In the Linux kernel, the following vulnerability has been resolved:
x86/mm: Disallow vsyscall page read for copy_from_kernel_nofault()
When trying to use copy_from_kernel_nofault() to read vsyscall page
through a bpf program, the following oops was reported:
BUG: unable to handle page fault for address: ffffffffff600000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 3231067 P4D 3231067 PUD 3233067 PMD 3235067 PTE 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 1 PID: 20390 Comm: test_progs ...... 6.7.0+ #58
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ......
RIP: 0010:copy_from_kernel_nofault+0x6f/0x110
......
Call Trace:
<TASK>
? copy_from_kernel_nofault+0x6f/0x110
bpf_probe_read_kernel+0x1d/0x50
bpf_prog_2061065e56845f08_do_probe_read+0x51/0x8d
trace_call_bpf+0xc5/0x1c0
perf_call_bpf_enter.isra.0+0x69/0xb0
perf_syscall_enter+0x13e/0x200
syscall_trace_enter+0x188/0x1c0
do_syscall_64+0xb5/0xe0
entry_SYSCALL_64_after_hwframe+0x6e/0x76
</TASK>
......
---[ end trace 0000000000000000 ]---
The oops is triggered when:
1) A bpf program uses bpf_probe_read_kernel() to read from the vsyscall
page and invokes copy_from_kernel_nofault() which in turn calls
__get_user_asm().
2) Because the vsyscall page address is not readable from kernel space,
a page fault exception is triggered accordingly.
3) handle_page_fault() considers the vsyscall page address as a user
space address instead of a kernel space address. This results in the
fix-up setup by bpf not being applied and a page_fault_oops() is invoked
due to SMAP.
Considering handle_page_fault() has already considered the vsyscall page
address as a userspace address, fix the problem by disallowing vsyscall
page read for copy_from_kernel_nofault().
Metrics
Affected Vendors & Products
References
History
Fri, 22 Nov 2024 12:00:00 +0000
Type | Values Removed | Values Added |
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References |
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Sat, 16 Nov 2024 03:00:00 +0000
Type | Values Removed | Values Added |
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CPEs | cpe:/a:redhat:rhel_eus:9.4 |
Wed, 13 Nov 2024 15:15:00 +0000
Type | Values Removed | Values Added |
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First Time appeared |
Redhat rhel Eus
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CPEs | cpe:/a:redhat:rhel_eus:9.2 cpe:/a:redhat:rhel_eus:9.2::nfv |
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Vendors & Products |
Redhat rhel Eus
|
Wed, 13 Nov 2024 02:45:00 +0000
Type | Values Removed | Values Added |
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CPEs | cpe:/a:redhat:enterprise_linux:9 cpe:/o:redhat:enterprise_linux:9 |
Tue, 05 Nov 2024 10:45:00 +0000
Type | Values Removed | Values Added |
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References |
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Wed, 11 Sep 2024 13:30:00 +0000
Type | Values Removed | Values Added |
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Metrics |
ssvc
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MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2024-04-17T10:27:53.573Z
Updated: 2024-11-05T09:17:57.653Z
Reserved: 2024-02-19T14:20:24.187Z
Link: CVE-2024-26906
Vulnrichment
Updated: 2024-08-02T00:21:05.490Z
NVD
Status : Awaiting Analysis
Published: 2024-04-17T11:15:11.207
Modified: 2024-11-21T09:03:21.097
Link: CVE-2024-26906
Redhat