CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
AI Score
Confidence
High
EPSS
Percentile
9.5%
In the Linux kernel, the following vulnerability has been resolved:
filemap: replace pte_offset_map() with pte_offset_map_nolock()
The vmf->ptl in filemap_fault_recheck_pte_none() is still set from
handle_pte_fault(). But at the same time, we did a pte_unmap(vmf->pte).
After a pte_unmap(vmf->pte) unmap and rcu_read_unlock(), the page table
may be racily changed and vmf->ptl maybe fails to protect the actual page
table. Fix this by replacing pte_offset_map() with
pte_offset_map_nolock().
As David said, the PTL pointer might be stale so if we continue to use
it infilemap_fault_recheck_pte_none(), it might trigger UAF. Also, if
the PTL fails, the issue fixed by commit 58f327f2ce80 (“filemap: avoid
unnecessary major faults in filemap_fault()”) might reappear.
Vendor | Product | Version | CPE |
---|---|---|---|
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
[
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"mm/filemap.c"
],
"versions": [
{
"version": "58f327f2ce80",
"lessThan": "6a6c2aec1a89",
"status": "affected",
"versionType": "git"
},
{
"version": "58f327f2ce80",
"lessThan": "24be02a42181",
"status": "affected",
"versionType": "git"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"mm/filemap.c"
],
"versions": [
{
"version": "6.9",
"status": "affected"
},
{
"version": "0",
"lessThan": "6.9",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.9.10",
"lessThanOrEqual": "6.9.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.10",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
]
}
]