The patch below does not apply to the 4.4-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 8c4bca10ceafc43b1ca0a9fab5fa27e13cbce99e Mon Sep 17 00:00:00 2001

From: Eric Biggers ebiggers@google.com Date: Thu, 1 Jul 2021 23:53:47 -0700 Subject: [PATCH] ext4: 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 ext4_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: f348c252320b ("ext4 crypto: add symlink encryption") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210702065350.209646-3-ebiggers@kernel.org Signed-off-by: Eric Biggers ebiggers@google.com

diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c index dd05af983092..69109746e6e2 100644 --- a/fs/ext4/symlink.c +++ b/fs/ext4/symlink.c @@ -52,10 +52,20 @@ static const char *ext4_encrypted_get_link(struct dentry *dentry, return paddr; }

+static int ext4_encrypted_symlink_getattr(struct user_namespace *mnt_userns, + const struct path *path, + struct kstat *stat, u32 request_mask, + unsigned int query_flags) +{ + ext4_getattr(mnt_userns, path, stat, request_mask, query_flags); + + return fscrypt_symlink_getattr(path, stat); +} + const struct inode_operations ext4_encrypted_symlink_inode_operations = { .get_link = ext4_encrypted_get_link, .setattr = ext4_setattr, - .getattr = ext4_getattr, + .getattr = ext4_encrypted_symlink_getattr, .listxattr = ext4_listxattr, };