Patch "ext4: report correct st_size for encrypted symlinks" has been added to the 5.4-stable tree

[gregkh at linuxfoundation.org]

This is a note to let you know that I've just added the patch titled

    ext4: report correct st_size for encrypted symlinks

to the 5.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ext4-report-correct-st_size-for-encrypted-symlinks.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable at vger.kernel.org> know about it.


>From foo at baz Fri Sep  3 03:56:23 PM CEST 2021
From: Eric Biggers <ebiggers at kernel.org>
Date: Wed,  1 Sep 2021 09:40:39 -0700
Subject: ext4: report correct st_size for encrypted symlinks
To: stable at vger.kernel.org
Cc: linux-fscrypt at vger.kernel.org, linux-ext4 at vger.kernel.org, linux-f2fs-devel at lists.sourceforge.net, linux-mtd at lists.infradead.org
Message-ID: <20210901164041.176238-3-ebiggers at kernel.org>

From: Eric Biggers <ebiggers at google.com>

commit 8c4bca10ceafc43b1ca0a9fab5fa27e13cbce99e upstream.

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 at vger.kernel.org
Link: https://lore.kernel.org/r/20210702065350.209646-3-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers at google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 fs/ext4/symlink.c |   11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

--- a/fs/ext4/symlink.c
+++ b/fs/ext4/symlink.c
@@ -52,10 +52,19 @@ static const char *ext4_encrypted_get_li
 	return paddr;
 }
 
+static int ext4_encrypted_symlink_getattr(const struct path *path,
+					  struct kstat *stat, u32 request_mask,
+					  unsigned int query_flags)
+{
+	ext4_getattr(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,
 };
 


Patches currently in stable-queue which might be from ebiggers at kernel.org are

queue-5.4/ubifs-report-correct-st_size-for-encrypted-symlinks.patch
queue-5.4/ext4-report-correct-st_size-for-encrypted-symlinks.patch
queue-5.4/fscrypt-add-fscrypt_symlink_getattr-for-computing-st_size.patch
queue-5.4/f2fs-report-correct-st_size-for-encrypted-symlinks.patch