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一、漏洞信息
漏洞编号：CVE-2022-48853
漏洞归属组件：kernel
漏洞归属的版本：4.19.140,4.19.194,4.19.90,5.10.0,6.1.0,6.1.14,6.1.19,6.1.5,6.1.6,6.1.8,6.4.0,6.6.0
CVSS V3.0分值：
BaseScore：5.5 Medium
Vector：CVSS：3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
漏洞简述：
In the Linux kernel, the following vulnerability has been resolved:swiotlb: fix info leak with DMA_FROM_DEVICEThe problem I m addressing was discovered by the LTP test coveringcve-2018-1000204.A short description of what happens follows:1) The test case issues a command code 00 (TEST UNIT READY) via the SG_IO interface with: dxfer_len == 524288, dxdfer_dir == SG_DXFER_FROM_DEV and a corresponding dxferp. The peculiar thing about this is that TUR is not reading from the device.2) In sg_start_req() the invocation of blk_rq_map_user() effectively bounces the user-space buffer. As if the device was to transfer into it. Since commit a45b599ad808 ( scsi: sg: allocate with __GFP_ZERO in sg_build_indirect() ) we make sure this first bounce buffer is allocated with GFP_ZERO.3) For the rest of the story we keep ignoring that we have a TUR, so the device won t touch the buffer we prepare as if the we had a DMA_FROM_DEVICE type of situation. My setup uses a virtio-scsi device and the buffer allocated by SG is mapped by the function virtqueue_add_split() which uses DMA_FROM_DEVICE for the in sgs (here scatter-gather and not scsi generics). This mapping involves bouncing via the swiotlb (we need swiotlb to do virtio in protected guest like s390 Secure Execution, or AMD SEV).4) When the SCSI TUR is done, we first copy back the content of the second (that is swiotlb) bounce buffer (which most likely contains some previous IO data), to the first bounce buffer, which contains all zeros. Then we copy back the content of the first bounce buffer to the user-space buffer.5) The test case detects that the buffer, which it zero-initialized, ain t all zeros and fails.One can argue that this is an swiotlb problem, because without swiotlbwe leak all zeros, and the swiotlb should be transparent in a sense thatit does not affect the outcome (if all other participants are wellbehaved).Copying the content of the original buffer into the swiotlb buffer isthe only way I can think of to make swiotlb transparent in suchscenarios. So let s do just that if in doubt, but allow the driverto tell us that the whole mapped buffer is going to be overwritten,in which case we can preserve the old behavior and avoid the performanceimpact of the extra bounce.
漏洞公开时间：2024-07-16 21:15:12
漏洞创建时间：2024-07-17 01:16:23
漏洞详情参考链接：
https://nvd.nist.gov/vuln/detail/CVE-2022-48853
漏洞分析指导链接：
https://gitee.com/openeuler/cve-manager/blob/master/cve-vulner-manager/doc/md/manual.md
漏洞数据来源:
其它
漏洞补丁信息：
无
二、漏洞分析结构反馈
影响性分析说明：
In the Linux kernel, the following vulnerability has been resolved:swiotlb: fix info leak with DMA_FROM_DEVICEThe problem I m addressing was discovered by the LTP test coveringcve-2018-1000204.A short description of what happens follows:1) The test case issues a command code 00 (TEST UNIT READY) via the SG_IO interface with: dxfer_len == 524288, dxdfer_dir == SG_DXFER_FROM_DEV and a corresponding dxferp. The peculiar thing about this is that TUR is not reading from the device.2) In sg_start_req() the invocation of blk_rq_map_user() effectively bounces the user-space buffer. As if the device was to transfer into it. Since commit a45b599ad808 ( scsi: sg: allocate with __GFP_ZERO in sg_build_indirect() ) we make sure this first bounce buffer is allocated with GFP_ZERO.3) For the rest of the story we keep ignoring that we have a TUR, so the device won t touch the buffer we prepare as if the we had a DMA_FROM_DEVICE type of situation. My setup uses a virtio-scsi device and the buffer allocated by SG is mapped by the function virtqueue_add_split() which uses DMA_FROM_DEVICE for the in sgs (here scatter-gather and not scsi generics). This mapping involves bouncing via the swiotlb (we need swiotlb to do virtio in protected guest like s390 Secure Execution, or AMD SEV).4) When the SCSI TUR is done, we first copy back the content of the second (that is swiotlb) bounce buffer (which most likely contains some previous IO data), to the first bounce buffer, which contains all zeros. Then we copy back the content of the first bounce buffer to the user-space buffer.5) The test case detects that the buffer, which it zero-initialized, ain t all zeros and fails.One can argue that this is an swiotlb problem, because without swiotlbwe leak all zeros, and the swiotlb should be transparent in a sense thatit does not affect the outcome (if all other participants are wellbehaved).Copying the content of the original buffer into the swiotlb buffer isthe only way I can think of to make swiotlb transparent in suchscenarios. So let s do just that if in doubt, but allow the driverto tell us that the whole mapped buffer is going to be overwritten,in which case we can preserve the old behavior and avoid the performanceimpact of the extra bounce.
