ALSA: emu10k1: move patch loader assertions into low-level functions

Convert some checks in snd_emu10k1_sample_new() back into assertions (as
they were prior to da3cec35 (ALSA: Kill snd_assert() in sound/pci/*,
2008-08-08)), and move them into the low-level memory access functions
they protect.
Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>

Message-ID: <20240406064830.1029573-9-oswald.buddenhagen@gmx.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/emu10k1/emu10k1_patch.c

@@ -65,8 +65,6 @@ snd_emu10k1_sample_new(struct snd_emux *rec, struct snd_sf_sample *sp,
 	size = BLANK_HEAD_SIZE;
 	if (! (sp->v.mode_flags & SNDRV_SFNT_SAMPLE_8BITS))
 		size *= 2;
-	if (offset + size > blocksize)
-		return -EINVAL;
 	snd_emu10k1_synth_bzero(emu, sp->block, offset, size);
 	offset += size;
 
@@ -74,8 +72,6 @@ snd_emu10k1_sample_new(struct snd_emux *rec, struct snd_sf_sample *sp,
 	size = sp->v.size;
 	if (! (sp->v.mode_flags & SNDRV_SFNT_SAMPLE_8BITS))
 		size *= 2;
-	if (offset + size > blocksize)
-		return -EINVAL;
 	if (snd_emu10k1_synth_copy_from_user(emu, sp->block, offset, data, size)) {
 		snd_emu10k1_synth_free(emu, sp->block);
 		sp->block = NULL;

sound/pci/emu10k1/memory.c

@@ -574,6 +574,9 @@ int snd_emu10k1_synth_bzero(struct snd_emu10k1 *emu, struct snd_util_memblk *blk
 	void *ptr;
 	struct snd_emu10k1_memblk *p = (struct snd_emu10k1_memblk *)blk;
 
+	if (snd_BUG_ON(offset + size > p->mem.size))
+		return -EFAULT;
+
 	offset += blk->offset & (PAGE_SIZE - 1);
 	end_offset = offset + size;
 	page = get_aligned_page(offset);
@@ -604,6 +607,9 @@ int snd_emu10k1_synth_copy_from_user(struct snd_emu10k1 *emu, struct snd_util_me
 	void *ptr;
 	struct snd_emu10k1_memblk *p = (struct snd_emu10k1_memblk *)blk;
 
+	if (snd_BUG_ON(offset + size > p->mem.size))
+		return -EFAULT;
+
 	offset += blk->offset & (PAGE_SIZE - 1);
 	end_offset = offset + size;
 	page = get_aligned_page(offset);