| From | Sasha Levin <> | Subject | [PATCH AUTOSEL 4.19 083/100] fs: ocfs2: fix a possible null-pointer dereference in ocfs2_info_scan_inode_alloc() | Date | Fri, 18 Oct 2019 18:05:08 -0400 |
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From: Jia-Ju Bai <baijiaju1990@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-baijiaju1990@gmail.com Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@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 994726ada857c..a6c328211dccd 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
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