From 789b6cc2a5f9123b9c549b886fdc47c865cfe0ba Mon Sep 17 00:00:00 2001 From: Dust Li Date: Wed, 1 Dec 2021 11:02:30 +0800 Subject: net/smc: fix wrong list_del in smc_lgr_cleanup_early MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit smc_lgr_cleanup_early() meant to delete the link group from the link group list, but it deleted the list head by mistake. This may cause memory corruption since we didn't remove the real link group from the list and later memseted the link group structure. We got a list corruption panic when testing: [  231.277259] list_del corruption. prev->next should be ffff8881398a8000, but was 0000000000000000 [  231.278222] ------------[ cut here ]------------ [  231.278726] kernel BUG at lib/list_debug.c:53! [  231.279326] invalid opcode: 0000 [#1] SMP NOPTI [  231.279803] CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.10.46+ #435 [  231.280466] Hardware name: Alibaba Cloud ECS, BIOS 8c24b4c 04/01/2014 [  231.281248] Workqueue: events smc_link_down_work [  231.281732] RIP: 0010:__list_del_entry_valid+0x70/0x90 [  231.282258] Code: 4c 60 82 e8 7d cc 6a 00 0f 0b 48 89 fe 48 c7 c7 88 4c 60 82 e8 6c cc 6a 00 0f 0b 48 89 fe 48 c7 c7 c0 4c 60 82 e8 5b cc 6a 00 <0f> 0b 48 89 fe 48 c7 c7 00 4d 60 82 e8 4a cc 6a 00 0f 0b cc cc cc [  231.284146] RSP: 0018:ffffc90000033d58 EFLAGS: 00010292 [  231.284685] RAX: 0000000000000054 RBX: ffff8881398a8000 RCX: 0000000000000000 [  231.285415] RDX: 0000000000000001 RSI: ffff88813bc18040 RDI: ffff88813bc18040 [  231.286141] RBP: ffffffff8305ad40 R08: 0000000000000003 R09: 0000000000000001 [  231.286873] R10: ffffffff82803da0 R11: ffffc90000033b90 R12: 0000000000000001 [  231.287606] R13: 0000000000000000 R14: ffff8881398a8000 R15: 0000000000000003 [  231.288337] FS:  0000000000000000(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000 [  231.289160] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [  231.289754] CR2: 0000000000e72058 CR3: 000000010fa96006 CR4: 00000000003706f0 [  231.290485] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [  231.291211] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [  231.291940] Call Trace: [  231.292211]  smc_lgr_terminate_sched+0x53/0xa0 [  231.292677]  smc_switch_conns+0x75/0x6b0 [  231.293085]  ? update_load_avg+0x1a6/0x590 [  231.293517]  ? ttwu_do_wakeup+0x17/0x150 [  231.293907]  ? update_load_avg+0x1a6/0x590 [  231.294317]  ? newidle_balance+0xca/0x3d0 [  231.294716]  smcr_link_down+0x50/0x1a0 [  231.295090]  ? __wake_up_common_lock+0x77/0x90 [  231.295534]  smc_link_down_work+0x46/0x60 [  231.295933]  process_one_work+0x18b/0x350 Fixes: a0a62ee15a829 ("net/smc: separate locks for SMCD and SMCR link group lists") Signed-off-by: Dust Li Acked-by: Karsten Graul Reviewed-by: Tony Lu Signed-off-by: David S. Miller --- net/smc/smc_core.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'net/smc') diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index bb52c8b5f148..387d28b2f8dd 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -625,18 +625,17 @@ int smcd_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb) void smc_lgr_cleanup_early(struct smc_connection *conn) { struct smc_link_group *lgr = conn->lgr; - struct list_head *lgr_list; spinlock_t *lgr_lock; if (!lgr) return; smc_conn_free(conn); - lgr_list = smc_lgr_list_head(lgr, &lgr_lock); + smc_lgr_list_head(lgr, &lgr_lock); spin_lock_bh(lgr_lock); /* do not use this link group for new connections */ - if (!list_empty(lgr_list)) - list_del_init(lgr_list); + if (!list_empty(&lgr->list)) + list_del_init(&lgr->list); spin_unlock_bh(lgr_lock); __smc_lgr_terminate(lgr, true); } -- cgit v1.2.3 From 00e158fb91dfaff3f94746f260d11f1a4853506e Mon Sep 17 00:00:00 2001 From: Tony Lu Date: Wed, 1 Dec 2021 14:42:16 +0800 Subject: net/smc: Keep smc_close_final rc during active close When smc_close_final() returns error, the return code overwrites by kernel_sock_shutdown() in smc_close_active(). The return code of smc_close_final() is more important than kernel_sock_shutdown(), and it will pass to userspace directly. Fix it by keeping both return codes, if smc_close_final() raises an error, return it or kernel_sock_shutdown()'s. Link: https://lore.kernel.org/linux-s390/1f67548e-cbf6-0dce-82b5-10288a4583bd@linux.ibm.com/ Fixes: 606a63c9783a ("net/smc: Ensure the active closing peer first closes clcsock") Suggested-by: Karsten Graul Signed-off-by: Tony Lu Reviewed-by: Wen Gu Acked-by: Karsten Graul Signed-off-by: David S. Miller --- net/smc/smc_close.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'net/smc') diff --git a/net/smc/smc_close.c b/net/smc/smc_close.c index 3715d2f5ad55..292e4d904ab6 100644 --- a/net/smc/smc_close.c +++ b/net/smc/smc_close.c @@ -195,6 +195,7 @@ int smc_close_active(struct smc_sock *smc) int old_state; long timeout; int rc = 0; + int rc1 = 0; timeout = current->flags & PF_EXITING ? 0 : sock_flag(sk, SOCK_LINGER) ? @@ -232,8 +233,11 @@ again: /* actively shutdown clcsock before peer close it, * prevent peer from entering TIME_WAIT state. */ - if (smc->clcsock && smc->clcsock->sk) - rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR); + if (smc->clcsock && smc->clcsock->sk) { + rc1 = kernel_sock_shutdown(smc->clcsock, + SHUT_RDWR); + rc = rc ? rc : rc1; + } } else { /* peer event has changed the state */ goto again; -- cgit v1.2.3