3.18-stable patches

added patches:
	fix-io_destroy-aio_complete-race.patch

diff --git a/queue-3.18/fix-io_destroy-aio_complete-race.patch b/queue-3.18/fix-io_destroy-aio_complete-race.patch
new file mode 100644 (file)
index 0000000..442e8d4
--- /dev/null
+++ b/queue-3.18/fix-io_destroy-aio_complete-race.patch
@@ -0,0 +1,42 @@
+From 4faa99965e027cc057c5145ce45fa772caa04e8d Mon Sep 17 00:00:00 2001
+From: Al Viro <viro@zeniv.linux.org.uk>
+Date: Wed, 23 May 2018 22:53:22 -0400
+Subject: fix io_destroy()/aio_complete() race
+
+From: Al Viro <viro@zeniv.linux.org.uk>
+
+commit 4faa99965e027cc057c5145ce45fa772caa04e8d upstream.
+
+If io_destroy() gets to cancelling everything that can be cancelled and
+gets to kiocb_cancel() calling the function driver has left in ->ki_cancel,
+it becomes vulnerable to a race with IO completion.  At that point req
+is already taken off the list and aio_complete() does *NOT* spin until
+we (in free_ioctx_users()) releases ->ctx_lock.  As the result, it proceeds
+to kiocb_free(), freing req just it gets passed to ->ki_cancel().
+
+Fix is simple - remove from the list after the call of kiocb_cancel().  All
+instances of ->ki_cancel() already have to cope with the being called with
+iocb still on list - that's what happens in io_cancel(2).
+
+Cc: stable@kernel.org
+Fixes: 0460fef2a921 "aio: use cancellation list lazily"
+Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ fs/aio.c |    3 +--
+ 1 file changed, 1 insertion(+), 2 deletions(-)
+
+--- a/fs/aio.c
++++ b/fs/aio.c
+@@ -560,9 +560,8 @@ static void free_ioctx_users(struct perc
+       while (!list_empty(&ctx->active_reqs)) {
+               req = list_first_entry(&ctx->active_reqs,
+                                      struct kiocb, ki_list);
+-
+-              list_del_init(&req->ki_list);
+               kiocb_cancel(req);
++              list_del_init(&req->ki_list);
+       }
+ 
+       spin_unlock_irq(&ctx->ctx_lock);

diff --git a/queue-3.18/series b/queue-3.18/series
index 95b52e6f49b23c451292005deaa03a4a9b05272f..202f954d01f0c965585b3c3fa2a17c90a1401ef6 100644 (file)
--- a/queue-3.18/series
+++ b/queue-3.18/series
@@ -4,3 +4,4 @@ cfg80211-further-limit-wiphy-names-to-64-bytes.patch
 tcp-avoid-integer-overflows-in-tcp_rcv_space_adjust.patch
 mips-ptrace-fix-ptrace_peekusr-requests-for-64-bit-fgrs.patch
 drm-i915-disable-lvds-on-radiant-p845.patch
+fix-io_destroy-aio_complete-race.patch