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Diffstat (limited to 'kernels/linux-libre-lts-knock/0001-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch')
-rw-r--r--kernels/linux-libre-lts-knock/0001-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch83
1 files changed, 0 insertions, 83 deletions
diff --git a/kernels/linux-libre-lts-knock/0001-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch b/kernels/linux-libre-lts-knock/0001-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
deleted file mode 100644
index cb659dc7d..000000000
--- a/kernels/linux-libre-lts-knock/0001-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
+++ /dev/null
@@ -1,83 +0,0 @@
-From 4291086b1f081b869c6d79e5b7441633dc3ace00 Mon Sep 17 00:00:00 2001
-From: Peter Hurley <peter@hurleysoftware.com>
-Date: Sat, 3 May 2014 14:04:59 +0200
-Subject: [PATCH] n_tty: Fix n_tty_write crash when echoing in raw mode
-
-The tty atomic_write_lock does not provide an exclusion guarantee for
-the tty driver if the termios settings are LECHO & !OPOST. And since
-it is unexpected and not allowed to call TTY buffer helpers like
-tty_insert_flip_string concurrently, this may lead to crashes when
-concurrect writers call pty_write. In that case the following two
-writers:
-* the ECHOing from a workqueue and
-* pty_write from the process
-race and can overflow the corresponding TTY buffer like follows.
-
-If we look into tty_insert_flip_string_fixed_flag, there is:
- int space = __tty_buffer_request_room(port, goal, flags);
- struct tty_buffer *tb = port->buf.tail;
- ...
- memcpy(char_buf_ptr(tb, tb->used), chars, space);
- ...
- tb->used += space;
-
-so the race of the two can result in something like this:
- A B
-__tty_buffer_request_room
- __tty_buffer_request_room
-memcpy(buf(tb->used), ...)
-tb->used += space;
- memcpy(buf(tb->used), ...) ->BOOM
-
-B's memcpy is past the tty_buffer due to the previous A's tb->used
-increment.
-
-Since the N_TTY line discipline input processing can output
-concurrently with a tty write, obtain the N_TTY ldisc output_lock to
-serialize echo output with normal tty writes. This ensures the tty
-buffer helper tty_insert_flip_string is not called concurrently and
-everything is fine.
-
-Note that this is nicely reproducible by an ordinary user using
-forkpty and some setup around that (raw termios + ECHO). And it is
-present in kernels at least after commit
-d945cb9cce20ac7143c2de8d88b187f62db99bdc (pty: Rework the pty layer to
-use the normal buffering logic) in 2.6.31-rc3.
-
-js: add more info to the commit log
-js: switch to bool
-js: lock unconditionally
-js: lock only the tty->ops->write call
-
-References: CVE-2014-0196
-Reported-and-tested-by: Jiri Slaby <jslaby@suse.cz>
-Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
-Signed-off-by: Jiri Slaby <jslaby@suse.cz>
-Cc: Linus Torvalds <torvalds@linux-foundation.org>
-Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
-Cc: <stable@vger.kernel.org>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
----
- drivers/tty/n_tty.c | 4 ++++
- 1 file changed, 4 insertions(+)
-
-diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
-index 41fe8a0..fe9d129 100644
---- a/drivers/tty/n_tty.c
-+++ b/drivers/tty/n_tty.c
-@@ -2353,8 +2353,12 @@ static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
- if (tty->ops->flush_chars)
- tty->ops->flush_chars(tty);
- } else {
-+ struct n_tty_data *ldata = tty->disc_data;
-+
- while (nr > 0) {
-+ mutex_lock(&ldata->output_lock);
- c = tty->ops->write(tty, b, nr);
-+ mutex_unlock(&ldata->output_lock);
- if (c < 0) {
- retval = c;
- goto break_out;
---
-1.9.2
-