From 594c11d0e1d445f580898a2b8c850f2e3f099368 Mon Sep 17 00:00:00 2001 From: Corey Minyard Date: Tue, 27 Jan 2026 07:22:35 -0600 Subject: [PATCH 1/9] ipmi: Fix use-after-free and list corruption on sender error The analysis from Breno: When the SMI sender returns an error, smi_work() delivers an error response but then jumps back to restart without cleaning up properly: 1. intf->curr_msg is not cleared, so no new message is pulled 2. newmsg still points to the message, causing sender() to be called again with the same message 3. If sender() fails again, deliver_err_response() is called with the same recv_msg that was already queued for delivery This causes list_add corruption ("list_add double add") because the recv_msg is added to the user_msgs list twice. Subsequently, the corrupted list leads to use-after-free when the memory is freed and reused, and eventually a NULL pointer dereference when accessing recv_msg->done. The buggy sequence: sender() fails -> deliver_err_response(recv_msg) // recv_msg queued for delivery -> goto restart // curr_msg not cleared! sender() fails again (same message!) -> deliver_err_response(recv_msg) // tries to queue same recv_msg -> LIST CORRUPTION Fix this by freeing the message and setting it to NULL on a send error. Also, always free the newmsg on a send error, otherwise it will leak. Reported-by: Breno Leitao Closes: https://lore.kernel.org/lkml/20260127-ipmi-v1-0-ba5cc90f516f@debian.org/ Fixes: 9cf93a8fa9513 ("ipmi: Allow an SMI sender to return an error") Cc: stable@vger.kernel.org # 4.18 Reviewed-by: Breno Leitao Signed-off-by: Corey Minyard --- drivers/char/ipmi/ipmi_msghandler.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index 3f48fc6ab596..a590a67294e2 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -4852,8 +4852,15 @@ static void smi_work(struct work_struct *t) if (newmsg->recv_msg) deliver_err_response(intf, newmsg->recv_msg, cc); - else - ipmi_free_smi_msg(newmsg); + if (!run_to_completion) + spin_lock_irqsave(&intf->xmit_msgs_lock, + flags); + intf->curr_msg = NULL; + if (!run_to_completion) + spin_unlock_irqrestore(&intf->xmit_msgs_lock, + flags); + ipmi_free_smi_msg(newmsg); + newmsg = NULL; goto restart; } } From 1d90e6c1a56f6ab83e5c9d30ded19e7ac8155713 Mon Sep 17 00:00:00 2001 From: Corey Minyard Date: Tue, 27 Jan 2026 07:35:02 -0600 Subject: [PATCH 2/9] ipmi: Consolidate the run to completion checking for xmit msgs lock It made things hard to read, move the check to a function. Signed-off-by: Corey Minyard Reviewed-by: Breno Leitao --- drivers/char/ipmi/ipmi_msghandler.c | 42 ++++++++++++++++------------- 1 file changed, 24 insertions(+), 18 deletions(-) diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index a590a67294e2..a042b1596933 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -602,6 +602,22 @@ static int __ipmi_bmc_register(struct ipmi_smi *intf, static int __scan_channels(struct ipmi_smi *intf, struct ipmi_device_id *id, bool rescan); +static void ipmi_lock_xmit_msgs(struct ipmi_smi *intf, int run_to_completion, + unsigned long *flags) +{ + if (run_to_completion) + return; + spin_lock_irqsave(&intf->xmit_msgs_lock, *flags); +} + +static void ipmi_unlock_xmit_msgs(struct ipmi_smi *intf, int run_to_completion, + unsigned long *flags) +{ + if (run_to_completion) + return; + spin_unlock_irqrestore(&intf->xmit_msgs_lock, *flags); +} + static