kernel/git/stable/linux.git/drivers/char, branch linux-6.17.y

random: use offstack cpumask when necessary

2025-12-18T12:59:29+00:00

[ Upstream commit 5d49f1a5bd358d24e5f88b23b46da833de1dbec8 ] The entropy generation function keeps a local cpu mask on the stack, which can trigger warnings in configurations with a large number of CPUs: drivers/char/random.c:1292:20: error: stack frame size (1288) exceeds limit (1280) in 'try_to_generate_entropy' [-Werror,-Wframe-larger-than] Use the cpumask interface to dynamically allocate it in those configurations. Fixes: 1c21fe00eda7 ("random: spread out jitter callback to different CPUs") Signed-off-by: Arnd Bergmann Signed-off-by: Jason A. Donenfeld Signed-off-by: Sasha Levin

char: Use list_del_init() in misc_deregister() to reinitialize list pointer

2025-11-13T20:37:16+00:00

[ Upstream commit e28022873c0d051e980c4145f1965cab5504b498 ] Currently, misc_deregister() uses list_del() to remove the device from the list. After list_del(), the list pointers are set to LIST_POISON1 and LIST_POISON2, which may help catch use-after-free bugs, but does not reset the list head. If misc_deregister() is called more than once on the same device, list_empty() will not return true, and list_del() may be called again, leading to undefined behavior. Replace list_del() with list_del_init() to reinitialize the list head after deletion. This makes the code more robust against double deregistration and allows safe usage of list_empty() on the miscdevice after deregistration. [ Note, this seems to keep broken out-of-tree drivers from doing foolish things. While this does not matter for any in-kernel drivers, external drivers could use a bit of help to show them they shouldn't be doing stuff like re-registering misc devices - gregkh ] Signed-off-by: Xion Wang Link: https://lore.kernel.org/r/20250904063714.28925-2-xion.wang@mediatek.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

char: misc: Does not request module for miscdevice with dynamic minor

2025-11-13T20:37:04+00:00

[ Upstream commit 1ba0fb42aa6a5f072b1b8c0b0520b32ad4ef4b45 ] misc_open() may request module for miscdevice with dynamic minor, which is meaningless since: - The dynamic minor allocated is unknown in advance without registering miscdevice firstly. - Macro MODULE_ALIAS_MISCDEV() is not applicable for dynamic minor. Fix by only requesting module for miscdevice with fixed minor. Acked-by: Thadeu Lima de Souza Cascardo Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20250714-rfc_miscdev-v6-6-2ed949665bde@oss.qualcomm.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

char: misc: Make misc_register() reentry for miscdevice who wants dynamic minor

2025-11-13T20:37:04+00:00

[ Upstream commit 52e2bb5ff089d65e2c7d982fe2826dc88e473d50 ] For miscdevice who wants dynamic minor, it may fail to be registered again without reinitialization after being de-registered, which is illustrated by kunit test case miscdev_test_dynamic_reentry() newly added. There is a real case found by cascardo when a part of minor range were contained by range [0, 255): 1) wmi/dell-smbios registered minor 122, and acpi_thermal_rel registered minor 123 2) unbind "int3400 thermal" driver from its device, this will de-register acpi_thermal_rel 3) rmmod then insmod dell_smbios again, now wmi/dell-smbios is using minor 123 4) bind the device to "int3400 thermal" driver again, acpi_thermal_rel fails to register. Some drivers may reuse the miscdevice structure after they are deregistered If the intention is to allocate a dynamic minor, if the minor number is not reset to MISC_DYNAMIC_MINOR before calling misc_register(), it will try to register a previously dynamically allocated minor number, which may have been registered by a different driver. One such case is the acpi_thermal_rel misc device, registered by the int3400 thermal driver. If the device is unbound from the driver and later bound, if there was another dynamic misc device registered in between, it would fail to register the acpi_thermal_rel misc device. Other drivers behave similarly. Actually, this kind of issue is prone to happen if APIs misc_register()/misc_deregister() are invoked by driver's probe()/remove() separately. Instead of fixing all the drivers, just reset the minor member to MISC_DYNAMIC_MINOR in misc_deregister() in case it was a dynamically allocated minor number, as error handling of misc_register() does. Cc: Thadeu Lima de Souza Cascardo Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20250714-rfc_miscdev-v6-5-2ed949665bde@oss.qualcomm.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

