The patch below does not apply to the 5.10-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 461b43a8f92e68e96c4424b31e15f2b35f1bbfa9 Mon Sep 17 00:00:00 2001

From: Eric Biggers ebiggers@google.com Date: Thu, 1 Jul 2021 23:53:48 -0700 Subject: [PATCH] f2fs: 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 f2fs_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: cbaf042a3cc6 ("f2fs crypto: add symlink encryption") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210702065350.209646-4-ebiggers@kernel.org Signed-off-by: Eric Biggers ebiggers@google.com

diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c index e149c8c66a71..9c528e583c9d 100644 --- a/fs/f2fs/namei.c +++ b/fs/f2fs/namei.c @@ -1323,9 +1323,19 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry, return target; }

+static int f2fs_encrypted_symlink_getattr(struct user_namespace *mnt_userns, + const struct path *path, + struct kstat *stat, u32 request_mask, + unsigned int query_flags) +{ + f2fs_getattr(mnt_userns, path, stat, request_mask, query_flags); + + return fscrypt_symlink_getattr(path, stat); +} + const struct inode_operations f2fs_encrypted_symlink_inode_operations = { .get_link = f2fs_encrypted_get_link, - .getattr = f2fs_getattr, + .getattr = f2fs_encrypted_symlink_getattr, .setattr = f2fs_setattr, .listxattr = f2fs_listxattr, };