void free_ipmi_user(struct kref *ref) { struct ipmi_user *user = container_of(ref, struct ipmi_user, refcount); @@ -1878,11 +1894,9 @@ static void smi_send(struct ipmi_smi *intf, int run_to_completion = READ_ONCE(intf->run_to_completion); unsigned long flags = 0; - if (!run_to_completion) - spin_lock_irqsave(&intf->xmit_msgs_lock, flags); + ipmi_lock_xmit_msgs(intf, run_to_completion, &flags); smi_msg = smi_add_send_msg(intf, smi_msg, priority); - if (!run_to_completion) - spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags); + ipmi_unlock_xmit_msgs(intf, run_to_completion, &flags); if (smi_msg) handlers->sender(intf->send_info, smi_msg); @@ -4826,8 +4840,7 @@ static void smi_work(struct work_struct *t) * message delivery. */ restart: - if (!run_to_completion) - spin_lock_irqsave(&intf->xmit_msgs_lock, flags); + ipmi_lock_xmit_msgs(intf, run_to_completion, &flags); if (intf->curr_msg == NULL && !intf->in_shutdown) { struct list_head *entry = NULL; @@ -4843,8 +4856,7 @@ static void smi_work(struct work_struct *t) intf->curr_msg = newmsg; } } - if (!run_to_completion) - spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags); + ipmi_unlock_xmit_msgs(intf, run_to_completion, &flags); if (newmsg) { cc = intf->handlers->sender(intf->send_info, newmsg); @@ -4852,13 +4864,9 @@ static void smi_work(struct work_struct *t) if (newmsg->recv_msg) deliver_err_response(intf, newmsg->recv_msg, cc); - if (!run_to_completion) - spin_lock_irqsave(&intf->xmit_msgs_lock, - flags); + ipmi_lock_xmit_msgs(intf, run_to_completion, &flags); intf->curr_msg = NULL; - if (!run_to_completion) - spin_unlock_irqrestore(&intf->xmit_msgs_lock, - flags); + ipmi_unlock_xmit_msgs(intf, run_to_completion, &flags); ipmi_free_smi_msg(newmsg); newmsg = NULL; goto restart; @@ -4928,16 +4936,14 @@ void ipmi_smi_msg_received(struct ipmi_smi *intf, spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock, flags); - if (!run_to_completion) - spin_lock_irqsave(&intf->xmit_msgs_lock, flags); + ipmi_lock_xmit_msgs(intf, run_to_completion, &flags); /* * We can get an asynchronous event or receive message in addition * to commands we send. */ if (msg == intf->curr_msg) intf->curr_msg = NULL; - if (!run_to_completion) - spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags); + ipmi_unlock_xmit_msgs(intf, run_to_completion, &flags); if (run_to_completion) smi_work(&intf->smi_work); From 9f235ccecd03c436cb1683eac16b12f119e54aa9 Mon Sep 17 00:00:00 2001 From: Matt Johnston Date: Tue, 13 Jan 2026 17:41:34 +0800 Subject: [PATCH 3/9] ipmi: ipmb: initialise event handler read bytes IPMB doesn't use i2c reads, but the handler needs to set a value. Otherwise an i2c read will return an uninitialised value from the bus driver. Fixes: 63c4eb347164 ("ipmi:ipmb: Add initial support for IPMI over IPMB") Signed-off-by: Matt Johnston Message-ID: <20260113-ipmb-read-init-v1-1-a9cbce7b94e3@codeconstruct.com.au> Signed-off-by: Corey Minyard --- drivers/char/ipmi/ipmi_ipmb.