mirror of
https://github.com/torvalds/linux.git
synced 2024-12-25 20:32:22 +00:00
6560ffd1cc
The function regmap_bulk_read() calls the regmap_read() for each register if set of register has volatile and cache is enabled. In this case, last few register read makes the memory corruption if the register size is not the size of unsigned int. The regam_read() takes argument as unsigned int for returning value and it update the value as *val = map->format.parse_val(map->work_buf); This causes complete 4 bytes (size of unsigned int) to get written. Now if client pass the memory pointer for value which is equal to the required size of register count in regmap_bulk_read() then last few register read actually update the memory beyond passed pointer size. Avoid this by using local variable for read and then do memcpy() for actual byte copy to passed pointer based on register size. I allocated one pointer ptr and take first 16 bytes dump of that pointer then call regmap_bulk_read() with pointer which is just on top of this allocated pointer and register count of 128. Here register size is 1 byte. The memory trace of last 5 register read are as follows: [ 5.438589] regmap_bulk_read after regamp_read() for register 122 [ 5.447421] 0xef993c20 0xef993c00 0x00000000 0x00000001 [ 5.467535] regmap_bulk_read after regamp_read() for register 123 [ 5.476374] 0xef993c20 0xef993c00 0x00000000 0x00000001 [ 5.496425] regmap_bulk_read after regamp_read() for register 124 [ 5.505260] 0xef993c20 0xef993c00 0x00000000 0x00000001 [ 5.525372] regmap_bulk_read after regamp_read() for register 125 [ 5.534205] 0xef993c00 0xef993c00 0x00000000 0x00000001 [ 5.554258] regmap_bulk_read after regamp_read() for register 126 [ 5.563100] 0xef990000 0xef993c00 0x00000000 0x00000001 [ 5.554258] regmap_bulk_read after regamp_read() for register 127 [ 5.587108] 0xef000000 0xef993c00 0x00000000 0x00000001 Here it is observed that the memory content at first word started changing on last 3 regmap_read() and so corruption happened. Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> |
||
|---|---|---|
| .. | ||
| power | ||
| regmap | ||
| attribute_container.c | ||
| base.h | ||
| bus.c | ||
| class.c | ||
| core.c | ||
| cpu.c | ||
| dd.c | ||
| devres.c | ||
| devtmpfs.c | ||
| dma-buf.c | ||
| dma-coherent.c | ||
| dma-mapping.c | ||
| driver.c | ||
| firmware_class.c | ||
| firmware.c | ||
| hypervisor.c | ||
| init.c | ||
| isa.c | ||
| Kconfig | ||
| Makefile | ||
| map.c | ||
| memory.c | ||
| module.c | ||
| node.c | ||
| platform.c | ||
| soc.c | ||
| syscore.c | ||
| topology.c | ||
| transport_class.c | ||