Re: [PATCH] ALSA: sound/isa/gus: check the return value of kstrdup()
Note: Compare with the last email, this one is using my full name. kstrdup() returns NULL when some internal memory errors happen, it is better to check the return value of it. Otherwise, we may not to be able to catch some memory errors in time.
Signed-off-by: Xiaoke Wang xkernel.wang@foxmail.com --- sound/isa/gus/gus_mem.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/sound/isa/gus/gus_mem.c b/sound/isa/gus/gus_mem.c index ff9480f..f8d915f 100644 --- a/sound/isa/gus/gus_mem.c +++ b/sound/isa/gus/gus_mem.c @@ -199,6 +199,8 @@ struct snd_gf1_mem_block *snd_gf1_mem_alloc(struct snd_gf1_mem * alloc, int owne memcpy(&block.share_id, share_id, sizeof(block.share_id)); block.owner = owner; block.name = kstrdup(name, GFP_KERNEL); + if (block.name == NULL) + return NULL; nblock = snd_gf1_mem_xalloc(alloc, &block); snd_gf1_mem_lock(alloc, 1); return nblock; @@ -237,13 +239,13 @@ int snd_gf1_mem_init(struct snd_gus_card * gus) block.ptr = 0; block.size = 1024; block.name = kstrdup("InterWave LFOs", GFP_KERNEL); - if (snd_gf1_mem_xalloc(alloc, &block) == NULL) + if (block.name == NULL || snd_gf1_mem_xalloc(alloc, &block) == NULL) return -ENOMEM; } block.ptr = gus->gf1.default_voice_address; block.size = 4; block.name = kstrdup("Voice default (NULL's)", GFP_KERNEL); - if (snd_gf1_mem_xalloc(alloc, &block) == NULL) + if (block.name == NULL || snd_gf1_mem_xalloc(alloc, &block) == NULL) return -ENOMEM; #ifdef CONFIG_SND_DEBUG snd_card_ro_proc_new(gus->card, "gusmem", gus, snd_gf1_mem_info_read); --
On Mon, 13 Dec 2021 09:06:47 +0100, Xiaoke Wang wrote:
Note: Compare with the last email, this one is using my full name. kstrdup() returns NULL when some internal memory errors happen, it is better to check the return value of it. Otherwise, we may not to be able to catch some memory errors in time.
Signed-off-by: Xiaoke Wang xkernel.wang@foxmail.com
The patch again forgot about the proper error handling... This will leave the mutex unbalanced.
Please be careful when writing this kind of fix at the next time. Many code paths require the proper error handling, e.g. freeing the rest memory or unlock/lock something.
In this particular case, snd_gf1_mem_lock(alloc, 1) is needed at the first chunk.
And, the easiest way to fix would be to have a NULL check in snd_gf1_mem_xalloc(). Then that will cover all callers by once.
thanks,
Takashi
sound/isa/gus/gus_mem.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/sound/isa/gus/gus_mem.c b/sound/isa/gus/gus_mem.c index ff9480f..f8d915f 100644 --- a/sound/isa/gus/gus_mem.c +++ b/sound/isa/gus/gus_mem.c @@ -199,6 +199,8 @@ struct snd_gf1_mem_block *snd_gf1_mem_alloc(struct snd_gf1_mem * alloc, int owne memcpy(&block.share_id, share_id, sizeof(block.share_id)); block.owner = owner; block.name = kstrdup(name, GFP_KERNEL);
- if (block.name == NULL)
nblock = snd_gf1_mem_xalloc(alloc, &block); snd_gf1_mem_lock(alloc, 1); return nblock;return NULL;
@@ -237,13 +239,13 @@ int snd_gf1_mem_init(struct snd_gus_card * gus) block.ptr = 0; block.size = 1024; block.name = kstrdup("InterWave LFOs", GFP_KERNEL);
if (snd_gf1_mem_xalloc(alloc, &block) == NULL)
} block.ptr = gus->gf1.default_voice_address; block.size = 4; block.name = kstrdup("Voice default (NULL's)", GFP_KERNEL);if (block.name == NULL || snd_gf1_mem_xalloc(alloc, &block) == NULL) return -ENOMEM;
- if (snd_gf1_mem_xalloc(alloc, &block) == NULL)
- if (block.name == NULL || snd_gf1_mem_xalloc(alloc, &block) == NULL) return -ENOMEM;
#ifdef CONFIG_SND_DEBUG snd_card_ro_proc_new(gus->card, "gusmem", gus, snd_gf1_mem_info_read); --
participants (2)
-
Takashi Iwai
-
Xiaoke Wang