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authorMark Hasemeyer <markhas@chromium.org>2023-11-07 14:47:43 -0700
committerMark Brown <broonie@kernel.org>2023-11-10 13:54:58 +0000
commitbef4a48f4ef798c4feddf045d49e53c8a97d5e37 (patch)
tree0335be36ea68996ddf09f3a21d4bffef53706264 /include/linux/spi/spi.h
parentc2ded280a4b1b7bd93e53670528504be08d24967 (diff)
spi: Fix null dereference on suspend
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
Diffstat (limited to 'include/linux/spi/spi.h')
-rw-r--r--include/linux/spi/spi.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 86825c88b576..255a0562aea5 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -566,6 +566,7 @@ struct spi_controller {
#define SPI_CONTROLLER_MUST_RX BIT(3) /* Requires rx */
#define SPI_CONTROLLER_MUST_TX BIT(4) /* Requires tx */
#define SPI_CONTROLLER_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;