af_unix: Update last skb marker in manage_oob().
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.6.160, 5.16, 6.2, 6.9, 6.12.111, and 2 more
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
In the Linux kernel, the following vulnerability has been resolved: af_unix: Update last skb marker in manage_oob(). Fahad Alharbi reported that blocking recv(MSG_PEEK) could hog CPU due to OOB skb. In the following cases, manage_oob() skips OOB skb(s) and returns NULL for the last recv(MSG_PEEK): socketpair(AF_UNIX, SOCK_STREAM, 0, sk); 1) skb -> OOB skb -> NULL send(sk[0], "ab", 2, MSG_OOB); recv(sk[1], buf, 0, MSG_PEEK); 2) skb -> consumed OOB skb -> NULL send(sk[0], "ab", 2, MSG_OOB); recv(sk[1], buf, 1, MSG_OOB); recv(sk[1], buf, 0, MSG_PEEK); 3) consumed OOB skb -> OOB skb -> NULL send(sk[0], "a", 1, MSG_OOB); recv(sk[1], buf, 0, MSG_OOB); send(sk[0], "b", 1, MSG_OOB); recv(sk[1], buf, 1, MSG_PEEK); Then, @copied is 0 in unix_stream_read_generic() (zero-length buffer, or non-OOB skb is not yet consumed), and unix_stream_data_wait() is called. However, it returns immediately because @last is not updated in unix_stream_read_generic(), and the thread busy-waits for a new skb. Let's update @last in manage_oob(). For MSG_PEEK, @last is updated with the skipped OOB, and for the non-peek case, @last matches the returned value (when !copied) because OOB is unlinked. Note that manage_oob() is inlined and no stack canary is added.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From 022d81a709cd553bbe2db8675f8e824f4aee6284 · fixed in bd91dc313afe21e9d6b31ca6a47606a33ca5e35c; From 22dd70eb2c3d754862964377a75abafd3167346b · fixed in 0630bfc773d85ac44da05b2c5a037dbbd39301ab; From 22dd70eb2c3d754862964377a75abafd3167346b · fixed in f1816b3d7ce80dcf086bb68ff5ae6e09520ca1fa; From 22dd70eb2c3d754862964377a75abafd3167346b · fixed in fc62a26493a98a0424d9dae2eb92a1daa1321f65; From 22dd70eb2c3d754862964377a75abafd3167346b · fixed in 94fd4debd2e3a69cf93e766c8b328a810c228119; From 6.6.29 · fixed in 6.6.160; From 5.15.157 · fixed in 5.16; From 6.1.88 · fixed in 6.2; From 6.8.8 · fixed in 6.9
- Linux Linux
6.9
- KernelLinux
fixed in 6.6.160; From 6.7.0 · fixed in 6.12.111; From 6.9.0 · fixed in 6.18.53; From 6.13.0 · fixed in 7.2.7