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一、漏洞信息
漏洞编号：CVE-2024-49878
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:N/I:N/A:H
漏洞简述：
In the Linux kernel, the following vulnerability has been resolved:resource: fix region_intersects() vs add_memory_driver_managed()On a system with CXL memory, the resource tree (/proc/iomem) related toCXL memory may look like something as follows.490000000-50fffffff : CXL Window 0 490000000-50fffffff : region0 490000000-50fffffff : dax0.0 490000000-50fffffff : System RAM (kmem)Because drivers/dax/kmem.c calls add_memory_driver_managed() duringonlining CXL memory, which makes System RAM (kmem) a descendant of CXLWindow X . This confuses region_intersects(), which expects all SystemRAM resources to be at the top level of iomem_resource. This can lead tobugs.For example, when the following command line is executed to write somememory in CXL memory range via /dev/mem, ddif=dataof=/dev/membs=((1 << 10)) seek=$((0x490000000 >> 10)) count=1 dd: error writing /dev/mem : Bad address 1+0 records in 0+0 records out 0 bytes copied, 0.0283507 s, 0.0 kB/sthe command fails as expected. However, the error code is wrong. Itshould be Operation not permitted instead of Bad address . Moreseriously, the /dev/mem permission checking in devmem_is_allowed() passesincorrectly. Although the accessing is prevented later because ioremap()isn t allowed to map system RAM, it is a potential security issue. Duringcommand executing, the following warning is reported in the kernel log forcalling ioremap() on system RAM. ioremap on RAM at 0x0000000490000000 - 0x0000000490000fff WARNING: CPU: 2 PID: 416 at arch/x86/mm/ioremap.c:216 __ioremap_caller.constprop.0+0x131/0x35d Call Trace: memremap+0xcb/0x184 xlate_dev_mem_ptr+0x25/0x2f write_mem+0x94/0xfb vfs_write+0x128/0x26d ksys_write+0xac/0xfe do_syscall_64+0x9a/0xfd entry_SYSCALL_64_after_hwframe+0x4b/0x53The details of command execution process are as follows. In the aboveresource tree, System RAM is a descendant of CXL Window 0 instead of atop level resource. So, region_intersects() will report no System RAMresources in the CXL memory region incorrectly, because it only checks thetop level resources. Consequently, devmem_is_allowed() will return 1(allow access via /dev/mem) for CXL memory region incorrectly. Fortunately, ioremap() doesn t allow to map System RAM and reject theaccess.So, region_intersects() needs to be fixed to work correctly with theresource tree with System RAM not at top level as above. To fix it, ifwe found a unmatched resource in the top level, we will continue to searchmatched resources in its descendant resources. So, we will not miss anymatched resources in resource tree anymore.In the new implementation, an example resource tree|------------- CXL Window 0 ------------||-- System RAM --|will behave similar as the following fake resource tree forregion_intersects(, IORESOURCE_SYSTEM_RAM, ),|-- System RAM --||-- CXL Window 0a --|Where CXL Window 0a is part of the original CXL Window 0 thatisn t covered by System RAM .
