| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
mm/vma: fix anon_vma UAF on mremap() faulted, unfaulted merge
Patch series "mm/vma: fix anon_vma UAF on mremap() faulted, unfaulted
merge", v2.
Commit 879bca0a2c4f ("mm/vma: fix incorrectly disallowed anonymous VMA
merges") introduced the ability to merge previously unavailable VMA merge
scenarios.
However, it is handling merges incorrectly when it comes to mremap() of a
faulted VMA adjacent to an unfaulted VMA. The issues arise in three
cases:
1. Previous VMA unfaulted:
copied -----|
v
|-----------|.............|
| unfaulted |(faulted VMA)|
|-----------|.............|
prev
2. Next VMA unfaulted:
copied -----|
v
|.............|-----------|
|(faulted VMA)| unfaulted |
|.............|-----------|
next
3. Both adjacent VMAs unfaulted:
copied -----|
v
|-----------|.............|-----------|
| unfaulted |(faulted VMA)| unfaulted |
|-----------|.............|-----------|
prev next
This series fixes each of these cases, and introduces self tests to assert
that the issues are corrected.
I also test a further case which was already handled, to assert that my
changes continues to correctly handle it:
4. prev unfaulted, next faulted:
copied -----|
v
|-----------|.............|-----------|
| unfaulted |(faulted VMA)| faulted |
|-----------|.............|-----------|
prev next
This bug was discovered via a syzbot report, linked to in the first patch
in the series, I confirmed that this series fixes the bug.
I also discovered that we are failing to check that the faulted VMA was
not forked when merging a copied VMA in cases 1-3 above, an issue this
series also addresses.
I also added self tests to assert that this is resolved (and confirmed
that the tests failed prior to this).
I also cleaned up vma_expand() as part of this work, renamed
vma_had_uncowed_parents() to vma_is_fork_child() as the previous name was
unduly confusing, and simplified the comments around this function.
This patch (of 4):
Commit 879bca0a2c4f ("mm/vma: fix incorrectly disallowed anonymous VMA
merges") introduced the ability to merge previously unavailable VMA merge
scenarios.
The key piece of logic introduced was the ability to merge a faulted VMA
immediately next to an unfaulted VMA, which relies upon dup_anon_vma() to
correctly handle anon_vma state.
In the case of the merge of an existing VMA (that is changing properties
of a VMA and then merging if those properties are shared by adjacent
VMAs), dup_anon_vma() is invoked correctly.
However in the case of the merge of a new VMA, a corner case peculiar to
mremap() was missed.
The issue is that vma_expand() only performs dup_anon_vma() if the target
(the VMA that will ultimately become the merged VMA): is not the next VMA,
i.e. the one that appears after the range in which the new VMA is to be
established.
A key insight here is that in all other cases other than mremap(), a new
VMA merge either expands an existing VMA, meaning that the target VMA will
be that VMA, or would have anon_vma be NULL.
Specifically:
* __mmap_region() - no anon_vma in place, initial mapping.
* do_brk_flags() - expanding an existing VMA.
* vma_merge_extend() - expanding an existing VMA.
* relocate_vma_down() - no anon_vma in place, initial mapping.
In addition, we are in the unique situation of needing to duplicate
anon_vma state from a VMA that is neither the previous or next VMA being
merged with.
dup_anon_vma() deals exclusively with the target=unfaulted, src=faulted
case. This leaves four possibilities, in each case where the copied VMA
is faulted:
1. Previous VMA unfaulted:
copied -----|
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
netrom: fix double-free in nr_route_frame()
In nr_route_frame(), old_skb is immediately freed without checking if
nr_neigh->ax25 pointer is NULL. Therefore, if nr_neigh->ax25 is NULL,
the caller function will free old_skb again, causing a double-free bug.
Therefore, to prevent this, we need to modify it to check whether
nr_neigh->ax25 is NULL before freeing old_skb. |
| In the Linux kernel, the following vulnerability has been resolved:
mptcp: fix race in mptcp_pm_nl_flush_addrs_doit()
syzbot and Eulgyu Kim reported crashes in mptcp_pm_nl_get_local_id()
and/or mptcp_pm_nl_is_backup()
Root cause is list_splice_init() in mptcp_pm_nl_flush_addrs_doit()
which is not RCU ready.
list_splice_init_rcu() can not be called here while holding pernet->lock
spinlock.
Many thanks to Eulgyu Kim for providing a repro and testing our patches. |
| Object lifecycle issue in PowerVR in Google Chrome on Android prior to 145.0.7632.159 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. (Chromium security severity: Critical) |
| Heap buffer overflow in WebML in Google Chrome prior to 146.0.7680.71 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. (Chromium security severity: Critical) |
| Out of bounds read in Web Speech in Google Chrome prior to 146.0.7680.71 allowed a remote attacker to potentially perform a sandbox escape via a crafted HTML page. (Chromium security severity: High) |
| Use after free in Agents in Google Chrome prior to 146.0.7680.71 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. (Chromium security severity: High) |
| Use after free in Extensions in Google Chrome prior to 146.0.7680.71 allowed an attacker who convinced a user to install a malicious extension to potentially exploit heap corruption via a crafted HTML page. (Chromium security severity: High) |
| Out of bounds memory access in WebML in Google Chrome prior to 146.0.7680.71 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. (Chromium security severity: High) |
| Use after free in TextEncoding in Google Chrome prior to 146.0.7680.71 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. (Chromium security severity: High) |
| Use after free in MediaStream in Google Chrome prior to 146.0.7680.71 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. (Chromium security severity: High) |
| Use after free in WebMIDI in Google Chrome prior to 146.0.7680.71 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. (Chromium security severity: High) |
| Out of bounds read in V8 in Google Chrome prior to 146.0.7680.71 allowed a remote attacker to perform out of bounds memory access via a crafted HTML page. (Chromium security severity: Medium) |
| Side-channel information leakage in ResourceTiming in Google Chrome prior to 146.0.7680.71 allowed a remote attacker to leak cross-origin data via a crafted HTML page. (Chromium security severity: Medium) |
| Unsafe navigation in Navigation in Google Chrome on iOS prior to 146.0.7680.71 allowed a remote attacker to bypass navigation restrictions via a crafted HTML page. (Chromium security severity: Medium) |
| Insufficient policy enforcement in ChromeDriver in Google Chrome prior to 146.0.7680.71 allowed a remote attacker to bypass same origin policy via a crafted HTML page. (Chromium security severity: Medium) |
| Incorrect security UI in WebAppInstalls in Google Chrome prior to 146.0.7680.71 allowed a remote attacker to perform UI spoofing via a crafted HTML page. (Chromium security severity: Medium) |
| Insufficient policy enforcement in Clipboard in Google Chrome prior to 146.0.7680.71 allowed a remote attacker who had compromised the renderer process to leak cross-origin data via a crafted HTML page. (Chromium security severity: Low) |
| Insufficient policy enforcement in PDF in Google Chrome prior to 146.0.7680.71 allowed a remote attacker to bypass navigation restrictions via a crafted PDF file. (Chromium security severity: Low) |
| Incorrect security UI in PictureInPicture in Google Chrome prior to 146.0.7680.71 allowed a remote attacker to perform UI spoofing via a crafted HTML page. (Chromium security severity: Low) |
