net/smc: fix use-after-free in smc_rx_pipe_buf_release()
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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 6.1.188, 6.6.157, 6.12.109, 6.18.50, 7.2.4
- 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
- Exploitation: none
- Automatable: no
- Technical impact: total
Summary
In the Linux kernel, the following vulnerability has been resolved: net/smc: fix use-after-free in smc_rx_pipe_buf_release() smc_rx_splice() hands RMB pages to a pipe and takes a socket reference per entry so the smc_sock stays alive until the reader finishes. The connection does not: a concurrent close runs smc_conn_free(), which releases the receive buffer back to the link group pool. smc_rx_pipe_buf_release() tests sk_state before taking the socket lock. The state can change between the test and the lock, and smc_rx_update_cons() then dereferences conn->rmb_desc and walks conn->lgr, which smc_conn_free() has already released. On the is_reg_err path smcr_buf_unuse() frees the descriptor outright, so this is a use-after-free. Take the socket lock first and test conn->freed instead. smc_conn_free() sets that flag before releasing anything, and every caller holds the socket lock. The two paths exclude each other: either the pipe release runs first with everything valid, or it sees the flag and skips the update.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- Linux Linux
From 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f · fixed in dadd97c8296b23aa816e91ed70041820ae087baa; From 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f · fixed in df441f3efbb50eb0f120b8de4bf441c31fb0551d; From 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f · fixed in 6a644a7340df978785f3109d1e0726a982ce2c6f; From 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f · fixed in 0761e49aa78c2f1362511054c6e9670653858837; From 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f · fixed in 0926f59ca0f94120895b92180c636a48d0ed3a6d; From 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f · fixed in c924884743e948e25625b7fbf3ee2a9325a204a7
- Linux Linux
4.18
- KernelLinux
From 4.18.0 · fixed in 6.1.188; From 6.2.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.109; From 6.13.0 · fixed in 6.18.50; From 6.19.0 · fixed in 7.2.4