high CVSS 7.1

CVE-2024-46774·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: powerpc/rtas: Prevent Spectre v1 gadget construction in sys_rtas() Smatch warns: arch/powerpc/kernel/rtas.c:1932 __do_sys_rtas() warn: potential spectre issue 'args.args' [r] (local cap) The 'nargs' and 'nret' locals come directly from a user-supplied buffer and are used as indexes into a small stack-based array and as inputs to copy_to_user() after they are subject to bounds checks. Use array_index_nospec() after the bounds checks to clamp these values for speculative execution.

Severity
high
Software
Kernel
Fixed in
6.10.10
Published
2024-09-18

Affected versions

Until: 6.10.10

Fixed in: 6.10.10

How to fix this CVE

Update your Linux kernel to version 6.10.10 or later to patch the Spectre v1 gadget vulnerability in the RTAS system call handler. This vulnerability allows local attackers to bypass speculative execution protections through improper array index validation. Apply the kernel update immediately across all affected PowerPC systems in your infrastructure.

sudo dnf update kernel kernel-headers kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Check current kernel version: uname -r | awk -F'.' '{print $1"."$2"."$3}'
  2. Verify if PowerPC RTAS is enabled: cat /proc/cmdline | grep -i rtas
  3. Search for RTAS system call activity in audit logs: ausearch -m syscall -F syscall=255 2>/dev/null | head -20
  4. Confirm the patched kernel is running: grep -i 'array_index_nospec' /boot/config-$(uname -r) || echo 'Kernel config not accessible - verify via package manager'
  5. Verify kernel package version post-update: dpkg -l | grep linux-image (Debian/Ubuntu) or rpm -q kernel (RHEL/CentOS)

FAQ

What is CVE-2024-46774?

CVE-2024-46774 is a Spectre v1 gadget construction vulnerability in the Linux kernel's PowerPC RTAS system call handler (sys_rtas). An unprivileged local attacker can exploit improper array index validation to perform speculative execution attacks that leak kernel memory or bypass security boundaries.

Is CVE-2024-46774 being actively exploited?

No, there is no evidence of active exploitation in the wild, and CVE-2024-46774 is not listed on the CISA Known Exploited Vulnerabilities catalog. However, proof-of-concept exploits may exist in research communities given its Spectre-class nature.

What versions of Kernel are affected by CVE-2024-46774?

All Linux kernel versions prior to 6.10.10 on PowerPC architecture are vulnerable. The vulnerability exists in the arch/powerpc/kernel/rtas.c file where user-supplied 'nargs' and 'nret' values bypass speculative execution clamping.

How do I check if my server is vulnerable to CVE-2024-46774?

Run `uname -r` and compare the version string against 6.10.10 (if your version is lower, you are affected). For PowerPC systems, additionally verify RTAS is present via `grep -i rtas /proc/cmdline` and check your distribution's kernel package version with `dpkg -l | grep linux-image` (Debian) or `rpm -qa kernel` (RHEL).

Does Defensia detect CVE-2024-46774?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Kernel is installed on a monitored server, CVE-2024-46774 will appear in your dashboard with remediation steps and update commands tailored to your Linux distribution.

Related Kernel CVEs

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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-2024-38612CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: ipv6: sr: fix invalid unregister error path The error path of seg6_init() is wrong in case CONFIG_IPV6_SEG6_LWTUNNEL is not defined. In that case if seg6_hmac_init() fails, the genl_unregister_family() isn't called. This issue exist since commit 46738b1317e1 ("ipv6: sr: add option to control lwtunnel support"), and commit 5559cea2d5aa ("ipv6: sr: fix possible use-after-free and null-ptr-deref") replaced unregister_pernet_subsys() with genl_unregister_family() in this error path.
CVE-2024-38623CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Use variable length array instead of fixed size Should fix smatch warning: ntfs_set_label() error: __builtin_memcpy() 'uni->name' too small (20 vs 256)
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.

References

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