hwrng: timeriomem - Use us_to_ktime() where appropriate

2025-11-13T20:37:02+00:00

[ Upstream commit 817fcdbd4ca29834014a5dadbe8e11efeb12800c ] It is better to replace ns_to_ktime() with us_to_ktime(), which can make the code clearer. Signed-off-by: Xichao Zhao Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin

ipmi: Fix handling of messages with provided receive message pointer

2025-10-19T14:37:42+00:00

commit e2c69490dda5d4c9f1bfbb2898989c8f3530e354 upstream. Prior to commit b52da4054ee0 ("ipmi: Rework user message limit handling"), i_ipmi_request() used to increase the user reference counter if the receive message is provided by the caller of IPMI API functions. This is no longer the case. However, ipmi_free_recv_msg() is still called and decreases the reference counter. This results in the reference counter reaching zero, the user data pointer is released, and all kinds of interesting crashes are seen. Fix the problem by increasing user reference counter if the receive message has been provided by the caller. Fixes: b52da4054ee0 ("ipmi: Rework user message limit handling") Reported-by: Eric Dumazet Cc: Eric Dumazet Cc: Greg Thelen Signed-off-by: Guenter Roeck Message-ID: <20251006201857.3433837-1-linux@roeck-us.net> Signed-off-by: Corey Minyard Signed-off-by: Greg Kroah-Hartman

Revert "ipmi: fix msg stack when IPMI is disconnected"

2025-10-19T14:37:30+00:00

commit 5d09ee1bec870263f4ace439402ea840503b503b upstream. This reverts commit c608966f3f9c2dca596967501d00753282b395fc. This patch has a subtle bug that can cause the IPMI driver to go into an infinite loop if the BMC misbehaves in a certain way. Apparently certain BMCs do misbehave this way because several reports have come in recently about this. Signed-off-by: Corey Minyard Tested-by: Eric Hagberg Cc: # 6.2 Signed-off-by: Greg Kroah-Hartman

ipmi:msghandler:Change seq_lock to a mutex

2025-10-19T14:37:27+00:00

commit 8fd8ea2869cfafb3b1d6f95ff49561b13a73438d upstream. Dan Carpenter got a Smatch warning: drivers/char/ipmi/ipmi_msghandler.c:5265 ipmi_free_recv_msg() warn: sleeping in atomic context due to the recent rework of the IPMI driver's locking. I didn't realize vfree could block. But there is an easy solution to this, now that almost everything in the message handler runs in thread context. I wanted to spend the time earlier to see if seq_lock could be converted from a spinlock to a mutex, but I wanted the previous changes to go in and soak before I did that. So I went ahead and did the analysis and converting should work. And solve this problem. Reported-by: kernel test robot Reported-by: Dan Carpenter Closes: https://lore.kernel.org/r/202503240244.LR7pOwyr-lkp@intel.com/ Fixes: 3be997d5a64a ("ipmi:msghandler: Remove srcu from the ipmi user structure") Cc: # 6.16 Signed-off-by: Corey Minyard Signed-off-by: Greg Kroah-Hartman

ipmi: Rework user message limit handling

2025-10-19T14:37:27+00:00

commit b52da4054ee0bf9ecb44996f2c83236ff50b3812 upstream. The limit on the number of user messages had a number of issues, improper counting in some cases and a use after free. Restructure how this is all done to handle more in the receive message allocation routine, so all refcouting and user message limit counts are done in that routine. It's a lot cleaner and safer. Reported-by: Gilles BULOZ Closes: https://lore.kernel.org/lkml/aLsw6G0GyqfpKs2S@mail.minyard.net/ Fixes: 8e76741c3d8b ("ipmi: Add a limit on the number of users that may use IPMI") Cc: # 4.19 Signed-off-by: Corey Minyard Tested-by: Gilles BULOZ Signed-off-by: Greg Kroah-Hartman

tpm_tis: Fix incorrect arguments in tpm_tis_probe_irq_single

2025-10-19T14:37:15+00:00

[ Upstream commit 8a81236f2cb0882c7ea6c621ce357f7f3f601fe5 ] The tpm_tis_write8() call specifies arguments in wrong order. Should be (data, addr, value) not (data, value, addr). The initial correct order was changed during the major refactoring when the code was split. Fixes: 41a5e1cf1fe1 ("tpm/tpm_tis: Split tpm_tis driver into a core and TCG TIS compliant phy") Signed-off-by: Gunnar Kudrjavets Reviewed-by: Justinien Bouron Reviewed-by: Jarkko Sakkinen Reviewed-by: Paul Menzel Signed-off-by: Jarkko Sakkinen Signed-off-by: Sasha Levin