The probe session-duplication overflow check incremented the session
count also when there were no more available sessions so that memory
beyond the fixed-size slab-allocated session array could be corrupted in
fastrpc_session_alloc() on open().
Fixes: f6f9279f2bf0 ("misc: fastrpc: Add Qualcomm fastrpc basic driver model")
Cc: stable@xxxxxxxxxxxxxxx # 5.1
Signed-off-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
---
drivers/misc/fastrpc.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index 88091778c1b8..6e312ac85668 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -1948,7 +1948,7 @@ static int fastrpc_cb_probe(struct platform_device *pdev)
spin_unlock_irqrestore(&cctx->lock, flags);
return -ENOSPC;
}
- sess = &cctx->session[cctx->sesscount];
+ sess = &cctx->session[cctx->sesscount++];
sess->used = false;
sess->valid = true;
sess->dev = dev;
@@ -1961,13 +1961,12 @@ static int fastrpc_cb_probe(struct platform_device *pdev)
struct fastrpc_session_ctx *dup_sess;
for (i = 1; i < sessions; i++) {
- if (cctx->sesscount++ >= FASTRPC_MAX_SESSIONS)
+ if (cctx->sesscount >= FASTRPC_MAX_SESSIONS)
break;
- dup_sess = &cctx->session[cctx->sesscount];
+ dup_sess = &cctx->session[cctx->sesscount++];
memcpy(dup_sess, sess, sizeof(*dup_sess));
}
}
- cctx->sesscount++;
spin_unlock_irqrestore(&cctx->lock, flags);
rc = dma_set_mask(dev, DMA_BIT_MASK(32));
if (rc) {
--
2.35.1
