UBUNTU-CVE-2024-42126
In the Linux kernel, the following vulnerability has been resolved: powerpc: Avoid nmi_enter/nmi_exit in real mode interrupt. nmi_enter()/nmi_exit() touches per cpu variables which can lead to kernel crash when invoked during real mode interrupt handling (e.g. early HMI/MCE interrupt handler) if percpu allocation comes from vmalloc area. Early HMI/MCE handlers are called through DEFINE_INTERRUPT_HANDLER_NMI() wrapper which invokes nmi_enter/nmi_exit calls. We don't see any issue when percpu allocation is from the embedded first chunk. However with CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK enabled there are chances where percpu allocation can come from the vmalloc area. With kernel command line "percpu_alloc=page" we can force percpu allocation to come from vmalloc area and can see kernel crash in machine_check_early: [ 1.215714] NIP [c000000000e49eb4] rcu_nmi_enter+0x24/0x110 [ 1.215717] LR [c0000000000461a0] machine_check_early+0xf0/0x2c0 [ 1.215719] --- interrupt: 200 [ 1.215720] [c000000fffd73180] [0000000000000000] 0x0 (unreliable) [ 1.215722] [c000000fffd731b0] [0000000000000000] 0x0 [ 1.215724] [c000000fffd73210] [c000000000008364] machine_check_early_common+0x134/0x1f8 Fix this by avoiding use of nmi_enter()/nmi_exit() in real mode if percpu first chunk is not embedded.
02 / AFFECTED SOFTWARE
Affected packages
11 explicit affected versions
53 explicit affected versions
116 explicit affected versions
38 explicit affected versions
52 explicit affected versions
50 explicit affected versions
6 explicit affected versions
12 explicit affected versions
19 explicit affected versions
6 explicit affected versions
61 explicit affected versions
57 explicit affected versions
12 explicit affected versions
47 explicit affected versions
91 explicit affected versions
57 explicit affected versions
47 explicit affected versions
10 explicit affected versions
6 explicit affected versions
12 explicit affected versions
54 explicit affected versions
191 explicit affected versions
7 explicit affected versions
53 explicit affected versions
7 explicit affected versions
13 explicit affected versions
85 explicit affected versions
9 explicit affected versions
35 explicit affected versions
14 explicit affected versions
18 explicit affected versions
18 explicit affected versions
15 explicit affected versions
118 explicit affected versions
64 explicit affected versions
12 explicit affected versions
120 explicit affected versions
13 explicit affected versions
4 explicit affected versions
121 explicit affected versions
23 explicit affected versions
16 explicit affected versions
124 explicit affected versions
1 explicit affected versions
21 explicit affected versions
16 explicit affected versions
10 explicit affected versions
76 explicit affected versions
14 explicit affected versions
7 explicit affected versions
12 explicit affected versions
111 explicit affected versions
45 explicit affected versions
12 explicit affected versions
14 explicit affected versions
7 explicit affected versions
104 explicit affected versions
12 explicit affected versions
105 explicit affected versions
12 explicit affected versions
7 explicit affected versions
120 explicit affected versions
14 explicit affected versions
7 explicit affected versions
1 explicit affected versions
10 explicit affected versions
37 explicit affected versions
13 explicit affected versions
5 explicit affected versions
10 explicit affected versions
33 explicit affected versions
1 explicit affected versions
26 explicit affected versions
13 explicit affected versions
144 explicit affected versions
9 explicit affected versions
1 explicit affected versions
29 explicit affected versions
111 explicit affected versions
13 explicit affected versions
58 explicit affected versions
6 explicit affected versions
7 explicit affected versions
1 explicit affected versions
100 explicit affected versions
56 explicit affected versions
18 explicit affected versions
33 explicit affected versions
23 explicit affected versions
10 explicit affected versions
1 explicit affected versions
188 explicit affected versions
11 explicit affected versions
12 explicit affected versions
7 explicit affected versions
12 explicit affected versions
138 explicit affected versions
2 explicit affected versions
45 explicit affected versions
39 explicit affected versions
132 explicit affected versions
55 explicit affected versions
165 explicit affected versions
154 explicit affected versions
10 explicit affected versions
26 explicit affected versions
14 explicit affected versions
1 explicit affected versions
5 explicit affected versions
15 explicit affected versions
13 explicit affected versions
14 explicit affected versions
139 explicit affected versions
78 explicit affected versions
16 explicit affected versions
58 explicit affected versions
15 explicit affected versions
