[PATCH] gfs2: Fix error path kobject memory leak

From: Andreas Gruenbacher
Date: Mon May 13 2019 - 16:00:49 EST


From: "Tobin C. Harding" <tobin@xxxxxxxxxx>

If a call to kobject_init_and_add() fails we must call kobject_put()
otherwise we leak memory.

Function gfs2_sys_fs_add always calls kobject_init_and_add() which
always calls kobject_init().

It is safe to leave object destruction up to the kobject release
function and never free it manually.

Remove call to kfree() and always call kobject_put() in the error path.

Signed-off-by: Tobin C. Harding <tobin@xxxxxxxxxx>
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
---
fs/gfs2/sys.c | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/fs/gfs2/sys.c b/fs/gfs2/sys.c
index 1787d295834e..08e4996adc23 100644
--- a/fs/gfs2/sys.c
+++ b/fs/gfs2/sys.c
@@ -650,7 +650,6 @@ int gfs2_sys_fs_add(struct gfs2_sbd *sdp)
char ro[20];
char spectator[20];
char *envp[] = { ro, spectator, NULL };
- int sysfs_frees_sdp = 0;

sprintf(ro, "RDONLY=%d", sb_rdonly(sb));
sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
@@ -661,8 +660,6 @@ int gfs2_sys_fs_add(struct gfs2_sbd *sdp)
if (error)
goto fail_reg;

- sysfs_frees_sdp = 1; /* Freeing sdp is now done by sysfs calling
- function gfs2_sbd_release. */
error = sysfs_create_group(&sdp->sd_kobj, &tune_group);
if (error)
goto fail_reg;
@@ -687,10 +684,7 @@ int gfs2_sys_fs_add(struct gfs2_sbd *sdp)
fail_reg:
free_percpu(sdp->sd_lkstats);
fs_err(sdp, "error %d adding sysfs files\n", error);
- if (sysfs_frees_sdp)
- kobject_put(&sdp->sd_kobj);
- else
- kfree(sdp);
+ kobject_put(&sdp->sd_kobj);
sb->s_fs_info = NULL;
return error;
}
--
2.20.1