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authorAbel Vesa <abel.vesa@linaro.org>2022-11-24 17:49:40 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-01-20 13:23:09 +0100
commit5bb96c8f9268e2fdb0e5321cbc358ee5941efc15 (patch)
treede04bbb85af704bd9f05a8b4d29f2d7abb6079d7 /drivers/misc
parent9446fa1683a7e3937d9970248ced427c1983a1c5 (diff)
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: b49f6d83e290 ("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>
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/fastrpc.c18
1 files changed, 9 insertions, 9 deletions
diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index dedc067fbec8..9f8d52b59ed2 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -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 @@ 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);
@@ -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);