From: Fabian Frederick Date: Thu, 15 Sep 2016 15:39:52 +0000 (-0400) Subject: ext4: fix memory leak in ext4_insert_range() X-Git-Tag: firefly_0821_release~176^2~4^2~23^2~8 X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=6f6c12ce00e8bb3f36b12ebb83b004f3cf4ec695;p=firefly-linux-kernel-4.4.55.git ext4: fix memory leak in ext4_insert_range() commit edf15aa180d7b98fe16bd3eda42f9dd0e60dee20 upstream. 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 Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 8eac7d586997..9da42ace762a 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -5738,6 +5738,9 @@ 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,