misc: fastrpc: Fix dma_buf object leak in fastrpc_map_lookup

commit fff111bf45cbeeb659324316d68554e35d350092 upstream.

In fastrpc_map_lookup, dma_buf_get is called to obtain a reference to
the dma_buf for comparison purposes. However, this reference is never
released when the function returns, leading to a dma_buf memory leak.

Fix this by adding dma_buf_put before returning from the function,
ensuring that the temporarily acquired reference is properly released
regardless of whether a matching map is found.

Fixes: 9031626ade38 ("misc: fastrpc: Fix fastrpc_map_lookup operation")
Cc: stable@kernel.org
Signed-off-by: Junhao Xie <bigfoot@radxa.com>
Tested-by: Xilin Wu <sophon@radxa.com>
Link: https://lore.kernel.org/stable/48B368FB4C7007A7%2B20251017083906.3259343-1-bigfoot%40radxa.com
Link: https://patch.msgid.link/48B368FB4C7007A7+20251017083906.3259343-1-bigfoot@radxa.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index 7eec907ed454243a6a6db875be9d8eb141dc973e..7dceb2db67a3acb37cf17cd2af583f1c23bd3e0c 100644 (file)
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -384,6 +384,8 @@ static int fastrpc_map_lookup(struct fastrpc_user *fl, int fd,
        }
        spin_unlock(&fl->lock);
 
+       dma_buf_put(buf);
+
        return ret;
 }