From: Takashi Iwai Date: Mon, 25 Nov 2024 14:20:25 +0000 (+0100) Subject: ALSA: rawmidi: Fix kvfree() call in spinlock X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=237e7fa2c844280f469eca87d8d1e7d9d9fa1e8d;p=linux ALSA: rawmidi: Fix kvfree() call in spinlock commit 20c0c49720dc4e205d4c1d64add56a5043c5ec5f upstream. At the conversion of locking with guard(), I overlooked that kvfree() must not be called inside the spinlock unlike kfree(), and this was caught by syzkaller now. This patch reverts the conversion partially for restoring the kvfree() call outside the spinlock. It's not trivial to use guard() in this context, unfortunately. Fixes: 84bb065b316e ("ALSA: rawmidi: Use guard() for locking") Reported-by: syzbot+351f8764833934c68836@syzkaller.appspotmail.com Reported-by: Eric Dumazet Closes: https://lore.kernel.org/6744737b.050a0220.1cc393.007e.GAE@google.com Cc: Link: https://patch.msgid.link/20241125142041.16578-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c index 7accf9a1ddf4..3386c2a03844 100644 --- a/sound/core/rawmidi.c +++ b/sound/core/rawmidi.c @@ -724,8 +724,9 @@ static int resize_runtime_buffer(struct snd_rawmidi_substream *substream, newbuf = kvzalloc(params->buffer_size, GFP_KERNEL); if (!newbuf) return -ENOMEM; - guard(spinlock_irq)(&substream->lock); + spin_lock_irq(&substream->lock); if (runtime->buffer_ref) { + spin_unlock_irq(&substream->lock); kvfree(newbuf); return -EBUSY; } @@ -733,6 +734,7 @@ static int resize_runtime_buffer(struct snd_rawmidi_substream *substream, runtime->buffer = newbuf; runtime->buffer_size = params->buffer_size; __reset_runtime_ptrs(runtime, is_input); + spin_unlock_irq(&substream->lock); kvfree(oldbuf); } runtime->avail_min = params->avail_min;