kernel/linux.git/drivers/i2c, branch v6.12.107

i2c: imx: Cancel hrtimer before clearing slave pointer

2026-08-09T18:23:18+00:00

commit 6ac7702b6cc2b94aaed9ef2d95bfbefcdc90061f upstream. In i2c_imx_unreg_slave(), the slave pointer is set to NULL after disabling interrupts. However, a pending interrupt might already have started the hrtimer (i2c_imx_slave_timeout) before the pointer was cleared. If the hrtimer fires after i2c_imx->slave is set to NULL, the timer callback i2c_imx_slave_finish_op() will call i2c_imx_slave_event() with a NULL slave pointer, which results in a use-after-free / NULL pointer dereference. Fix by canceling the hrtimer and waiting for it to complete after disabling interrupts, before clearing the slave pointer. Fixes: f7414cd6923f ("i2c: imx: support slave mode for imx I2C driver") Signed-off-by: Liem Cc: # v5.11+ Acked-by: Carlos Song Reviewed-by: Frank Li Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260629023829.152651-3-liem16213@gmail.com Signed-off-by: Greg Kroah-Hartman

i2c: imx: Fix slave registration race and error handling

2026-08-09T18:23:18+00:00

commit d64ec362c369bbc33833f7936d5f3a706b0d5c45 upstream. In i2c_imx_reg_slave(), the slave pointer was assigned before pm_runtime_resume_and_get(). If pm_runtime_resume_and_get() failed, the error path returned without clearing i2c_imx->slave, leaving it non-NULL and causing all subsequent registration attempts to fail with -EBUSY. Additionally, because this driver uses a shared IRQ, the interrupt handler i2c_imx_isr() can execute concurrently and, after acquiring slave_lock, dereference i2c_imx->slave. The previous fix attempt added a lockless i2c_imx->slave = NULL on the error path, but that could race with the ISR under the lock and still cause a NULL pointer dereference. Fix both issues by deferring the assignment of i2c_imx->slave and i2c_imx->last_slave_event to after a successful resume, and by performing the assignment inside the slave_lock critical section. This guarantees that the slave pointer is never left stale on the error path and is always valid when observed by the interrupt handler. Fixes: f7414cd6923f ("i2c: imx: support slave mode for imx I2C driver") Signed-off-by: Liem Cc: # v5.11+ Reviewed-by: Frank Li Acked-by: Carlos Song Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260629023829.152651-2-liem16213@gmail.com Signed-off-by: Greg Kroah-Hartman

i2c: iproc: reset bus after timeout if START_BUSY is stuck

2026-08-09T18:23:18+00:00

commit 98f2e9e6d6f91a6abb43f166b244b428ba85fa2b upstream. If a transaction times out, the START_BUSY signal can stay up, and subsequent transactaction attempts will fail as the bus is still considered busy. I can easily trigger this by attempting to read from an address with no device, e.g. when running i2cdetect. After the first read times out, all subsequent read attempts return busy. To get to a working state again, the controller needs to be reset to clear the START_BUSY signal. So check for START_BUSY still asserted on a timeout, and do reset in case it is, This is also done by the original non-upstream iproc-smbus driver implementation [1]. Works around situations like: bcm-iproc-2c 1803b000.i2c: transaction timed out bcm-iproc-2c 1803b000.i2c: bus is busy bcm-iproc-2c 1803b000.i2c: bus is busy bcm-iproc-2c 1803b000.i2c: bus is busy bcm-iproc-2c 1803b000.i2c: bus is busy bcm-iproc-2c 1803b000.i2c: bus is busy ... where the bus never recovers after a timeout. [1] https://github.com/opencomputeproject/onie/blob/master/patches/kernel/3.2.69/driver-iproc-smbus.patch Fixes: e6e5dd3566e0 ("i2c: iproc: Add Broadcom iProc I2C Driver") Signed-off-by: Jonas Gorski Cc: # v4.0+ Acked-by: Ray Jui Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260717085507.34209-1-jonas.gorski@bisdn.de Signed-off-by: Greg Kroah-Hartman