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/char/ipmi/ipmi_ipmb.c b/drivers/char/ipmi/ipmi_ipmb.c index 3a51e58b2487..28818952a7a4 100644 --- a/drivers/char/ipmi/ipmi_ipmb.c +++ b/drivers/char/ipmi/ipmi_ipmb.c @@ -202,11 +202,16 @@ static int ipmi_ipmb_slave_cb(struct i2c_client *client, break; case I2C_SLAVE_READ_REQUESTED: + *val = 0xff; + ipmi_ipmb_check_msg_done(iidev); + break; + case I2C_SLAVE_STOP: ipmi_ipmb_check_msg_done(iidev); break; case I2C_SLAVE_READ_PROCESSED: + *val = 0xff; break; } From 6b157b408d0c7d125e4d7c62e11e7d9376a5d150 Mon Sep 17 00:00:00 2001 From: Corey Minyard Date: Fri, 16 Jan 2026 17:22:01 -0600 Subject: [PATCH 4/9] ipmi:ls2k: Make ipmi_ls2k_platform_driver static No need for it to be global. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202601170753.3zDBerGP-lkp@intel.com/ Signed-off-by: Corey Minyard --- drivers/char/ipmi/ipmi_si_ls2k.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/ipmi/ipmi_si_ls2k.c b/drivers/char/ipmi/ipmi_si_ls2k.c index 45442c257efd..4c1da80f256c 100644 --- a/drivers/char/ipmi/ipmi_si_ls2k.c +++ b/drivers/char/ipmi/ipmi_si_ls2k.c @@ -168,7 +168,7 @@ static void ipmi_ls2k_remove(struct platform_device *pdev) ipmi_si_remove_by_dev(&pdev->dev); } -struct platform_driver ipmi_ls2k_platform_driver = { +static struct platform_driver ipmi_ls2k_platform_driver = { .driver = { .name = "ls2k-ipmi-si", }, From 52c9ee202edd21d0599ac3b5a6fe1da2a2f053e5 Mon Sep 17 00:00:00 2001 From: Corey Minyard Date: Fri, 6 Feb 2026 09:59:32 -0600 Subject: [PATCH 5/9] ipmi:si: Handle waiting messages when BMC failure detected If a BMC failure is detected, the current message is returned with an error. However, if there was a waiting message, it would not be handled. Add a check for the waiting message after handling the current message. Suggested-by: Guenter Roeck Reported-by: Rafael J. Wysocki Closes: https://lore.kernel.org/linux-acpi/CAK8fFZ58fidGUCHi5WFX0uoTPzveUUDzT=k=AAm4yWo3bAuCFg@mail.gmail.com/ Fixes: bc3a9d217755 ("ipmi:si: Gracefully handle if the BMC is non-functional") Cc: stable@vger.kernel.org # 4.18 Signed-off-by: Corey Minyard --- drivers/char/ipmi/ipmi_si_intf.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c index 5459ffdde8dc..ff159b1162b9 100644 --- a/drivers/char/ipmi/ipmi_si_intf.c +++ b/drivers/char/ipmi/ipmi_si_intf.c @@ -809,6 +809,12 @@ static enum si_sm_result smi_event_handler(struct smi_info *smi_info, */ return_hosed_msg(smi_info, IPMI_BUS_ERR); } + if (smi_info->waiting_msg != NULL) { + /* Also handle if there was a message waiting. */ + smi_info->curr_msg = smi_info->waiting_msg; + smi_info->waiting_msg = NULL; + return_hosed_msg(smi_info, IPMI_BUS_ERR); + } smi_mod_timer(smi_info, jiffies + SI_TIMEOUT_HOSED); goto out; } From c3bb3295637cc9bf514f690941ca9a385bf30113 Mon Sep 17 00:00:00 2001 From: Corey Minyard Date: Fri, 6 Feb 2026 10:33:52 -0600 Subject: [PATCH 6/9] ipmi:si: Use a long timeout when the BMC is misbehaving If the driver goes into HOSED state, don't reset the timeout to the short timeout in the timeout handler. Reported-by: Igor Raits Closes: https://lore.kernel.org/linux-acpi/CAK8fFZ58fidGUCHi5WFX0uoTPzveUUDzT=k=AAm4yWo3bAuCFg@mail.gmail.com/ Fixes: bc3a9d217755 ("ipmi:si: Gracefully handle if the BMC is non-functional") Cc: stable@vger.kernel.org # 4.18 Signed-off-by: Corey Minyard --- drivers/char/ipmi/ipmi_si_intf.