fkie_cve-2022-50625
Vulnerability from fkie_nvd
Published
2025-12-08 02:15
Modified
2025-12-08 18:26
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
serial: amba-pl011: avoid SBSA UART accessing DMACR register
Chapter "B Generic UART" in "ARM Server Base System Architecture" [1]
documentation describes a generic UART interface. Such generic UART
does not support DMA. In current code, sbsa_uart_pops and
amba_pl011_pops share the same stop_rx operation, which will invoke
pl011_dma_rx_stop, leading to an access of the DMACR register. This
commit adds a using_rx_dma check in pl011_dma_rx_stop to avoid the
access to DMACR register for SBSA UARTs which does not support DMA.
When the kernel enables DMA engine with "CONFIG_DMA_ENGINE=y", Linux
SBSA PL011 driver will access PL011 DMACR register in some functions.
For most real SBSA Pl011 hardware implementations, the DMACR write
behaviour will be ignored. So these DMACR operations will not cause
obvious problems. But for some virtual SBSA PL011 hardware, like Xen
virtual SBSA PL011 (vpl011) device, the behaviour might be different.
Xen vpl011 emulation will inject a data abort to guest, when guest is
accessing an unimplemented UART register. As Xen VPL011 is SBSA
compatible, it will not implement DMACR register. So when Linux SBSA
PL011 driver access DMACR register, it will get an unhandled data abort
fault and the application will get a segmentation fault:
Unhandled fault at 0xffffffc00944d048
Mem abort info:
ESR = 0x96000000
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x00: ttbr address size fault
Data abort info:
ISV = 0, ISS = 0x00000000
CM = 0, WnR = 0
swapper pgtable: 4k pages, 39-bit VAs, pgdp=0000000020e2e000
[ffffffc00944d048] pgd=100000003ffff803, p4d=100000003ffff803, pud=100000003ffff803, pmd=100000003fffa803, pte=006800009c090f13
Internal error: ttbr address size fault: 96000000 [#1] PREEMPT SMP
...
Call trace:
pl011_stop_rx+0x70/0x80
tty_port_shutdown+0x7c/0xb4
tty_port_close+0x60/0xcc
uart_close+0x34/0x8c
tty_release+0x144/0x4c0
__fput+0x78/0x220
____fput+0x1c/0x30
task_work_run+0x88/0xc0
do_notify_resume+0x8d0/0x123c
el0_svc+0xa8/0xc0
el0t_64_sync_handler+0xa4/0x130
el0t_64_sync+0x1a0/0x1a4
Code: b9000083 b901f001 794038a0 8b000042 (b9000041)
---[ end trace 83dd93df15c3216f ]---
note: bootlogd[132] exited with preempt_count 1
/etc/rcS.d/S07bootlogd: line 47: 132 Segmentation fault start-stop-daemon
This has been discussed in the Xen community, and we think it should fix
this in Linux. See [2] for more information.
[1] https://developer.arm.com/documentation/den0094/c/?lang=en
[2] https://lists.xenproject.org/archives/html/xen-devel/2022-11/msg00543.html
References
Impacted products
| Vendor | Product | Version |
|---|
{
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nserial: amba-pl011: avoid SBSA UART accessing DMACR register\n\nChapter \"B Generic UART\" in \"ARM Server Base System Architecture\" [1]\ndocumentation describes a generic UART interface. Such generic UART\ndoes not support DMA. In current code, sbsa_uart_pops and\namba_pl011_pops share the same stop_rx operation, which will invoke\npl011_dma_rx_stop, leading to an access of the DMACR register. This\ncommit adds a using_rx_dma check in pl011_dma_rx_stop to avoid the\naccess to DMACR register for SBSA UARTs which does not support DMA.\n\nWhen the kernel enables DMA engine with \"CONFIG_DMA_ENGINE=y\", Linux\nSBSA PL011 driver will access PL011 DMACR register in some functions.\nFor most real SBSA Pl011 hardware implementations, the DMACR write\nbehaviour will be ignored. So these DMACR operations will not cause\nobvious problems. But for some virtual SBSA PL011 hardware, like Xen\nvirtual SBSA PL011 (vpl011) device, the behaviour might be different.\nXen vpl011 emulation will inject a data abort to guest, when guest is\naccessing an unimplemented UART register. As Xen VPL011 is SBSA\ncompatible, it will not implement DMACR register. So when Linux SBSA\nPL011 driver access DMACR register, it will get an unhandled data abort\nfault and the application will get a segmentation fault:\nUnhandled fault at 0xffffffc00944d048\nMem abort info:\n ESR = 0x96000000\n EC = 0x25: DABT (current EL), IL = 32 bits\n SET = 0, FnV = 0\n EA = 0, S1PTW = 0\n FSC = 0x00: ttbr address size fault\nData abort info:\n ISV = 0, ISS = 0x00000000\n CM = 0, WnR = 0\nswapper pgtable: 4k pages, 39-bit VAs, pgdp=0000000020e2e000\n[ffffffc00944d048] pgd=100000003ffff803, p4d=100000003ffff803, pud=100000003ffff803, pmd=100000003fffa803, pte=006800009c090f13\nInternal error: ttbr address size fault: 96000000 [#1] PREEMPT SMP\n...\nCall trace:\n pl011_stop_rx+0x70/0x80\n tty_port_shutdown+0x7c/0xb4\n tty_port_close+0x60/0xcc\n uart_close+0x34/0x8c\n tty_release+0x144/0x4c0\n __fput+0x78/0x220\n ____fput+0x1c/0x30\n task_work_run+0x88/0xc0\n do_notify_resume+0x8d0/0x123c\n el0_svc+0xa8/0xc0\n el0t_64_sync_handler+0xa4/0x130\n el0t_64_sync+0x1a0/0x1a4\nCode: b9000083 b901f001 794038a0 8b000042 (b9000041)\n---[ end trace 83dd93df15c3216f ]---\nnote: bootlogd[132] exited with preempt_count 1\n/etc/rcS.d/S07bootlogd: line 47: 132 Segmentation fault start-stop-daemon\n\nThis has been discussed in the Xen community, and we think it should fix\nthis in Linux. See [2] for more information.\n\n[1] https://developer.arm.com/documentation/den0094/c/?lang=en\n[2] https://lists.xenproject.org/archives/html/xen-devel/2022-11/msg00543.html"
}
],
"id": "CVE-2022-50625",
"lastModified": "2025-12-08T18:26:19.900",
"metrics": {},
"published": "2025-12-08T02:15:48.510",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1c5f0d3f480abd8c26761b6b1f486822e77faea3"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/38a10fdd54d17590d45cb1c43b9889da383b6b1a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/64bc5dbc3260230e2f022288c71e5c680059384a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/78d837ce20517e0c1ff3ebe08ad64636e02c2e48"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/94cdb9f33698478b0e7062586633c42c6158a786"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/965f07ea5fd1b9591bcccc825a93ad883e56222c"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a4ea20ab82aa2b197dc7b08f51e1d615578276a0"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/d5b16eb076f46c88d02d41ece5bec4e0d89158bb"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/d71a611fca1984c0765f9317ff471ac8cd0e3e2f"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis"
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
Loading…
Loading…