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* [PATCH] ext4: memory leakage in ext4_mb_free_blocks()
@ 2010-03-24 13:55 jing zhang
  2010-03-24 17:01 ` Aneesh Kumar K. V
  0 siblings, 1 reply; 3+ messages in thread
From: jing zhang @ 2010-03-24 13:55 UTC (permalink / raw)
  To: linux-ext4; +Cc: Theodore Ts'o, Andreas Dilger, Dave Kleikamp

From: Jing Zhang <zj.barak@gmail.com>

Date: Wed Mar 24 21:54:22     2010

There is memory leakage in ext4_mb_free_blocks(), if error, double
free of blocks, occurs in ext4_mb_free_metadata().

Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Andreas Dilger <adilger@sun.com>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Jing Zhang <zj.barak@gmail.com>

---

--- linux-2.6.32/fs/ext4/mballoc.c	2009-12-03 11:51:22.000000000 +0800
+++ ext4_mm_leak/mballoc8.c	2010-03-24 21:46:50.000000000 +0800
@@ -4419,7 +4419,8 @@ ext4_mb_free_metadata(handle_t *handle,
 	spin_lock(&sbi->s_md_lock);
 	list_add(&new_entry->list, &handle->h_transaction->t_private_list);
 	spin_unlock(&sbi->s_md_lock);
-	return 0;
+	/* info the caller new_entry is used */
+	return 1;
 }

 /*
@@ -4547,7 +4548,8 @@ do_more:

 		ext4_lock_group(sb, block_group);
 		mb_clear_bits(bitmap_bh->b_data, bit, count);
-		ext4_mb_free_metadata(handle, &e4b, new_entry);
+		if (0 == ext4_mb_free_metadata(handle, &e4b, new_entry))
+			kmem_cache_free(ext4_free_ext_cachep, new_entry);
 	} else {
 		/* need to update group_info->bb_free and bitmap
 		 * with group lock held. generate_buddy look at

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2010-03-25 14:09 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2010-03-24 13:55 [PATCH] ext4: memory leakage in ext4_mb_free_blocks() jing zhang
2010-03-24 17:01 ` Aneesh Kumar K. V
2010-03-25 14:09   ` jing zhang

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