tty: wipe buffer if not echoing data (b97b3d9f) · Commits · 戴 / test

drivers/tty/n_tty.c

+17 −3

Original line number	Diff line number	Diff line
		@@ -152,17 +152,28 @@ static inline unsigned char echo_buf_addr(struct n_tty_data ldata, size_t i)
		return &ldata->echo_buf[i & (N_TTY_BUF_SIZE - 1)];
		}

		/* If we are not echoing the data, perhaps this is a secret so erase it */
		static void zero_buffer(struct tty_struct tty, u8 buffer, int size)
		{
		bool icanon = !!L_ICANON(tty);
		bool no_echo = !L_ECHO(tty);

		if (icanon && no_echo)
		memset(buffer, 0x00, size);
		}

		static int tty_copy_to_user(struct tty_struct tty, void __user to,
		size_t tail, size_t n)
		{
		struct n_tty_data *ldata = tty->disc_data;
		size_t size = N_TTY_BUF_SIZE - tail;
		const void *from = read_buf_addr(ldata, tail);
		void *from = read_buf_addr(ldata, tail);
		int uncopied;

		if (n > size) {
		tty_audit_add_data(tty, from, size);
		uncopied = copy_to_user(to, from, size);
		zero_buffer(tty, from, size - uncopied);
		if (uncopied)
		return uncopied;
		to += size;
		@@ -171,7 +182,9 @@ static int tty_copy_to_user(struct tty_struct tty, void __user to,
		}

		tty_audit_add_data(tty, from, n);
		return copy_to_user(to, from, n);
		uncopied = copy_to_user(to, from, n);
		zero_buffer(tty, from, n - uncopied);
		return uncopied;
		}

		/**
		@@ -1960,11 +1973,12 @@ static int copy_from_read_buf(struct tty_struct *tty,
		n = min(head - ldata->read_tail, N_TTY_BUF_SIZE - tail);
		n = min(*nr, n);
		if (n) {
		const unsigned char *from = read_buf_addr(ldata, tail);
		unsigned char *from = read_buf_addr(ldata, tail);
		retval = copy_to_user(*b, from, n);
		n -= retval;
		is_eof = n == 1 && *from == EOF_CHAR(tty);
		tty_audit_add_data(tty, from, n);
		zero_buffer(tty, from, n);
		smp_store_release(&ldata->read_tail, ldata->read_tail + n);
		/* Turn single EOF into zero-length read */
		if (L_EXTPROC(tty) && ldata->icanon && is_eof &&

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