46 explicit affected versions
116 explicit affected versions
3 explicit affected versions
132 explicit affected versions
93 explicit affected versions
1 explicit affected versions
2 explicit affected versions
51 explicit affected versions
92 explicit affected versions
12 explicit affected versions
12 explicit affected versions
44 explicit affected versions
27 explicit affected versions
30 explicit affected versions
121 explicit affected versions
1 explicit affected versions
1 explicit affected versions
98 explicit affected versions
8 explicit affected versions
8 explicit affected versions
19 explicit affected versions
5 explicit affected versions
8 explicit affected versions
1 explicit affected versions
10 explicit affected versions
11 explicit affected versions
13 explicit affected versions
110 explicit affected versions
13 explicit affected versions
72 explicit affected versions
7 explicit affected versions
140 explicit affected versions
94 explicit affected versions
50 explicit affected versions
10 explicit affected versions
14 explicit affected versions
12 explicit affected versions
108 explicit affected versions
80 explicit affected versions
56 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
26 explicit affected versions
44 explicit affected versions
37 explicit affected versions
15 explicit affected versions
14 explicit affected versions
38 explicit affected versions
167 explicit affected versions
47 explicit affected versions
9 explicit affected versions
47 explicit affected versions
11 explicit affected versions
6 explicit affected versions
1 explicit affected versions
55 explicit affected versions
7 explicit affected versions
28 explicit affected versions
97 explicit affected versions
121 explicit affected versions
4 explicit affected versions
1 explicit affected versions
1 explicit affected versions
53 explicit affected versions
13 explicit affected versions
43 explicit affected versions
77 explicit affected versions
119 explicit affected versions
10 explicit affected versions
8 explicit affected versions
10 explicit affected versions
88 explicit affected versions
14 explicit affected versions
4 explicit affected versions
78 explicit affected versions
11 explicit affected versions
1 explicit affected versions
69 explicit affected versions
123 explicit affected versions
8 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: powerpc: Avoid nmi_enter/nmi_exit in real mode interrupt. nmi_enter()/nmi_exit() touches per cpu variables which can lead to kernel crash when invoked during real mode interrupt handling (e.g. early HMI/MCE interrupt handler) if percpu allocation comes from vmalloc area. Early HMI/MCE handlers are called through DEFINE_INTERRUPT_HANDLER_NMI() wrapper which invokes nmi_enter/nmi_exit calls. We don't see any issue when percpu allocation is from the embedded first chunk. However with CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK enabled there are chances where percpu allocation can come from the vmalloc area. With kernel command line "percpu_alloc=page" we can force percpu allocation to come from vmalloc area and can see kernel crash in machine_check_early: [ 1.215714] NIP [c000000000e49eb4] rcu_nmi_enter+0x24/0x110 [ 1.215717] LR [c0000000000461a0] machine_check_early+0xf0/0x2c0 [ 1.215719] --- interrupt: 200 [ 1.215720] [c000000fffd73180] [0000000000000000] 0x0 (unreliable) [ 1.215722] [c000000fffd731b0] [0000000000000000] 0x0 [ 1.215724] [c000000fffd73210] [c000000000008364] machine_check_early_common+0x134/0x1f8 Fix this by avoiding use of nmi_enter()/nmi_exit() in real mode if percpu first chunk is not embedded.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/0db880fc865ffb522141ced4bfa66c12ab1fbb70
- https://git.kernel.org/stable/c/0db880fc865ffb522141ced4bfa66c12ab1fbb70
- https://git.kernel.org/stable/c/0f37946c62c48a907625348cbc720a7a0c547d1e
- https://git.kernel.org/stable/c/2c78c9411e685dbc9eac8c2845111b03501975b8
- https://git.kernel.org/stable/c/8d3f83dfb23674540c827a8d65fba20aa300b252
- https://ubuntu.com/security/CVE-2024-42126
- https://ubuntu.com/security/notices/USN-7089-1
- https://ubuntu.com/security/notices/USN-7089-2
- https://ubuntu.com/security/notices/USN-7089-3
- https://ubuntu.com/security/notices/USN-7089-4
- https://ubuntu.com/security/notices/USN-7089-5
- https://ubuntu.com/security/notices/USN-7089-6
- https://ubuntu.com/security/notices/USN-7089-7
- https://ubuntu.com/security/notices/USN-7090-1
- https://ubuntu.com/security/notices/USN-7095-1
- https://ubuntu.com/security/notices/USN-7100-1
- https://ubuntu.com/security/notices/USN-7100-2
- https://ubuntu.com/security/notices/USN-7123-1
- https://ubuntu.com/security/notices/USN-7144-1
- https://ubuntu.com/security/notices/USN-7156-1
- https://ubuntu.com/security/notices/USN-7194-1
- https://www.cve.org/CVERecord?id=CVE-2024-42126