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![Tetsuo Handa](/assets/img/avatar_default.png)
[ Upstream commitd031f4e8b4
] syzbot is reporting that sec->length is not initialized. Since security_inode_init_security() returns 0 when initxattrs is provided but call_int_hook(inode_init_security) returned -EOPNOTSUPP, control will reach to "if (sec->length && ...) {" without initializing sec->length. Reported-by: syzbot <syzbot+00a3779539a23cbee38c@syzkaller.appspotmail.com> Closes: https://syzkaller.appspot.com/bug?extid=00a3779539a23cbee38c Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Fixes:52ca4b6435
("reiserfs: Switch to security_inode_init_security()") Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
127 lines
3.2 KiB
C
127 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include "reiserfs.h"
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/pagemap.h>
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#include <linux/xattr.h>
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#include <linux/slab.h>
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#include "xattr.h"
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#include <linux/security.h>
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#include <linux/uaccess.h>
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static int
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security_get(const struct xattr_handler *handler, struct dentry *unused,
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struct inode *inode, const char *name, void *buffer, size_t size)
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{
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if (IS_PRIVATE(inode))
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return -EPERM;
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return reiserfs_xattr_get(inode, xattr_full_name(handler, name),
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buffer, size);
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}
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static int
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security_set(const struct xattr_handler *handler,
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struct mnt_idmap *idmap, struct dentry *unused,
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struct inode *inode, const char *name, const void *buffer,
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size_t size, int flags)
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{
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if (IS_PRIVATE(inode))
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return -EPERM;
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return reiserfs_xattr_set(inode,
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xattr_full_name(handler, name),
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buffer, size, flags);
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}
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static bool security_list(struct dentry *dentry)
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{
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return !IS_PRIVATE(d_inode(dentry));
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}
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static int
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reiserfs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
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void *fs_info)
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{
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struct reiserfs_security_handle *sec = fs_info;
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sec->value = kmemdup(xattr_array->value, xattr_array->value_len,
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GFP_KERNEL);
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if (!sec->value)
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return -ENOMEM;
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sec->name = xattr_array->name;
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sec->length = xattr_array->value_len;
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return 0;
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}
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/* Initializes the security context for a new inode and returns the number
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* of blocks needed for the transaction. If successful, reiserfs_security
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* must be released using reiserfs_security_free when the caller is done. */
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int reiserfs_security_init(struct inode *dir, struct inode *inode,
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const struct qstr *qstr,
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struct reiserfs_security_handle *sec)
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{
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int blocks = 0;
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int error;
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sec->name = NULL;
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sec->value = NULL;
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sec->length = 0;
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/* Don't add selinux attributes on xattrs - they'll never get used */
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if (IS_PRIVATE(dir))
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return 0;
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error = security_inode_init_security(inode, dir, qstr,
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&reiserfs_initxattrs, sec);
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if (error) {
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sec->name = NULL;
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sec->value = NULL;
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sec->length = 0;
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return error;
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}
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if (sec->length && reiserfs_xattrs_initialized(inode->i_sb)) {
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blocks = reiserfs_xattr_jcreate_nblocks(inode) +
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reiserfs_xattr_nblocks(inode, sec->length);
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/* We don't want to count the directories twice if we have
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* a default ACL. */
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REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
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}
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return blocks;
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}
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int reiserfs_security_write(struct reiserfs_transaction_handle *th,
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struct inode *inode,
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struct reiserfs_security_handle *sec)
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{
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char xattr_name[XATTR_NAME_MAX + 1] = XATTR_SECURITY_PREFIX;
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int error;
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if (XATTR_SECURITY_PREFIX_LEN + strlen(sec->name) > XATTR_NAME_MAX)
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return -EINVAL;
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strlcat(xattr_name, sec->name, sizeof(xattr_name));
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error = reiserfs_xattr_set_handle(th, inode, xattr_name, sec->value,
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sec->length, XATTR_CREATE);
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if (error == -ENODATA || error == -EOPNOTSUPP)
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error = 0;
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return error;
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}
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void reiserfs_security_free(struct reiserfs_security_handle *sec)
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{
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kfree(sec->value);
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sec->name = NULL;
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sec->value = NULL;
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}
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const struct xattr_handler reiserfs_xattr_security_handler = {
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.prefix = XATTR_SECURITY_PREFIX,
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.get = security_get,
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.set = security_set,
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.list = security_list,
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};
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