openEuler评分：
5.5
Vector：CVSS：2.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
受影响版本排查(受影响/不受影响)：
1.openEuler-20.03-LTS-SP4(4.19.90):不受影响
2.openEuler-22.03-LTS-SP1(5.10.0):不受影响
3.openEuler-22.03-LTS-SP3(5.10.0):不受影响
4.openEuler-22.03-LTS-SP4(5.10.0):不受影响
5.master(6.1.0):不受影响
6.openEuler-24.03-LTS(6.6.0):不受影响
7.openEuler-24.03-LTS-Next(6.6.0):不受影响
修复是否涉及abi变化(是/否)：
1.openEuler-20.03-LTS-SP4(4.19.90):否
2.openEuler-22.03-LTS-SP1(5.10.0):否
3.openEuler-22.03-LTS-SP3(5.10.0):否
4.master(6.1.0):否
5.openEuler-24.03-LTS(6.6.0):否
6.openEuler-24.03-LTS-Next(6.6.0):否
7.openEuler-22.03-LTS-SP4(5.10.0):否
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说明：补丁链接仅供初步排查参考，实际可用性请人工再次确认，补丁下载验证可使用CVE补丁工具。
若补丁不准确，烦请在此issue下评论 '/report-patch 参考网址 补丁链接1,补丁链接2' 反馈正确信息，便于我们不断优化工具，不胜感激。
如 /report-patch https://security-tracker.debian.org/tracker/CVE-2021-3997 https://github.com/systemd/systemd/commit/5b1cf7a9be37e20133c0208005274ce4a5b5c6a1
hulk-robot
10个月前
CVE-2022-48853
影响性分析说明：
In the Linux kernel, the following vulnerability has been resolved:
swiotlb: fix info leak with DMA_FROM_DEVICE
The problem I'm addressing was discovered by the LTP test covering
cve-2018-1000204.
A short description of what happens follows:
One can argue that this is an swiotlb problem, because without swiotlb
we leak all zeros, and the swiotlb should be transparent in a sense that
it does not affect the outcome (if all other participants are well
behaved).
Copying the content of the original buffer into the swiotlb buffer is
the only way I can think of to make swiotlb transparent in such
scenarios. So let's do just that if in doubt, but allow the driver
to tell us that the whole mapped buffer is going to be overwritten,
in which case we can preserve the old behavior and avoid the performance
impact of the extra bounce.
The Linux kernel CVE team has assigned CVE-2022-48853 to this issue.
openEuler评分:(评分和向量)
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
受影响版本排查(受影响/不受影响):
1.openEuler-20.03-LTS-SP4:受影响
2.openEuler-22.03-LTS-SP1:不受影响
3.openEuler-22.03-LTS-SP3:不受影响
4.openEuler-22.03-LTS-SP4:不受影响
5.master(6.1.0):不受影响
6.openEuler-24.03-LTS:不受影响
7.openEuler-24.03-LTS-Next:不受影响
修复是否涉及abi变化(是/否)：
1.openEuler-20.03-LTS-SP4:否
2.openEuler-22.03-LTS-SP1:否
3.openEuler-22.03-LTS-SP3:否
4.master(6.1.0):否
5.openEuler-24.03-LTS:否
6.openEuler-24.03-LTS-Next:否
7.openEuler-22.03-LTS-SP4:否
@ 经过 cve-manager 解析, 已分析的内容如下表所示:
| 状态 | 需分析 | 内容 |
|---|---|---|
| 已分析 | 1.影响性分析说明 | In the Linux kernel, the following vulnerability has been resolved:swiotlb: fix info leak with DMA_FROM_DEVICEThe problem I'm addressing was discovered by the LTP test coveringcve-2018-1000204.A short description of what happens follows:1) The test case issues a command code 00 (TEST UNIT READY) via the SG_IO interface with: dxfer_len == 524288, dxdfer_dir == SG_DXFER_FROM_DEV and a corresponding dxferp. The peculiar thing about this is that TUR is not reading from the device.2) In sg_start_req() the invocation of blk_rq_map_user() effectively bounces the user-space buffer. As if the device was to transfer into it. Since commit a45b599ad808 ("scsi: sg: allocate with __GFP_ZERO in sg_build_indirect()") we make sure this first bounce buffer is allocated with GFP_ZERO.3) For the rest of the story we keep ignoring that we have a TUR, so the device won't touch the buffer we prepare as if the we had a DMA_FROM_DEVICE type of situation. My setup uses a virtio-scsi device and the buffer allocated by SG is mapped by the function virtqueue_add_split() which uses DMA_FROM_DEVICE for the "in" sgs (here scatter-gather and not scsi generics). This mapping involves bouncing via the swiotlb (we need swiotlb to do virtio in protected guest like s390 Secure Execution, or AMD SEV).4) When the SCSI TUR is done, we first copy back the content of the second (that is swiotlb) bounce buffer (which most likely contains some previous IO data), to the first bounce buffer, which contains all zeros. Then we copy back the content of the first bounce buffer to the user-space buffer.5) The test case detects that the buffer, which it zero-initialized, ain't all zeros and fails.One can argue that this is an swiotlb problem, because without swiotlbwe leak all zeros, and the swiotlb should be transparent in a sense thatit does not affect the outcome (if all other participants are wellbehaved).Copying the content of the original buffer into the swiotlb buffer isthe only way I can think of to make swiotlb transparent in suchscenarios. So let's do just that if in doubt, but allow the driverto tell us that the whole mapped buffer is going to be overwritten,in which case we can preserve the old behavior and avoid the performanceimpact of the extra bounce.The Linux kernel CVE team has assigned CVE-2022-48853 to this issue. |
| 已分析 | 2.openEulerScore | 5.5 |
| 已分析 | 3.openEulerVector | AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| 已分析 | 4.受影响版本排查 | openEuler-20.03-LTS-SP4:受影响,openEuler-22.03-LTS-SP1:不受影响,openEuler-22.03-LTS-SP3:不受影响,openEuler-22.03-LTS-SP4:不受影响,master:不受影响,openEuler-24.03-LTS:不受影响,openEuler-24.03-LTS-Next:不受影响 |
| 已分析 | 5.修复是否涉及abi变化 | openEuler-20.03-LTS-SP4:否,openEuler-22.03-LTS-SP1:否,openEuler-22.03-LTS-SP3:否,master:否,openEuler-24.03-LTS:否,openEuler-24.03-LTS-Next:否,openEuler-22.03-LTS-SP4:否 |
请确认分析内容的准确性, 确认无误后, 您可以进行后续步骤, 否则您可以继续分析.
hulk-robot
10个月前
CVE-2022-48853
影响性分析说明：
In the Linux kernel, the following vulnerability has been resolved:
swiotlb: fix info leak with DMA_FROM_DEVICE
The problem I'm addressing was discovered by the LTP test covering
cve-2018-1000204.
A short description of what happens follows:
One can argue that this is an swiotlb problem, because without swiotlb
we leak all zeros, and the swiotlb should be transparent in a sense that
it does not affect the outcome (if all other participants are well
behaved).
Copying the content of the original buffer into the swiotlb buffer is
the only way I can think of to make swiotlb transparent in such
scenarios. So let's do just that if in doubt, but allow the driver
to tell us that the whole mapped buffer is going to be overwritten,
in which case we can preserve the old behavior and avoid the performance
impact of the extra bounce.
The Linux kernel CVE team has assigned CVE-2022-48853 to this issue.
