Description
In the Linux kernel, the following vulnerability has been resolved: net/smc: fix socket refcount leak in smc_switch_conns() smc_switch_conns() takes a reference on the SMC socket before dropping lgr->conns_lock, so the connection stays alive while the CDC slot is fetched: sock_hold(&smc->sk); read_unlock_bh(&lgr->conns_lock); /* pre-fetch buffer outside of send_lock, might sleep */ rc = smc_cdc_get_free_slot(conn, to_lnk, &wr_buf, NULL, &pend); if (rc) goto err_out; The err_out label only drops the wr_tx link reference, so this early exit returns without the matching sock_put(). The second error exit is not affected, because sock_put() has already run by then. A leaked sk_refcnt means the smc_sock is never destroyed. Its send and receive buffers stay allocated, and for a user socket the reference held on the network namespace is never released, so the netns can no longer be torn down. smc_cdc_get_free_slot() fails when the target link goes down or when the connection has been killed while the switch is in progress. Both are reachable during the link failover this function implements, so the leak is triggered by the same hardware events that make smc_switch_conns() run in the first place. Restructure so there is a single sock_put() covering both outcomes, instead of adding a second one to the error path.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
99f19566b1c4d3dc4d934ee2ef43faadebb56d70 to < 8cb289eb764ff18000a33ddbc287d676d8597eeaaffected95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a to < a3378466704e0bbe93aef9769552dca7673a7eb6affected95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a to < e20227019d9da73f8fdf16f0951c2e188c84933faffected95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a to < 09d7a9e162ee1a269878c126aee3d7eff43e4130affected95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a to < 84dea0585f6b538ae895a8b1d025f4897737f3b1affected95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a to < d89dc1bd8845c669a700eee58c64ebd3cc1b6d2daffected95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a to < d9a879ac25958bdaecb669ce70e58f8e2ff170deaffected95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a to < 719296c4aa8213d4ac8002e77d5956d436bc98d0affected0d9ddf515cde793841f738490037560fd6559c63affected5.10.90 to < 5.10.273affected5.14.14 to < 5.15affected
Linux Linux
Default version status: affected
5.15affected0 to < 5.15unaffected5.10.273 to ≤ 5.10.*unaffected5.15.221 to ≤ 5.15.*unaffected6.1.188 to ≤ 6.1.*unaffected6.6.157 to ≤ 6.6.*unaffected6.12.109 to ≤ 6.12.*unaffected6.18.50 to ≤ 6.18.*unaffected7.2.4 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/8cb289eb764ff18000a33ddbc287d676d8597eea ↗
- https://git.kernel.org/stable/c/a3378466704e0bbe93aef9769552dca7673a7eb6 ↗
- https://git.kernel.org/stable/c/e20227019d9da73f8fdf16f0951c2e188c84933f ↗
- https://git.kernel.org/stable/c/09d7a9e162ee1a269878c126aee3d7eff43e4130 ↗
- https://git.kernel.org/stable/c/84dea0585f6b538ae895a8b1d025f4897737f3b1 ↗
- https://git.kernel.org/stable/c/d89dc1bd8845c669a700eee58c64ebd3cc1b6d2d ↗
- https://git.kernel.org/stable/c/d9a879ac25958bdaecb669ce70e58f8e2ff170de ↗
- https://git.kernel.org/stable/c/719296c4aa8213d4ac8002e77d5956d436bc98d0 ↗