# CVE-2024-46749: Bluetooth: btnxpuart: Fix Null pointer dereference in btnxpuart_flush() > A null pointer dereference in the btnxpuart Bluetooth driver causes a kernel crash when removing the driver after a failed firmware download. - **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`) - **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:** Yes - **Published:** 18 Sep 2024 - **Updated:** 11 May 2026 - **Also known as:** AZL-49401, BELL-CVE-2024-46749, DEBIAN-CVE-2024-46749, GHSA-6cf5-rv3h-c7jx, ROOT-OS-UBUNTU-2204-CVE-2024-46749, UBUNTU-CVE-2024-46749 ## What is CVE-2024-46749? CVE-2024-46749 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: Bluetooth: btnxpuart: Fix Null pointer dereference in btnxpuart_flush() This adds a check before freeing the rx->skb in flush and close functions to handle the kernel crash seen while removing driver after FW download fails or before FW download completes. dmesg log: [ 54.634586] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000080 [ 54.643398] Mem abort info: [ 54.646204] ESR = 0x0000000096000004 [ 54.649964] EC = 0x25: DABT (current EL), IL = 32 bits [ 54.655286] SET = 0, FnV = 0 [ 54.658348] EA = 0, S1PTW = 0 [ 54.661498] FSC = 0x04: level 0 translation fault [ 54.666391] Data abort info: [ 54.669273] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 [ 54.674768] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 54.674771] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 54.674775] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000048860000 [ 54.674780] [0000000000000080] pgd=0000000000000000, p4d=0000000000000000 [ 54.703880] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP [ 54.710152] Modules linked in: btnxpuart(-) overlay fsl_jr_uio caam_jr caamkeyblob_desc caamhash_desc caamalg_desc crypto_engine authenc libdes crct10dif_ce polyval_ce polyval_generic snd_soc_imx_spdif snd_soc_imx_card snd_soc_ak5558 snd_soc_ak4458 caam secvio error snd_soc_fsl_micfil snd_soc_fsl_spdif snd_soc_fsl_sai snd_soc_fsl_utils imx_pcm_dma gpio_ir_recv rc_core sch_fq_codel fuse [ 54.744357] CPU: 3 PID: 72 Comm: kworker/u9:0 Not tainted 6.6.3-otbr-g128004619037 #2 [ 54.744364] Hardware name: FSL i.MX8MM EVK board (DT) [ 54.744368] Workqueue: hci0 hci_power_on [ 54.757244] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 54.757249] pc : kfree_skb_reason+0x18/0xb0 [ 54.772299] lr : btnxpuart_flush+0x40/0x58 [btnxpuart] [ 54.782921] sp : ffff8000805ebca0 [ 54.782923] x29: ffff8000805ebca0 x28: ffffa5c6cf1869c0 x27: ffffa5c6cf186000 [ 54.782931] x26: ffff377b84852400 x25: ffff377b848523c0 x24: ffff377b845e7230 [ 54.782938] x23: ffffa5c6ce8dbe08 x22: ffffa5c6ceb65410 x21: 00000000ffffff92 [ 54.782945] x20: ffffa5c6ce8dbe98 x19: ffffffffffffffac x18: ffffffffffffffff [ 54.807651] x17: 0000000000000000 x16: ffffa5c6ce2824ec x15: ffff8001005eb857 [ 54.821917] x14: 0000000000000000 x13: ffffa5c6cf1a02e0 x12: 0000000000000642 [ 54.821924] x11: 0000000000000040 x10: ffffa5c6cf19d690 x9 : ffffa5c6cf19d688 [ 54.821931] x8 : ffff377b86000028 x7 : 0000000000000000 x6 : 0000000000000000 [ 54.821938] x5 : ffff377b86000000 x4 : 0000000000000000 x3 : 0000000000000000 [ 54.843331] x2 : 0000000000000000 x1 : 0000000000000002 x0 : ffffffffffffffac [ 54.857599] Call trace: [ 54.857601] kfree_skb_reason+0x18/0xb0 [ 54.863878] btnxpuart_flush+0x40/0x58 [btnxpuart] [ 54.863888] hci_dev_open_sync+0x3a8/0xa04 [ 54.872773] hci_power_on+0x54/0x2e4 [ 54.881832] process_one_work+0x138/0x260 [ 54.881842] worker_thread+0x32c/0x438 [ 54.881847] kthread+0x118/0x11c [ 54.881853] ret_from_fork+0x10/0x20 [ 54.896406] Code: a9be7bfd 910003fd f9000bf3 aa0003f3 (b940d400) [ 54.896410] ---[ end trace 0000000000000000 ]--- Weakness: CWE-476 (NULL Pointer Dereference) ## Which versions are affected by CVE-2024-46749? It affects 1 product. Products: Linux kernel. ## How do I fix CVE-2024-46749? Apply the vendor's patch. ## Is CVE-2024-46749 being exploited? There is no known exploitation of CVE-2024-46749 in the wild and no public exploit code. ## Other vulnerabilities in Linux kernel - [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild) - [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild) - [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild) - [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild) - [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2024-46749 and fix it if it is affected. What it is: CVE-2024-46749 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. Exploitation: There is no known exploitation of CVE-2024-46749 in the wild and no public exploit code. Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2024-46749/ (Markdown: https://insights.sbomify.com/CVE-2024-46749/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2024-46749 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-46749 - OSV: https://osv.dev/vulnerability/CVE-2024-46749 --- From sbomify Insights: https://insights.sbomify.com/CVE-2024-46749/ Summaries are generated and may contain mistakes; the official description above is the record.