Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL 4.9 21/29] fs: ocfs2: fix a possible null-pointer dereference in ocfs2_write_end_nolock() | Date | Fri, 18 Oct 2019 18:09:12 -0400 |
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From: Jia-Ju Bai <baijiaju1990@gmail.com>
[ Upstream commit 583fee3e12df0e6f1f66f063b989d8e7fed0e65a ]
In ocfs2_write_end_nolock(), there are an if statement on lines 1976, 2047 and 2058, to check whether handle is NULL:
if (handle)
When handle is NULL, it is used on line 2045:
ocfs2_update_inode_fsync_trans(handle, inode, 1); oi->i_sync_tid = handle->h_transaction->t_tid;
Thus, a possible null-pointer dereference may occur.
To fix this bug, handle is checked before calling ocfs2_update_inode_fsync_trans().
This bug is found by a static analysis tool STCheck written by us.
Link: http://lkml.kernel.org/r/20190726033705.32307-1-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/aops.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c index 7c20a23c0ed7d..6ad76397b31de 100644 --- a/fs/ocfs2/aops.c +++ b/fs/ocfs2/aops.c @@ -2046,7 +2046,8 @@ int ocfs2_write_end_nolock(struct address_space *mapping, inode->i_mtime = inode->i_ctime = current_time(inode); di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec); di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec); - ocfs2_update_inode_fsync_trans(handle, inode, 1); + if (handle) + ocfs2_update_inode_fsync_trans(handle, inode, 1); } if (handle) ocfs2_journal_dirty(handle, wc->w_di_bh); -- 2.20.1
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