UBUNTU-CVE-2024-56638
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_inner: incorrect percpu area handling under softirq Softirq can interrupt ongoing packet from process context that is walking over the percpu area that contains inner header offsets. Disable bh and perform three checks before restoring the percpu inner header offsets to validate that the percpu area is valid for this skbuff: 1) If the NFT_PKTINFO_INNER_FULL flag is set on, then this skbuff has already been parsed before for inner header fetching to register. 2) Validate that the percpu area refers to this skbuff using the skbuff pointer as a cookie. If there is a cookie mismatch, then this skbuff needs to be parsed again. 3) Finally, validate if the percpu area refers to this tunnel type. Only after these three checks the percpu area is restored to a on-stack copy and bh is enabled again. After inner header fetching, the on-stack copy is stored back to the percpu area.
02 / AFFECTED SOFTWARE
Affected packages
16 explicit affected versions
2 explicit affected versions
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29 explicit affected versions
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15 explicit affected versions
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2 explicit affected versions
18 explicit affected versions
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10 explicit affected versions
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17 explicit affected versions
11 explicit affected versions
78 explicit affected versions
45 explicit affected versions
37 explicit affected versions
8 explicit affected versions
4 explicit affected versions
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10 explicit affected versions
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33 explicit affected versions
16 explicit affected versions
13 explicit affected versions
2 explicit affected versions
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38 explicit affected versions
1 explicit affected versions
51 explicit affected versions
13 explicit affected versions
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10 explicit affected versions
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1 explicit affected versions
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10 explicit affected versions
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14 explicit affected versions
20 explicit affected versions
12 explicit affected versions
26 explicit affected versions
1 explicit affected versions
16 explicit affected versions
23 explicit affected versions
13 explicit affected versions
14 explicit affected versions
5 explicit affected versions
3 explicit affected versions
23 explicit affected versions
26 explicit affected versions
21 explicit affected versions
12 explicit affected versions
44 explicit affected versions
21 explicit affected versions
4 explicit affected versions
4 explicit affected versions
22 explicit affected versions
16 explicit affected versions
9 explicit affected versions
12 explicit affected versions
7 explicit affected versions
19 explicit affected versions
13 explicit affected versions
26 explicit affected versions
21 explicit affected versions
8 explicit affected versions
7 explicit affected versions
13 explicit affected versions
7 explicit affected versions
10 explicit affected versions
14 explicit affected versions
25 explicit affected versions
12 explicit affected versions
18 explicit affected versions
24 explicit affected versions
3 explicit affected versions
16 explicit affected versions
19 explicit affected versions
43 explicit affected versions
11 explicit affected versions
35 explicit affected versions
12 explicit affected versions
13 explicit affected versions
6 explicit affected versions
12 explicit affected versions
1 explicit affected versions
50 explicit affected versions
11 explicit affected versions
12 explicit affected versions
15 explicit affected versions
27 explicit affected versions
12 explicit affected versions
7 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_inner: incorrect percpu area handling under softirq Softirq can interrupt ongoing packet from process context that is walking over the percpu area that contains inner header offsets. Disable bh and perform three checks before restoring the percpu inner header offsets to validate that the percpu area is valid for this skbuff: 1) If the NFT_PKTINFO_INNER_FULL flag is set on, then this skbuff has already been parsed before for inner header fetching to register. 2) Validate that the percpu area refers to this skbuff using the skbuff pointer as a cookie. If there is a cookie mismatch, then this skbuff needs to be parsed again. 3) Finally, validate if the percpu area refers to this tunnel type. Only after these three checks the percpu area is restored to a on-stack copy and bh is enabled again. After inner header fetching, the on-stack copy is stored back to the percpu area.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/7b1d83da254be3bf054965c8f3b1ad976f460ae5
- https://git.kernel.org/stable/c/53c7314208c865086d78b4e88da53bc33da0b603
- https://git.kernel.org/stable/c/7b1d83da254be3bf054965c8f3b1ad976f460ae5
- https://git.kernel.org/stable/c/da5cc778e7bf78fe525bc90ec2043f41415c31d9
- https://ubuntu.com/security/CVE-2024-56638
- https://ubuntu.com/security/notices/USN-7379-1
- https://ubuntu.com/security/notices/USN-7379-2
- https://ubuntu.com/security/notices/USN-7380-1
- https://ubuntu.com/security/notices/USN-7381-1
- https://ubuntu.com/security/notices/USN-7382-1
- https://ubuntu.com/security/notices/USN-7449-1
- https://ubuntu.com/security/notices/USN-7449-2
- https://ubuntu.com/security/notices/USN-7450-1
- https://ubuntu.com/security/notices/USN-7451-1
- https://ubuntu.com/security/notices/USN-7452-1
- https://ubuntu.com/security/notices/USN-7453-1
- https://ubuntu.com/security/notices/USN-7468-1
- https://ubuntu.com/security/notices/USN-7523-1
- https://ubuntu.com/security/notices/USN-7524-1
- https://www.cve.org/CVERecord?id=CVE-2024-56638