UBUNTU-CVE-2024-56549
In the Linux kernel, the following vulnerability has been resolved: cachefiles: Fix NULL pointer dereference in object->file At present, the object->file has the NULL pointer dereference problem in ondemand-mode. The root cause is that the allocated fd and object->file lifetime are inconsistent, and the user-space invocation to anon_fd uses object->file. Following is the process that triggers the issue: [write fd] [umount] cachefiles_ondemand_fd_write_iter fscache_cookie_state_machine cachefiles_withdraw_cookie if (!file) return -ENOBUFS cachefiles_clean_up_object cachefiles_unmark_inode_in_use fput(object->file) object->file = NULL // file NULL pointer dereference! __cachefiles_write(..., file, ...) Fix this issue by add an additional reference count to the object->file before write/llseek, and decrement after it finished.
02 / AFFECTED SOFTWARE
Affected packages
11 explicit affected versions
50 explicit affected versions
6 explicit affected versions
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19 explicit affected versions
6 explicit affected versions
21 explicit affected versions
10 explicit affected versions
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19 explicit affected versions
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35 explicit affected versions
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21 explicit affected versions
13 explicit affected versions
4 explicit affected versions
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26 explicit affected versions
1 explicit affected versions
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10 explicit affected versions
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1 explicit affected versions
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13 explicit affected versions
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10 explicit affected versions
37 explicit affected versions
1 explicit affected versions
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14 explicit affected versions
10 explicit affected versions
26 explicit affected versions
13 explicit affected versions
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13 explicit affected versions
15 explicit affected versions
16 explicit affected versions
33 explicit affected versions
23 explicit affected versions
10 explicit affected versions
1 explicit affected versions
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12 explicit affected versions
10 explicit affected versions
26 explicit affected versions
20 explicit affected versions
11 explicit affected versions
23 explicit affected versions
13 explicit affected versions
21 explicit affected versions
16 explicit affected versions
24 explicit affected versions
3 explicit affected versions
1 explicit affected versions
51 explicit affected versions
7 explicit affected versions
20 explicit affected versions
12 explicit affected versions
27 explicit affected versions
17 explicit affected versions
8 explicit affected versions
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8 explicit affected versions
10 explicit affected versions
20 explicit affected versions
13 explicit affected versions
13 explicit affected versions
7 explicit affected versions
2 explicit affected versions
10 explicit affected versions
12 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
25 explicit affected versions
14 explicit affected versions
38 explicit affected versions
9 explicit affected versions
11 explicit affected versions
15 explicit affected versions
7 explicit affected versions
7 explicit affected versions
4 explicit affected versions
1 explicit affected versions
13 explicit affected versions
43 explicit affected versions
10 explicit affected versions
8 explicit affected versions
19 explicit affected versions
14 explicit affected versions
4 explicit affected versions
78 explicit affected versions
11 explicit affected versions
1 explicit affected versions
14 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: cachefiles: Fix NULL pointer dereference in object->file At present, the object->file has the NULL pointer dereference problem in ondemand-mode. The root cause is that the allocated fd and object->file lifetime are inconsistent, and the user-space invocation to anon_fd uses object->file. Following is the process that triggers the issue: [write fd] [umount] cachefiles_ondemand_fd_write_iter fscache_cookie_state_machine cachefiles_withdraw_cookie if (!file) return -ENOBUFS cachefiles_clean_up_object cachefiles_unmark_inode_in_use fput(object->file) object->file = NULL // file NULL pointer dereference! __cachefiles_write(..., file, ...) Fix this issue by add an additional reference count to the object->file before write/llseek, and decrement after it finished.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/31ad74b20227ce6b40910ff78b1c604e42975cf1
- https://git.kernel.org/stable/c/31ad74b20227ce6b40910ff78b1c604e42975cf1
- https://git.kernel.org/stable/c/9582c7664103c9043e80a78f5c382aa6bdd67418
- https://git.kernel.org/stable/c/f98770440c9bc468e2fd878212ec9526dbe08293
- https://ubuntu.com/security/CVE-2024-56549
- https://ubuntu.com/security/notices/USN-7276-1
- https://ubuntu.com/security/notices/USN-7277-1
- https://ubuntu.com/security/notices/USN-7310-1
- 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-2024-56549