From: Jia-Ju Bai <baijiaju1...@gmail.com> [ Upstream commit 2abb7d3b12d007c30193f48bebed781009bebdd2 ]
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-baijiaju1...@gmail.com Signed-off-by: Jia-Ju Bai <baijiaju1...@gmail.com> Reviewed-by: Joseph Qi <joseph...@linux.alibaba.com> Cc: Mark Fasheh <m...@fasheh.com> Cc: Joel Becker <jl...@evilplan.org> Cc: Junxiao Bi <junxiao...@oracle.com> Cc: Changwei Ge <gechang...@live.cn> Cc: Gang He <g...@suse.com> Cc: Jun Piao <piao...@huawei.com> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> Signed-off-by: Sasha Levin <sas...@kernel.org> --- 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 ab30c005cc4bc..9fa98abecfc6b 100644 --- a/fs/ocfs2/ioctl.c +++ b/fs/ocfs2/ioctl.c @@ -290,7 +290,7 @@ 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); -- 2.20.1