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c index ff159b1162b9..0049e3792ba1 100644 --- a/drivers/char/ipmi/ipmi_si_intf.c +++ b/drivers/char/ipmi/ipmi_si_intf.c @@ -1119,7 +1119,9 @@ static void smi_timeout(struct timer_list *t) * SI_USEC_PER_JIFFY); smi_result = smi_event_handler(smi_info, time_diff); - if ((smi_info->io.irq) && (!smi_info->interrupt_disabled)) { + if (smi_info->si_state == SI_HOSED) { + timeout = jiffies + SI_TIMEOUT_HOSED; + } else if ((smi_info->io.irq) && (!smi_info->interrupt_disabled)) { /* Running with interrupts, only do long timeouts. */ timeout = jiffies + SI_TIMEOUT_JIFFIES; smi_inc_stat(smi_info, long_timeouts); From f895e5df80316a308c2f7d64d13a78494630ea05 Mon Sep 17 00:00:00 2001 From: Corey Minyard Date: Thu, 12 Feb 2026 21:52:48 -0600 Subject: [PATCH 7/9] ipmi:si: Don't block module unload if the BMC is messed up If the BMC is in a bad state, don't bother waiting for queues messages since there can't be any. Otherwise the unload is blocked until the BMC is back in a good state. Reported-by: Rafael J. Wysocki Fixes: bc3a9d217755 ("ipmi:si: Gracefully handle if the BMC is non-functional") Cc: stable@vger.kernel.org # 4.18 Signed-off-by: Corey Minyard Reviewed-by: Rafael J. Wysocki (Intel) --- drivers/char/ipmi/ipmi_si_intf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c index 0049e3792ba1..3667033fcc51 100644 --- a/drivers/char/ipmi/ipmi_si_intf.c +++ b/drivers/char/ipmi/ipmi_si_intf.c @@ -2234,7 +2234,8 @@ static void wait_msg_processed(struct smi_info *smi_info) unsigned long jiffies_now; long time_diff; - while (smi_info->curr_msg || (smi_info->si_state != SI_NORMAL)) { + while (smi_info->si_state != SI_HOSED && + (smi_info->curr_msg || (smi_info->si_state != SI_NORMAL))) { jiffies_now = jiffies; time_diff = (((long)jiffies_now - (long)smi_info->last_timeout_jiffies) * SI_USEC_PER_JIFFY); From 62cd145453d577113f993efd025f258dd86aa183 Mon Sep 17 00:00:00 2001 From: Corey Minyard Date: Thu, 12 Feb 2026 21:56:54 -0600 Subject: [PATCH 8/9] ipmi:msghandler: Handle error returns from the SMI sender It used to be, until recently, that the sender operation on the low level interfaces would not fail. That's not the case any more with recent changes. So check the return value from the sender operation, and propagate it back up from there and handle the errors in all places. Reported-by: Rafael J. Wysocki Fixes: bc3a9d217755 ("ipmi:si: Gracefully handle if the BMC is non-functional") Cc: stable@vger.kernel.org # 4.18 Signed-off-by: Corey Minyard Reviewed-by: Rafael J. Wysocki (Intel) --- drivers/char/ipmi/ipmi_msghandler.c | 102 +++++++++++++++++++--------- 1 file changed, 69 insertions(+), 33 deletions(-) diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index a042b1596933..f8c3c1e44520 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -1887,19 +1887,32 @@ static struct ipmi_smi_msg *smi_add_send_msg(struct ipmi_smi *intf, return smi_msg; } -static void smi_send(struct ipmi_smi *intf, +static int smi_send(struct ipmi_smi *intf, const struct ipmi_smi_handlers *handlers, struct ipmi_smi_msg *smi_msg, int priority) { int run_to_completion = READ_ONCE(intf->run_to_completion); unsigned long flags = 0; + int rv = 0; ipmi_lock_xmit_msgs(intf, run_to_completion, &flags); smi_msg = smi_add_send_msg(intf, smi_msg, priority); ipmi_unlock_xmit_msgs(intf, run_to_completion, &flags); - if (smi_msg) - handlers->sender(intf->send_info, smi_msg); + if (smi_msg) { + rv = handlers->sender(intf->send_info, smi_msg); + if (rv) { + ipmi_lock_xmit_msgs(intf, run_to_completion, &flags); + intf->curr_msg = NULL; + ipmi_unlock_xmit_msgs(intf, run_to_completion, &flags); + /* + * Something may have been