mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-18 09:16:55 +07:00
36cf9ae54b
[ Upstream commit 5d069dbe8aaf2a197142558b6fb2978189ba3454 ]
Jan Kara's analysis of the syzbot report (edited):
The reproducer opens a directory on FUSE filesystem, it then attaches
dnotify mark to the open directory. After that a fuse_do_getattr() call
finds that attributes returned by the server are inconsistent, and calls
make_bad_inode() which, among other things does:
inode->i_mode = S_IFREG;
This then confuses dnotify which doesn't tear down its structures
properly and eventually crashes.
Avoid calling make_bad_inode() on a live inode: switch to a private flag on
the fuse inode. Also add the test to ops which the bad_inode_ops would
have caught.
This bug goes back to the initial merge of fuse in 2.6.14...
Reported-by: syzbot+f427adf9324b92652ccc@syzkaller.appspotmail.com
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Tested-by: Jan Kara <jack@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
106 lines
2.3 KiB
C
106 lines
2.3 KiB
C
/*
|
|
* FUSE: Filesystem in Userspace
|
|
* Copyright (C) 2016 Canonical Ltd. <seth.forshee@canonical.com>
|
|
*
|
|
* This program can be distributed under the terms of the GNU GPL.
|
|
* See the file COPYING.
|
|
*/
|
|
|
|
#include "fuse_i.h"
|
|
|
|
#include <linux/posix_acl.h>
|
|
#include <linux/posix_acl_xattr.h>
|
|
|
|
struct posix_acl *fuse_get_acl(struct inode *inode, int type)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
int size;
|
|
const char *name;
|
|
void *value = NULL;
|
|
struct posix_acl *acl;
|
|
|
|
if (fuse_is_bad(inode))
|
|
return ERR_PTR(-EIO);
|
|
|
|
if (!fc->posix_acl || fc->no_getxattr)
|
|
return NULL;
|
|
|
|
if (type == ACL_TYPE_ACCESS)
|
|
name = XATTR_NAME_POSIX_ACL_ACCESS;
|
|
else if (type == ACL_TYPE_DEFAULT)
|
|
name = XATTR_NAME_POSIX_ACL_DEFAULT;
|
|
else
|
|
return ERR_PTR(-EOPNOTSUPP);
|
|
|
|
value = kmalloc(PAGE_SIZE, GFP_KERNEL);
|
|
if (!value)
|
|
return ERR_PTR(-ENOMEM);
|
|
size = fuse_getxattr(inode, name, value, PAGE_SIZE);
|
|
if (size > 0)
|
|
acl = posix_acl_from_xattr(fc->user_ns, value, size);
|
|
else if ((size == 0) || (size == -ENODATA) ||
|
|
(size == -EOPNOTSUPP && fc->no_getxattr))
|
|
acl = NULL;
|
|
else if (size == -ERANGE)
|
|
acl = ERR_PTR(-E2BIG);
|
|
else
|
|
acl = ERR_PTR(size);
|
|
|
|
kfree(value);
|
|
return acl;
|
|
}
|
|
|
|
int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
const char *name;
|
|
int ret;
|
|
|
|
if (fuse_is_bad(inode))
|
|
return -EIO;
|
|
|
|
if (!fc->posix_acl || fc->no_setxattr)
|
|
return -EOPNOTSUPP;
|
|
|
|
if (type == ACL_TYPE_ACCESS)
|
|
name = XATTR_NAME_POSIX_ACL_ACCESS;
|
|
else if (type == ACL_TYPE_DEFAULT)
|
|
name = XATTR_NAME_POSIX_ACL_DEFAULT;
|
|
else
|
|
return -EINVAL;
|
|
|
|
if (acl) {
|
|
/*
|
|
* Fuse userspace is responsible for updating access
|
|
* permissions in the inode, if needed. fuse_setxattr
|
|
* invalidates the inode attributes, which will force
|
|
* them to be refreshed the next time they are used,
|
|
* and it also updates i_ctime.
|
|
*/
|
|
size_t size = posix_acl_xattr_size(acl->a_count);
|
|
void *value;
|
|
|
|
if (size > PAGE_SIZE)
|
|
return -E2BIG;
|
|
|
|
value = kmalloc(size, GFP_KERNEL);
|
|
if (!value)
|
|
return -ENOMEM;
|
|
|
|
ret = posix_acl_to_xattr(fc->user_ns, acl, value, size);
|
|
if (ret < 0) {
|
|
kfree(value);
|
|
return ret;
|
|
}
|
|
|
|
ret = fuse_setxattr(inode, name, value, size, 0);
|
|
kfree(value);
|
|
} else {
|
|
ret = fuse_removexattr(inode, name);
|
|
}
|
|
forget_all_cached_acls(inode);
|
|
fuse_invalidate_attr(inode);
|
|
|
|
return ret;
|
|
}
|