4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Gustavo A. R. Silva" <garsilva@xxxxxxxxxxxxxx> [ Upstream commit baed3c4bc4c13de93e0dba0a26d601411ebcb389 ] _channel_ is being dereferenced before it is null checked, hence there is a potential null pointer dereference. Fix this by moving the pointer dereference after _channel_ has been null checked. This issue was detected with the help of Coccinelle. Fixes: c5f5d0f99794 ("[media] c8sectpfe: STiH407/10 Linux DVB demux support") Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx> Acked-by: Patrice Chotard <patrice.chotard@xxxxxx> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c +++ b/drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c @@ -83,7 +83,7 @@ static void c8sectpfe_timer_interrupt(st static void channel_swdemux_tsklet(unsigned long data) { struct channel_info *channel = (struct channel_info *)data; - struct c8sectpfei *fei = channel->fei; + struct c8sectpfei *fei; unsigned long wp, rp; int pos, num_packets, n, size; u8 *buf; @@ -91,6 +91,8 @@ static void channel_swdemux_tsklet(unsig if (unlikely(!channel || !channel->irec)) return; + fei = channel->fei; + wp = readl(channel->irec + DMA_PRDS_BUSWP_TP(0)); rp = readl(channel->irec + DMA_PRDS_BUSRP_TP(0));