Re: [PATCH] media: vidtv: fix general protection fault in vidtv_psi_ts_psi_write_into

From: Soham Kute

Date: Sat Feb 07 2026 - 15:49:22 EST


v2: resend with correct syzbot Reported-by and maintainer To: list.


On Sun, Feb 8, 2026 at 1:52 AM syzbot <syzbot@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> Add defensive validation for psi_write_args pointers to avoid
> null pointer dereference reported by syzbot.
>
> Reported-by: syzbot+814c351d094f41a1b86@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> Signed-off-by: Soham Kute <officialsohamkute@xxxxxxxxx>
> ---
>  drivers/media/test-drivers/vidtv/vidtv_psi.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/test-drivers/vidtv/vidtv_psi.c b/drivers/media/test-drivers/vidtv/vidtv_psi.c
> index 2a51c898c..bac0ea03b 100644
> --- a/drivers/media/test-drivers/vidtv/vidtv_psi.c
> +++ b/drivers/media/test-drivers/vidtv/vidtv_psi.c
> @@ -156,7 +156,13 @@ static void vidtv_psi_set_sec_len(struct vidtv_psi_table_header *h, u16 new_len)
>   * add stuffing (i.e. padding bytes) after the CRC
>   */
>  static u32 vidtv_psi_ts_psi_write_into(struct psi_write_args *args)
> -{
> +{   
> +     if (!args || !args->dest_buf || !args->from ||
> +         !args->continuity_counter) {
> +             pr_warn_once("%s: invalid write arguments\n", __func__);
> +             return 0;
> +     }
> +
>       struct vidtv_mpeg_ts ts_header = {
>               .sync_byte = TS_SYNC_BYTE,
>               .bitfield = cpu_to_be16((args->new_psi_section << 14) | args->pid),
> --
> 2.34.1
>

I see the command but can't find the corresponding bug.
The email is sent to  syzbot+HASH@xxxxxxxxxxxxxxxxxxxxxxxxx address
but the HASH does not correspond to any known bug.
Please double check the address.

From fd746b95987239073f7872275cd68fe8cb29e0ed Mon Sep 17 00:00:00 2001
From: Soham Kute <officialsohamkute@xxxxxxxxx>
Date: Sun, 8 Feb 2026 01:43:40 +0530
Subject: [PATCH] [PATCH v2] media: vidtv: fix general protection fault in
vidtv_psi_ts_psi_write_into

Add defensive validation for psi_write_args pointers to avoid
null pointer dereference reported by syzbot.

Reported-by: syzbot+814c351d094f41a1b86@xxxxxxxxxxxxxxxxxxxxxxxxx

Signed-off-by: Soham Kute <officialsohamkute@xxxxxxxxx>
---
drivers/media/test-drivers/vidtv/vidtv_psi.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/media/test-drivers/vidtv/vidtv_psi.c b/drivers/media/test-drivers/vidtv/vidtv_psi.c
index 2a51c898c..bac0ea03b 100644
--- a/drivers/media/test-drivers/vidtv/vidtv_psi.c
+++ b/drivers/media/test-drivers/vidtv/vidtv_psi.c
@@ -156,7 +156,13 @@ static void vidtv_psi_set_sec_len(struct vidtv_psi_table_header *h, u16 new_len)
* add stuffing (i.e. padding bytes) after the CRC
*/
static u32 vidtv_psi_ts_psi_write_into(struct psi_write_args *args)
-{
+{
+ if (!args || !args->dest_buf || !args->from ||
+ !args->continuity_counter) {
+ pr_warn_once("%s: invalid write arguments\n", __func__);
+ return 0;
+ }
+
struct vidtv_mpeg_ts ts_header = {
.sync_byte = TS_SYNC_BYTE,
.bitfield = cpu_to_be16((args->new_psi_section << 14) | args->pid),
--
2.34.1