i2c: jz4780: Cache host clock rate at probe to prevent CCF prepare_lock deadlock

2026-08-09T18:23:18+00:00

commit d99607c888f26e8a4e9fe9772860cef4aff86bb4 upstream. Fix a severe AB/BA deadlock between the Common Clock Framework (CCF) and the I2C adapter lock, which triggers when an I2C-controlled clock generator client (like the Si5351) is registered or modified under the CCF. During an i2c client clock (generator) frequency change, the CCF acquires its global 'prepare_lock' mutex and the driver calls i2c_transfer() to update the client's chip registers, stalling for the adapter's I2C bus lock. Concurrently, an independent, parallel transfer on the same bus (e.g., a GPIO expander handling LEDs) can hold the I2C adapter lock. Inside this parallel transfer path, jz4780_i2c_set_speed() calls clk_get_rate() on the host controller's input clock to calculate bus timings. This call attempts to acquire the blocked CCF 'prepare_lock', creating a circular dependency that freezes the system. The jz4780 host controller clock itself is static and never changes at runtime. However, calling clk_get_rate() inside the active transfer path introduces an unnecessary dependency on the CCF internal locks. Eliminate this synchronous clk_get_rate() call from the active transfer path by caching the static host peripheral clock rate once - inside the private jz4780_i2c structure during jz4780_i2c_probe(). Update jz4780_i2c_set_speed() to use this cached value, safely decoupling active I2C transactions from the CCF internal locks without any risk of stale timings. Assisted-by web based Google AI (pinpointing the bug and writing the message). Fixes: ba92222ed63a12 ("i2c: jz4780: Add i2c bus controller driver for Ingenic JZ4780") Signed-off-by: H. Nikolaus Schaller Cc: # v4.1+ Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/2db6fd233aceb7238474e4833f4d25ca681c3ffb.1784492382.git.hns@goldelico.com Signed-off-by: Greg Kroah-Hartman

i2c: amd-mp2: Unregister callback on adapter add failure

2026-08-09T18:23:16+00:00

commit 82048795242f04275a3f49ffc66ad851b6120954 upstream. amd_mp2_register_cb() stores the platform I2C context in the MP2 PCI driver's callback table before the adapter is registered. If i2c_add_adapter() fails, probe returns and devres frees the context, but the PCI driver can still dereference the stale pointer from its IRQ and system-sleep callbacks. Unregister the callback before returning the adapter registration error. Fixes: 529766e0a011 ("i2c: Add drivers for the AMD PCIe MP2 I2C controller") Co-developed-by: Ijae Kim Signed-off-by: Ijae Kim Signed-off-by: Myeonghun Pak Cc: # v5.2+ Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260721144147.31150-1-mhun512@gmail.com Signed-off-by: Greg Kroah-Hartman

i2c: imx: fix locked bus on SMBus block-read of 0 (atomic)

2026-08-03T09:17:34+00:00

[ Upstream commit cb2fc37857693b55909fb77dc2c87cfbc1cdc476 ] SMBus 3.1 6.5.7 allows a Block Read byte count of 0, but the atomic (polling) path rejects it as -EPROTO. Worse, it returns without a NACK+STOP: the next receive cycle has already started, so the target keeps holding SDA and the bus stays stuck until a power cycle for this i2c controller. Reading I2DR to obtain the count likewise arms the next byte on the count > I2C_SMBUS_BLOCK_MAX path, which also returned -EPROTO directly and left the bus held. Handle both: NACK the in-flight dummy byte (TXAK) and extend msgs->len so the existing last-byte handling emits STOP; the dummy byte is discarded. A count of 0 is a valid empty block read; a count above I2C_SMBUS_BLOCK_MAX is still reported as -EPROTO, but only after the bus has been released. The interrupt-driven path has the same flaw from a later commit and is fixed separately, as it carries a different Fixes: tag and stable range. Fixes: 8e8782c71595 ("i2c: imx: add SMBus block read support") Signed-off-by: Vincent Jardin Cc: # v3.16+ Acked-by: Oleksij Rempel Acked-by: Carlos Song Reviewed-by: Stefan Eichenberger Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260713-for-upstream-i2c-lx2160-fix-v1-v3-1-073ac9e103a5@free.fr Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

