spi: Fixes for v6.9
A few small fixes for v6.9, the core fix is for issues with reuse of a
spi_message in the case where we've got queued messages (a relatively
rare occurrence with modern code so it wasn't noticed in testing). We
also avoid an issue with the Kunpeng driver by simply removing the debug
interface that could trigger it, and address issues with confusing and
corrupted output when printing the IP version of the AXI SPI engine.
spi: fix null pointer dereference within spi_sync
If spi_sync() is called with the non-empty queue and the same spi_message
is then reused, the complete callback for the message remains set while
the context is cleared, leading to a null pointer dereference when the
callback is invoked from spi_finalize_current_message().
With function inlining disabled, the call stack might look like this:
_raw_spin_lock_irqsave from complete_with_flags+0x18/0x58
complete_with_flags from spi_complete+0x8/0xc
spi_complete from spi_finalize_current_message+0xec/0x184
spi_finalize_current_message from spi_transfer_one_message+0x2a8/0x474
spi_transfer_one_message from __spi_pump_transfer_message+0x104/0x230
__spi_pump_transfer_message from __spi_transfer_message_noqueue+0x30/0xc4
__spi_transfer_message_noqueue from __spi_sync+0x204/0x248
__spi_sync from spi_sync+0x24/0x3c
spi_sync from mcp251xfd_regmap_crc_read+0x124/0x28c [mcp251xfd]
mcp251xfd_regmap_crc_read [mcp251xfd] from _regmap_raw_read+0xf8/0x154
_regmap_raw_read from _regmap_bus_read+0x44/0x70
_regmap_bus_read from _regmap_read+0x60/0xd8
_regmap_read from regmap_read+0x3c/0x5c
regmap_read from mcp251xfd_alloc_can_err_skb+0x1c/0x54 [mcp251xfd]
mcp251xfd_alloc_can_err_skb [mcp251xfd] from mcp251xfd_irq+0x194/0xe70 [mcp251xfd]
mcp251xfd_irq [mcp251xfd] from irq_thread_fn+0x1c/0x78
irq_thread_fn from irq_thread+0x118/0x1f4
irq_thread from kthread+0xd8/0xf4
kthread from ret_from_fork+0x14/0x28
Fix this by also setting message->complete to NULL when the transfer is
complete.
Fixes: ae7d2346dc89 ("spi: Don't use the message queue if possible in spi_sync")
Signed-off-by: Mans Rullgard <mans@mansr.com>
Link: https://lore.kernel.org/r/20240430182705.13019-1-mans@mansr.com
Signed-off-by: Mark Brown <broonie@kernel.org>
1 file changed
