ipc: convert do_mq_open() to FD_ADD()

Christian Brauner <brauner@kernel.org> says:

The fix sent in [1] was squashed into this commit.

Fixes: https://lore.kernel.org/c41de645-8234-465f-a3be-f0385e3a163c@sirena.org.uk [1]
Reported-by: Mark Brown <broonie@kernel.org> [1]
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> [1]
Link: https://patch.msgid.link/20251123-work-fd-prepare-v4-22-b6efa1706cfd@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Christian Brauner 2025-11-23 17:33:40 +01:00
parent 1ad7810c6d
commit f2573685bd
No known key found for this signature in database
GPG Key ID: 91C61BC06578DCA2
1 changed files with 25 additions and 29 deletions

View File

@ -892,14 +892,35 @@ static int prepare_open(struct dentry *dentry, int oflag, int ro,
return inode_permission(&nop_mnt_idmap, d_inode(dentry), acc);
}
static struct file *mqueue_file_open(struct filename *name,
struct vfsmount *mnt, int oflag, bool ro,
umode_t mode, struct mq_attr *attr)
{
struct path path __free(path_put) = {};
struct dentry *dentry;
int ret;
dentry = lookup_noperm(&QSTR(name->name), mnt->mnt_root);
if (IS_ERR(dentry))
return ERR_CAST(dentry);
path.dentry = dentry;
path.mnt = mntget(mnt);
ret = prepare_open(path.dentry, oflag, ro, mode, name, attr);
if (ret)
return ERR_PTR(ret);
return dentry_open(&path, oflag, current_cred());
}
static int do_mq_open(const char __user *u_name, int oflag, umode_t mode,
struct mq_attr *attr)
{
struct filename *name __free(putname) = NULL;;
struct vfsmount *mnt = current->nsproxy->ipc_ns->mq_mnt;
struct dentry *root = mnt->mnt_root;
struct filename *name;
struct path path;
int fd, error;
int fd;
int ro;
audit_mq_open(oflag, mode, attr);
@ -908,37 +929,12 @@ static int do_mq_open(const char __user *u_name, int oflag, umode_t mode,
if (IS_ERR(name))
return PTR_ERR(name);
fd = get_unused_fd_flags(O_CLOEXEC);
if (fd < 0)
goto out_putname;
ro = mnt_want_write(mnt); /* we'll drop it in any case */
inode_lock(d_inode(root));
path.dentry = lookup_noperm(&QSTR(name->name), root);
if (IS_ERR(path.dentry)) {
error = PTR_ERR(path.dentry);
goto out_putfd;
}
path.mnt = mntget(mnt);
error = prepare_open(path.dentry, oflag, ro, mode, name, attr);
if (!error) {
struct file *file = dentry_open(&path, oflag, current_cred());
if (!IS_ERR(file))
fd_install(fd, file);
else
error = PTR_ERR(file);
}
path_put(&path);
out_putfd:
if (error) {
put_unused_fd(fd);
fd = error;
}
fd = FD_ADD(O_CLOEXEC, mqueue_file_open(name, mnt, oflag, ro, mode, attr));
inode_unlock(d_inode(root));
if (!ro)
mnt_drop_write(mnt);
out_putname:
putname(name);
return fd;
}