CVE-2024-46793 ASoC: Intel: Boards: Fix NULL pointer deref in BYT/CHT boards harder
A NULL pointer dereference in Intel ASoC board drivers can cause a kernel crash, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-46793?
CVE-2024-46793 is a medium-severity vulnerability in Linux kernel, published on 18 Sep 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ASoC: Intel: Boards: Fix NULL pointer deref in BYT/CHT boards harder
Since commit 13f58267cda3 ("ASoC: soc.h: don't create dummy Component via COMP_DUMMY()") dummy codecs declared like this:
SND_SOC_DAILINK_DEF(dummy, DAILINK_COMP_ARRAY(COMP_DUMMY()));
expand to:
static struct snd_soc_dai_link_component dummy[] = { };
Which means that dummy is a zero sized array and thus dais[i].codecs should not be dereferenced *at all* since it points to the address of the next variable stored in the data section as the "dummy" variable has an address but no size, so even dereferencing dais[0] is already an out of bounds array reference.
Which means that the if (dais[i].codecs->name) check added in commit 7d99a70b6595 ("ASoC: Intel: Boards: Fix NULL pointer deref in BYT/CHT boards") relies on that the part of the next variable which the name member maps to just happens to be NULL.
Which apparently so far it usually is, except when it isn't and then it results in crashes like this one:
[ 28.795659] BUG: unable to handle page fault for address: 0000000000030011 ... [ 28.795780] Call Trace: [ 28.795787] <TASK> ... [ 28.795862] ? strcmp+0x18/0x40 [ 28.795872] 0xffffffffc150c605 [ 28.795887] platform_probe+0x40/0xa0 ... [ 28.795979] ? __pfx_init_module+0x10/0x10 [snd_soc_sst_bytcr_wm5102]
Really fix things this time around by checking dais.num_codecs != 0.
Weakness: CWE-476
Which versions are affected by CVE-2024-46793?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-46793?
Apply the vendor's patch.
Is CVE-2024-46793 being exploited?
There is no known exploitation of CVE-2024-46793 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-46793, DEBIAN-CVE-2024-46793, GHSA-47fg-g734-5wff, UBUNTU-CVE-2024-46793.