wg: fix a number of issues with module load failure handling

If MOD_LOAD fails, then MOD_UNLOAD will be called to unwind module
state, but wg_module_init() will have already deinitialized everything
it needs to in a manner that renders it unsafe to call MOD_UNLOAD
after (e.g., freed zone not reset to NULL, wg_osd_jail_slot not reset
to 0).  Let's simply stop trying to handle freeing everything in
wg_module_init() to simplify it; let the subsequent MOD_UNLOAD deal with
it, and let's make that robust against partially-constructed state.

jhb@ notes that MOD_UNLOAD being called if MOD_LOAD fails is kind of an
anomaly that doesn't match other paradigms in the kernel; e.g., if
device_attach() fails, we don't invoke device_detach().  It's likely
that a future commit will revert this and instead stop calling
MOD_UNLOAD if MOD_LOAD fails, expecting modules to clean up after
themselves in MOD_LOAD upon failure.  Some other modules already do this
and may see similar problems to the wg module (see: carp).  The proper
fix is decidedly a bit too invasive to do this close to 14 branching,
and it requires auditing all kmods (base + ports) for potential leaks.

PR:		272089
Reviewed by:	emaste
MFC after:	3 days
Differential Revision:	https://reviews.freebsd.org/D40708
This commit is contained in:
Kyle Evans 2023-06-21 13:56:58 -05:00
parent ad9f4e6351
commit b08ee10c06
2 changed files with 17 additions and 20 deletions

View File

@ -2984,39 +2984,27 @@ static inline bool wg_run_selftests(void) { return true; }
static int
wg_module_init(void)
{
int ret = ENOMEM;
int ret;
osd_method_t methods[PR_MAXMETHOD] = {
[PR_METHOD_REMOVE] = wg_prison_remove,
};
if ((wg_packet_zone = uma_zcreate("wg packet", sizeof(struct wg_packet),
NULL, NULL, NULL, NULL, 0, 0)) == NULL)
goto free_none;
return (ENOMEM);
ret = crypto_init();
if (ret != 0)
goto free_zone;
return (ret);
ret = cookie_init();
if (ret != 0)
goto free_crypto;
return (ret);
wg_osd_jail_slot = osd_jail_register(NULL, methods);
ret = ENOTRECOVERABLE;
if (!wg_run_selftests())
goto free_all;
return (ENOTRECOVERABLE);
return (0);
free_all:
osd_jail_deregister(wg_osd_jail_slot);
cookie_deinit();
free_crypto:
crypto_deinit();
free_zone:
uma_zdestroy(wg_packet_zone);
free_none:
return (ret);
}
static void
@ -3034,10 +3022,12 @@ wg_module_deinit(void)
VNET_LIST_RUNLOCK();
NET_EPOCH_WAIT();
MPASS(LIST_EMPTY(&wg_list));
osd_jail_deregister(wg_osd_jail_slot);
if (wg_osd_jail_slot != 0)
osd_jail_deregister(wg_osd_jail_slot);
cookie_deinit();
crypto_deinit();
uma_zdestroy(wg_packet_zone);
if (wg_packet_zone != NULL)
uma_zdestroy(wg_packet_zone);
}
static int

View File

@ -55,6 +55,7 @@ struct ratelimit {
struct callout rl_gc;
LIST_HEAD(, ratelimit_entry) rl_table[RATELIMIT_SIZE];
size_t rl_table_num;
bool rl_initialized;
};
static void precompute_key(uint8_t *,
@ -102,7 +103,8 @@ cookie_deinit(void)
#ifdef INET6
ratelimit_deinit(&ratelimit_v6);
#endif
uma_zdestroy(ratelimit_zone);
if (ratelimit_zone != NULL)
uma_zdestroy(ratelimit_zone);
}
void
@ -350,16 +352,21 @@ ratelimit_init(struct ratelimit *rl)
for (i = 0; i < RATELIMIT_SIZE; i++)
LIST_INIT(&rl->rl_table[i]);
rl->rl_table_num = 0;
rl->rl_initialized = true;
}
static void
ratelimit_deinit(struct ratelimit *rl)
{
if (!rl->rl_initialized)
return;
mtx_lock(&rl->rl_mtx);
callout_stop(&rl->rl_gc);
ratelimit_gc(rl, true);
mtx_unlock(&rl->rl_mtx);
mtx_destroy(&rl->rl_mtx);
rl->rl_initialized = false;
}
static void