openEuler评分:(评分和向量)
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
受影响版本排查(受影响/不受影响):
1.openEuler-20.03-LTS-SP4:受影响
2.openEuler-22.03-LTS-SP1:不受影响
3.openEuler-22.03-LTS-SP3:不受影响
4.openEuler-22.03-LTS-SP4:不受影响
5.master(6.1.0):不受影响
6.openEuler-24.03-LTS:不受影响
7.openEuler-24.03-LTS-Next:不受影响
修复是否涉及abi变化(是/否)：
1.openEuler-20.03-LTS-SP4:否
2.openEuler-22.03-LTS-SP1:否
3.openEuler-22.03-LTS-SP3:否
4.master(6.1.0):否
5.openEuler-24.03-LTS:否
6.openEuler-24.03-LTS-Next:否
7.openEuler-22.03-LTS-SP4:否
@ 经过 cve-manager 解析, 已分析的内容如下表所示:
| 状态 | 需分析 | 内容 |
|---|---|---|
| 已分析 | 1.影响性分析说明 | In the Linux kernel, the following vulnerability has been resolved:swiotlb: fix info leak with DMA_FROM_DEVICEThe problem I'm addressing was discovered by the LTP test coveringcve-2018-1000204.A short description of what happens follows:1) The test case issues a command code 00 (TEST UNIT READY) via the SG_IO interface with: dxfer_len == 524288, dxdfer_dir == SG_DXFER_FROM_DEV and a corresponding dxferp. The peculiar thing about this is that TUR is not reading from the device.2) In sg_start_req() the invocation of blk_rq_map_user() effectively bounces the user-space buffer. As if the device was to transfer into it. Since commit a45b599ad808 ("scsi: sg: allocate with __GFP_ZERO in sg_build_indirect()") we make sure this first bounce buffer is allocated with GFP_ZERO.3) For the rest of the story we keep ignoring that we have a TUR, so the device won't touch the buffer we prepare as if the we had a DMA_FROM_DEVICE type of situation. My setup uses a virtio-scsi device and the buffer allocated by SG is mapped by the function virtqueue_add_split() which uses DMA_FROM_DEVICE for the "in" sgs (here scatter-gather and not scsi generics). This mapping involves bouncing via the swiotlb (we need swiotlb to do virtio in protected guest like s390 Secure Execution, or AMD SEV).4) When the SCSI TUR is done, we first copy back the content of the second (that is swiotlb) bounce buffer (which most likely contains some previous IO data), to the first bounce buffer, which contains all zeros. Then we copy back the content of the first bounce buffer to the user-space buffer.5) The test case detects that the buffer, which it zero-initialized, ain't all zeros and fails.One can argue that this is an swiotlb problem, because without swiotlbwe leak all zeros, and the swiotlb should be transparent in a sense thatit does not affect the outcome (if all other participants are wellbehaved).Copying the content of the original buffer into the swiotlb buffer isthe only way I can think of to make swiotlb transparent in suchscenarios. So let's do just that if in doubt, but allow the driverto tell us that the whole mapped buffer is going to be overwritten,in which case we can preserve the old behavior and avoid the performanceimpact of the extra bounce.The Linux kernel CVE team has assigned CVE-2022-48853 to this issue. |
| 已分析 | 2.openEulerScore | 5.5 |
| 已分析 | 3.openEulerVector | AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| 已分析 | 4.受影响版本排查 | openEuler-20.03-LTS-SP4:受影响,openEuler-22.03-LTS-SP1:不受影响,openEuler-22.03-LTS-SP3:不受影响,openEuler-22.03-LTS-SP4:不受影响,master:不受影响,openEuler-24.03-LTS:不受影响,openEuler-24.03-LTS-Next:不受影响 |
| 已分析 | 5.修复是否涉及abi变化 | openEuler-20.03-LTS-SP4:否,openEuler-22.03-LTS-SP1:否,openEuler-22.03-LTS-SP3:否,master:否,openEuler-24.03-LTS:否,openEuler-24.03-LTS-Next:否,openEuler-22.03-LTS-SP4:否 |
请确认分析内容的准确性, 确认无误后, 您可以进行后续步骤, 否则您可以继续分析.
hulk-robot
10个月前
CVE-2022-48853
影响性分析说明：
In the Linux kernel, the following vulnerability has been resolved:
swiotlb: fix info leak with DMA_FROM_DEVICE
The problem I'm addressing was discovered by the LTP test covering
cve-2018-1000204.
A short description of what happens follows:
One can argue that this is an swiotlb problem, because without swiotlb
we leak all zeros, and the swiotlb should be transparent in a sense that
it does not affect the outcome (if all other participants are well
behaved).
Copying the content of the original buffer into the swiotlb buffer is
the only way I can think of to make swiotlb transparent in such
scenarios. So let's do just that if in doubt, but allow the driver
to tell us that the whole mapped buffer is going to be overwritten,
in which case we can preserve the old behavior and avoid the performance
impact of the extra bounce.
The Linux kernel CVE team has assigned CVE-2022-48853 to this issue.
