UBUNTU-CVE-2026-46314
In the Linux kernel, the following vulnerability has been resolved: drm/v3d: Reject empty multisync extension to prevent infinite loop v3d_get_extensions() walks a userspace-provided singly-linked list of ioctl extensions without any bound on the chain length. A local user can craft a self-referential extension (ext->next == &ext) with zero in_sync_count and out_sync_count, which bypasses the existing duplicate- extension guard: if (se->in_sync_count || se->out_sync_count) return -EINVAL; The guard never fires because v3d_get_multisync_post_deps() returns immediately when count is zero, leaving both fields at zero on every iteration. The result is an infinite loop in kernel context, blocking the calling thread and pegging a CPU core indefinitely. Fix this by rejecting a multisync extension where both in_sync_count and out_sync_count are zero in v3d_get_multisync_submit_deps(). An empty multisync carries no synchronization information and serves no useful purpose, so returning -EINVAL for such an extension is the correct defense against this attack vector.
02 / AFFECTED SOFTWARE
Affected packages
11 explicit affected versions
4 explicit affected versions
50 explicit affected versions
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10 explicit affected versions
37 explicit affected versions
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35 explicit affected versions
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41 explicit affected versions
9 explicit affected versions
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16 explicit affected versions
6 explicit affected versions
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10 explicit affected versions
11 explicit affected versions
13 explicit affected versions
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3 explicit affected versions
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11 explicit affected versions
26 explicit affected versions
10 explicit affected versions
13 explicit affected versions
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13 explicit affected versions
12 explicit affected versions
41 explicit affected versions
40 explicit affected versions
8 explicit affected versions
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17 explicit affected versions
5 explicit affected versions
10 explicit affected versions
26 explicit affected versions
39 explicit affected versions
35 explicit affected versions
48 explicit affected versions
11 explicit affected versions
10 explicit affected versions
13 explicit affected versions
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16 explicit affected versions
50 explicit affected versions
10 explicit affected versions
3 explicit affected versions
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16 explicit affected versions
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43 explicit affected versions
12 explicit affected versions
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3 explicit affected versions
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43 explicit affected versions
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7 explicit affected versions
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10 explicit affected versions
12 explicit affected versions
9 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
26 explicit affected versions
45 explicit affected versions
37 explicit affected versions
50 explicit affected versions
14 explicit affected versions
38 explicit affected versions
9 explicit affected versions
17 explicit affected versions
11 explicit affected versions
39 explicit affected versions
18 explicit affected versions
14 explicit affected versions
6 explicit affected versions
7 explicit affected versions
4 explicit affected versions
10 explicit affected versions
1 explicit affected versions
7 explicit affected versions
13 explicit affected versions
43 explicit affected versions
16 explicit affected versions
10 explicit affected versions
8 explicit affected versions
45 explicit affected versions
14 explicit affected versions
4 explicit affected versions
78 explicit affected versions
14 explicit affected versions
11 explicit affected versions
1 explicit affected versions
19 explicit affected versions
6 explicit affected versions
39 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: drm/v3d: Reject empty multisync extension to prevent infinite loop v3d_get_extensions() walks a userspace-provided singly-linked list of ioctl extensions without any bound on the chain length. A local user can craft a self-referential extension (ext->next == &ext) with zero in_sync_count and out_sync_count, which bypasses the existing duplicate- extension guard: if (se->in_sync_count || se->out_sync_count) return -EINVAL; The guard never fires because v3d_get_multisync_post_deps() returns immediately when count is zero, leaving both fields at zero on every iteration. The result is an infinite loop in kernel context, blocking the calling thread and pegging a CPU core indefinitely. Fix this by rejecting a multisync extension where both in_sync_count and out_sync_count are zero in v3d_get_multisync_submit_deps(). An empty multisync carries no synchronization information and serves no useful purpose, so returning -EINVAL for such an extension is the correct defense against this attack vector.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/fb44d589bf3148e13452185a6e772a7efbf2d684
- https://git.kernel.org/stable/c/4fa42a249e8cd6ed17aea04e5695b6e9001f2433
- https://git.kernel.org/stable/c/9c5164781cb388d219d8f49fa0f0b04cf86ad544
- https://git.kernel.org/stable/c/fb44d589bf3148e13452185a6e772a7efbf2d684
- https://ubuntu.com/security/CVE-2026-46314
- https://ubuntu.com/security/notices/USN-8566-1
- https://ubuntu.com/security/notices/USN-8567-1
- https://ubuntu.com/security/notices/USN-8568-1
- https://ubuntu.com/security/notices/USN-8569-1
- https://ubuntu.com/security/notices/USN-8574-1
- https://ubuntu.com/security/notices/USN-8574-2
- https://ubuntu.com/security/notices/USN-8574-3
- https://ubuntu.com/security/notices/USN-8593-1
- https://ubuntu.com/security/notices/USN-8595-1
- https://ubuntu.com/security/notices/USN-8595-2
- https://ubuntu.com/security/notices/USN-8595-3
- https://ubuntu.com/security/notices/USN-8596-1
- https://ubuntu.com/security/notices/USN-8603-1
- https://ubuntu.com/security/notices/USN-8606-1
- https://ubuntu.com/security/notices/USN-8607-1
- https://ubuntu.com/security/notices/USN-8608-1
- https://ubuntu.com/security/notices/USN-8609-1
- https://ubuntu.com/security/notices/USN-8618-1
- https://ubuntu.com/security/notices/USN-8619-1
- https://www.cve.org/CVERecord?id=CVE-2026-46314