Re: Patch "f2fs: report correct st_size for encrypted symlinks" has been added to the 5.4-stable tree

Re: Patch "f2fs: report correct st_size for encrypted symlinks" has been added to the 5.4-stable tree

[Greg KH]

On Wed, Sep 01, 2021 at 12:52:46PM +0200, gregkh@linuxfoundation.org wrote:
> 
> This is a note to let you know that I've just added the patch titled
> 
>     f2fs: 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

Oops, nope, breaks the build, now dropping.

Patch "f2fs: report correct st_size for encrypted symlinks" has been added to the 5.4-stable tree

[gregkh]

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

    f2fs: 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:
     f2fs-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@vger.kernel.org> know about it.


From foo@baz Fri Sep  3 03:56:23 PM CEST 2021
From: Eric Biggers <ebiggers@kernel.org>
Date: Wed,  1 Sep 2021 09:40:40 -0700
Subject: f2fs: report correct st_size for encrypted symlinks
To: stable@vger.kernel.org
Cc: linux-fscrypt@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org
Message-ID: <20210901164041.176238-4-ebiggers@kernel.org>

From: Eric Biggers <ebiggers@google.com>

commit 461b43a8f92e68e96c4424b31e15f2b35f1bbfa9 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 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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/f2fs/namei.c |   11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -1256,9 +1256,18 @@ static const char *f2fs_encrypted_get_li
 	return target;
 }
 
+static int f2fs_encrypted_symlink_getattr(const struct path *path,
+					  struct kstat *stat, u32 request_mask,
+					  unsigned int query_flags)
+{
+	f2fs_getattr(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,
 #ifdef CONFIG_F2FS_FS_XATTR
 	.listxattr	= f2fs_listxattr,


Patches currently in stable-queue which might be from ebiggers@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

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