From: Takashi Iwai <tiwai@xxxxxxx> commit d2913a07d9037fe7aed4b7e680684163eaed6bc4 upstream. A driver might allow the mmap access before initializing its runtime->dma_area properly. Add a proper NULL check before passing to virt_to_page() for avoiding a panic. Reported-by: syzbot+4bf62a7b1d0f4fdb7ae2@xxxxxxxxxxxxxxxxxxxxxxxxx Cc: <stable@xxxxxxxxxxxxxxx> Link: https://patch.msgid.link/20241120141104.7060-1-tiwai@xxxxxxx Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- sound/core/pcm_native.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -3789,9 +3789,11 @@ static vm_fault_t snd_pcm_mmap_data_faul return VM_FAULT_SIGBUS; if (substream->ops->page) page = substream->ops->page(substream, offset); - else if (!snd_pcm_get_dma_buf(substream)) + else if (!snd_pcm_get_dma_buf(substream)) { + if (WARN_ON_ONCE(!runtime->dma_area)) + return VM_FAULT_SIGBUS; page = virt_to_page(runtime->dma_area + offset); - else + } else page = snd_sgbuf_get_page(snd_pcm_get_dma_buf(substream), offset); if (!page) return VM_FAULT_SIGBUS; Patches currently in stable-queue which might be from tiwai@xxxxxxx are queue-6.11/alsa-pcm-add-sanity-null-check-for-the-default-mmap-fault-handler.patch queue-6.11/alsa-hda-realtek-set-pcbeep-to-default-value-for-alc274.patch queue-6.11/alsa-6fire-release-resources-at-card-release.patch queue-6.11/alsa-hda-realtek-add-subwoofer-quirk-for-infinix-zer.patch queue-6.11/alsa-hda-realtek-apply-quirk-for-medion-e15433.patch queue-6.11/alsa-ump-fix-evaluation-of-midi-1.0-fb-info.patch queue-6.11/alsa-usx2y-use-snd_card_free_when_closed-at-disconne.patch queue-6.11/alsa-hda-realtek-fix-internal-speaker-and-mic-boost-of-infinix-y4-max.patch queue-6.11/alsa-us122l-use-snd_card_free_when_closed-at-disconn.patch queue-6.11/alsa-caiaq-use-snd_card_free_when_closed-at-disconne.patch queue-6.11/alsa-usb-audio-fix-out-of-bounds-reads-when-finding-clock-sources.patch queue-6.11/alsa-core-fix-possible-null-dereference-caused-by-ku.patch queue-6.11/alsa-usb-audio-fix-potential-out-of-bound-accesses-for-extigy-and-mbox-devices.patch queue-6.11/alsa-usb-audio-fix-yamaha-p-125-quirk-entry.patch queue-6.11/alsa-rawmidi-fix-kvfree-call-in-spinlock.patch queue-6.11/alsa-hda-realtek-update-alc225-depop-procedure.patch queue-6.11/alsa-hda-realtek-update-alc256-depop-procedure.patch
