UBUNTU-CVE-2024-26718
In the Linux kernel, the following vulnerability has been resolved: dm-crypt, dm-verity: disable tasklets Tasklets have an inherent problem with memory corruption. The function tasklet_action_common calls tasklet_trylock, then it calls the tasklet callback and then it calls tasklet_unlock. If the tasklet callback frees the structure that contains the tasklet or if it calls some code that may free it, tasklet_unlock will write into free memory. The commits 8e14f610159d and d9a02e016aaf try to fix it for dm-crypt, but it is not a sufficient fix and the data corruption can still happen [1]. There is no fix for dm-verity and dm-verity will write into free memory with every tasklet-processed bio. There will be atomic workqueues implemented in the kernel 6.9 [2]. They will have better interface and they will not suffer from the memory corruption problem. But we need something that stops the memory corruption now and that can be backported to the stable kernels. So, I'm proposing this commit that disables tasklets in both dm-crypt and dm-verity. This commit doesn't remove the tasklet support, because the tasklet code will be reused when atomic workqueues will be implemented. [1] https://lore.kernel.org/all/[email protected]/T/ [2] https://lore.kernel.org/lkml/[email protected]/
02 / AFFECTED SOFTWARE
Affected packages
9 explicit affected versions
41 explicit affected versions
57 explicit affected versions
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6 explicit affected versions
12 explicit affected versions
18 explicit affected versions
6 explicit affected versions
67 explicit affected versions
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18 explicit affected versions
18 explicit affected versions
41 explicit affected versions
13 explicit affected versions
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10 explicit affected versions
7 explicit affected versions
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50 explicit affected versions
12 explicit affected versions
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7 explicit affected versions
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37 explicit affected versions
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34 explicit affected versions
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13 explicit affected versions
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33 explicit affected versions
23 explicit affected versions
10 explicit affected versions
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50 explicit affected versions
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10 explicit affected versions
26 explicit affected versions
1 explicit affected versions
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63 explicit affected versions
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51 explicit affected versions
1 explicit affected versions
12 explicit affected versions
47 explicit affected versions
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34 explicit affected versions
8 explicit affected versions
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5 explicit affected versions
8 explicit affected versions
10 explicit affected versions
11 explicit affected versions
13 explicit affected versions
7 explicit affected versions
52 explicit affected versions
10 explicit affected versions
12 explicit affected versions
15 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
12 explicit affected versions
38 explicit affected versions
52 explicit affected versions
9 explicit affected versions
51 explicit affected versions
11 explicit affected versions
60 explicit affected versions
8 explicit affected versions
7 explicit affected versions
33 explicit affected versions
4 explicit affected versions
1 explicit affected versions
1 explicit affected versions
58 explicit affected versions
11 explicit affected versions
43 explicit affected versions
10 explicit affected versions
8 explicit affected versions
14 explicit affected versions
4 explicit affected versions
9 explicit affected versions
1 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: dm-crypt, dm-verity: disable tasklets Tasklets have an inherent problem with memory corruption. The function tasklet_action_common calls tasklet_trylock, then it calls the tasklet callback and then it calls tasklet_unlock. If the tasklet callback frees the structure that contains the tasklet or if it calls some code that may free it, tasklet_unlock will write into free memory. The commits 8e14f610159d and d9a02e016aaf try to fix it for dm-crypt, but it is not a sufficient fix and the data corruption can still happen [1]. There is no fix for dm-verity and dm-verity will write into free memory with every tasklet-processed bio. There will be atomic workqueues implemented in the kernel 6.9 [2]. They will have better interface and they will not suffer from the memory corruption problem. But we need something that stops the memory corruption now and that can be backported to the stable kernels. So, I'm proposing this commit that disables tasklets in both dm-crypt and dm-verity. This commit doesn't remove the tasklet support, because the tasklet code will be reused when atomic workqueues will be implemented. [1] https://lore.kernel.org/all/[email protected]/T/ [2] https://lore.kernel.org/lkml/[email protected]/
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/0a9bab391e336489169b95cb0d4553d921302189
- https://git.kernel.org/stable/c/0a9bab391e336489169b95cb0d4553d921302189
- https://git.kernel.org/stable/c/0c45a20cbe68bc4d681734f5c03891124a274257
- https://git.kernel.org/stable/c/30884a44e0cedc3dfda8c22432f3ba4078ec2d94
- https://git.kernel.org/stable/c/5735a2671ffb70ea29ca83969fe01316ee2ed6fc
- https://ubuntu.com/security/CVE-2024-26718
- https://ubuntu.com/security/notices/USN-6895-1
- https://ubuntu.com/security/notices/USN-6895-2
- https://ubuntu.com/security/notices/USN-6895-3
- https://ubuntu.com/security/notices/USN-6895-4
- https://ubuntu.com/security/notices/USN-6900-1
- https://ubuntu.com/security/notices/USN-7288-1
- https://ubuntu.com/security/notices/USN-7288-2
- https://ubuntu.com/security/notices/USN-7289-1
- https://ubuntu.com/security/notices/USN-7289-2
- https://ubuntu.com/security/notices/USN-7289-3
- https://ubuntu.com/security/notices/USN-7289-4
- https://ubuntu.com/security/notices/USN-7291-1
- https://ubuntu.com/security/notices/USN-7305-1
- https://ubuntu.com/security/notices/USN-7308-1
- https://ubuntu.com/security/notices/USN-7331-1
- https://ubuntu.com/security/notices/USN-7388-1
- https://ubuntu.com/security/notices/USN-7389-1
- https://ubuntu.com/security/notices/USN-7390-1
- https://ubuntu.com/security/notices/USN-7458-1
- https://www.cve.org/CVERecord?id=CVE-2024-26718