[PATCH] media: pci: cx23885: handle adding to list failure

[Nicholas Mc Guire]

 altera_hw_filt_init() which calls append_internal() assumes
that the node was successfully linked in while in fact it can
silently fail. So the call-site needs to set return to -ENOMEM
on append_internal() returning NULL and exit through the err path.

Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx>
Fixes: 349bcf02e361 ("[media] Altera FPGA based CI driver module")
---

Problem located with experimental coccinelle script

Patch was compile tested with: x86_64_defconfig + CONFIG_MEDIA_SUPPORT=y,
CONFIG_OF=y, CONFIG_MEDIA_ANALOG_TV_SUPPORT=y,
CONFIG_MEDIA_DIGITAL_TV_SUPPORT=y, CONFIG_MEDIA_PCI_SUPPORT=y,
CONFIG_DRM_SIL_SII8620=y, CONFIG_VIDEO_CX23885=y, CONFIG_MEDIA_ALTERA_CI=y

Patch is against 4.19-rc2 (localversion-next is next-20180907)

 drivers/media/pci/cx23885/altera-ci.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/media/pci/cx23885/altera-ci.c b/drivers/media/pci/cx23885/altera-ci.c
index 62bc804..198c05e 100644
--- a/drivers/media/pci/cx23885/altera-ci.c
+++ b/drivers/media/pci/cx23885/altera-ci.c
@@ -665,6 +665,10 @@ static int altera_hw_filt_init(struct altera_ci_config *config, int hw_filt_nr)
 		}
 
 		temp_int = append_internal(inter);
+		if (!temp_int) {
+			ret = -ENOMEM;
+			goto err;
+		}
 		inter->filts_used = 1;
 		inter->dev = config->dev;
 		inter->fpga_rw = config->fpga_rw;
@@ -699,6 +703,7 @@ static int altera_hw_filt_init(struct altera_ci_config *config, int hw_filt_nr)
 		     __func__, ret);
 
 	kfree(pid_filt);
+	kfree(inter);
 
 	return ret;
 }
@@ -733,6 +738,10 @@ int altera_ci_init(struct altera_ci_config *config, int ci_nr)
 		}
 
 		temp_int = append_internal(inter);
+		if (!temp_int) {
+			ret = -ENOMEM;
+			goto err;
+		}
 		inter->cis_used = 1;
 		inter->dev = config->dev;
 		inter->fpga_rw = config->fpga_rw;
@@ -801,6 +810,7 @@ int altera_ci_init(struct altera_ci_config *config, int ci_nr)
 	ci_dbg_print("%s: Cannot initialize CI: Error %d.\n", __func__, ret);
 
 	kfree(state);
+	kfree(inter);
 
 	return ret;
 }
-- 
2.1.4