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@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 8c4bca10ceafc43b1ca0a9fab5fa27e13cbce99e Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers@xxxxxxxxxx>
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@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20210702065350.209646-3-ebiggers@xxxxxxxxxx
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
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,
};
