From f67b55b6588bcf9316a1e6e8d529100a5aa3ebe6 Mon Sep 17 00:00:00 2001 From: Benjamin Coddington Date: Tue, 22 Aug 2023 14:22:38 -0400 Subject: NFS: Guard against READDIR loop when entry names exceed MAXNAMELEN Commit 64cfca85bacd asserts the only valid return values for nfs2/3_decode_dirent should not include -ENAMETOOLONG, but for a server that sends a filename3 which exceeds MAXNAMELEN in a READDIR response the client's behavior will be to endlessly retry the operation. We could map -ENAMETOOLONG into -EBADCOOKIE, but that would produce truncated listings without any error. The client should return an error for this case to clearly assert that the server implementation must be corrected. Fixes: 64cfca85bacd ("NFS: Return valid errors from nfs2/3_decode_dirent()") Signed-off-by: Benjamin Coddington Signed-off-by: Anna Schumaker --- fs/nfs/nfs2xdr.c | 2 +- fs/nfs/nfs3xdr.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/nfs') diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c index 05c3b4b2b3dd..c19093814296 100644 --- a/fs/nfs/nfs2xdr.c +++ b/fs/nfs/nfs2xdr.c @@ -949,7 +949,7 @@ int nfs2_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry, error = decode_filename_inline(xdr, &entry->name, &entry->len); if (unlikely(error)) - return -EAGAIN; + return error == -ENAMETOOLONG ? -ENAMETOOLONG : -EAGAIN; /* * The type (size and byte order) of nfscookie isn't defined in diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c index 3b0b650c9c5a..60f032be805a 100644 --- a/fs/nfs/nfs3xdr.c +++ b/fs/nfs/nfs3xdr.c @@ -1991,7 +1991,7 @@ int nfs3_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry, error = decode_inline_filename3(xdr, &entry->name, &entry->len); if (unlikely(error)) - return -EAGAIN; + return error == -ENAMETOOLONG ? -ENAMETOOLONG : -EAGAIN; error = decode_cookie3(xdr, &new_cookie); if (unlikely(error)) -- cgit v1.2.3