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| author | Takashi Iwai <tiwai@suse.de> | 2022-09-19 14:35:16 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2022-09-19 14:36:06 +0200 |
| commit | c3afa2a402d1ecefa59f88d55d9e765f52f75bd9 (patch) | |
| tree | 8d0b048f96395fff57d2c0e830277541e106711a /sound | |
| parent | 496322302bf1e58dc2ff134173527493105f51ab (diff) | |
| download | lwn-c3afa2a402d1ecefa59f88d55d9e765f52f75bd9.tar.gz lwn-c3afa2a402d1ecefa59f88d55d9e765f52f75bd9.zip | |
ALSA: core: Fix double-free at snd_card_new()
During the code change to add the support for devres-managed card
instance, we put an explicit kfree(card) call at the error path in
snd_card_new(). This is needed for the early error path before the
card is initialized with the device, but is rather superfluous and
causes a double-free at the error path after the card instance is
initialized, as the destructor of the card object already contains a
kfree() call.
This patch fixes the double-free situation by removing the superfluous
kfree(). Meanwhile we need to call kfree() explicitly for the early
error path, so it's added there instead.
Fixes: e8ad415b7a55 ("ALSA: core: Add managed card creation")
Reported-by: Rondreis <linhaoguo86@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/CAB7eexL1zBnB636hwS27d-LdPYZ_R1-5fJS_h=ZbCWYU=UPWJg@mail.gmail.com
Link: https://lore.kernel.org/r/20220919123516.28222-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/core/init.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/sound/core/init.c b/sound/core/init.c index 193dae361fac..5377f94eb211 100644 --- a/sound/core/init.c +++ b/sound/core/init.c @@ -178,10 +178,8 @@ int snd_card_new(struct device *parent, int idx, const char *xid, return -ENOMEM; err = snd_card_init(card, parent, idx, xid, module, extra_size); - if (err < 0) { - kfree(card); - return err; - } + if (err < 0) + return err; /* card is freed by error handler */ *card_ret = card; return 0; @@ -233,7 +231,7 @@ int snd_devm_card_new(struct device *parent, int idx, const char *xid, card->managed = true; err = snd_card_init(card, parent, idx, xid, module, extra_size); if (err < 0) { - devres_free(card); + devres_free(card); /* in managed mode, we need to free manually */ return err; } @@ -297,6 +295,8 @@ static int snd_card_init(struct snd_card *card, struct device *parent, mutex_unlock(&snd_card_mutex); dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n", idx, snd_ecards_limit - 1, err); + if (!card->managed) + kfree(card); /* manually free here, as no destructor called */ return err; } set_bit(idx, snd_cards_lock); /* lock it */ |