Vulnerability Details : CVE-2021-47100
In the Linux kernel, the following vulnerability has been resolved:
ipmi: Fix UAF when uninstall ipmi_si and ipmi_msghandler module
Hi,
When testing install and uninstall of ipmi_si.ko and ipmi_msghandler.ko,
the system crashed.
The log as follows:
[ 141.087026] BUG: unable to handle kernel paging request at ffffffffc09b3a5a
[ 141.087241] PGD 8fe4c0d067 P4D 8fe4c0d067 PUD 8fe4c0f067 PMD 103ad89067 PTE 0
[ 141.087464] Oops: 0010 [#1] SMP NOPTI
[ 141.087580] CPU: 67 PID: 668 Comm: kworker/67:1 Kdump: loaded Not tainted 4.18.0.x86_64 #47
[ 141.088009] Workqueue: events 0xffffffffc09b3a40
[ 141.088009] RIP: 0010:0xffffffffc09b3a5a
[ 141.088009] Code: Bad RIP value.
[ 141.088009] RSP: 0018:ffffb9094e2c3e88 EFLAGS: 00010246
[ 141.088009] RAX: 0000000000000000 RBX: ffff9abfdb1f04a0 RCX: 0000000000000000
[ 141.088009] RDX: 0000000000000000 RSI: 0000000000000246 RDI: 0000000000000246
[ 141.088009] RBP: 0000000000000000 R08: ffff9abfffee3cb8 R09: 00000000000002e1
[ 141.088009] R10: ffffb9094cb73d90 R11: 00000000000f4240 R12: ffff9abfffee8700
[ 141.088009] R13: 0000000000000000 R14: ffff9abfdb1f04a0 R15: ffff9abfdb1f04a8
[ 141.088009] FS: 0000000000000000(0000) GS:ffff9abfffec0000(0000) knlGS:0000000000000000
[ 141.088009] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 141.088009] CR2: ffffffffc09b3a30 CR3: 0000008fe4c0a001 CR4: 00000000007606e0
[ 141.088009] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 141.088009] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 141.088009] PKRU: 55555554
[ 141.088009] Call Trace:
[ 141.088009] ? process_one_work+0x195/0x390
[ 141.088009] ? worker_thread+0x30/0x390
[ 141.088009] ? process_one_work+0x390/0x390
[ 141.088009] ? kthread+0x10d/0x130
[ 141.088009] ? kthread_flush_work_fn+0x10/0x10
[ 141.088009] ? ret_from_fork+0x35/0x40] BUG: unable to handle kernel paging request at ffffffffc0b28a5a
[ 200.223240] PGD 97fe00d067 P4D 97fe00d067 PUD 97fe00f067 PMD a580cbf067 PTE 0
[ 200.223464] Oops: 0010 [#1] SMP NOPTI
[ 200.223579] CPU: 63 PID: 664 Comm: kworker/63:1 Kdump: loaded Not tainted 4.18.0.x86_64 #46
[ 200.224008] Workqueue: events 0xffffffffc0b28a40
[ 200.224008] RIP: 0010:0xffffffffc0b28a5a
[ 200.224008] Code: Bad RIP value.
[ 200.224008] RSP: 0018:ffffbf3c8e2a3e88 EFLAGS: 00010246
[ 200.224008] RAX: 0000000000000000 RBX: ffffa0799ad6bca0 RCX: 0000000000000000
[ 200.224008] RDX: 0000000000000000 RSI: 0000000000000246 RDI: 0000000000000246
[ 200.224008] RBP: 0000000000000000 R08: ffff9fe43fde3cb8 R09: 00000000000000d5
[ 200.224008] R10: ffffbf3c8cb53d90 R11: 00000000000f4240 R12: ffff9fe43fde8700
[ 200.224008] R13: 0000000000000000 R14: ffffa0799ad6bca0 R15: ffffa0799ad6bca8
[ 200.224008] FS: 0000000000000000(0000) GS:ffff9fe43fdc0000(0000) knlGS:0000000000000000
[ 200.224008] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 200.224008] CR2: ffffffffc0b28a30 CR3: 00000097fe00a002 CR4: 00000000007606e0
[ 200.224008] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 200.224008] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 200.224008] PKRU: 55555554
[ 200.224008] Call Trace:
[ 200.224008] ? process_one_work+0x195/0x390
[ 200.224008] ? worker_thread+0x30/0x390
[ 200.224008] ? process_one_work+0x390/0x390
[ 200.224008] ? kthread+0x10d/0x130
[ 200.224008] ? kthread_flush_work_fn+0x10/0x10
[ 200.224008] ? ret_from_fork+0x35/0x40
[ 200.224008] kernel fault(0x1) notification starting on CPU 63
[ 200.224008] kernel fault(0x1) notification finished on CPU 63
[ 200.224008] CR2: ffffffffc0b28a5a
[ 200.224008] ---[ end trace c82a412d93f57412 ]---
The reason is as follows:
T1: rmmod ipmi_si.
->ipmi_unregister_smi()
-> ipmi_bmc_unregister()
-> __ipmi_bmc_unregister()
-> kref_put(&bmc->usecount, cleanup_bmc_device);
-> schedule_work(&bmc->remove_work);
T2: rmmod ipmi_msghandl
---truncated---
Products affected by CVE-2021-47100
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.16:rc1:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.16:rc2:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.16:rc3:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.16:rc4:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.16:rc5:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.16:rc6:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-47100
0.05%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 12 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-47100
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
---|---|---|---|---|---|---|
5.5
|
MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
1.8
|
3.6
|
NIST | 2025-02-03 |
CWE ids for CVE-2021-47100
-
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.Assigned by: nvd@nist.gov (Primary)
References for CVE-2021-47100
-
https://git.kernel.org/stable/c/6b3f7e4b10f343f05b5fb513b07a9168fbf1172e
ipmi: Fix UAF when uninstall ipmi_si and ipmi_msghandler module - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/ffb76a86f8096a8206be03b14adda6092e18e275
ipmi: Fix UAF when uninstall ipmi_si and ipmi_msghandler module - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/6809da5185141e61401da5b01896b79a4deed1ad
ipmi: Fix UAF when uninstall ipmi_si and ipmi_msghandler module - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/925229d552724e1bba1abf01d3a0b1318539b012
ipmi: Fix UAF when uninstall ipmi_si and ipmi_msghandler module - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/992649b8b16843d27eb39ceea5f9cf85ffb50a18
ipmi: Fix UAF when uninstall ipmi_si and ipmi_msghandler module - kernel/git/stable/linux.git - Linux kernel stable treePatch
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