Commit ee7b127d authored by Max Kellermann's avatar Max Kellermann Committed by Zizhi Wo
Browse files

fs/pipe: move check to pipe_has_watch_queue() 

stable inclusion
from stable-v5.10.210
commit b6f27626f56e44c2437cf66e183e9e1a844cac19
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9Q9EU
CVE: CVE-2023-52672

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b6f27626f56e44c2437cf66e183e9e1a844cac19



--------------------------------

[ Upstream commit b4bd6b4bac8edd61eb8f7b836969d12c0c6af165 ]

This declutters the code by reducing the number of #ifdefs and makes
the watch_queue checks simpler.  This has no runtime effect; the
machine code is identical.

Signed-off-by: default avatarMax Kellermann <max.kellermann@ionos.com>
Message-Id: <20230921075755.1378787-2-max.kellermann@ionos.com>
Reviewed-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
Stable-dep-of: e95aada4cb93 ("pipe: wakeup wr_wait after setting max_usage")
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarZizhi Wo <wozizhi@huawei.com>
parent 43993247

fs/pipe.c

+3 −9
Original line number Diff line number Diff line
@@ -435,12 +435,10 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from) 
		goto out;

	}



#ifdef CONFIG_WATCH_QUEUE

	if (pipe->watch_queue) {

	if (pipe_has_watch_queue(pipe)) {

		ret = -EXDEV;

		goto out;

	}

#endif



	/*

	 * If it wasn't empty we try to merge new data into
@@ -1321,10 +1319,8 @@ static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long arg) 
	unsigned int nr_slots, size;

	long ret = 0;



#ifdef CONFIG_WATCH_QUEUE

	if (pipe->watch_queue)

	if (pipe_has_watch_queue(pipe))

		return -EBUSY;

#endif



	size = round_pipe_size(arg);

	nr_slots = size >> PAGE_SHIFT;
@@ -1377,10 +1373,8 @@ struct pipe_inode_info *get_pipe_info(struct file *file, bool for_splice) 


	if (file->f_op != &pipefifo_fops || !pipe)

		return NULL;

#ifdef CONFIG_WATCH_QUEUE

	if (for_splice && pipe->watch_queue)

	if (for_splice && pipe_has_watch_queue(pipe))

		return NULL;

#endif

	return pipe;

}

include/linux/pipe_fs_i.h

+16 −0
Original line number Diff line number Diff line
@@ -124,6 +124,22 @@ struct pipe_buf_operations { 
	bool (*get)(struct pipe_inode_info *, struct pipe_buffer *);

};



/**

 * pipe_has_watch_queue - Check whether the pipe is a watch_queue,

 * i.e. it was created with O_NOTIFICATION_PIPE

 * @pipe: The pipe to check

 *

 * Return: true if pipe is a watch queue, false otherwise.

 */

static inline bool pipe_has_watch_queue(const struct pipe_inode_info *pipe)

{

#ifdef CONFIG_WATCH_QUEUE

	return pipe->watch_queue != NULL;

#else

	return false;

#endif

}



/**

 * pipe_empty - Return true if the pipe is empty

 * @head: The pipe ring head pointer