openEuler评分:(评分和向量)
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
受影响版本排查(受影响/不受影响):
1.openEuler-20.03-LTS-SP4:受影响
2.openEuler-22.03-LTS-SP1:不受影响
3.openEuler-22.03-LTS-SP3:不受影响
4.openEuler-22.03-LTS-SP4:不受影响
5.master(6.1.0):不受影响
6.openEuler-24.03-LTS:不受影响
7.openEuler-24.03-LTS-Next:不受影响
修复是否涉及abi变化(是/否)：
1.openEuler-20.03-LTS-SP4:否
2.openEuler-22.03-LTS-SP1:否
3.openEuler-22.03-LTS-SP3:否
4.master(6.1.0):否
5.openEuler-24.03-LTS:否
6.openEuler-24.03-LTS-Next:否
7.openEuler-22.03-LTS-SP4:否
@ 经过 cve-manager 解析, 已分析的内容如下表所示:
| 状态 | 需分析 | 内容 |
|---|---|---|
| 已分析 | 1.影响性分析说明 | In the Linux kernel, the following vulnerability has been resolved:swiotlb: fix info leak with DMA_FROM_DEVICEThe problem I'm addressing was discovered by the LTP test coveringcve-2018-1000204.A short description of what happens follows:1) The test case issues a command code 00 (TEST UNIT READY) via the SG_IO interface with: dxfer_len == 524288, dxdfer_dir == SG_DXFER_FROM_DEV and a corresponding dxferp. The peculiar thing about this is that TUR is not reading from the device.2) In sg_start_req() the invocation of blk_rq_map_user() effectively bounces the user-space buffer. As if the device was to transfer into it. Since commit a45b599ad808 ("scsi: sg: allocate with __GFP_ZERO in sg_build_indirect()") we make sure this first bounce buffer is allocated with GFP_ZERO.3) For the rest of the story we keep ignoring that we have a TUR, so the device won't touch the buffer we prepare as if the we had a DMA_FROM_DEVICE type of situation. My setup uses a virtio-scsi device and the buffer allocated by SG is mapped by the function virtqueue_add_split() which uses DMA_FROM_DEVICE for the "in" sgs (here scatter-gather and not scsi generics). This mapping involves bouncing via the swiotlb (we need swiotlb to do virtio in protected guest like s390 Secure Execution, or AMD SEV).4) When the SCSI TUR is done, we first copy back the content of the second (that is swiotlb) bounce buffer (which most likely contains some previous IO data), to the first bounce buffer, which contains all zeros. Then we copy back the content of the first bounce buffer to the user-space buffer.5) The test case detects that the buffer, which it zero-initialized, ain't all zeros and fails.One can argue that this is an swiotlb problem, because without swiotlbwe leak all zeros, and the swiotlb should be transparent in a sense thatit does not affect the outcome (if all other participants are wellbehaved).Copying the content of the original buffer into the swiotlb buffer isthe only way I can think of to make swiotlb transparent in suchscenarios. So let's do just that if in doubt, but allow the driverto tell us that the whole mapped buffer is going to be overwritten,in which case we can preserve the old behavior and avoid the performanceimpact of the extra bounce.The Linux kernel CVE team has assigned CVE-2022-48853 to this issue. |
| 已分析 | 2.openEulerScore | 5.5 |
| 已分析 | 3.openEulerVector | AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| 已分析 | 4.受影响版本排查 | openEuler-20.03-LTS-SP4:受影响,openEuler-22.03-LTS-SP1:不受影响,openEuler-22.03-LTS-SP3:不受影响,openEuler-22.03-LTS-SP4:不受影响,master:不受影响,openEuler-24.03-LTS:不受影响,openEuler-24.03-LTS-Next:不受影响 |
| 已分析 | 5.修复是否涉及abi变化 | openEuler-20.03-LTS-SP4:否,openEuler-22.03-LTS-SP1:否,openEuler-22.03-LTS-SP3:否,master:否,openEuler-24.03-LTS:否,openEuler-24.03-LTS-Next:否,openEuler-22.03-LTS-SP4:否 |
请确认分析内容的准确性, 确认无误后, 您可以进行后续步骤, 否则您可以继续分析.
hulk-robot
10个月前
CVE-2022-48853
影响性分析说明：
In the Linux kernel, the following vulnerability has been resolved:
swiotlb: fix info leak with DMA_FROM_DEVICE
The problem I'm addressing was discovered by the LTP test covering
cve-2018-1000204.
A short description of what happens follows:
One can argue that this is an swiotlb problem, because without swiotlb
we leak all zeros, and the swiotlb should be transparent in a sense that
it does not affect the outcome (if all other participants are well
behaved).
Copying the content of the original buffer into the swiotlb buffer is
the only way I can think of to make swiotlb transparent in such
scenarios. So let's do just that if in doubt, but allow the driver
to tell us that the whole mapped buffer is going to be overwritten,
in which case we can preserve the old behavior and avoid the performance
impact of the extra bounce.
