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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Eric Biggers <ebiggers@google.com>
Subject: [PATCH 5.14 07/11] ext4: report correct st_size for encrypted symlinks
Date: Wed,  1 Sep 2021 14:29:15 +0200	[thread overview]
Message-ID: <20210901122249.761292606@linuxfoundation.org> (raw)
In-Reply-To: <20210901122249.520249736@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 |   12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

--- a/fs/ext4/symlink.c
+++ b/fs/ext4/symlink.c
@@ -52,10 +52,20 @@ static const char *ext4_encrypted_get_li
 	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,
 };
 



  parent reply	other threads:[~2021-09-01 12:55 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-01 12:29 [PATCH 5.14 00/11] 5.14.1-rc1 review Greg Kroah-Hartman
2021-09-01 12:29 ` [PATCH 5.14 01/11] vt_kdsetmode: extend console locking Greg Kroah-Hartman
2021-09-01 12:29 ` [PATCH 5.14 02/11] Bluetooth: btusb: check conditions before enabling USB ALT 3 for WBS Greg Kroah-Hartman
2021-09-01 12:29 ` [PATCH 5.14 03/11] net: dsa: mt7530: fix VLAN traffic leaks again Greg Kroah-Hartman
2021-09-01 12:29 ` [PATCH 5.14 04/11] btrfs: fix NULL pointer dereference when deleting device by invalid id Greg Kroah-Hartman
2021-09-01 12:29 ` [PATCH 5.14 05/11] Revert "floppy: reintroduce O_NDELAY fix" Greg Kroah-Hartman
2021-09-01 12:29 ` [PATCH 5.14 06/11] fscrypt: add fscrypt_symlink_getattr() for computing st_size Greg Kroah-Hartman
2021-09-01 12:29 ` Greg Kroah-Hartman [this message]
2021-09-01 12:29 ` [PATCH 5.14 08/11] f2fs: report correct st_size for encrypted symlinks Greg Kroah-Hartman
2021-09-01 12:29 ` [PATCH 5.14 09/11] ubifs: " Greg Kroah-Hartman
2021-09-01 12:29 ` [PATCH 5.14 10/11] net: dont unconditionally copy_from_user a struct ifreq for socket ioctls Greg Kroah-Hartman
2021-09-01 12:29 ` [PATCH 5.14 11/11] audit: move put_tree() to avoid trim_trees refcount underflow and UAF Greg Kroah-Hartman
2021-09-01 19:04 ` [PATCH 5.14 00/11] 5.14.1-rc1 review Fox Chen
2021-09-01 21:20 ` Shuah Khan
2021-09-02  8:44 ` Naresh Kamboju
2021-09-02 21:51 ` Guenter Roeck
2021-09-02 23:58 ` Florian Fainelli

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