6.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Olga Kornievskaia <kolga@xxxxxxxxxx> [ Upstream commit 28568c906c1bb5f7560e18082ed7d6295860f1c2 ] In commit 4ca9f31a2be66 ("NFSv4.1 test and add 4.1 trunking transport"), we introduce the ability to query the NFS server for possible trunking locations of the existing filesystem. However, we never checked the returned file system path for these alternative locations. According to the RFC, the server can say that the filesystem currently known under "fs_root" of fs_location also resides under these server locations under the following "rootpath" pathname. The client cannot handle trunking a filesystem that reside under different location under different paths other than what the main path is. This patch enforces the check that fs_root path and rootpath path in fs_location reply is the same. Fixes: 4ca9f31a2be6 ("NFSv4.1 test and add 4.1 trunking transport") Signed-off-by: Olga Kornievskaia <kolga@xxxxxxxxxx> Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- fs/nfs/nfs4proc.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index c93c12063b3af..3a816c4a6d5e2 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -4023,6 +4023,23 @@ static void test_fs_location_for_trunking(struct nfs4_fs_location *location, } } +static bool _is_same_nfs4_pathname(struct nfs4_pathname *path1, + struct nfs4_pathname *path2) +{ + int i; + + if (path1->ncomponents != path2->ncomponents) + return false; + for (i = 0; i < path1->ncomponents; i++) { + if (path1->components[i].len != path2->components[i].len) + return false; + if (memcmp(path1->components[i].data, path2->components[i].data, + path1->components[i].len)) + return false; + } + return true; +} + static int _nfs4_discover_trunking(struct nfs_server *server, struct nfs_fh *fhandle) { @@ -4056,9 +4073,13 @@ static int _nfs4_discover_trunking(struct nfs_server *server, if (status) goto out_free_3; - for (i = 0; i < locations->nlocations; i++) + for (i = 0; i < locations->nlocations; i++) { + if (!_is_same_nfs4_pathname(&locations->fs_path, + &locations->locations[i].rootpath)) + continue; test_fs_location_for_trunking(&locations->locations[i], clp, server); + } out_free_3: kfree(locations->fattr); out_free_2: -- 2.43.0