The Linux kernel CVE team has assigned CVE-2022-48853 to this issue.
openEuler评分:(评分和向量)
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
受影响版本排查(受影响/不受影响):
1.openEuler-20.03-LTS-SP4:不受影响
2.openEuler-22.03-LTS-SP1:不受影响
3.openEuler-22.03-LTS-SP3:不受影响
4.openEuler-22.03-LTS-SP4:不受影响
5.master(6.1.0):不受影响
6.openEuler-24.03-LTS:不受影响
7.openEuler-24.03-LTS-Next:不受影响
修复是否涉及abi变化(是/否)：
1.openEuler-20.03-LTS-SP4:否
2.openEuler-22.03-LTS-SP1:否
3.openEuler-22.03-LTS-SP3:否
4.master(6.1.0):否
5.openEuler-24.03-LTS:否
6.openEuler-24.03-LTS-Next:否
7.openEuler-22.03-LTS-SP4:否
@ 经过 cve-manager 解析, 已分析的内容如下表所示:
| 状态 | 需分析 | 内容 |
|---|---|---|
| 已分析 | 1.影响性分析说明 | In the Linux kernel, the following vulnerability has been resolved:swiotlb: fix info leak with DMA_FROM_DEVICEThe problem I'm addressing was discovered by the LTP test coveringcve-2018-1000204.A short description of what happens follows:1) The test case issues a command code 00 (TEST UNIT READY) via the SG_IO interface with: dxfer_len == 524288, dxdfer_dir == SG_DXFER_FROM_DEV and a corresponding dxferp. The peculiar thing about this is that TUR is not reading from the device.2) In sg_start_req() the invocation of blk_rq_map_user() effectively bounces the user-space buffer. As if the device was to transfer into it. Since commit a45b599ad808 ("scsi: sg: allocate with __GFP_ZERO in sg_build_indirect()") we make sure this first bounce buffer is allocated with GFP_ZERO.3) For the rest of the story we keep ignoring that we have a TUR, so the device won't touch the buffer we prepare as if the we had a DMA_FROM_DEVICE type of situation. My setup uses a virtio-scsi device and the buffer allocated by SG is mapped by the function virtqueue_add_split() which uses DMA_FROM_DEVICE for the "in" sgs (here scatter-gather and not scsi generics). This mapping involves bouncing via the swiotlb (we need swiotlb to do virtio in protected guest like s390 Secure Execution, or AMD SEV).4) When the SCSI TUR is done, we first copy back the content of the second (that is swiotlb) bounce buffer (which most likely contains some previous IO data), to the first bounce buffer, which contains all zeros. Then we copy back the content of the first bounce buffer to the user-space buffer.5) The test case detects that the buffer, which it zero-initialized, ain't all zeros and fails.One can argue that this is an swiotlb problem, because without swiotlbwe leak all zeros, and the swiotlb should be transparent in a sense thatit does not affect the outcome (if all other participants are wellbehaved).Copying the content of the original buffer into the swiotlb buffer isthe only way I can think of to make swiotlb transparent in suchscenarios. So let's do just that if in doubt, but allow the driverto tell us that the whole mapped buffer is going to be overwritten,in which case we can preserve the old behavior and avoid the performanceimpact of the extra bounce.The Linux kernel CVE team has assigned CVE-2022-48853 to this issue. |
| 已分析 | 2.openEulerScore | 5.5 |
| 已分析 | 3.openEulerVector | AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| 已分析 | 4.受影响版本排查 | openEuler-20.03-LTS-SP4:不受影响,openEuler-22.03-LTS-SP1:不受影响,openEuler-22.03-LTS-SP3:不受影响,openEuler-22.03-LTS-SP4:不受影响,master:不受影响,openEuler-24.03-LTS:不受影响,openEuler-24.03-LTS-Next:不受影响 |
| 已分析 | 5.修复是否涉及abi变化 | openEuler-20.03-LTS-SP4:否,openEuler-22.03-LTS-SP1:否,openEuler-22.03-LTS-SP3:否,master:否,openEuler-24.03-LTS:否,openEuler-24.03-LTS-Next:否,openEuler-22.03-LTS-SP4:否 |
请确认分析内容的准确性, 确认无误后, 您可以进行后续步骤, 否则您可以继续分析.
hulk-robot
10个月前
CVE-2022-48853
影响性分析说明：
In the Linux kernel, the following vulnerability has been resolved:
swiotlb: fix info leak with DMA_FROM_DEVICE
The problem I'm addressing was discovered by the LTP test covering
cve-2018-1000204.
A short description of what happens follows:
One can argue that this is an swiotlb problem, because without swiotlb
we leak all zeros, and the swiotlb should be transparent in a sense that
it does not affect the outcome (if all other participants are well
behaved).
Copying the content of the original buffer into the swiotlb buffer is
the only way I can think of to make swiotlb transparent in such
scenarios. So let's do just that if in doubt, but allow the driver
to tell us that the whole mapped buffer is going to be overwritten,
in which case we can preserve the old behavior and avoid the performance
impact of the extra bounce.
