high CVSS 7.8

CVE-2021-46943·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: media: staging/intel-ipu3: Fix set_fmt error handling If there in an error during a set_fmt, do not overwrite the previous sizes with the invalid config. Without this patch, v4l2-compliance ends up allocating 4GiB of RAM and causing the following OOPs [ 38.662975] ipu3-imgu 0000:00:05.0: swiotlb buffer is full (sz: 4096 bytes) [ 38.662980] DMA: Out of SW-IOMMU space for 4096 bytes at device 0000:00:05.0 [ 38.663010] general protection fault: 0000 [#1] PREEMPT SMP

Severity
high
Software
Kernel
Fixed in
5.12.3
Published
2024-02-27

Affected versions

From: 5.12.0

Until: 5.12.3

Fixed in: 5.12.3

How to fix this CVE

Update your Linux kernel to version 5.12.3 or later to resolve this error handling vulnerability in the Intel IPU3 media driver. The fix prevents invalid video format configurations from persisting in memory, which was causing excessive memory allocation and system crashes. Apply this update during your next maintenance window, as it requires a kernel reboot to take effect.

sudo dnf update kernel

Defensia detects this vulnerability

How to check if you are affected

  1. Step 1: Check your kernel version with: uname -r — if it shows 5.12.0, 5.12.1, or 5.12.2, you are vulnerable
  2. Step 2: Verify Intel IPU3 driver presence with: lspci | grep -i ipu — look for Intel Image Processing Unit entries
  3. Step 3: Search system logs for DMA allocation failures: grep -i 'swiotlb buffer is full' /var/log/kern.log or journalctl -b | grep -i 'DMA: Out of SW-IOMMU'
  4. Step 4: After applying the update, reboot and confirm the new kernel is active: uname -r should show 5.12.3 or higher

FAQ

What is CVE-2021-46943?

This vulnerability exists in the Intel IPU3 media driver where failed video format configuration operations leave invalid memory state, causing subsequent operations to attempt allocating gigabytes of RAM and triggering kernel crashes and memory exhaustion.

Is CVE-2021-46943 being actively exploited?

No, this vulnerability is not listed in CISA's Known Exploited Vulnerabilities catalog and there are no public exploits available. Exploitation requires local access and privileged operations on the video format subsystem.

What versions of Kernel are affected by CVE-2021-46943?

Linux kernel versions 5.12.0 through 5.12.2 are affected. Version 5.12.3 and all later kernel versions contain the fix.

How do I check if my server is vulnerable to CVE-2021-46943?

Run 'uname -r' to check your kernel version — if it is 5.12.0, 5.12.1, or 5.12.2 AND the system has Intel IPU3 hardware (check with 'lspci | grep ipu'), then you are vulnerable.

Does Defensia detect CVE-2021-46943?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Kernel is installed on a monitored server, CVE-2021-46943 will appear in your dashboard with remediation steps.

Related Kernel CVEs

CVE-2024-42256CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: cifs: Fix server re-repick on subrequest retry When a subrequest is marked for needing retry, netfs will call cifs_prepare_write() which will make cifs repick the server for the op before renegotiating credits; it then calls cifs_issue_write() which invokes smb2_async_writev() - which re-repicks the server. If a different server is then selected, this causes the increment of server->in_flight to happen against one record and the decrement to happen against another, leading to misaccounting. Fix this by just removing the repick code in smb2_async_writev(). As this is only called from netfslib-driven code, cifs_prepare_write() should always have been called first, and so server should never be NULL and the preparatory step is repeated in the event that we do a retry. The problem manifests as a warning looking something like: WARNING: CPU: 4 PID: 72896 at fs/smb/client/smb2ops.c:97 smb2_add_credits+0x3f0/0x9e0 [cifs] ... RIP: 0010:smb2_add_credits+0x3f0/0x9e0 [cifs] ... smb2_writev_callback+0x334/0x560 [cifs] cifs_demultiplex_thread+0x77a/0x11b0 [cifs] kthread+0x187/0x1d0 ret_from_fork+0x34/0x60 ret_from_fork_asm+0x1a/0x30 Which may be triggered by a number of different xfstests running against an Azure server in multichannel mode. generic/249 seems the most repeatable, but generic/215, generic/249 and generic/308 may also show it.
CVE-2022-48716CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: ASoC: codecs: wcd938x: fix incorrect used of portid Mixer controls have the channel id in mixer->reg, which is not same as port id. port id should be derived from chan_info array. So fix this. Without this, its possible that we could corrupt struct wcd938x_sdw_priv by accessing port_map array out of range with channel id instead of port id.
CVE-2021-47548CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: ethernet: hisilicon: hns: hns_dsaf_misc: fix a possible array overflow in hns_dsaf_ge_srst_by_port() The if statement: if (port >= DSAF_GE_NUM) return; limits the value of port less than DSAF_GE_NUM (i.e., 8). However, if the value of port is 6 or 7, an array overflow could occur: port_rst_off = dsaf_dev->mac_cb[port]->port_rst_off; because the length of dsaf_dev->mac_cb is DSAF_MAX_PORT_NUM (i.e., 6). To fix this possible array overflow, we first check port and if it is greater than or equal to DSAF_MAX_PORT_NUM, the function returns.
CVE-2024-36031CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: keys: Fix overwrite of key expiration on instantiation The expiry time of a key is unconditionally overwritten during instantiation, defaulting to turn it permanent. This causes a problem for DNS resolution as the expiration set by user-space is overwritten to TIME64_MAX, disabling further DNS updates. Fix this by restoring the condition that key_set_expiry is only called when the pre-parser sets a specific expiry.
CVE-2024-38541CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: of: module: add buffer overflow check in of_modalias() In of_modalias(), if the buffer happens to be too small even for the 1st snprintf() call, the len parameter will become negative and str parameter (if not NULL initially) will point beyond the buffer's end. Add the buffer overflow check after the 1st snprintf() call and fix such check after the strlen() call (accounting for the terminating NUL char).

References

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