[PATCH v1] media: meson: vdec: Fix memory leak in error path of vdec_open

[Anand Moon <linux.amoon@gmail.com>]

If vdec_init_ctrls(sess) fails, or any subsequent initialization step
during vdec_open fails, the control handler allocated for the session
is not released. This causes a memory leak of the v4l2_ctrl_handler
and its associated control objects.

Add a call to v4l2_ctrl_handler_free() in the err_m2m_release error
path to ensure resources are properly reclaimed.

unreferenced object 0xffff0000205d6878 (size 8):
  comm "v4l_id", pid 5289, jiffies 4294938580
  hex dump (first 8 bytes):
    40 d2 49 18 00 00 ff ff                          @.I.....
  backtrace (crc d3204599):
    kmemleak_alloc+0xc8/0xf0
    __kvmalloc_node_noprof+0x60c/0x850
    v4l2_ctrl_handler_init_class+0x1b4/0x2e8 [videodev]
    vdec_open+0x1f4/0x788 [meson_vdec]
    v4l2_open+0x144/0x460 [videodev]
    chrdev_open+0x1ac/0x500
    do_dentry_open+0x3f0/0xfe8
    vfs_open+0x68/0x320
    do_open+0x2d8/0x9a8
    path_openat+0x1d0/0x4f0
    do_filp_open+0x190/0x380
    do_sys_openat2+0xf8/0x1b0
    __arm64_sys_openat+0x13c/0x1e8
    invoke_syscall+0xdc/0x268
    el0_svc_common.constprop.0+0x178/0x258
    do_el0_svc+0x4c/0x70

Fixes: 3e7f51bd9607 ("media: meson: add v4l2 m2m video decoder driver")
Signed-off-by: Anand Moon <linux.amoon@gmail.com>
---
 drivers/staging/media/meson/vdec/vdec.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/staging/media/meson/vdec/vdec.c b/drivers/staging/media/meson/vdec/vdec.c
index 4b77ec1af5a7..a5ab0c2390f5 100644
--- a/drivers/staging/media/meson/vdec/vdec.c
+++ b/drivers/staging/media/meson/vdec/vdec.c
@@ -914,6 +914,7 @@ static int vdec_open(struct file *file)
 	return 0;
 
 err_m2m_release:
+	v4l2_ctrl_handler_free(&sess->ctrl_handler);
 	v4l2_m2m_release(sess->m2m_dev);
 err_free_sess:
 	kfree(sess);
@@ -926,6 +927,7 @@ static int vdec_close(struct file *file)
 
 	v4l2_m2m_ctx_release(sess->m2m_ctx);
 	v4l2_m2m_release(sess->m2m_dev);
+	v4l2_ctrl_handler_free(&sess->ctrl_handler);
 	v4l2_fh_del(&sess->fh, file);
 	v4l2_fh_exit(&sess->fh);
 

base-commit: 0031c06807cfa8aa51a759ff8aa09e1aa48149af
-- 
2.50.1