The Linux kernel CVE team has assigned CVE-2022-48853 to this issue.
openEuler评分:(评分和向量)
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
受影响版本排查(受影响/不受影响):
1.openEuler-20.03-LTS-SP4:不受影响
2.openEuler-22.03-LTS-SP1:不受影响
3.openEuler-22.03-LTS-SP3:不受影响
4.openEuler-22.03-LTS-SP4:不受影响
5.master(6.1.0):不受影响
6.openEuler-24.03-LTS:不受影响
7.openEuler-24.03-LTS-Next:不受影响
修复是否涉及abi变化(是/否)：
1.openEuler-20.03-LTS-SP4:否
2.openEuler-22.03-LTS-SP1:否
3.openEuler-22.03-LTS-SP3:否
4.master(6.1.0):否
5.openEuler-24.03-LTS:否
6.openEuler-24.03-LTS-Next:否
7.openEuler-22.03-LTS-SP4:否
@ 经过 cve-manager 解析, 已分析的内容如下表所示:
| 状态 | 需分析 | 内容 |
|---|---|---|
| 已分析 | 1.影响性分析说明 | In the Linux kernel, the following vulnerability has been resolved:swiotlb: fix info leak with DMA_FROM_DEVICEThe problem I'm addressing was discovered by the LTP test coveringcve-2018-1000204.A short description of what happens follows:1) The test case issues a command code 00 (TEST UNIT READY) via the SG_IO interface with: dxfer_len == 524288, dxdfer_dir == SG_DXFER_FROM_DEV and a corresponding dxferp. The peculiar thing about this is that TUR is not reading from the device.2) In sg_start_req() the invocation of blk_rq_map_user() effectively bounces the user-space buffer. As if the device was to transfer into it. Since commit a45b599ad808 ("scsi: sg: allocate with __GFP_ZERO in sg_build_indirect()") we make sure this first bounce buffer is allocated with GFP_ZERO.3) For the rest of the story we keep ignoring that we have a TUR, so the device won't touch the buffer we prepare as if the we had a DMA_FROM_DEVICE type of situation. My setup uses a virtio-scsi device and the buffer allocated by SG is mapped by the function virtqueue_add_split() which uses DMA_FROM_DEVICE for the "in" sgs (here scatter-gather and not scsi generics). This mapping involves bouncing via the swiotlb (we need swiotlb to do virtio in protected guest like s390 Secure Execution, or AMD SEV).4) When the SCSI TUR is done, we first copy back the content of the second (that is swiotlb) bounce buffer (which most likely contains some previous IO data), to the first bounce buffer, which contains all zeros. Then we copy back the content of the first bounce buffer to the user-space buffer.5) The test case detects that the buffer, which it zero-initialized, ain't all zeros and fails.One can argue that this is an swiotlb problem, because without swiotlbwe leak all zeros, and the swiotlb should be transparent in a sense thatit does not affect the outcome (if all other participants are wellbehaved).Copying the content of the original buffer into the swiotlb buffer isthe only way I can think of to make swiotlb transparent in suchscenarios. So let's do just that if in doubt, but allow the driverto tell us that the whole mapped buffer is going to be overwritten,in which case we can preserve the old behavior and avoid the performanceimpact of the extra bounce.The Linux kernel CVE team has assigned CVE-2022-48853 to this issue. |
| 已分析 | 2.openEulerScore | 5.5 |
| 已分析 | 3.openEulerVector | AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| 已分析 | 4.受影响版本排查 | openEuler-20.03-LTS-SP4:不受影响,openEuler-22.03-LTS-SP1:不受影响,openEuler-22.03-LTS-SP3:不受影响,openEuler-22.03-LTS-SP4:不受影响,master:不受影响,openEuler-24.03-LTS:不受影响,openEuler-24.03-LTS-Next:不受影响 |
| 已分析 | 5.修复是否涉及abi变化 | openEuler-20.03-LTS-SP4:否,openEuler-22.03-LTS-SP1:否,openEuler-22.03-LTS-SP3:否,master:否,openEuler-24.03-LTS:否,openEuler-24.03-LTS-Next:否,openEuler-22.03-LTS-SP4:否 |
请确认分析内容的准确性, 确认无误后, 您可以进行后续步骤, 否则您可以继续分析.
CVE-2022-48853
影响性分析说明：
In the Linux kernel, the following vulnerability has been resolved:
swiotlb: fix info leak with DMA_FROM_DEVICE
The problem I'm addressing was discovered by the LTP test covering
cve-2018-1000204.