漏洞公开时间：2024-10-22 02:15:09
漏洞创建时间：2024-10-22 04:23:17
漏洞详情参考链接：
https://nvd.nist.gov/vuln/detail/CVE-2024-49878
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:
openBrain开源漏洞感知系统
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:resource: fix region_intersects() vs add_memory_driver_managed()On a system with CXL memory, the resource tree (/proc/iomem) related toCXL memory may look like something as follows.490000000-50fffffff : CXL Window 0 490000000-50fffffff : region0 490000000-50fffffff : dax0.0 490000000-50fffffff : System RAM (kmem)Because drivers/dax/kmem.c calls add_memory_driver_managed() duringonlining CXL memory, which makes System RAM (kmem) a descendant of CXLWindow X . This confuses region_intersects(), which expects all SystemRAM resources to be at the top level of iomem_resource. This can lead tobugs.For example, when the following command line is executed to write somememory in CXL memory range via /dev/mem, ddif=dataof=/dev/membs=((1 << 10)) seek=$((0x490000000 >> 10)) count=1 dd: error writing /dev/mem : Bad address 1+0 records in 0+0 records out 0 bytes copied, 0.0283507 s, 0.0 kB/sthe command fails as expected. However, the error code is wrong. Itshould be Operation not permitted instead of Bad address . Moreseriously, the /dev/mem permission checking in devmem_is_allowed() passesincorrectly. Although the accessing is prevented later because ioremap()isn t allowed to map system RAM, it is a potential security issue. Duringcommand executing, the following warning is reported in the kernel log forcalling ioremap() on system RAM. ioremap on RAM at 0x0000000490000000 - 0x0000000490000fff WARNING: CPU: 2 PID: 416 at arch/x86/mm/ioremap.c:216 __ioremap_caller.constprop.0+0x131/0x35d Call Trace: memremap+0xcb/0x184 xlate_dev_mem_ptr+0x25/0x2f write_mem+0x94/0xfb vfs_write+0x128/0x26d ksys_write+0xac/0xfe do_syscall_64+0x9a/0xfd entry_SYSCALL_64_after_hwframe+0x4b/0x53The details of command execution process are as follows. In the aboveresource tree, System RAM is a descendant of CXL Window 0 instead of atop level resource. So, region_intersects() will report no System RAMresources in the CXL memory region incorrectly, because it only checks thetop level resources. Consequently, devmem_is_allowed() will return 1(allow access via /dev/mem) for CXL memory region incorrectly. Fortunately, ioremap() doesn t allow to map System RAM and reject theaccess.So, region_intersects() needs to be fixed to work correctly with theresource tree with System RAM not at top level as above. To fix it, ifwe found a unmatched resource in the top level, we will continue to searchmatched resources in its descendant resources. So, we will not miss anymatched resources in resource tree anymore.In the new implementation, an example resource tree|------------- CXL Window 0 ------------||-- System RAM --|will behave similar as the following fake resource tree forregion_intersects(, IORESOURCE_SYSTEM_RAM, ),|-- System RAM --||-- CXL Window 0a --|Where CXL Window 0a is part of the original CXL Window 0 thatisn t covered by System RAM .
openEuler评分：
3.9
Vector：CVSS：3.0/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:L
受影响版本排查(受影响/不受影响)：
1.openEuler-20.03-LTS-SP4(4.19.90):受影响
2.openEuler-22.03-LTS-SP1(5.10.0):受影响
3.openEuler-22.03-LTS-SP3(5.10.0):受影响
4.openEuler-22.03-LTS-SP4(5.10.0):受影响
5.openEuler-24.03-LTS(6.6.0):受影响
6.master(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(6.6.0):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
原因说明：
1.master(6.6.0):
2.openEuler-20.03-LTS-SP4(4.19.90):
3.openEuler-22.03-LTS-SP1(5.10.0):
4.openEuler-22.03-LTS-SP3(5.10.0):
5.openEuler-22.03-LTS-SP4(5.10.0):
6.openEuler-24.03-LTS(6.6.0):
7.openEuler-24.03-LTS-Next(6.6.0):
8.openEuler-24.03-LTS-SP1:
三、漏洞修复
安全公告链接：https://www.openeuler.org/zh/security/safety-bulletin/detail/?id=openEuler-SA-2024-2426
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issue处理注意事项:
1. 当前issue受影响的分支提交pr时, 须在pr描述中填写当前issue编号进行关联, 否则无法关闭当前issue;
2. 模板内容需要填写完整, 无论是受影响或者不受影响都需要填写完整内容,未引入的分支不需要填写, 否则无法关闭当前issue;
3. 以下为模板中需要填写完整的内容, 请复制到评论区回复, 注: 内容的标题名称(影响性分析说明, openEuler评分, 受影响版本排查(受影响/不受影响), 修复是否涉及abi变化(是/否))不能省略,省略后cve-manager将无法正常解析填写内容.
