From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Fri, 29 Aug 2014 22:29:29 +0000 (-0700)
Subject: 3.10-stable patches
X-Git-Tag: v3.10.54~20
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=304d29e4d4094ab7ce5c64f7b5789fbd10ddc395;p=thirdparty%2Fkernel%2Fstable-queue.git

3.10-stable patches

added patches:
	ext4-fix-bug_on-in-mb_free_blocks.patch
---

diff --git a/queue-3.10/ext4-fix-bug_on-in-mb_free_blocks.patch b/queue-3.10/ext4-fix-bug_on-in-mb_free_blocks.patch
new file mode 100644
index 00000000000..9cc9dfd5d3c
--- /dev/null
+++ b/queue-3.10/ext4-fix-bug_on-in-mb_free_blocks.patch
@@ -0,0 +1,62 @@
+From c99d1e6e83b06744c75d9f5e491ed495a7086b7b Mon Sep 17 00:00:00 2001
+From: Theodore Ts'o <tytso@mit.edu>
+Date: Sat, 23 Aug 2014 17:47:28 -0400
+Subject: ext4: fix BUG_ON in mb_free_blocks()
+
+From: Theodore Ts'o <tytso@mit.edu>
+
+commit c99d1e6e83b06744c75d9f5e491ed495a7086b7b upstream.
+
+If we suffer a block allocation failure (for example due to a memory
+allocation failure), it's possible that we will call
+ext4_discard_allocated_blocks() before we've actually allocated any
+blocks.  In that case, fe_len and fe_start in ac->ac_f_ex will still
+be zero, and this will result in mb_free_blocks(inode, e4b, 0, 0)
+triggering the BUG_ON on mb_free_blocks():
+
+	BUG_ON(last >= (sb->s_blocksize << 3));
+
+Fix this by bailing out of ext4_discard_allocated_blocks() if fs_len
+is zero.
+
+Also fix a missing ext4_mb_unload_buddy() call in
+ext4_discard_allocated_blocks().
+
+Google-Bug-Id: 16844242
+
+Fixes: 86f0afd463215fc3e58020493482faa4ac3a4d69
+Signed-off-by: Theodore Ts'o <tytso@mit.edu>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ fs/ext4/mballoc.c |    5 +++++
+ 1 file changed, 5 insertions(+)
+
+--- a/fs/ext4/mballoc.c
++++ b/fs/ext4/mballoc.c
+@@ -1396,6 +1396,8 @@ static void mb_free_blocks(struct inode
+ 	int last = first + count - 1;
+ 	struct super_block *sb = e4b->bd_sb;
+ 
++	if (WARN_ON(count == 0))
++		return;
+ 	BUG_ON(last >= (sb->s_blocksize << 3));
+ 	assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
+ 	mb_check_buddy(e4b);
+@@ -3181,6 +3183,8 @@ static void ext4_discard_allocated_block
+ 	int err;
+ 
+ 	if (pa == NULL) {
++		if (ac->ac_f_ex.fe_len == 0)
++			return;
+ 		err = ext4_mb_load_buddy(ac->ac_sb, ac->ac_f_ex.fe_group, &e4b);
+ 		if (err) {
+ 			/*
+@@ -3195,6 +3199,7 @@ static void ext4_discard_allocated_block
+ 		mb_free_blocks(ac->ac_inode, &e4b, ac->ac_f_ex.fe_start,
+ 			       ac->ac_f_ex.fe_len);
+ 		ext4_unlock_group(ac->ac_sb, ac->ac_f_ex.fe_group);
++		ext4_mb_unload_buddy(&e4b);
+ 		return;
+ 	}
+ 	if (pa->pa_type == MB_INODE_PA)
diff --git a/queue-3.10/series b/queue-3.10/series
index 05a15a4cb29..db08039d891 100644
--- a/queue-3.10/series
+++ b/queue-3.10/series
@@ -30,3 +30,4 @@ kvm-x86-always-exit-on-eois-for-interrupts-listed-in-the-ioapic-redir-table.patc
 kvm-nvmx-fix-acknowledge-interrupt-on-exit-when-apicv-is-in-use.patch
 revert-kvm-x86-increase-the-number-of-fixed-mtrr-regs-to-10.patch
 kvm-iommu-fix-the-third-parameter-of-kvm_iommu_put_pages-cve-2014-3601.patch
+ext4-fix-bug_on-in-mb_free_blocks.patch