Commit a01ac27b authored May 08, 2020 by Christoph Hellwig

fs: check FMODE_WRITE in __kernel_write



Add a WARN_ON_ONCE if the file isn't actually open for write.  This
matches the check done in vfs_write, but actually warn warns as a
kernel user calling write on a file not opened for writing is a pretty
obvious programming error.

Signed-off-by: Christoph Hellwig <hch@lst.de>

parent 9db97752

fs/read_write.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -505,6 +505,8 @@ ssize_t __kernel_write(struct file file, const void buf, size_t count, loff_t
		const char __user *p;
		ssize_t ret;

		if (WARN_ON_ONCE(!(file->f_mode & FMODE_WRITE)))
		return -EBADF;
		if (!(file->f_mode & FMODE_CAN_WRITE))
		return -EINVAL;

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