ifi_req)) { status = ocfs2_inode_lock(inode_alloc, &bh, 0); if (status < 0) { mlog_errno(status);