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2021-10-27nvmem: Fix shift-out-of-bound (UBSAN) with byte size cellsStephen Boyd
commit 5d388fa01fa6eb310ac023a363a6cb216d9d8fe9 upstream. If a cell has 'nbits' equal to a multiple of BITS_PER_BYTE the logic *p &= GENMASK((cell->nbits%BITS_PER_BYTE) - 1, 0); will become undefined behavior because nbits modulo BITS_PER_BYTE is 0, and we subtract one from that making a large number that is then shifted more than the number of bits that fit into an unsigned long. UBSAN reports this problem: UBSAN: shift-out-of-bounds in drivers/nvmem/core.c:1386:8 shift exponent 64 is too large for 64-bit type 'unsigned long' CPU: 6 PID: 7 Comm: kworker/u16:0 Not tainted 5.15.0-rc3+ #9 Hardware name: Google Lazor (rev3+) with KB Backlight (DT) Workqueue: events_unbound deferred_probe_work_func Call trace: dump_backtrace+0x0/0x170 show_stack+0x24/0x30 dump_stack_lvl+0x64/0x7c dump_stack+0x18/0x38 ubsan_epilogue+0x10/0x54 __ubsan_handle_shift_out_of_bounds+0x180/0x194 __nvmem_cell_read+0x1ec/0x21c nvmem_cell_read+0x58/0x94 nvmem_cell_read_variable_common+0x4c/0xb0 nvmem_cell_read_variable_le_u32+0x40/0x100 a6xx_gpu_init+0x170/0x2f4 adreno_bind+0x174/0x284 component_bind_all+0xf0/0x264 msm_drm_bind+0x1d8/0x7a0 try_to_bring_up_master+0x164/0x1ac __component_add+0xbc/0x13c component_add+0x20/0x2c dp_display_probe+0x340/0x384 platform_probe+0xc0/0x100 really_probe+0x110/0x304 __driver_probe_device+0xb8/0x120 driver_probe_device+0x4c/0xfc __device_attach_driver+0xb0/0x128 bus_for_each_drv+0x90/0xdc __device_attach+0xc8/0x174 device_initial_probe+0x20/0x2c bus_probe_device+0x40/0xa4 deferred_probe_work_func+0x7c/0xb8 process_one_work+0x128/0x21c process_scheduled_works+0x40/0x54 worker_thread+0x1ec/0x2a8 kthread+0x138/0x158 ret_from_fork+0x10/0x20 Fix it by making sure there are any bits to mask out. Fixes: 69aba7948cbe ("nvmem: Add a simple NVMEM framework for consumers") Cc: Douglas Anderson <dianders@chromium.org> Cc: stable@vger.kernel.org Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20211013124511.18726-1-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-25nvmem: core: return error code instead of NULL from nvmem_device_getSrinivas Kandagatla
[ Upstream commit ca6ac25cecf0e740d7cc8e03e0ebbf8acbeca3df ] nvmem_device_get() should return ERR_PTR() on error or valid pointer on success, but one of the code path seems to return NULL, so fix it. Reported-by: Niklas Cassel <niklas.cassel@linaro.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-22nvmem: core: fix read buffer in placeJorge Ramirez-Ortiz
[ Upstream commit 2fe518fecb3a4727393be286db9804cd82ee2d91 ] When the bit_offset in the cell is zero, the pointer to the msb will not be properly initialized (ie, will still be pointing to the first byte in the buffer). This being the case, if there are bits to clear in the msb, those will be left untouched while the mask will incorrectly clear bit positions on the first byte. This commit also makes sure that any byte unused in the cell is cleared. Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2015-10-04nvmem: core: Fix memory leak in nvmem_cell_writeAxel Lin
A tmp buffer is allocated if cell->bit_offset || cell->nbits. So the tmp buffer needs to be freed at the same condition to avoid leak. Signed-off-by: Axel Lin <axel.lin@ingics.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04nvmem: core: Handle shift bits in-place if cell->nbits is non-zeroAxel Lin
It's pointless to test (cell->bit_offset || cell->bit_offset). nvmem_shift_read_buffer_in_place() should be called when (cell->bit_offset || cell->nbits). Signed-off-by: Axel Lin <axel.lin@ingics.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04nvmem: core: fix the out-of-range leak in read/write()ZhengShunQian
The position to read/write must be less than max register size. Signed-off-by: ZhengShunQian <zhengsq@rock-chips.com> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05nvmem: Add nvmem_device based consumer apis.Srinivas Kandagatla
This patch adds read/write apis which are based on nvmem_device. It is common that the drivers like omap cape manager or qcom cpr driver to access bytes directly at particular offset in the eeprom and not from nvmem cell info in DT. These driver would need to get access to the nvmem directly, which is what these new APIS provide. These wrapper apis would help such users to avoid code duplication in there drivers and also avoid them reading a big eeprom blob and parsing it internally in there driver. Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Tested-by: Stefan Wahren <stefan.wahren@i2se.com> Tested-by: Philipp Zabel <p.zabel@pengutronix.de> Tested-by: Rajendra Nayak <rnayak@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05nvmem: Add a simple NVMEM framework for consumersSrinivas Kandagatla
This patch adds just consumers part of the framework just to enable easy review. Up until now, nvmem drivers were stored in drivers/misc, where they all had to duplicate pretty much the same code to register a sysfs file, allow in-kernel users to access the content of the devices they were driving, etc. This was also a problem as far as other in-kernel users were involved, since the solutions used were pretty much different from on driver to another, there was a rather big abstraction leak. This introduction of this framework aims at solving this. It also introduces DT representation for consumer devices to go get the data they require (MAC Addresses, SoC/Revision ID, part numbers, and so on) from the nvmems. Having regmap interface to this framework would give much better abstraction for nvmems on different buses. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> [Maxime Ripard: intial version of the framework] Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Tested-by: Stefan Wahren <stefan.wahren@i2se.com> Tested-by: Philipp Zabel <p.zabel@pengutronix.de> Tested-by: Rajendra Nayak <rnayak@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05nvmem: Add a simple NVMEM framework for nvmem providersSrinivas Kandagatla
This patch adds just providers part of the framework just to enable easy review. Up until now, NVMEM drivers like eeprom were stored in drivers/misc, where they all had to duplicate pretty much the same code to register a sysfs file, allow in-kernel users to access the content of the devices they were driving, etc. This was also a problem as far as other in-kernel users were involved, since the solutions used were pretty much different from on driver to another, there was a rather big abstraction leak. This introduction of this framework aims at solving this. It also introduces DT representation for consumer devices to go get the data they require (MAC Addresses, SoC/Revision ID, part numbers, and so on) from the nvmems. Having regmap interface to this framework would give much better abstraction for nvmems on different buses. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> [Maxime Ripard: intial version of eeprom framework] Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Tested-by: Stefan Wahren <stefan.wahren@i2se.com> Tested-by: Philipp Zabel <p.zabel@pengutronix.de> Tested-by: Rajendra Nayak <rnayak@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>