影响性分析说明:
openEuler评分: (评分和向量)
受影响版本排查(受影响/不受影响):
1.master(6.6.0):
2.openEuler-20.03-LTS-SP4(4.19.90):
3.openEuler-22.03-LTS-SP1(5.10.0):
4.openEuler-22.03-LTS-SP3(5.10.0):
5.openEuler-22.03-LTS-SP4(5.10.0):
6.openEuler-24.03-LTS(6.6.0):
7.openEuler-24.03-LTS-Next(6.6.0):
修复是否涉及abi变化(是/否)：
1.master(6.6.0):
2.openEuler-20.03-LTS-SP4(4.19.90):
3.openEuler-22.03-LTS-SP1(5.10.0):
4.openEuler-22.03-LTS-SP3(5.10.0):
5.openEuler-22.03-LTS-SP4(5.10.0):
6.openEuler-24.03-LTS(6.6.0):
7.openEuler-24.03-LTS-Next(6.6.0):
issue处理具体操作请参考:
https://gitee.com/openeuler/cve-manager/blob/master/cve-vulner-manager/doc/md/manual.md
pr关联issue具体操作请参考:
https://gitee.com/help/articles/4142
hulk-robot
6个月前
CVE-2024-49878
影响性分析说明：
In the Linux kernel, the following vulnerability has been resolved:
resource: fix region_intersects() vs add_memory_driver_managed()
On a system with CXL memory, the resource tree (/proc/iomem) related to
CXL memory may look like something as follows.
490000000-50fffffff : CXL Window 0
490000000-50fffffff : region0
490000000-50fffffff : dax0.0
490000000-50fffffff : System RAM (kmem)
Because drivers/dax/kmem.c calls add_memory_driver_managed() during
onlining CXL memory, which makes "System RAM (kmem)" a descendant of "CXL
Window X". This confuses region_intersects(), which expects all "System
RAM" resources to be at the top level of iomem_resource. This can lead to
bugs.
For example, when the following command line is executed to write some
memory in CXL memory range via /dev/mem,
ddif=dataof=/dev/membs=((1 << 10)) seek=$((0x490000000 >> 10)) count=1
dd: error writing '/dev/mem': Bad address
1+0 records in
0+0 records out
0 bytes copied, 0.0283507 s, 0.0 kB/s
the command fails as expected. However, the error code is wrong. It
should be "Operation not permitted" instead of "Bad address". More
seriously, the /dev/mem permission checking in devmem_is_allowed() passes
incorrectly. Although the accessing is prevented later because ioremap()
isn't allowed to map system RAM, it is a potential security issue. During
command executing, the following warning is reported in the kernel log for
calling ioremap() on system RAM.
ioremap on RAM at 0x0000000490000000 - 0x0000000490000fff
WARNING: CPU: 2 PID: 416 at arch/x86/mm/ioremap.c:216 __ioremap_caller.constprop.0+0x131/0x35d
Call Trace:
memremap+0xcb/0x184
xlate_dev_mem_ptr+0x25/0x2f
write_mem+0x94/0xfb
vfs_write+0x128/0x26d
ksys_write+0xac/0xfe
do_syscall_64+0x9a/0xfd
entry_SYSCALL_64_after_hwframe+0x4b/0x53
The details of command execution process are as follows. In the above
resource tree, "System RAM" is a descendant of "CXL Window 0" instead of a
top level resource. So, region_intersects() will report no System RAM
resources in the CXL memory region incorrectly, because it only checks the
top level resources. Consequently, devmem_is_allowed() will return 1
(allow access via /dev/mem) for CXL memory region incorrectly.
Fortunately, ioremap() doesn't allow to map System RAM and reject the
access.
So, region_intersects() needs to be fixed to work correctly with the
resource tree with "System RAM" not at top level as above. To fix it, if
we found a unmatched resource in the top level, we will continue to search
matched resources in its descendant resources. So, we will not miss any
matched resources in resource tree anymore.
In the new implementation, an example resource tree
|------------- "CXL Window 0" ------------|
|-- "System RAM" --|
will behave similar as the following fake resource tree for
region_intersects(, IORESOURCE_SYSTEM_RAM, ),
|-- "System RAM" --||-- "CXL Window 0a" --|
Where "CXL Window 0a" is part of the original "CXL Window 0" that
isn't covered by "System RAM".
