[PATCH][next] media: vidtv: fix a read from an object after it has been freed

From: Colin King
Date: Fri Nov 27 2020 - 08:28:36 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

Currently the call to vidtv_psi_pat_table_destroy frees the object
m->si.pat however m->si.pat->num_pmt is being accessed after the
free. Fix this by destroying m->si.pat after the m->si.pmt_secs[]
objects have been freed.

Addresses-Coverity: ("Read from pointer after free")
Fixes: 039b7caed173 ("media: vidtv: add a PID entry for the NIT table")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
drivers/media/test-drivers/vidtv/vidtv_channel.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/test-drivers/vidtv/vidtv_channel.c b/drivers/media/test-drivers/vidtv/vidtv_channel.c
index 8ad6c0744d36..7838e6272712 100644
--- a/drivers/media/test-drivers/vidtv/vidtv_channel.c
+++ b/drivers/media/test-drivers/vidtv/vidtv_channel.c
@@ -504,11 +504,11 @@ void vidtv_channel_si_destroy(struct vidtv_mux *m)
{
u32 i;

- vidtv_psi_pat_table_destroy(m->si.pat);
-
for (i = 0; i < m->si.pat->num_pmt; ++i)
vidtv_psi_pmt_table_destroy(m->si.pmt_secs[i]);

+ vidtv_psi_pat_table_destroy(m->si.pat);
+
kfree(m->si.pmt_secs);
vidtv_psi_sdt_table_destroy(m->si.sdt);
vidtv_psi_nit_table_destroy(m->si.nit);
--
2.29.2