CVE-2024-26870 Affecting kernel-headers package, versions <0:4.18.0-553.16.1.el8_10


Severity

Recommended
high

Based on AlmaLinux security rating.

Threat Intelligence

EPSS
0.04% (12th percentile)

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  • Snyk IDSNYK-ALMALINUX8-KERNELHEADERS-7655954
  • published9 Aug 2024
  • disclosed8 Aug 2024

Introduced: 8 Aug 2024

CVE-2024-26870  (opens in a new tab)

How to fix?

Upgrade AlmaLinux:8 kernel-headers to version 0:4.18.0-553.16.1.el8_10 or higher.
This issue was patched in ALSA-2024:5101.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-headers package and not the kernel-headers package as distributed by AlmaLinux. See How to fix? for AlmaLinux:8 relevant fixed versions and status.

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

NFSv4.2: fix nfs4_listxattr kernel BUG at mm/usercopy.c:102

A call to listxattr() with a buffer size = 0 returns the actual size of the buffer needed for a subsequent call. When size > 0, nfs4_listxattr() does not return an error because either generic_listxattr() or nfs4_listxattr_nfs4_label() consumes exactly all the bytes then size is 0 when calling nfs4_listxattr_nfs4_user() which then triggers the following kernel BUG:

[ 99.403778] kernel BUG at mm/usercopy.c:102! [ 99.404063] Internal error: Oops - BUG: 00000000f2000800 [#1] SMP [ 99.408463] CPU: 0 PID: 3310 Comm: python3 Not tainted 6.6.0-61.fc40.aarch64 #1 [ 99.415827] Call trace: [ 99.415985] usercopy_abort+0x70/0xa0 [ 99.416227] __check_heap_object+0x134/0x158 [ 99.416505] check_heap_object+0x150/0x188 [ 99.416696] __check_object_size.part.0+0x78/0x168 [ 99.416886] __check_object_size+0x28/0x40 [ 99.417078] listxattr+0x8c/0x120 [ 99.417252] path_listxattr+0x78/0xe0 [ 99.417476] __arm64_sys_listxattr+0x28/0x40 [ 99.417723] invoke_syscall+0x78/0x100 [ 99.417929] el0_svc_common.constprop.0+0x48/0xf0 [ 99.418186] do_el0_svc+0x24/0x38 [ 99.418376] el0_svc+0x3c/0x110 [ 99.418554] el0t_64_sync_handler+0x120/0x130 [ 99.418788] el0t_64_sync+0x194/0x198 [ 99.418994] Code: aa0003e3 d000a3e0 91310000 97f49bdb (d4210000)

Issue is reproduced when generic_listxattr() returns 'system.nfs4_acl', thus calling lisxattr() with size = 16 will trigger the bug.

Add check on nfs4_listxattr() to return ERANGE error when it is called with size > 0 and the return value is greater than size.

CVSS Scores

version 3.1