The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 064c734986011390b4d111f1a99372b7f26c3850 Mon Sep 17 00:00:00 2001
From: Eric Biggers ebiggers@google.com Date: Thu, 1 Jul 2021 23:53:49 -0700 Subject: [PATCH] ubifs: report correct st_size for encrypted symlinks
The stat() family of syscalls report the wrong size for encrypted symlinks, which has caused breakage in several userspace programs.
Fix this by calling fscrypt_symlink_getattr() after ubifs_getattr() for encrypted symlinks. This function computes the correct size by reading and decrypting the symlink target (if it's not already cached).
For more details, see the commit which added fscrypt_symlink_getattr().
Fixes: ca7f85be8d6c ("ubifs: Add support for encrypted symlinks") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210702065350.209646-5-ebiggers@kernel.org Signed-off-by: Eric Biggers ebiggers@google.com
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c index 2e4e1d159969..5cfa28cd00cd 100644 --- a/fs/ubifs/file.c +++ b/fs/ubifs/file.c @@ -1630,6 +1630,17 @@ static const char *ubifs_get_link(struct dentry *dentry, return fscrypt_get_symlink(inode, ui->data, ui->data_len, done); }
+static int ubifs_symlink_getattr(struct user_namespace *mnt_userns, + const struct path *path, struct kstat *stat, + u32 request_mask, unsigned int query_flags) +{ + ubifs_getattr(mnt_userns, path, stat, request_mask, query_flags); + + if (IS_ENCRYPTED(d_inode(path->dentry))) + return fscrypt_symlink_getattr(path, stat); + return 0; +} + const struct address_space_operations ubifs_file_address_operations = { .readpage = ubifs_readpage, .writepage = ubifs_writepage, @@ -1655,7 +1666,7 @@ const struct inode_operations ubifs_file_inode_operations = { const struct inode_operations ubifs_symlink_inode_operations = { .get_link = ubifs_get_link, .setattr = ubifs_setattr, - .getattr = ubifs_getattr, + .getattr = ubifs_symlink_getattr, .listxattr = ubifs_listxattr, .update_time = ubifs_update_time, };