i2c: imx: separate atomic, dma and non-dma use case

2026-08-03T09:17:34+00:00

[ Upstream commit b460b15b3cc23ef3639cc51043bf8b2a70ca1878 ] Separate the atomic, dma and non-dma use case as a preparation step for moving the non-dma use case to the isr to avoid rescheduling while a transfer is in progress. Signed-off-by: Stefan Eichenberger Reviewed-by: Frank Li Acked-by: Oleksij Rempel Signed-off-by: Andi Shyti Stable-dep-of: cb2fc3785769 ("i2c: imx: fix locked bus on SMBus block-read of 0 (atomic)") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

i2c: i801: fix hardware state machine corruption in error path

2026-08-03T09:17:30+00:00

[ Upstream commit 10dd1a736d557e310a77117832874729a0175d57 ] A severe livelock and subsequent Hung Task panic were observed in the i2c-i801 driver during concurrent Fuzzing. The crash is caused by an unconditional hardware register cleanup in the error handling path of i801_access(). When i801_check_pre() fails (e.g., returning -EBUSY because the SMBus controller is actively used by BIOS/ACPI), the kernel does not actually acquire the hardware ownership. However, the code jumps to the 'out' label and executes: iowrite8(SMBHSTSTS_INUSE_STS | STATUS_FLAGS, SMBHSTSTS(priv)); This forcefully clears the INUSE_STS lock and resets the hardware status flags without owning the controller. Doing so interrupts ongoing BIOS/ACPI transactions and totally corrupts the SMBus hardware state machine. Consequently, all subsequent i801_access() calls fail at the pre-check stage, triggering an endless stream of "SMBus is busy, can't use it!" error logs. Over a slow serial console, this printk flood monopolizes the CPU (Console Livelock), starving other processes trying to acquire the mmap_lock down_read semaphore, ultimately triggering the hung task watchdog. Fix this by moving the 'out' label below the hardware register cleanup. If i801_check_pre() fails, we safely bypass the iowrite8() and only release the software locks (pm_runtime and mutex), strictly adhering to the rule of not releasing resources that were never acquired. Fixes: 1f760b87e54c ("i2c: i801: Call i801_check_pre() from i801_access()") Signed-off-by: Mingyu Wang <25181214217@stu.xidian.edu.cn> Cc: # v6.3+ Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260512093534.348655-1-w15303746062@163.com Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

i2c: davinci: Unregister cpufreq notifier on probe failure

2026-08-03T09:17:30+00:00

[ Upstream commit e43f32816a1b1fe5a86279411626fe3a9be56d45 ] davinci_i2c_probe() registers a cpufreq transition notifier before adding the I2C adapter. If i2c_add_numbered_adapter() fails, the probe error path releases the device resources without unregistering the notifier. Add a dedicated error path to unregister the cpufreq notifier after i2c_add_numbered_adapter() fails. Fixes: 82c0de11b734 ("i2c: davinci: Add cpufreq support") Signed-off-by: Haoxiang Li Cc: # v2.6.36+ Reviewed-by: Bartosz Golaszewski Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260610030513.2651018-1-haoxiang_li2024@163.com Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

i2c: mlxbf: Fix use-after-free in mlxbf_i2c_init_resource()

2026-07-24T14:11:37+00:00

commit 71356737a7a55c76fee847563e3d33f8e6dc6b6d upstream. If devm_platform_get_and_ioremap_resource() returns an error, mlxbf_i2c_init_resource() frees tmp_res before reading tmp_res->io to get the error code. This results in a use-after-free. Save the error code before freeing tmp_res. Fixes: b5b5b32081cd ("i2c: mlxbf: I2C SMBus driver for Mellanox BlueField SoC") Signed-off-by: Xuanqiang Luo Cc: # v5.10+ Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260714150808.85045-1-xuanqiang.luo@linux.dev Signed-off-by: Greg Kroah-Hartman