6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: robelin robelin@nvidia.com
commit b4a90b543d9f62d3ac34ec1ab97fc5334b048565 upstream.
When using kernel with the following extra config,
- CONFIG_KASAN=y - CONFIG_KASAN_GENERIC=y - CONFIG_KASAN_INLINE=y - CONFIG_KASAN_VMALLOC=y - CONFIG_FRAME_WARN=4096
kernel detects that snd_pcm_suspend_all() access a freed 'snd_soc_pcm_runtime' object when the system is suspended, which leads to a use-after-free bug:
[ 52.047746] BUG: KASAN: use-after-free in snd_pcm_suspend_all+0x1a8/0x270 [ 52.047765] Read of size 1 at addr ffff0000b9434d50 by task systemd-sleep/2330
[ 52.047785] Call trace: [ 52.047787] dump_backtrace+0x0/0x3c0 [ 52.047794] show_stack+0x34/0x50 [ 52.047797] dump_stack_lvl+0x68/0x8c [ 52.047802] print_address_description.constprop.0+0x74/0x2c0 [ 52.047809] kasan_report+0x210/0x230 [ 52.047815] __asan_report_load1_noabort+0x3c/0x50 [ 52.047820] snd_pcm_suspend_all+0x1a8/0x270 [ 52.047824] snd_soc_suspend+0x19c/0x4e0
The snd_pcm_sync_stop() has a NULL check on 'substream->runtime' before making any access. So we need to always set 'substream->runtime' to NULL everytime we kfree() it.
Fixes: a72706ed8208 ("ASoC: codec2codec: remove ephemeral variables") Signed-off-by: robelin robelin@nvidia.com Signed-off-by: Sameer Pujar spujar@nvidia.com Link: https://patch.msgid.link/20240823144342.4123814-2-spujar@nvidia.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- sound/soc/soc-dapm.c | 1 + 1 file changed, 1 insertion(+)
--- a/sound/soc/soc-dapm.c +++ b/sound/soc/soc-dapm.c @@ -4018,6 +4018,7 @@ static int snd_soc_dai_link_event(struct
case SND_SOC_DAPM_POST_PMD: kfree(substream->runtime); + substream->runtime = NULL; break;
default: