Commit 5bb96c8f authored by Abel Vesa's avatar Abel Vesa Committed by Greg Kroah-Hartman

misc: fastrpc: Don't remove map on creater_process and device_release

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: b49f6d83 ("misc: fastrpc: Fix a possible double free")
Cc: stable <stable@kernel.org>
Co-developed-by: default avatarOla Jeppsson <ola@snap.com>
Signed-off-by: default avatarOla Jeppsson <ola@snap.com>
Signed-off-by: default avatarAbel Vesa <abel.vesa@linaro.org>
Signed-off-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20221124174941.418450-3-srinivas.kandagatla@linaro.orgSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 9446fa16
......@@ -334,6 +334,13 @@ 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);
}
......@@ -1434,12 +1441,7 @@ static int fastrpc_init_create_process(struct fastrpc_user *fl,
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);
}
err:
kfree(args);
......@@ -1515,10 +1517,8 @@ 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);
......
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