Author: tomwij
Date: 2014-05-15 13:30:10 +0000 (Thu, 15 May 2014)
New Revision: 2788
Added:
genpatches-2.6/trunk/3.12/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
genpatches-2.6/trunk/3.13/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
genpatches-2.6/trunk/3.15/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
genpatches-2.6/trunk/3.2/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
genpatches-2.6/trunk/3.4/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
Log:
Add security fix for CVE-2014-0196 (4291086b1f081b869c6d79e5b7441633dc3ace00)
to branches for which upstream has not applied the patch yet, to ensure that
the patch gets applied in the next release.
Added:
genpatches-2.6/trunk/3.12/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
===================================================================
---
genpatches-2.6/trunk/3.12/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
(rev 0)
+++
genpatches-2.6/trunk/3.12/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
2014-05-15 13:30:10 UTC (rev 2788)
@@ -0,0 +1,80 @@
+From 4291086b1f081b869c6d79e5b7441633dc3ace00 Mon Sep 17 00:00:00 2001
+From: Peter Hurley <pe...@hurleysoftware.com>
+Date: Sat, 3 May 2014 14:04:59 +0200
+Subject: 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 <jsl...@suse.cz>
+Signed-off-by: Peter Hurley <pe...@hurleysoftware.com>
+Signed-off-by: Jiri Slaby <jsl...@suse.cz>
+Cc: Linus Torvalds <torva...@linux-foundation.org>
+Cc: Alan Cox <a...@lxorguk.ukuu.org.uk>
+Cc: <sta...@vger.kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
+
+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;
+--
+cgit v0.10.1
+
Added:
genpatches-2.6/trunk/3.13/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
===================================================================
---
genpatches-2.6/trunk/3.13/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
(rev 0)
+++
genpatches-2.6/trunk/3.13/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
2014-05-15 13:30:10 UTC (rev 2788)
@@ -0,0 +1,80 @@
+From 4291086b1f081b869c6d79e5b7441633dc3ace00 Mon Sep 17 00:00:00 2001
+From: Peter Hurley <pe...@hurleysoftware.com>
+Date: Sat, 3 May 2014 14:04:59 +0200
+Subject: 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 <jsl...@suse.cz>
+Signed-off-by: Peter Hurley <pe...@hurleysoftware.com>
+Signed-off-by: Jiri Slaby <jsl...@suse.cz>
+Cc: Linus Torvalds <torva...@linux-foundation.org>
+Cc: Alan Cox <a...@lxorguk.ukuu.org.uk>
+Cc: <sta...@vger.kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
+
+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;
+--
+cgit v0.10.1
+
Added:
genpatches-2.6/trunk/3.15/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
===================================================================
---
genpatches-2.6/trunk/3.15/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
(rev 0)
+++
genpatches-2.6/trunk/3.15/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
2014-05-15 13:30:10 UTC (rev 2788)
@@ -0,0 +1,80 @@
+From 4291086b1f081b869c6d79e5b7441633dc3ace00 Mon Sep 17 00:00:00 2001
+From: Peter Hurley <pe...@hurleysoftware.com>
+Date: Sat, 3 May 2014 14:04:59 +0200
+Subject: 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 <jsl...@suse.cz>
+Signed-off-by: Peter Hurley <pe...@hurleysoftware.com>
+Signed-off-by: Jiri Slaby <jsl...@suse.cz>
+Cc: Linus Torvalds <torva...@linux-foundation.org>
+Cc: Alan Cox <a...@lxorguk.ukuu.org.uk>
+Cc: <sta...@vger.kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
+
+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;
+--
+cgit v0.10.1
+
Added:
genpatches-2.6/trunk/3.2/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
===================================================================
---
genpatches-2.6/trunk/3.2/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
(rev 0)
+++
genpatches-2.6/trunk/3.2/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
2014-05-15 13:30:10 UTC (rev 2788)
@@ -0,0 +1,80 @@
+From 4291086b1f081b869c6d79e5b7441633dc3ace00 Mon Sep 17 00:00:00 2001
+From: Peter Hurley <pe...@hurleysoftware.com>
+Date: Sat, 3 May 2014 14:04:59 +0200
+Subject: 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 <jsl...@suse.cz>
+Signed-off-by: Peter Hurley <pe...@hurleysoftware.com>
+Signed-off-by: Jiri Slaby <jsl...@suse.cz>
+Cc: Linus Torvalds <torva...@linux-foundation.org>
+Cc: Alan Cox <a...@lxorguk.ukuu.org.uk>
+Cc: <sta...@vger.kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
+
+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;
+--
+cgit v0.10.1
+
Added:
genpatches-2.6/trunk/3.4/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
===================================================================
---
genpatches-2.6/trunk/3.4/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
(rev 0)
+++
genpatches-2.6/trunk/3.4/1500_CVE-2014-0196-n_tty-Fix-n_tty_write-crash-when-echoing-in-raw-mode.patch
2014-05-15 13:30:10 UTC (rev 2788)
@@ -0,0 +1,80 @@
+From 4291086b1f081b869c6d79e5b7441633dc3ace00 Mon Sep 17 00:00:00 2001
+From: Peter Hurley <pe...@hurleysoftware.com>
+Date: Sat, 3 May 2014 14:04:59 +0200
+Subject: 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 <jsl...@suse.cz>
+Signed-off-by: Peter Hurley <pe...@hurleysoftware.com>
+Signed-off-by: Jiri Slaby <jsl...@suse.cz>
+Cc: Linus Torvalds <torva...@linux-foundation.org>
+Cc: Alan Cox <a...@lxorguk.ukuu.org.uk>
+Cc: <sta...@vger.kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
+
+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;
+--
+cgit v0.10.1
+
