linux-kernel - [PATCH 4/4] namei: make sure nd->depth is always valid

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Message-Id: <20210608113924.1391062-4-viro@zeniv.linux.org.uk>
Date:   Tue,  8 Jun 2021 11:39:24 +0000
From:   Al Viro <viro@...iv.linux.org.uk>
To:     linux-fsdevel@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org
Subject: [PATCH 4/4] namei: make sure nd->depth is always valid

Zero it in set_nameidata() rather than in path_init().  That way
it always matches the number of valid nd->stack[] entries.
Since terminate_walk() does zero it (after having emptied the
stack), we don't need to reinitialize it in subsequent path_init().

Signed-off-by: Al Viro <viro@...iv.linux.org.uk>
---
 fs/namei.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/namei.c b/fs/namei.c
index 40ffb249aa7f..d38b17ad604c 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -581,6 +581,7 @@ static void __set_nameidata(struct nameidata *p, int dfd, struct filename *name)
 {
 	struct nameidata *old = current->nameidata;
 	p->stack = p->internal;
+	p->depth = 0;
 	p->dfd = dfd;
 	p->name = name;
 	p->path.mnt = NULL;
@@ -2320,7 +2321,6 @@ static const char *path_init(struct nameidata *nd, unsigned flags)
 
 	nd->flags = flags;
 	nd->state |= ND_JUMPED;
-	nd->depth = 0;
 
 	nd->m_seq = __read_seqcount_begin(&mount_lock.seqcount);
 	nd->r_seq = __read_seqcount_begin(&rename_lock.seqcount);
-- 
2.11.0