Commit ca3881f6 authored by Petr Pavlu's avatar Petr Pavlu Committed by Daniel Gomez
Browse files

module: Fix memory deallocation on error path in move_module() 



The function move_module() uses the variable t to track how many memory
types it has allocated and consequently how many should be freed if an
error occurs.

The variable is initially set to 0 and is updated when a call to
module_memory_alloc() fails. However, move_module() can fail for other
reasons as well, in which case t remains set to 0 and no memory is freed.

Fix the problem by initializing t to MOD_MEM_NUM_TYPES. Additionally, make
the deallocation loop more robust by not relying on the mod_mem_type_t enum
having a signed integer as its underlying type.

Fixes: c7ee8aeb ("module: add stop-grap sanity check on module memcpy()")
Signed-off-by: default avatarPetr Pavlu <petr.pavlu@suse.com>
Reviewed-by: default avatarSami Tolvanen <samitolvanen@google.com>
Reviewed-by: default avatarDaniel Gomez <da.gomez@samsung.com>
Link: https://lore.kernel.org/r/20250618122730.51324-2-petr.pavlu@suse.com


Signed-off-by: default avatarDaniel Gomez <da.gomez@samsung.com>
Message-ID: <20250618122730.51324-2-petr.pavlu@suse.com>
parent d7b8f8e2

kernel/module/main.c

+2 −2
Original line number Diff line number Diff line
@@ -2697,7 +2697,7 @@ static int find_module_sections(struct module *mod, struct load_info *info) 
static int move_module(struct module *mod, struct load_info *info)

{

	int i;

	enum mod_mem_type t = 0;

	enum mod_mem_type t = MOD_MEM_NUM_TYPES;

	int ret = -ENOMEM;

	bool codetag_section_found = false;
@@ -2776,7 +2776,7 @@ static int move_module(struct module *mod, struct load_info *info) 
	return 0;

out_err:

	module_memory_restore_rox(mod);

	for (t--; t >= 0; t--)

	while (t--)

		module_memory_free(mod, t);

	if (codetag_section_found)

		codetag_free_module_sections(mod);