drop queue-4.4/tty-prevent-ldisc-drivers-from-re-using-stale-tty-fields.patch

It was already in this kernel!

diff --git a/queue-4.4/series b/queue-4.4/series
index 5d217f275bf2041638283fd9e2afa0f1422f13d5..bdd30661850a4fe454e7f1ac372d90a892ecff15 100644 (file)
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -64,7 +64,6 @@ usb-serial-mct_u232-fix-big-endian-baud-rate-handling.patch
 usb-serial-io_ti-fix-div-by-zero-in-set_termios.patch
 usb-hub-fix-ss-hub-descriptor-handling.patch
 usb-hub-fix-non-ss-hub-descriptor-handling.patch
-tty-prevent-ldisc-drivers-from-re-using-stale-tty-fields.patch
 ipx-call-ipxitf_put-in-ioctl-error-path.patch
 iio-proximity-as3935-fix-as3935_write.patch
 ceph-fix-recursion-between-ceph_set_acl-and-__ceph_setattr.patch

diff --git a/queue-4.4/tty-prevent-ldisc-drivers-from-re-using-stale-tty-fields.patch b/queue-4.4/tty-prevent-ldisc-drivers-from-re-using-stale-tty-fields.patch
deleted file mode 100644 (file)
index d9412e1..0000000
--- a/queue-4.4/tty-prevent-ldisc-drivers-from-re-using-stale-tty-fields.patch
+++ /dev/null
@@ -1,79 +0,0 @@
-From dd42bf1197144ede075a9d4793123f7689e164bc Mon Sep 17 00:00:00 2001
-From: Peter Hurley <peter@hurleysoftware.com>
-Date: Fri, 27 Nov 2015 14:30:21 -0500
-Subject: tty: Prevent ldisc drivers from re-using stale tty fields
-
-From: Peter Hurley <peter@hurleysoftware.com>
-
-commit dd42bf1197144ede075a9d4793123f7689e164bc upstream.
-
-Line discipline drivers may mistakenly misuse ldisc-related fields
-when initializing. For example, a failure to initialize tty->receive_room
-in the N_GIGASET_M101 line discipline was recently found and fixed [1].
-Now, the N_X25 line discipline has been discovered accessing the previous
-line discipline's already-freed private data [2].
-
-Harden the ldisc interface against misuse by initializing revelant
-tty fields before instancing the new line discipline.
-
-[1]
-    commit fd98e9419d8d622a4de91f76b306af6aa627aa9c
-    Author: Tilman Schmidt <tilman@imap.cc>
-    Date:   Tue Jul 14 00:37:13 2015 +0200
-
-    isdn/gigaset: reset tty->receive_room when attaching ser_gigaset
-
-[2] Report from Sasha Levin <sasha.levin@oracle.com>
-    [  634.336761] ==================================================================
-    [  634.338226] BUG: KASAN: use-after-free in x25_asy_open_tty+0x13d/0x490 at addr ffff8800a743efd0
-    [  634.339558] Read of size 4 by task syzkaller_execu/8981
-    [  634.340359] =============================================================================
-    [  634.341598] BUG kmalloc-512 (Not tainted): kasan: bad access detected
-    ...
-    [  634.405018] Call Trace:
-    [  634.405277] dump_stack (lib/dump_stack.c:52)
-    [  634.405775] print_trailer (mm/slub.c:655)
-    [  634.406361] object_err (mm/slub.c:662)
-    [  634.406824] kasan_report_error (mm/kasan/report.c:138 mm/kasan/report.c:236)
-    [  634.409581] __asan_report_load4_noabort (mm/kasan/report.c:279)
-    [  634.411355] x25_asy_open_tty (drivers/net/wan/x25_asy.c:559 (discriminator 1))
-    [  634.413997] tty_ldisc_open.isra.2 (drivers/tty/tty_ldisc.c:447)
-    [  634.414549] tty_set_ldisc (drivers/tty/tty_ldisc.c:567)
-    [  634.415057] tty_ioctl (drivers/tty/tty_io.c:2646 drivers/tty/tty_io.c:2879)
-    [  634.423524] do_vfs_ioctl (fs/ioctl.c:43 fs/ioctl.c:607)
-    [  634.427491] SyS_ioctl (fs/ioctl.c:622 fs/ioctl.c:613)
-    [  634.427945] entry_SYSCALL_64_fastpath (arch/x86/entry/entry_64.S:188)
-
-Cc: Tilman Schmidt <tilman@imap.cc>
-Cc: Sasha Levin <sasha.levin@oracle.com>
-Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
-Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
----
- drivers/tty/tty_ldisc.c |    7 +++++++
- 1 file changed, 7 insertions(+)
-
---- a/drivers/tty/tty_ldisc.c
-+++ b/drivers/tty/tty_ldisc.c
-@@ -421,6 +421,10 @@ EXPORT_SYMBOL_GPL(tty_ldisc_flush);
-  *    prevent the ldisc driver from re-using stale information for
-  *    the new ldisc instance.
-  *
-+ *    The line discipline-related tty_struct fields are reset to
-+ *    prevent the ldisc driver from re-using stale information for
-+ *    the new ldisc instance.
-+ *
-  *    Locking: takes termios_rwsem
-  */
- 
-@@ -619,6 +623,9 @@ static void tty_reset_termios(struct tty
-       tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios);
-       tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios);
-       up_write(&tty->termios_rwsem);
-+
-+      tty->disc_data = NULL;
-+      tty->receive_room = 0;
- }
- 
-