openEuler评分:(评分和向量)
3.9
AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:L
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:受影响
3.openEuler-22.03-LTS-SP3:受影响
4.openEuler-22.03-LTS-SP4:受影响
5.master(6.1.0):不受影响
6.openEuler-24.03-LTS: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 | 分析项目 | 内容 |
|---|---|---|
| 已分析 | 1.影响性分析说明 | In the Linux kernel, the following vulnerability has been resolved:resource: fix region_intersects() vs add_memory_driver_managed()On a system with CXL memory, the resource tree (/proc/iomem) related toCXL memory may look like something as follows.490000000-50fffffff : CXL Window 0 490000000-50fffffff : region0 490000000-50fffffff : dax0.0 490000000-50fffffff : System RAM (kmem)Because drivers/dax/kmem.c calls add_memory_driver_managed() duringonlining CXL memory, which makes "System RAM (kmem)" a descendant of "CXLWindow X". This confuses region_intersects(), which expects all "SystemRAM" resources to be at the top level of iomem_resource. This can lead tobugs.For example, when the following command line is executed to write somememory in CXL memory range via /dev/mem, ddif=dataof=/dev/membs=((1 << 10)) seek=$((0x490000000 >> 10)) count=1 dd: error writing '/dev/mem': Bad address 1+0 records in 0+0 records out 0 bytes copied, 0.0283507 s, 0.0 kB/sthe command fails as expected. However, the error code is wrong. Itshould be "Operation not permitted" instead of "Bad address". Moreseriously, the /dev/mem permission checking in devmem_is_allowed() passesincorrectly. Although the accessing is prevented later because ioremap()isn't allowed to map system RAM, it is a potential security issue. Duringcommand executing, the following warning is reported in the kernel log forcalling ioremap() on system RAM. ioremap on RAM at 0x0000000490000000 - 0x0000000490000fff WARNING: CPU: 2 PID: 416 at arch/x86/mm/ioremap.c:216 __ioremap_caller.constprop.0+0x131/0x35d Call Trace: memremap+0xcb/0x184 xlate_dev_mem_ptr+0x25/0x2f write_mem+0x94/0xfb vfs_write+0x128/0x26d ksys_write+0xac/0xfe do_syscall_64+0x9a/0xfd entry_SYSCALL_64_after_hwframe+0x4b/0x53The details of command execution process are as follows. In the aboveresource tree, "System RAM" is a descendant of "CXL Window 0" instead of atop level resource. So, region_intersects() will report no System RAMresources in the CXL memory region incorrectly, because it only checks thetop level resources. Consequently, devmem_is_allowed() will return 1(allow access via /dev/mem) for CXL memory region incorrectly. Fortunately, ioremap() doesn't allow to map System RAM and reject theaccess.So, region_intersects() needs to be fixed to work correctly with theresource tree with "System RAM" not at top level as above. To fix it, ifwe found a unmatched resource in the top level, we will continue to searchmatched resources in its descendant resources. So, we will not miss anymatched resources in resource tree anymore.In the new implementation, an example resource tree |
| 已分析 | 2.openEulerScore | 3.9 |
| 已分析 | 3.openEulerVector | AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:L |
| 已分析 | 4.受影响版本排查 | openEuler-20.03-LTS-SP4:受影响,openEuler-22.03-LTS-SP1:受影响,openEuler-22.03-LTS-SP3:受影响,openEuler-22.03-LTS-SP4:受影响,openEuler-24.03-LTS:受影响,master:不受影响,openEuler-24.03-LTS-Next:不受影响 |
| 已分析 | 5.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 |
| 已分析 | 6.原因说明 |
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
5个月前
CVE-2024-49878
影响性分析说明：
In the Linux kernel, the following vulnerability has been resolved:
resource: fix region_intersects() vs add_memory_driver_managed()
On a system with CXL memory, the resource tree (/proc/iomem) related to
CXL memory may look like something as follows.
490000000-50fffffff : CXL Window 0
490000000-50fffffff : region0
490000000-50fffffff : dax0.0
490000000-50fffffff : System RAM (kmem)
Because drivers/dax/kmem.c calls add_memory_driver_managed() during
onlining CXL memory, which makes "System RAM (kmem)" a descendant of "CXL
Window X". This confuses region_intersects(), which expects all "System
RAM" resources to be at the top level of iomem_resource. This can lead to
bugs.
For example, when the following command line is executed to write some
memory in CXL memory range via /dev/mem,
ddif=dataof=/dev/membs=((1 << 10)) seek=$((0x490000000 >> 10)) count=1
dd: error writing '/dev/mem': Bad address
1+0 records in
0+0 records out
0 bytes copied, 0.0283507 s, 0.0 kB/s
the command fails as expected. However, the error code is wrong. It
should be "Operation not permitted" instead of "Bad address". More
seriously, the /dev/mem permission checking in devmem_is_allowed() passes
incorrectly. Although the accessing is prevented later because ioremap()
isn't allowed to map system RAM, it is a potential security issue. During
command executing, the following warning is reported in the kernel log for
calling ioremap() on system RAM.
