linux_dsm_epyc7002/fs/ext4/symlink.c
Eric Biggers f99cbf2880 ext4: report correct st_size for encrypted symlinks
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: f348c25232 ("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>
2024-07-05 19:03:30 +02:00

134 lines
3.7 KiB
C

#ifndef MY_ABC_HERE
#define MY_ABC_HERE
#endif
// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/ext4/symlink.c
*
* Only fast symlinks left here - the rest is done by generic code. AV, 1999
*
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* from
*
* linux/fs/minix/symlink.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* ext4 symlink handling code
*/
#include <linux/fs.h>
#include <linux/namei.h>
#include "ext4.h"
#include "xattr.h"
static const char *ext4_encrypted_get_link(struct dentry *dentry,
struct inode *inode,
struct delayed_call *done)
{
struct page *cpage = NULL;
const void *caddr;
unsigned int max_size;
const char *paddr;
if (!dentry)
return ERR_PTR(-ECHILD);
if (ext4_inode_is_fast_symlink(inode)) {
caddr = EXT4_I(inode)->i_data;
max_size = sizeof(EXT4_I(inode)->i_data);
} else {
cpage = read_mapping_page(inode->i_mapping, 0, NULL);
if (IS_ERR(cpage))
return ERR_CAST(cpage);
caddr = page_address(cpage);
max_size = inode->i_sb->s_blocksize;
}
paddr = fscrypt_get_symlink(inode, caddr, max_size, done);
if (cpage)
put_page(cpage);
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 = {
#ifdef MY_ABC_HERE
.syno_getattr = ext4_syno_getattr,
#endif /* MY_ABC_HERE */
#if defined(MY_ABC_HERE) || defined(MY_ABC_HERE)
.syno_set_archive_bit = ext4_syno_set_archive_bit,
#endif /* MY_ABC_HERE || MY_ABC_HERE */
#ifdef MY_ABC_HERE
.syno_get_archive_version = ext4_syno_get_inode_archive_version,
.syno_set_archive_version = ext4_syno_set_inode_archive_version,
#endif /* MY_ABC_HERE */
.get_link = ext4_encrypted_get_link,
.setattr = ext4_setattr,
.getattr = ext4_encrypted_symlink_getattr,
.listxattr = ext4_listxattr,
#ifdef MY_ABC_HERE
.syno_get_crtime = ext4_syno_get_crtime,
.syno_set_crtime = ext4_syno_set_crtime,
#endif /* MY_ABC_HERE */
};
const struct inode_operations ext4_symlink_inode_operations = {
#ifdef MY_ABC_HERE
.syno_getattr = ext4_syno_getattr,
#endif /* MY_ABC_HERE */
#if defined(MY_ABC_HERE) || defined(MY_ABC_HERE)
.syno_set_archive_bit = ext4_syno_set_archive_bit,
#endif /* MY_ABC_HERE || MY_ABC_HERE */
#ifdef MY_ABC_HERE
.syno_get_archive_version = ext4_syno_get_inode_archive_version,
.syno_set_archive_version = ext4_syno_set_inode_archive_version,
#endif /* MY_ABC_HERE */
.get_link = page_get_link,
.setattr = ext4_setattr,
.getattr = ext4_getattr,
.listxattr = ext4_listxattr,
#ifdef MY_ABC_HERE
.syno_get_crtime = ext4_syno_get_crtime,
.syno_set_crtime = ext4_syno_set_crtime,
#endif /* MY_ABC_HERE */
};
const struct inode_operations ext4_fast_symlink_inode_operations = {
#ifdef MY_ABC_HERE
.syno_getattr = ext4_syno_getattr,
#endif /* MY_ABC_HERE */
#if defined(MY_ABC_HERE) || defined(MY_ABC_HERE)
.syno_set_archive_bit = ext4_syno_set_archive_bit,
#endif /* MY_ABC_HERE || MY_ABC_HERE */
#ifdef MY_ABC_HERE
.syno_get_archive_version = ext4_syno_get_inode_archive_version,
.syno_set_archive_version = ext4_syno_set_inode_archive_version,
#endif /* MY_ABC_HERE */
.get_link = simple_get_link,
.setattr = ext4_setattr,
.getattr = ext4_getattr,
.listxattr = ext4_listxattr,
#ifdef MY_ABC_HERE
.syno_get_crtime = ext4_syno_get_crtime,
.syno_set_crtime = ext4_syno_set_crtime,
#endif /* MY_ABC_HERE */
};
#ifdef MY_ABC_HERE
const struct file_operations ext4_symlink_file_operations = {
.unlocked_ioctl = ext4_symlink_ioctl,
};
#endif /* MY_ABC_HERE */