From: Fabian Frederick Subject: [PATCH 6/6 linux-next] ext4: fix memory leak in ext4_insert_range() Date: Wed, 24 Aug 2016 22:03:20 +0200 Message-ID: <1472069000-18897-7-git-send-email-fabf@skynet.be> References: <1472069000-18897-1-git-send-email-fabf@skynet.be> Cc: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, fabf@skynet.be To: tytso@mit.edu, Andreas Dilger Return-path: In-Reply-To: <1472069000-18897-1-git-send-email-fabf@skynet.be> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Running xfstests generic/013 with kmemleak gives the following: unreferenced object 0xffff8801d3d27de0 (size 96): comm "fsstress", pid 4941, jiffies 4294860168 (age 53.485s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 01 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [] kmemleak_alloc+0x23/0x40 [] __kmalloc+0xf5/0x1d0 [] ext4_find_extent+0x1ec/0x2f0 [] ext4_insert_range+0x34c/0x4a0 [] ext4_fallocate+0x4e2/0x8b0 [] vfs_fallocate+0x134/0x210 [] SyS_fallocate+0x3f/0x60 [] entry_SYSCALL_64_fastpath+0x13/0x8f [] 0xffffffffffffffff Problem seems mitigated by dropping refs and freeing path when there's no path[depth].p_ext Signed-off-by: Fabian Frederick --- fs/ext4/extents.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 5b0913d..2774df4 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -5711,6 +5711,9 @@ int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len) up_write(&EXT4_I(inode)->i_data_sem); goto out_stop; } + } else { + ext4_ext_drop_refs(path); + kfree(path); } ret = ext4_es_remove_extent(inode, offset_lblk, -- 2.8.1