added to the transmit + * queue, so schedule a check for that. + */ + queue_work(system_wq, &intf->smi_work); + } + } + return rv; } static bool is_maintenance_mode_cmd(struct kernel_ipmi_msg *msg) @@ -2312,6 +2325,7 @@ static int i_ipmi_request(struct ipmi_user *user, struct ipmi_recv_msg *recv_msg; int run_to_completion = READ_ONCE(intf->run_to_completion); int rv = 0; + bool in_seq_table = false; if (supplied_recv) { recv_msg = supplied_recv; @@ -2365,33 +2379,50 @@ static int i_ipmi_request(struct ipmi_user *user, rv = i_ipmi_req_ipmb(intf, addr, msgid, msg, smi_msg, recv_msg, source_address, source_lun, retries, retry_time_ms); + in_seq_table = true; } else if (is_ipmb_direct_addr(addr)) { rv = i_ipmi_req_ipmb_direct(intf, addr, msgid, msg, smi_msg, recv_msg, source_lun); } else if (is_lan_addr(addr)) { rv = i_ipmi_req_lan(intf, addr, msgid, msg, smi_msg, recv_msg, source_lun, retries, retry_time_ms); + in_seq_table = true; } else { - /* Unknown address type. */ + /* Unknown address type. */ ipmi_inc_stat(intf, sent_invalid_commands); rv = -EINVAL; } - if (rv) { + if (!rv) { + dev_dbg(intf->si_dev, "Send: %*ph\n", + smi_msg->data_size, smi_msg->data); + + rv = smi_send(intf, intf->handlers, smi_msg, priority); + if (rv != IPMI_CC_NO_ERROR) + /* smi_send() returns an IPMI err, return a Linux one. */ + rv = -EIO; + if (rv && in_seq_table) { + /* + * If it's in the sequence table, it will be + * retried later, so ignore errors. + */ + rv = 0; + /* But we need to fix the timeout. */ + intf_start_seq_timer(intf, smi_msg->msgid); + ipmi_free_smi_msg(smi_msg); + smi_msg = NULL; + } + } out_err: + if (!run_to_completion) + mutex_unlock(&intf->users_mutex); + + if (rv) { if (!supplied_smi) ipmi_free_smi_msg(smi_msg); if (!supplied_recv) ipmi_free_recv_msg(recv_msg); - } else { - dev_dbg(intf->si_dev, "Send: %*ph\n", - smi_msg->data_size, smi_msg->data); - - smi_send(intf, intf->handlers, smi_msg, priority); } - if (!run_to_completion) - mutex_unlock(&intf->users_mutex); - return rv; } @@ -3965,12 +3996,12 @@ static int handle_ipmb_get_msg_cmd(struct ipmi_smi *intf, dev_dbg(intf->si_dev, "Invalid command: %*ph\n", msg->data_size, msg->data); - smi_send(intf, intf->handlers, msg, 0); - /* - * We used the message, so return the value that - * causes it to not be freed or queued. - */ - rv = -1; + if (smi_send(intf, intf->handlers, msg, 0) == IPMI_CC_NO_ERROR) + /* + * We used the message, so return the value that + * causes it to not be freed or queued. + */ + rv = -1; } else if (!IS_ERR(recv_msg)) { /* Extract the source address from the data. */ ipmb_addr = (struct ipmi_ipmb_addr *) &recv_msg->addr; @@ -4044,12 +4075,12 @@ static int handle_ipmb_direct_rcv_cmd(struct ipmi_smi *intf, msg->data[4] = IPMI_INVALID_CMD_COMPLETION_CODE; msg->data_size = 5; - smi_send(intf, intf->handlers, msg, 0); - /* - * We used the message, so return the value that - * causes it to not be freed or queued. - */ - rv = -1; + if (smi_send(intf, intf->handlers, msg, 0) == IPMI_CC_NO_ERROR) + /* + * We used the message, so return the value that + * causes it to not be freed or queued. + */ + rv = -1; } else if (!IS_ERR(recv_msg)) { /* Extract the source address from the data. */ daddr = (struct ipmi_ipmb_direct_addr *)&recv_msg->addr; @@ -4189,7 +4220,7 @@ static int handle_lan_get_msg_cmd(struct ipmi_smi *intf, struct