media: meson: vdec: Fix memory leak in error path of vdec_open

The vdec_open() function previously jumped directly to
err_m2m_release when vdec_init_ctrls() failed, skipping
release of the m2m context. This caused a resource leak.

Fix it by introducing a proper err_m2m_ctx_release label
that calls v4l2_m2m_ctx_release(sess->m2m_ctx) before
releasing the m2m device.

This was identified via kmemleak:
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")
Cc: stable@vger.kernel.org
Signed-off-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

diff --git a/drivers/staging/media/meson/vdec/vdec.c b/drivers/staging/media/meson/vdec/vdec.c
index 4b77ec1af5a76a64ce0a38282ac93a3f2d3c91d0..a039d925c0fe5603a16814e7daa60c27761cab47 100644 (file)
--- a/drivers/staging/media/meson/vdec/vdec.c
+++ b/drivers/staging/media/meson/vdec/vdec.c
@@ -889,7 +889,7 @@ static int vdec_open(struct file *file)
 
        ret = vdec_init_ctrls(sess);
        if (ret)
-               goto err_m2m_release;
+               goto err_m2m_ctx_release;
 
        sess->pixfmt_cap = formats[0].pixfmts_cap[0];
        sess->fmt_out = &formats[0];
@@ -913,6 +913,8 @@ static int vdec_open(struct file *file)
 
        return 0;
 
+err_m2m_ctx_release:
+       v4l2_m2m_ctx_release(sess->m2m_ctx);
 err_m2m_release:
        v4l2_m2m_release(sess->m2m_dev);
 err_free_sess: