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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-fscrypt@vger.kernel.org, Eric Biggers <ebiggers@google.com>
Subject: [PATCH 5.10 03/29] ext4: report correct st_size for encrypted symlinks
Date: Mon,  6 Sep 2021 14:55:18 +0200	[thread overview]
Message-ID: <20210906125449.877712012@linuxfoundation.org> (raw)
In-Reply-To: <20210906125449.756437409@linuxfoundation.org>

From: Eric Biggers <ebiggers@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@vger.kernel.org
Link: https://lore.kernel.org/r/20210702065350.209646-3-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@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,
 };
 



  parent reply	other threads:[~2021-09-06 12:56 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20210906125449.756437409@linuxfoundation.org>
2021-09-06 12:55 ` [PATCH 5.10 02/29] fscrypt: add fscrypt_symlink_getattr() for computing st_size Greg Kroah-Hartman
2021-09-06 12:55 ` Greg Kroah-Hartman [this message]
2021-09-06 12:55 ` [PATCH 5.10 04/29] f2fs: report correct st_size for encrypted symlinks Greg Kroah-Hartman
2021-09-06 12:55 ` [PATCH 5.10 05/29] ubifs: " Greg Kroah-Hartman

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