ipmi_smi_msg *msg) { struct cmd_rcvr *rcvr; - int rv = 0; + int rv = 0; /* Free by default */ unsigned char netfn; unsigned char cmd; unsigned char chan; @@ -4242,12 +4273,12 @@ static int handle_lan_get_msg_cmd(struct ipmi_smi *intf, dev_dbg(intf->si_dev, "Invalid command: %*ph\n", msg->data_size, msg->data); - smi_send(intf, intf->handlers, msg, 0); - /* - * We used the message, so return the value that - * causes it to not be freed or queued. - */ - rv = -1; + if (smi_send(intf, intf->handlers, msg, 0) == IPMI_CC_NO_ERROR) + /* + * We used the message, so return the value that + * causes it to not be freed or queued. + */ + rv = -1; } else if (!IS_ERR(recv_msg)) { /* Extract the source address from the data. */ lan_addr = (struct ipmi_lan_addr *) &recv_msg->addr; @@ -5056,7 +5087,12 @@ static void check_msg_timeout(struct ipmi_smi *intf, struct seq_table *ent, ipmi_inc_stat(intf, retransmitted_ipmb_commands); - smi_send(intf, intf->handlers, smi_msg, 0); + /* If this fails we'll retry later or timeout. */ + if (smi_send(intf, intf->handlers, smi_msg, 0) != IPMI_CC_NO_ERROR) { + /* But fix the timeout. */ + intf_start_seq_timer(intf, smi_msg->msgid); + ipmi_free_smi_msg(smi_msg); + } } else ipmi_free_smi_msg(smi_msg); From cae66f1a1dcd23e17da5a015ef9d731129f9d2dd Mon Sep 17 00:00:00 2001 From: Corey Minyard Date: Fri, 13 Feb 2026 00:15:04 -0600 Subject: [PATCH 9/9] ipmi:si: Fix check for a misbehaving BMC There is a race on checking the state in the sender, it needs to be checked under a lock. But you also need a check to avoid issues with a misbehaving BMC for run to completion mode. So leave the check at the beginning for run to completion, and add a check under the lock to avoid the race. Reported-by: Rafael J. Wysocki Fixes: bc3a9d217755 ("ipmi:si: Gracefully handle if the BMC is non-functional") Cc: stable@vger.kernel.org # 4.18 Signed-off-by: Corey Minyard Reviewed-by: Rafael J. Wysocki (Intel) --- drivers/char/ipmi/ipmi_si_intf.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c index 3667033fcc51..6eda61664aaa 100644 --- a/drivers/char/ipmi/ipmi_si_intf.c +++ b/drivers/char/ipmi/ipmi_si_intf.c @@ -924,9 +924,14 @@ static int sender(void *send_info, struct ipmi_smi_msg *msg) { struct smi_info *smi_info = send_info; unsigned long flags; + int rv = IPMI_CC_NO_ERROR; debug_timestamp(smi_info, "Enqueue"); + /* + * Check here for run to completion mode. A check under lock is + * later. + */ if (smi_info->si_state == SI_HOSED) return IPMI_BUS_ERR; @@ -940,18 +945,15 @@ static int sender(void *send_info, struct ipmi_smi_msg *msg) } spin_lock_irqsave(&smi_info->si_lock, flags); - /* - * The following two lines don't need to be under the lock for - * the lock's sake, but they do need SMP memory barriers to - * avoid getting things out of order. We are already claiming - * the lock, anyway, so just do it under the lock to avoid the - * ordering problem. - */ - BUG_ON(smi_info->waiting_msg); - smi_info->waiting_msg = msg; - check_start_timer_thread(smi_info); + if (smi_info->si_state == SI_HOSED) { + rv = IPMI_BUS_ERR; + } else { + BUG_ON(smi_info->waiting_msg); + smi_info->waiting_msg = msg; + check_start_timer_thread(smi_info); + } spin_unlock_irqrestore(&smi_info->si_lock, flags); - return IPMI_CC_NO_ERROR; + return rv; } static void set_run_to_completion(void *send_info, bool i_run_to_completion)