From: julian-lagattuta <julian.lagattuta@gmail.com>
To: Luis Chamberlain <mcgrof@kernel.org>, Petr Pavlu <petr.pavlu@suse.com>
Cc: Sami Tolvanen <samitolvanen@google.com>,
Daniel Gomez <da.gomez@samsung.com>,
linux-modules@vger.kernel.org, linux-kernel@vger.kernel.org,
julian-lagattuta <julian.lagattuta@gmail.com>
Subject: [PATCH 3/6] module: move freeinit allocation to avoid memory leak
Date: Thu, 18 Sep 2025 16:11:10 -0400 [thread overview]
Message-ID: <20250918201109.24620-8-julian.lagattuta@gmail.com> (raw)
In-Reply-To: <20250918201109.24620-2-julian.lagattuta@gmail.com>
move freeinit allocation after do_one_initcall in case do_one_initcall crashes.
Otherwise, freeinit would leak memory after every initalization of a crashed module.
I could not find a reason for why freeinit allocation happened before do_one_initcall.
Signed-off-by: julian-lagattuta <julian.lagattuta@gmail.com>
---
kernel/module/main.c | 20 +++++++++-----------
1 file changed, 9 insertions(+), 11 deletions(-)
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 2277c53aef2e..2825ac177c62 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -3021,21 +3021,13 @@ static noinline int do_init_module(struct module *mod)
}
#endif
- freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
- if (!freeinit) {
- ret = -ENOMEM;
- goto fail;
- }
- freeinit->init_text = mod->mem[MOD_INIT_TEXT].base;
- freeinit->init_data = mod->mem[MOD_INIT_DATA].base;
- freeinit->init_rodata = mod->mem[MOD_INIT_RODATA].base;
do_mod_ctors(mod);
/* Start the module */
if (mod->init != NULL)
ret = do_one_initcall(mod->init);
if (ret < 0) {
- goto fail_free_freeinit;
+ goto fail;
}
if (ret > 0) {
pr_warn("%s: '%s'->init suspiciously returned %d, it should "
@@ -3045,6 +3037,14 @@ static noinline int do_init_module(struct module *mod)
dump_stack();
}
+ freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
+ if (!freeinit) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+ freeinit->init_text = mod->mem[MOD_INIT_TEXT].base;
+ freeinit->init_data = mod->mem[MOD_INIT_DATA].base;
+ freeinit->init_rodata = mod->mem[MOD_INIT_RODATA].base;
/* Now it's a first class citizen! */
mod->state = MODULE_STATE_LIVE;
blocking_notifier_call_chain(&module_notify_list,
@@ -3123,8 +3123,6 @@ static noinline int do_init_module(struct module *mod)
return 0;
-fail_free_freeinit:
- kfree(freeinit);
fail:
/* Try to protect us from buggy refcounters. */
mod->state = MODULE_STATE_GOING;
--
2.45.2
next prev parent reply other threads:[~2025-09-18 20:11 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-18 20:11 [PATCH 0/6] module: enable force unloading of modules that have crashed during init julian-lagattuta
2025-09-18 20:11 ` [PATCH 1/6] module: store init_pid and idempotent in module julian-lagattuta
2025-09-18 20:11 ` [PATCH 2/6] module: detect if init crashed and unload julian-lagattuta
2025-09-18 20:11 ` julian-lagattuta [this message]
2025-09-18 20:11 ` [PATCH 4/6] module: move idempotent allocation to heap julian-lagattuta
2025-09-18 20:11 ` [PATCH 5/6] module: store and complete idempotent upon force unloading julian-lagattuta
2025-09-18 20:11 ` [PATCH 6/6] module: comment describing new codepath julian-lagattuta
2025-09-23 7:21 ` [PATCH 0/6] module: enable force unloading of modules that have crashed during init Petr Pavlu
2025-09-24 22:16 ` Julian LaGattuta
2025-09-30 13:16 ` Petr Pavlu
2025-09-30 15:51 ` Julian LaGattuta
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