From 0511fdb4a378183ca18a9678d3d9044c8ec592c2 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 19 Sep 2023 22:28:16 -0400 Subject: [PATCH] cifs_get_link(): bail out in unsafe case ->d_revalidate() bails out there, anyway. It's not enough to prevent getting into ->get_link() in RCU mode, but that could happen only in a very contrieved setup. Not worth trying to do anything fancy here unless ->d_revalidate() stops kicking out of RCU mode at least in some cases. Reviewed-by: Christian Brauner Acked-by: Miklos Szeredi Signed-off-by: Al Viro --- fs/smb/client/cifsfs.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/smb/client/cifsfs.c b/fs/smb/client/cifsfs.c index e902de4e475a..630e74628dfe 100644 --- a/fs/smb/client/cifsfs.c +++ b/fs/smb/client/cifsfs.c @@ -1172,6 +1172,9 @@ const char *cifs_get_link(struct dentry *dentry, struct inode *inode, { char *target_path; + if (!dentry) + return ERR_PTR(-ECHILD); + target_path = kmalloc(PATH_MAX, GFP_KERNEL); if (!target_path) return ERR_PTR(-ENOMEM);