diff options
| author | Mark Hasemeyer | 2023-11-07 14:47:43 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-12-08 08:51:19 +0100 |
| commit | 4ec4508db97502a12daee88c74782e8d35ced068 (patch) | |
| tree | 75a33cddbafa17d24f53dee3baaacb117f26303a /include/linux | |
| parent | b57eebfb80e81f8cc01cd038ceaabca860a22236 (diff) | |
spi: Fix null dereference on suspend
[ Upstream commit bef4a48f4ef798c4feddf045d49e53c8a97d5e37 ]
A race condition exists where a synchronous (noqueue) transfer can be
active during a system suspend. This can cause a null pointer
dereference exception to occur when the system resumes.
Example order of events leading to the exception:
1. spi_sync() calls __spi_transfer_message_noqueue() which sets
ctlr->cur_msg
2. Spi transfer begins via spi_transfer_one_message()
3. System is suspended interrupting the transfer context
4. System is resumed
6. spi_controller_resume() calls spi_start_queue() which resets cur_msg
to NULL
7. Spi transfer context resumes and spi_finalize_current_message() is
called which dereferences cur_msg (which is now NULL)
Wait for synchronous transfers to complete before suspending by
acquiring the bus mutex and setting/checking a suspend flag.
Signed-off-by: Mark Hasemeyer <markhas@chromium.org>
Link: https://lore.kernel.org/r/20231107144743.v1.1.I7987f05f61901f567f7661763646cb7d7919b528@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/spi/spi.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index fbf8c0d95968..877395e075af 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -531,6 +531,7 @@ struct spi_controller { #define SPI_CONTROLLER_MUST_TX BIT(4) /* Requires tx */ #define SPI_MASTER_GPIO_SS BIT(5) /* GPIO CS must select slave */ +#define SPI_CONTROLLER_SUSPENDED BIT(6) /* Currently suspended */ /* Flag indicating if the allocation of this struct is devres-managed */ bool devm_allocated; |