From 35ddd482345c43d9eec1f3406c0f20a95ed4054b Mon Sep 17 00:00:00 2001 From: Abel Vesa Date: Thu, 24 Nov 2022 17:49:40 +0000 Subject: [PATCH] misc: fastrpc: Don't remove map on creater_process and device_release commit 5bb96c8f9268e2fdb0e5321cbc358ee5941efc15 upstream. Do not remove the map from the list on error path in fastrpc_init_create_process, instead call fastrpc_map_put, to avoid use-after-free. Do not remove it on fastrpc_device_release either, call fastrpc_map_put instead. The fastrpc_free_map is the only proper place to remove the map. This is called only after the reference count is 0. Fixes: b49f6d83e290 ("misc: fastrpc: Fix a possible double free") Cc: stable Co-developed-by: Ola Jeppsson Signed-off-by: Ola Jeppsson Signed-off-by: Abel Vesa Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20221124174941.418450-3-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/misc/fastrpc.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c index fc2173c..9ecbf67 100644 --- a/drivers/misc/fastrpc.c +++ b/drivers/misc/fastrpc.c @@ -316,6 +316,13 @@ static void fastrpc_free_map(struct kref *ref) dma_buf_put(map->buf); } + if (map->fl) { + spin_lock(&map->fl->lock); + list_del(&map->node); + spin_unlock(&map->fl->lock); + map->fl = NULL; + } + kfree(map); } @@ -1266,12 +1273,7 @@ err_invoke: fl->init_mem = NULL; fastrpc_buf_free(imem); err_alloc: - if (map) { - spin_lock(&fl->lock); - list_del(&map->node); - spin_unlock(&fl->lock); - fastrpc_map_put(map); - } + fastrpc_map_put(map); err: kfree(args); @@ -1347,10 +1349,8 @@ static int fastrpc_device_release(struct inode *inode, struct file *file) fastrpc_context_put(ctx); } - list_for_each_entry_safe(map, m, &fl->maps, node) { - list_del(&map->node); + list_for_each_entry_safe(map, m, &fl->maps, node) fastrpc_map_put(map); - } list_for_each_entry_safe(buf, b, &fl->mmaps, node) { list_del(&buf->node); -- 2.7.4