5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sidraya Jayagond [ Upstream commit 61cb282fe97b3b0ba32ca09417a693162bf4ae3f ] smcr_port_err() traverses smc_lgr_list.list without holding smc_lgr_list.lock, allowing a concurrent smc_lgr_terminate_sched() to free an lgr while it is still being dereferenced. Hold smc_lgr_list.lock across the traversal. Update smc_ib_gid_check() to call smcr_port_err() after releasing the lock. Fixes: 541afa10c126 ("net/smc: add smcr_port_err() and smcr_link_down() processing") Reviewed-by: Mahanta Jambigi Signed-off-by: Sidraya Jayagond Reviewed-by: Dust Li Link: https://patch.msgid.link/20260922073149.474762-1-sidraya@linux.ibm.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/smc/smc_core.c | 2 ++ net/smc/smc_ib.c | 10 ++++++++-- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index 311b54519f5bf..6da7d2145a6d2 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -1566,6 +1566,7 @@ void smcr_port_err(struct smc_ib_device *smcibdev, u8 ibport) struct smc_link_group *lgr, *n; int i; + spin_lock_bh(&smc_lgr_list.lock); list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) { if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id, SMC_MAX_PNETID_LEN)) @@ -1580,6 +1581,7 @@ void smcr_port_err(struct smc_ib_device *smcibdev, u8 ibport) smcr_link_down_cond_sched(lnk); } } + spin_unlock_bh(&smc_lgr_list.lock); } static void smc_link_down_work(struct work_struct *work) diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c index 04a8612529b36..612a698ebb776 100644 --- a/net/smc/smc_ib.c +++ b/net/smc/smc_ib.c @@ -247,6 +247,7 @@ static bool smc_ib_check_link_gid(u8 gid[SMC_GID_SIZE], bool smcrv2, static void smc_ib_gid_check(struct smc_ib_device *smcibdev, u8 ibport) { struct smc_link_group *lgr; + bool stale_gid = false; int i; spin_lock_bh(&smc_lgr_list.lock); @@ -262,11 +263,16 @@ static void smc_ib_gid_check(struct smc_ib_device *smcibdev, u8 ibport) continue; if (!smc_ib_check_link_gid(lgr->lnk[i].gid, lgr->smc_version == SMC_V2, - smcibdev, ibport)) - smcr_port_err(smcibdev, ibport); + smcibdev, ibport)) { + stale_gid = true; + goto out; + } } } +out: spin_unlock_bh(&smc_lgr_list.lock); + if (stale_gid) + smcr_port_err(smcibdev, ibport); } static int smc_ib_remember_port_attr(struct smc_ib_device *smcibdev, u8 ibport) -- 2.53.0