ioremap on RAM at 0x0000000490000000 - 0x0000000490000fff
WARNING: CPU: 2 PID: 416 at arch/x86/mm/ioremap.c:216 __ioremap_caller.constprop.0+0x131/0x35d
Call Trace:
memremap+0xcb/0x184
xlate_dev_mem_ptr+0x25/0x2f
write_mem+0x94/0xfb
vfs_write+0x128/0x26d
ksys_write+0xac/0xfe
do_syscall_64+0x9a/0xfd
entry_SYSCALL_64_after_hwframe+0x4b/0x53
The details of command execution process are as follows. In the above
resource tree, "System RAM" is a descendant of "CXL Window 0" instead of a
top level resource. So, region_intersects() will report no System RAM
resources in the CXL memory region incorrectly, because it only checks the
top level resources. Consequently, devmem_is_allowed() will return 1
(allow access via /dev/mem) for CXL memory region incorrectly.
Fortunately, ioremap() doesn't allow to map System RAM and reject the
access.
So, region_intersects() needs to be fixed to work correctly with the
resource tree with "System RAM" not at top level as above. To fix it, if
we found a unmatched resource in the top level, we will continue to search
matched resources in its descendant resources. So, we will not miss any
matched resources in resource tree anymore.
In the new implementation, an example resource tree
|------------- "CXL Window 0" ------------|
|-- "System RAM" --|
will behave similar as the following fake resource tree for
region_intersects(, IORESOURCE_SYSTEM_RAM, ),
|-- "System RAM" --||-- "CXL Window 0a" --|
Where "CXL Window 0a" is part of the original "CXL Window 0" that
isn't covered by "System RAM".
openEuler评分:(评分和向量)
3.9
AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:L
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:受影响
3.openEuler-22.03-LTS-SP3:受影响
4.openEuler-22.03-LTS-SP4:受影响
5.master(6.1.0):不受影响
6.openEuler-24.03-LTS: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
hulk-robot
5个月前
CVE-2024-49878
影响性分析说明：
In the Linux kernel, the following vulnerability has been resolved:
resource: fix region_intersects() vs add_memory_driver_managed()
On a system with CXL memory, the resource tree (/proc/iomem) related to
CXL memory may look like something as follows.
490000000-50fffffff : CXL Window 0
490000000-50fffffff : region0
490000000-50fffffff : dax0.0
490000000-50fffffff : System RAM (kmem)
Because drivers/dax/kmem.c calls add_memory_driver_managed() during
onlining CXL memory, which makes "System RAM (kmem)" a descendant of "CXL
Window X". This confuses region_intersects(), which expects all "System
RAM" resources to be at the top level of iomem_resource. This can lead to
bugs.
For example, when the following command line is executed to write some
memory in CXL memory range via /dev/mem,
ddif=dataof=/dev/membs=((1 << 10)) seek=$((0x490000000 >> 10)) count=1
dd: error writing '/dev/mem': Bad address
1+0 records in
0+0 records out
0 bytes copied, 0.0283507 s, 0.0 kB/s
the command fails as expected. However, the error code is wrong. It
should be "Operation not permitted" instead of "Bad address". More
seriously, the /dev/mem permission checking in devmem_is_allowed() passes
incorrectly. Although the accessing is prevented later because ioremap()
isn't allowed to map system RAM, it is a potential security issue. During
command executing, the following warning is reported in the kernel log for
calling ioremap() on system RAM.
ioremap on RAM at 0x0000000490000000 - 0x0000000490000fff
WARNING: CPU: 2 PID: 416 at arch/x86/mm/ioremap.c:216 __ioremap_caller.constprop.0+0x131/0x35d
Call Trace:
memremap+0xcb/0x184
xlate_dev_mem_ptr+0x25/0x2f
write_mem+0x94/0xfb
vfs_write+0x128/0x26d
ksys_write+0xac/0xfe
do_syscall_64+0x9a/0xfd
entry_SYSCALL_64_after_hwframe+0x4b/0x53
The details of command execution process are as follows. In the above
resource tree, "System RAM" is a descendant of "CXL Window 0" instead of a
top level resource. So, region_intersects() will report no System RAM
resources in the CXL memory region incorrectly, because it only checks the
top level resources. Consequently, devmem_is_allowed() will return 1
(allow access via /dev/mem) for CXL memory region incorrectly.
Fortunately, ioremap() doesn't allow to map System RAM and reject the
access.
