kernel/git/stable/linux.git/drivers/char/ipmi, branch linux-5.15.y

ipmi: si: Fix NULL pointer dereference after failed registration

2026-09-14T11:20:12+00:00

commit 6d920a75df9a83ab096b3cde7a643b656e4fdfeb upstream. try_smi_init() allocates new_smi->si_sm and later calls ipmi_register_smi_mod(), which maps to ipmi_add_smi(). During ipmi_add_smi(), the upper IPMI message handler obtains the initial BMC device information through __bmc_get_device_id(). This can fail if the BMC does not return a successful response to the Get Device ID command. When the BMC returns a nonzero completion code, the device-id helper retries the command and eventually returns -EIO if the device ID still cannot be fetched. On this failure path, ipmi_add_smi() logs "Unable to get the device id" and goes to out_err_started, where it invokes the lower driver's shutdown callback. try_smi_init() then logs the returned registration failure: ipmi_si IPI0001:00: IPMI message handler: Unable to get the device id: -5 ipmi_si IPI0001:00: Unable to register device: error -5 For ipmi_si, the shutdown callback is shutdown_smi(), which cleans up the SI state machine data, frees smi_info->si_sm, and sets smi_info->si_sm and smi_info->intf to NULL. However, intf->in_shutdown is not set on this failed-registration rollback path. Therefore, the asynchronous redo_bmc_reg work item can still retry BMC device-id probing after the lower driver has already cleared its SI state machine data. In the observed case, that retry path reached start_next_msg(), which passed the NULL smi_info->si_sm pointer to the selected KCS state machine handler: BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 Workqueue: events redo_bmc_reg [ipmi_msghandler] RIP: start_kcs_transaction+0x2c/0x190 [ipmi_si] Call Trace: start_next_msg+0x50/0x80 [ipmi_si] check_start_timer_thread.part.9+0x3b/0x50 [ipmi_si] sender+0x69/0x80 [ipmi_si] i_ipmi_request+0x2ac/0x9d0 [ipmi_msghandler] __get_device_id.isra.29+0xaa/0x180 [ipmi_msghandler] __bmc_get_device_id+0xef/0x950 [ipmi_msghandler] redo_bmc_reg+0x52/0x60 [ipmi_msghandler] process_one_work+0x1a7/0x360 Set intf->in_shutdown on the out_err_started path before invoking the lower driver's shutdown callback. This prevents later redo_bmc_reg retries from using an interface whose lower driver state has been cleaned up, and applies the same shutdown state to other IPMI interfaces as well. Fixes: 2512e40e48d2 ("ipmi: Rework SMI registration failure") Cc: stable@vger.kernel.org Signed-off-by: Seiji Nishikawa Message-ID: <20260630174348.1483814-1-snishika@redhat.com> Signed-off-by: Corey Minyard Signed-off-by: Greg Kroah-Hartman

ipmi: ipmb: validate write message length

2026-09-14T11:20:12+00:00

commit 53637506884dbd5c91a89b1a3547d99d80f8ed2c upstream. ipmb_write() read message fields before validating the length byte. A zero or short write can read uninitialized stack bytes. A length smaller than the SMBus header underflows the block write length. Require a non-empty buffer and the minimum IPMB request length. Also require the length byte plus payload before parsing the message. Fixes: 51bd6f291583 ("Add support for IPMB driver") Cc: stable@vger.kernel.org Signed-off-by: Yousef Alhouseen Message-ID: <20260624175353.8592-1-alhouseenyousef@gmail.com> Signed-off-by: Corey Minyard Signed-off-by: Greg Kroah-Hartman

ipmi:ssif: NULL thread on error

2026-06-01T15:35:20+00:00

commit a8aebe93a4938c0ca1941eeaae821738f869be3d upstream. Cleanup code was checking the thread for NULL, but it was possibly a PTR_ERR() in one spot. Spotted with static analysis. Link: https://sourceforge.net/p/openipmi/mailman/message/59324676/ Fixes: 75c486cb1bca ("ipmi:ssif: Clean up kthread on errors") Cc: # 91eb7ec72612: ipmi:ssif: Remove unnecessary indention Cc: stable@vger.kernel.org Signed-off-by: Corey Minyard Signed-off-by: Sasha Levin

