From 909e22e05353a783c526829427e9a8de122fba9c Mon Sep 17 00:00:00 2001 From: YueHaibing Date: Mon, 19 Nov 2018 11:32:41 +0800 Subject: exportfs: fix 'passing zero to ERR_PTR()' warning Fix a static code checker warning: fs/exportfs/expfs.c:171 reconnect_one() warn: passing zero to 'ERR_PTR' The error path for lookup_one_len_unlocked failure should set err to PTR_ERR. Fixes: bbf7a8a3562f ("exportfs: move most of reconnect_path to helper function") Signed-off-by: YueHaibing Signed-off-by: Al Viro --- fs/exportfs/expfs.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/exportfs/expfs.c') diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c index 645158dc33f1..c8a3dfda1764 100644 --- a/fs/exportfs/expfs.c +++ b/fs/exportfs/expfs.c @@ -147,6 +147,7 @@ static struct dentry *reconnect_one(struct vfsmount *mnt, tmp = lookup_one_len_unlocked(nbuf, parent, strlen(nbuf)); if (IS_ERR(tmp)) { dprintk("%s: lookup failed: %d\n", __func__, PTR_ERR(tmp)); + err = PTR_ERR(tmp); goto out_err; } if (tmp != dentry) { -- cgit v1.2.3 From 2084ac6c505a58f7efdec13eba633c6aaa085ca5 Mon Sep 17 00:00:00 2001 From: Pan Bian Date: Fri, 23 Nov 2018 15:56:33 +0800 Subject: exportfs: do not read dentry after free The function dentry_connected calls dput(dentry) to drop the previously acquired reference to dentry. In this case, dentry can be released. After that, IS_ROOT(dentry) checks the condition (dentry == dentry->d_parent), which may result in a use-after-free bug. This patch directly compares dentry with its parent obtained before dropping the reference. Fixes: a056cc8934c("exportfs: stop retrying once we race with rename/remove") Signed-off-by: Pan Bian Signed-off-by: Al Viro --- fs/exportfs/expfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/exportfs/expfs.c') diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c index c8a3dfda1764..c69927bed4ef 100644 --- a/fs/exportfs/expfs.c +++ b/fs/exportfs/expfs.c @@ -77,7 +77,7 @@ static bool dentry_connected(struct dentry *dentry) struct dentry *parent = dget_parent(dentry); dput(dentry); - if (IS_ROOT(dentry)) { + if (dentry == parent) { dput(parent); return false; } -- cgit v1.2.3