So, region_intersects() needs to be fixed to work correctly with the
resource tree with "System RAM" not at top level as above. To fix it, if
we found a unmatched resource in the top level, we will continue to search
matched resources in its descendant resources. So, we will not miss any
matched resources in resource tree anymore.
In the new implementation, an example resource tree
|------------- "CXL Window 0" ------------|
|-- "System RAM" --|
will behave similar as the following fake resource tree for
region_intersects(, IORESOURCE_SYSTEM_RAM, ),
|-- "System RAM" --||-- "CXL Window 0a" --|
Where "CXL Window 0a" is part of the original "CXL Window 0" that
isn't covered by "System RAM".
openEuler评分:(评分和向量)
5.3
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
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:受影响
3.openEuler-22.03-LTS-SP3:受影响
4.openEuler-22.03-LTS-SP4:受影响
5.master(6.1.0):不受影响
6.openEuler-24.03-LTS: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
hulk-robot
5个月前
CVE-2024-49878
影响性分析说明：
In the Linux kernel, the following vulnerability has been resolved:
resource: fix region_intersects() vs add_memory_driver_managed()
On a system with CXL memory, the resource tree (/proc/iomem) related to
CXL memory may look like something as follows.
490000000-50fffffff : CXL Window 0
490000000-50fffffff : region0
490000000-50fffffff : dax0.0
490000000-50fffffff : System RAM (kmem)
Because drivers/dax/kmem.c calls add_memory_driver_managed() during
onlining CXL memory, which makes "System RAM (kmem)" a descendant of "CXL
Window X". This confuses region_intersects(), which expects all "System
RAM" resources to be at the top level of iomem_resource. This can lead to
bugs.
For example, when the following command line is executed to write some
memory in CXL memory range via /dev/mem,
ddif=dataof=/dev/membs=((1 << 10)) seek=$((0x490000000 >> 10)) count=1
dd: error writing '/dev/mem': Bad address
1+0 records in
0+0 records out
0 bytes copied, 0.0283507 s, 0.0 kB/s
the command fails as expected. However, the error code is wrong. It
should be "Operation not permitted" instead of "Bad address". More
seriously, the /dev/mem permission checking in devmem_is_allowed() passes
incorrectly. Although the accessing is prevented later because ioremap()
isn't allowed to map system RAM, it is a potential security issue. During
command executing, the following warning is reported in the kernel log for
calling ioremap() on system RAM.
ioremap on RAM at 0x0000000490000000 - 0x0000000490000fff
WARNING: CPU: 2 PID: 416 at arch/x86/mm/ioremap.c:216 __ioremap_caller.constprop.0+0x131/0x35d
Call Trace:
memremap+0xcb/0x184
xlate_dev_mem_ptr+0x25/0x2f
write_mem+0x94/0xfb
vfs_write+0x128/0x26d
ksys_write+0xac/0xfe
do_syscall_64+0x9a/0xfd
entry_SYSCALL_64_after_hwframe+0x4b/0x53
The details of command execution process are as follows. In the above
resource tree, "System RAM" is a descendant of "CXL Window 0" instead of a
top level resource. So, region_intersects() will report no System RAM
resources in the CXL memory region incorrectly, because it only checks the
top level resources. Consequently, devmem_is_allowed() will return 1
(allow access via /dev/mem) for CXL memory region incorrectly.
Fortunately, ioremap() doesn't allow to map System RAM and reject the
access.
So, region_intersects() needs to be fixed to work correctly with the
resource tree with "System RAM" not at top level as above. To fix it, if
we found a unmatched resource in the top level, we will continue to search
matched resources in its descendant resources. So, we will not miss any
matched resources in resource tree anymore.
In the new implementation, an example resource tree
|------------- "CXL Window 0" ------------|
|-- "System RAM" --|
will behave similar as the following fake resource tree for
region_intersects(, IORESOURCE_SYSTEM_RAM, ),
|-- "System RAM" --||-- "CXL Window 0a" --|
Where "CXL Window 0a" is part of the original "CXL Window 0" that
isn't covered by "System RAM".
openEuler评分:(评分和向量)
5.3
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
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:受影响
3.openEuler-22.03-LTS-SP3:受影响
4.openEuler-22.03-LTS-SP4:受影响
5.master(6.1.0):不受影响
6.openEuler-24.03-LTS: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
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