ipmi:ssif: Remove unnecessary indention

2026-06-01T15:35:20+00:00

commit 91eb7ec7261254b6875909df767185838598e21e upstream. A section was in {} that didn't need to be, move the variable definition to the top and set th eindentino properly. Signed-off-by: Corey Minyard Signed-off-by: Sasha Levin

ipmi:ssif: Clean up kthread on errors

2026-06-01T15:35:20+00:00

commit 75c486cb1bcaa1a3ec3a6438498176a3a4998ae4 upstream. If an error occurs after the ssif kthread is created, but before the main IPMI code starts the ssif interface, the ssif kthread will not be stopped. So make sure the kthread is stopped on an error condition if it is running. Fixes: 259307074bfc ("ipmi: Add SMBus interface driver (SSIF)") Reported-by: Li Xiao <<252270051@hdu.edu.cn> Cc: stable@vger.kernel.org Reviewed-by: Li Xiao <252270051@hdu.edu.cn> [Adjusted for stopping flag and complete operation still being present.] Signed-off-by: Corey Minyard Signed-off-by: Sasha Levin

ipmi:ssif: Fix a shutdown race

2026-06-01T15:35:20+00:00

It was possible for the SSIF thread to stop and quit before the kthread_stop() call because ssif->stopping was set before the stop. So only exit the SSIF thread is kthread_should_stop() returns true. In the mainstream kernel this was fixed in 6bd0eb6d759b ("ipmi:ssif: Fix a shutdown race"). However, that requires a fix in kernel version 6.1 has a fix to kthread stop to cause interruptible waits to return -ERESTARTSYS on a stop. This has not been backported to older kernels, and that would probably be a bad idea. But it means that the mainstrem kernel fix for this will not work. Instead, wait for kthread_should_stop() to return true before exiting the thread. Signed-off-by: Corey Minyard Signed-off-by: Sasha Levin

ipmi:si: Return state to normal if message allocation fails

2026-06-01T15:35:19+00:00

commit 09dd798270ff582d7309f285d4aaf5dbebae01cb upstream. There were places where nothing would get started if a message allocation failed, so the driver needs to return to normal state. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: Signed-off-by: Corey Minyard Signed-off-by: Greg Kroah-Hartman

ipmi: Check event message buffer response for bad data

2026-06-01T15:35:19+00:00

commit 36920f30e78e69df01f9691c470b6f3ba8aebf98 upstream. The event message buffer response data size got checked later when processing, but check it right after the response comes back. It appears some BMCs may return an empty message instead of an error when fetching events. There are apparently some new BMCs that make this error, so we need to compensate. Reported-by: Matt Fleming Closes: https://lore.kernel.org/lkml/20260415115930.3428942-1-matt@readmodwrite.com/ Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: Signed-off-by: Corey Minyard Signed-off-by: Greg Kroah-Hartman

ipmi: Add limits to event and receive message requests

2026-06-01T15:35:19+00:00

commit c4cca236968683eb0d59abfb12d5c7e4d8514227 upstream. The driver would just fetch events and receive messages until the BMC said it was done. To avoid issues with BMCs that never say they are done, add a limit of 10 fetches at a time. In addition, an si interface has an attn state it can return from the hardware which is supposed to cause a flag fetch to see if the driver needs to fetch events or message or a few other things. If the attn bit gets stuck, it's a similar problem. So allow messages in between flag fetches so the driver itself doesn't get stuck. This is a more general fix than the previous fix for the specific bad BMC, but should fix the more general issue of a BMC that won't stop saying it has data. This has been there from the beginning of the driver. It's not a bug per-se, but it is accounting for bugs in BMCs. Reported-by: Matt Fleming Closes: https://lore.kernel.org/lkml/20260415115930.3428942-1-matt@readmodwrite.com/ Fixes: <1da177e4c3f4> ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Corey Minyard Signed-off-by: Greg Kroah-Hartman

ipmi: Fix __scan_channels() failing to rescan channels

2026-01-19T12:09:46+00:00

[ Upstream commit 6bd30d8fc523fb880b4be548e8501bc0fe8f42d4 ] channel_handler() sets intf->channels_ready to true but never clears it, so __scan_channels() skips any rescan. When the BMC firmware changes a rescan is required. Allow it by clearing the flag before starting a new scan. Signed-off-by: Jinhui Guo Message-ID: <20250930074239.2353-3-guojinhui.liam@bytedance.com> Signed-off-by: Corey Minyard Signed-off-by: Sasha Levin