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

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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: b49f6d83e2 ("misc: fastrpc: Fix a possible double free")
Cc: stable <stable@kernel.org>
Co-developed-by: Ola Jeppsson <ola@snap.com>
Signed-off-by: Ola Jeppsson <ola@snap.com>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20221124174941.418450-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Abel Vesa
2022-11-24 17:49:40 +00:00
committed by Greg Kroah-Hartman
parent e0db5d44bc
commit 193cd85314
1 changed files with 9 additions and 9 deletions
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18
drivers/misc/fastrpc.c
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@@ -247,6 +247,13 @@ static void fastrpc_free_map(struct kref *ref)
dma_buf_put(map->buf); 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); kfree(map);
} }
@@ -1112,12 +1119,7 @@ err_invoke:
fl->init_mem = NULL; fl->init_mem = NULL;
fastrpc_buf_free(imem); fastrpc_buf_free(imem);
err_alloc: err_alloc:
if (map) { fastrpc_map_put(map);
spin_lock(&fl->lock);
list_del(&map->node);
spin_unlock(&fl->lock);
fastrpc_map_put(map);
}
err: err:
kfree(args); kfree(args);
@@ -1194,10 +1196,8 @@ static int fastrpc_device_release(struct inode *inode, struct file *file)
fastrpc_context_put(ctx); fastrpc_context_put(ctx);
} }
list_for_each_entry_safe(map, m, &fl->maps, node) { list_for_each_entry_safe(map, m, &fl->maps, node)
list_del(&map->node);
fastrpc_map_put(map); fastrpc_map_put(map);
}
list_for_each_entry_safe(buf, b, &fl->mmaps, node) { list_for_each_entry_safe(buf, b, &fl->mmaps, node) {
list_del(&buf->node); list_del(&buf->node);