In the Linux kernel, the following vulnerability has been resolved:
fork: only invoke khugepaged, ksm hooks if no error
There is no reason to invoke these hooks early against an mm that is in an
incomplete state.
The change in commit d24062914837 ("fork: use __mt_dup() to duplicate
maple tree in dup_mmap()") makes this more pertinent as we may be in a
state where entries in the maple tree are not yet consistent.
Their placement early in dup_mmap() only appears to have been meaningful
for early error checking, and since functionally it'd require a very small
allocation to fail (in practice 'too small to fail') that'd only occur in
the most dire circumstances, meaning the fork would fail or be OOM'd in
any case.
Since both khugepaged and KSM tracking are there to provide optimisations
to memory performance rather than critical functionality, it doesn't
really matter all that much if, under such dire memory pressure, we fail
to register an mm with these.
As a result, we follow the example of commit d2081b2bf819 ("mm:
khugepaged: make khugepaged_enter() void function") and make ksm_fork() a
void function also.
We only expose the mm to these functions once we are done with them and
only if no error occurred in the fork operation.
Metrics
Affected Vendors & Products
References
History
Mon, 09 Dec 2024 21:45:00 +0000
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References |
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Fri, 22 Nov 2024 14:00:00 +0000
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threat_severity
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threat_severity
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Thu, 14 Nov 2024 16:45:00 +0000
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First Time appeared |
Linux
Linux linux Kernel |
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Weaknesses | NVD-CWE-noinfo | |
CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.12:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.12:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.12:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.12:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.12:rc5:*:*:*:*:*:* |
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Vendors & Products |
Linux
Linux linux Kernel |
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Metrics |
cvssV3_1
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Mon, 11 Nov 2024 14:15:00 +0000
Type | Values Removed | Values Added |
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Description | In the Linux kernel, the following vulnerability has been resolved: fork: only invoke khugepaged, ksm hooks if no error There is no reason to invoke these hooks early against an mm that is in an incomplete state. The change in commit d24062914837 ("fork: use __mt_dup() to duplicate maple tree in dup_mmap()") makes this more pertinent as we may be in a state where entries in the maple tree are not yet consistent. Their placement early in dup_mmap() only appears to have been meaningful for early error checking, and since functionally it'd require a very small allocation to fail (in practice 'too small to fail') that'd only occur in the most dire circumstances, meaning the fork would fail or be OOM'd in any case. Since both khugepaged and KSM tracking are there to provide optimisations to memory performance rather than critical functionality, it doesn't really matter all that much if, under such dire memory pressure, we fail to register an mm with these. As a result, we follow the example of commit d2081b2bf819 ("mm: khugepaged: make khugepaged_enter() void function") and make ksm_fork() a void function also. We only expose the mm to these functions once we are done with them and only if no error occurred in the fork operation. | |
Title | fork: only invoke khugepaged, ksm hooks if no error | |
References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2024-11-11T13:58:18.577Z
Updated: 2024-12-19T09:36:49.763Z
Reserved: 2024-10-21T19:36:19.982Z
Link: CVE-2024-50263
Vulnrichment
No data.
NVD
Status : Modified
Published: 2024-11-11T14:15:15.473
Modified: 2024-12-09T22:15:22.497
Link: CVE-2024-50263
Redhat