A short description of what happens follows:
One can argue that this is an swiotlb problem, because without swiotlb
we leak all zeros, and the swiotlb should be transparent in a sense that
it does not affect the outcome (if all other participants are well
behaved).
Copying the content of the original buffer into the swiotlb buffer is
the only way I can think of to make swiotlb transparent in such
scenarios. So let's do just that if in doubt, but allow the driver
to tell us that the whole mapped buffer is going to be overwritten,
in which case we can preserve the old behavior and avoid the performance
impact of the extra bounce.
openEuler评分:(评分和向量)
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
受影响版本排查(受影响/不受影响):
1.openEuler-20.03-LTS-SP4:不受影响
2.openEuler-22.03-LTS-SP1:不受影响
3.openEuler-22.03-LTS-SP3:不受影响
4.openEuler-22.03-LTS-SP4:不受影响
5.master(6.1.0):不受影响
6.openEuler-24.03-LTS:不受影响
7.openEuler-24.03-LTS-Next:不受影响
修复是否涉及abi变化(是/否)：
1.openEuler-20.03-LTS-SP4:否
2.openEuler-22.03-LTS-SP1:否
3.openEuler-22.03-LTS-SP3:否
4.master(6.1.0):否
5.openEuler-24.03-LTS:否
6.openEuler-24.03-LTS-Next:否
7.openEuler-22.03-LTS-SP4:否
===========================================================
@ 经过 cve-manager 解析, 已分析的内容如下表所示:
| 状态 | 需分析 | 内容 |
|---|---|---|
| 已分析 | 1.影响性分析说明 | In the Linux kernel, the following vulnerability has been resolved:swiotlb: fix info leak with DMA_FROM_DEVICEThe problem I'm addressing was discovered by the LTP test coveringcve-2018-1000204.A short description of what happens follows:1) The test case issues a command code 00 (TEST UNIT READY) via the SG_IO interface with: dxfer_len == 524288, dxdfer_dir == SG_DXFER_FROM_DEV and a corresponding dxferp. The peculiar thing about this is that TUR is not reading from the device.2) In sg_start_req() the invocation of blk_rq_map_user() effectively bounces the user-space buffer. As if the device was to transfer into it. Since commit a45b599ad808 ("scsi: sg: allocate with __GFP_ZERO in sg_build_indirect()") we make sure this first bounce buffer is allocated with GFP_ZERO.3) For the rest of the story we keep ignoring that we have a TUR, so the device won't touch the buffer we prepare as if the we had a DMA_FROM_DEVICE type of situation. My setup uses a virtio-scsi device and the buffer allocated by SG is mapped by the function virtqueue_add_split() which uses DMA_FROM_DEVICE for the "in" sgs (here scatter-gather and not scsi generics). This mapping involves bouncing via the swiotlb (we need swiotlb to do virtio in protected guest like s390 Secure Execution, or AMD SEV).4) When the SCSI TUR is done, we first copy back the content of the second (that is swiotlb) bounce buffer (which most likely contains some previous IO data), to the first bounce buffer, which contains all zeros. Then we copy back the content of the first bounce buffer to the user-space buffer.5) The test case detects that the buffer, which it zero-initialized, ain't all zeros and fails.One can argue that this is an swiotlb problem, because without swiotlbwe leak all zeros, and the swiotlb should be transparent in a sense thatit does not affect the outcome (if all other participants are wellbehaved).Copying the content of the original buffer into the swiotlb buffer isthe only way I can think of to make swiotlb transparent in suchscenarios. So let's do just that if in doubt, but allow the driverto tell us that the whole mapped buffer is going to be overwritten,in which case we can preserve the old behavior and avoid the performanceimpact of the extra bounce. |
| 已分析 | 2.openEulerScore | 5.5 |
| 已分析 | 3.openEulerVector | AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
| 已分析 | 4.受影响版本排查 | openEuler-20.03-LTS-SP4:不受影响,openEuler-22.03-LTS-SP1:不受影响,openEuler-22.03-LTS-SP3:不受影响,openEuler-22.03-LTS-SP4:不受影响,master:不受影响,openEuler-24.03-LTS:不受影响,openEuler-24.03-LTS-Next:不受影响 |
| 已分析 | 5.修复是否涉及abi变化 | openEuler-20.03-LTS-SP4:否,openEuler-22.03-LTS-SP1:否,openEuler-22.03-LTS-SP3:否,master:否,openEuler-24.03-LTS:否,openEuler-24.03-LTS-Next:否,openEuler-22.03-LTS-SP4:否 |
请确认分析内容的准确性, 确认无误后, 您可以进行后续步骤, 否则您可以继续分析.
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