media: qcom: camss: vfe: Fix out-of-bounds access in vfe_isr_reg_update()

vfe_isr() iterates using MSM_VFE_IMAGE_MASTERS_NUM(7) as the loop
bound and passes the index to vfe_isr_reg_update(). However,
vfe->line[] array is defined with VFE_LINE_NUM_MAX(4):

    struct vfe_line line[VFE_LINE_NUM_MAX];

When index is 4, 5, 6, the access to vfe->line[line_id] exceeds
the array bounds and resulting in out-of-bounds memory access.

Fix this by using separate loops for output lines and write masters.

Fixes: 4edc8eae715c ("media: camss: Add initial support for VFE hardware version Titan 480")
Signed-off-by: Alper Ak <alperyasinak1@gmail.com>
Cc: stable@vger.kernel.org
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Bryan O'Donoghue <bod@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

diff --git a/drivers/media/platform/qcom/camss/camss-vfe-480.c b/drivers/media/platform/qcom/camss/camss-vfe-480.c
index 4feea590a47bc3355051f462814ece9539335641..d73f733fde04599ffa5550d037967a4e7d193ef8 100644 (file)
--- a/drivers/media/platform/qcom/camss/camss-vfe-480.c
+++ b/drivers/media/platform/qcom/camss/camss-vfe-480.c
@@ -202,11 +202,13 @@ static irqreturn_t vfe_isr(int irq, void *dev)
                writel_relaxed(status, vfe->base + VFE_BUS_IRQ_CLEAR(0));
                writel_relaxed(1, vfe->base + VFE_BUS_IRQ_CLEAR_GLOBAL);
 
-               /* Loop through all WMs IRQs */
-               for (i = 0; i < MSM_VFE_IMAGE_MASTERS_NUM; i++) {
+               for (i = 0; i < MAX_VFE_OUTPUT_LINES; i++) {
                        if (status & BUS_IRQ_MASK_0_RDI_RUP(vfe, i))
                                vfe_isr_reg_update(vfe, i);
+               }
 
+               /* Loop through all WMs IRQs */
+               for (i = 0; i < MSM_VFE_IMAGE_MASTERS_NUM; i++) {
                        if (status & BUS_IRQ_MASK_0_COMP_DONE(vfe, RDI_COMP_GROUP(i)))
                                vfe_buf_done(vfe, i);
                }