vulnerability

Ubuntu: (Multiple Advisories) (CVE-2024-36927): Linux kernel vulnerabilities

Severity
4
CVSS
(AV:L/AC:M/Au:S/C:N/I:N/A:C)
Published
05/30/2024
Added
08/09/2024
Modified
02/19/2025

Description

In the Linux kernel, the following vulnerability has been resolved:

ipv4: Fix uninit-value access in __ip_make_skb()

KMSAN reported uninit-value access in __ip_make_skb() [1]. __ip_make_skb()
tests HDRINCL to know if the skb has icmphdr. However, HDRINCL can cause a
race condition. If calling setsockopt(2) with IP_HDRINCL changes HDRINCL
while __ip_make_skb() is running, the function will access icmphdr in the
skb even if it is not included. This causes the issue reported by KMSAN.

Check FLOWI_FLAG_KNOWN_NH on fl4->flowi4_flags instead of testing HDRINCL
on the socket.

Also, fl4->fl4_icmp_type and fl4->fl4_icmp_code are not initialized. These
are union in struct flowi4 and are implicitly initialized by
flowi4_init_output(), but we should not rely on specific union layout.

Initialize these explicitly in raw_sendmsg().

[1]
BUG: KMSAN: uninit-value in __ip_make_skb+0x2b74/0x2d20 net/ipv4/ip_output.c:1481
__ip_make_skb+0x2b74/0x2d20 net/ipv4/ip_output.c:1481
ip_finish_skb include/net/ip.h:243 [inline]
ip_push_pending_frames+0x4c/0x5c0 net/ipv4/ip_output.c:1508
raw_sendmsg+0x2381/0x2690 net/ipv4/raw.c:654
inet_sendmsg+0x27b/0x2a0 net/ipv4/af_inet.c:851
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0x274/0x3c0 net/socket.c:745
__sys_sendto+0x62c/0x7b0 net/socket.c:2191
__do_sys_sendto net/socket.c:2203 [inline]
__se_sys_sendto net/socket.c:2199 [inline]
__x64_sys_sendto+0x130/0x200 net/socket.c:2199
do_syscall_64+0xd8/0x1f0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x6d/0x75

Uninit was created at:
slab_post_alloc_hook mm/slub.c:3804 [inline]
slab_alloc_node mm/slub.c:3845 [inline]
kmem_cache_alloc_node+0x5f6/0xc50 mm/slub.c:3888
kmalloc_reserve+0x13c/0x4a0 net/core/skbuff.c:577
__alloc_skb+0x35a/0x7c0 net/core/skbuff.c:668
alloc_skb include/linux/skbuff.h:1318 [inline]
__ip_append_data+0x49ab/0x68c0 net/ipv4/ip_output.c:1128
ip_append_data+0x1e7/0x260 net/ipv4/ip_output.c:1365
raw_sendmsg+0x22b1/0x2690 net/ipv4/raw.c:648
inet_sendmsg+0x27b/0x2a0 net/ipv4/af_inet.c:851
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0x274/0x3c0 net/socket.c:745
__sys_sendto+0x62c/0x7b0 net/socket.c:2191
__do_sys_sendto net/socket.c:2203 [inline]
__se_sys_sendto net/socket.c:2199 [inline]
__x64_sys_sendto+0x130/0x200 net/socket.c:2199
do_syscall_64+0xd8/0x1f0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x6d/0x75

CPU: 1 PID: 15709 Comm: syz-executor.7 Not tainted 6.8.0-11567-gb3603fcb79b1 #25
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-1.fc39 04/01/2014

Solution(s)

ubuntu-upgrade-linux-image-6-8-0-1008-gkeubuntu-upgrade-linux-image-6-8-0-1009-raspiubuntu-upgrade-linux-image-6-8-0-1010-ibmubuntu-upgrade-linux-image-6-8-0-1010-oemubuntu-upgrade-linux-image-6-8-0-1010-oracleubuntu-upgrade-linux-image-6-8-0-1010-oracle-64kubuntu-upgrade-linux-image-6-8-0-1011-nvidiaubuntu-upgrade-linux-image-6-8-0-1011-nvidia-64kubuntu-upgrade-linux-image-6-8-0-1011-nvidia-lowlatencyubuntu-upgrade-linux-image-6-8-0-1011-nvidia-lowlatency-64kubuntu-upgrade-linux-image-6-8-0-1012-azureubuntu-upgrade-linux-image-6-8-0-1012-azure-fdeubuntu-upgrade-linux-image-6-8-0-1012-gcpubuntu-upgrade-linux-image-6-8-0-1013-awsubuntu-upgrade-linux-image-6-8-0-40-genericubuntu-upgrade-linux-image-6-8-0-40-generic-64kubuntu-upgrade-linux-image-6-8-0-40-lowlatencyubuntu-upgrade-linux-image-6-8-0-40-lowlatency-64kubuntu-upgrade-linux-image-awsubuntu-upgrade-linux-image-azureubuntu-upgrade-linux-image-azure-fdeubuntu-upgrade-linux-image-gcpubuntu-upgrade-linux-image-genericubuntu-upgrade-linux-image-generic-64kubuntu-upgrade-linux-image-generic-64k-hwe-24-04ubuntu-upgrade-linux-image-generic-hwe-24-04ubuntu-upgrade-linux-image-generic-lpaeubuntu-upgrade-linux-image-gkeubuntu-upgrade-linux-image-ibmubuntu-upgrade-linux-image-ibm-classicubuntu-upgrade-linux-image-ibm-lts-24-04ubuntu-upgrade-linux-image-kvmubuntu-upgrade-linux-image-lowlatencyubuntu-upgrade-linux-image-lowlatency-64kubuntu-upgrade-linux-image-nvidiaubuntu-upgrade-linux-image-nvidia-6-8ubuntu-upgrade-linux-image-nvidia-64kubuntu-upgrade-linux-image-nvidia-64k-6-8ubuntu-upgrade-linux-image-nvidia-lowlatencyubuntu-upgrade-linux-image-nvidia-lowlatency-64kubuntu-upgrade-linux-image-oem-24-04ubuntu-upgrade-linux-image-oem-24-04aubuntu-upgrade-linux-image-oracleubuntu-upgrade-linux-image-oracle-64kubuntu-upgrade-linux-image-raspiubuntu-upgrade-linux-image-virtualubuntu-upgrade-linux-image-virtual-hwe-24-04
Title
NEW

Explore Exposure Command

Confidently identify and prioritize exposures from endpoint to cloud with full attack surface visibility and threat-aware risk context.