From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Tue, 3 Nov 2020 11:14:28 +0000 (+0100)
Subject: 4.4-stable patches
X-Git-Tag: v4.14.204~46
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=feb435f93e70def48bbde30a54d226944a4ba2b1;p=thirdparty%2Fkernel%2Fstable-queue.git

4.4-stable patches

added patches:
	md-raid5-fix-oops-during-stripe-resizing.patch
---

diff --git a/queue-4.4/md-raid5-fix-oops-during-stripe-resizing.patch b/queue-4.4/md-raid5-fix-oops-during-stripe-resizing.patch
new file mode 100644
index 00000000000..d1e98b7a4b9
--- /dev/null
+++ b/queue-4.4/md-raid5-fix-oops-during-stripe-resizing.patch
@@ -0,0 +1,75 @@
+From b44c018cdf748b96b676ba09fdbc5b34fc443ada Mon Sep 17 00:00:00 2001
+From: Song Liu <songliubraving@fb.com>
+Date: Mon, 5 Oct 2020 09:35:21 -0700
+Subject: md/raid5: fix oops during stripe resizing
+
+From: Song Liu <songliubraving@fb.com>
+
+commit b44c018cdf748b96b676ba09fdbc5b34fc443ada upstream.
+
+KoWei reported crash during raid5 reshape:
+
+[ 1032.252932] Oops: 0002 [#1] SMP PTI
+[...]
+[ 1032.252943] RIP: 0010:memcpy_erms+0x6/0x10
+[...]
+[ 1032.252947] RSP: 0018:ffffba1ac0c03b78 EFLAGS: 00010286
+[ 1032.252949] RAX: 0000784ac0000000 RBX: ffff91bec3d09740 RCX: 0000000000001000
+[ 1032.252951] RDX: 0000000000001000 RSI: ffff91be6781c000 RDI: 0000784ac0000000
+[ 1032.252953] RBP: ffffba1ac0c03bd8 R08: 0000000000001000 R09: ffffba1ac0c03bf8
+[ 1032.252954] R10: 0000000000000000 R11: 0000000000000000 R12: ffffba1ac0c03bf8
+[ 1032.252955] R13: 0000000000001000 R14: 0000000000000000 R15: 0000000000000000
+[ 1032.252958] FS:  0000000000000000(0000) GS:ffff91becf500000(0000) knlGS:0000000000000000
+[ 1032.252959] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
+[ 1032.252961] CR2: 0000784ac0000000 CR3: 000000031780a002 CR4: 00000000001606e0
+[ 1032.252962] Call Trace:
+[ 1032.252969]  ? async_memcpy+0x179/0x1000 [async_memcpy]
+[ 1032.252977]  ? raid5_release_stripe+0x8e/0x110 [raid456]
+[ 1032.252982]  handle_stripe_expansion+0x15a/0x1f0 [raid456]
+[ 1032.252988]  handle_stripe+0x592/0x1270 [raid456]
+[ 1032.252993]  handle_active_stripes.isra.0+0x3cb/0x5a0 [raid456]
+[ 1032.252999]  raid5d+0x35c/0x550 [raid456]
+[ 1032.253002]  ? schedule+0x42/0xb0
+[ 1032.253006]  ? schedule_timeout+0x10e/0x160
+[ 1032.253011]  md_thread+0x97/0x160
+[ 1032.253015]  ? wait_woken+0x80/0x80
+[ 1032.253019]  kthread+0x104/0x140
+[ 1032.253022]  ? md_start_sync+0x60/0x60
+[ 1032.253024]  ? kthread_park+0x90/0x90
+[ 1032.253027]  ret_from_fork+0x35/0x40
+
+This is because cache_size_mutex was unlocked too early in resize_stripes,
+which races with grow_one_stripe() that grow_one_stripe() allocates a
+stripe with wrong pool_size.
+
+Fix this issue by unlocking cache_size_mutex after updating pool_size.
+
+Cc: <stable@vger.kernel.org> # v4.4+
+Reported-by: KoWei Sung <winders@amazon.com>
+Signed-off-by: Song Liu <songliubraving@fb.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/md/raid5.c |    4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+--- a/drivers/md/raid5.c
++++ b/drivers/md/raid5.c
+@@ -2238,8 +2238,6 @@ static int resize_stripes(struct r5conf
+ 	} else
+ 		err = -ENOMEM;
+ 
+-	mutex_unlock(&conf->cache_size_mutex);
+-
+ 	conf->slab_cache = sc;
+ 	conf->active_name = 1-conf->active_name;
+ 
+@@ -2262,6 +2260,8 @@ static int resize_stripes(struct r5conf
+ 
+ 	if (!err)
+ 		conf->pool_size = newsize;
++	mutex_unlock(&conf->cache_size_mutex);
++
+ 	return err;
+ }
+ 
diff --git a/queue-4.4/series b/queue-4.4/series
index fbbc0c29200..d771c3dfe6d 100644
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -32,3 +32,4 @@ gfs2-add-validation-checks-for-size-of-superblock.patch
 memory-emif-remove-bogus-debugfs-error-handling.patch
 arm-dts-s5pv210-move-pmu-node-out-of-clock-controlle.patch
 arm-dts-s5pv210-remove-dedicated-audio-subsystem-nod.patch
+md-raid5-fix-oops-during-stripe-resizing.patch