From: Emmanuel Grumbach emmanuel.grumbach@intel.com
[ Upstream commit 79f25b10c9da3dbc953e47033d0494e51580ac3b ]
We can dump data from the firmware either when it crashes, or when the firmware is alive. Not all the data is available if the firmware is running (like the Tx / Rx FIFOs which are available only when the firmware is halted), so we first check that the firmware is alive to compute the required size for the dump and then fill the buffer with the data.
When we allocate the buffer, we test the STATUS_FW_ERROR bit to check if the firmware is alive or not. This bit can be changed during the course of the dump since it is modified in the interrupt handler.
We hit a case where we allocate the buffer while the firmware is sill working, and while we start to fill the buffer, the firmware crashes. Then we test STATUS_FW_ERROR again and decide to fill the buffer with data like the FIFOs even if no room was allocated for this data in the buffer. This means that we overflow the buffer that was allocated leading to memory corruption.
To fix this, test the STATUS_FW_ERROR bit only once and rely on local variables to check if we should dump fifos or other firmware components.
Fixes: 04fd2c28226f ("iwlwifi: mvm: add rxf and txf to dump data") Signed-off-by: Emmanuel Grumbach emmanuel.grumbach@intel.com Signed-off-by: Luca Coelho luciano.coelho@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/intel/iwlwifi/fw/dbg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/wireless/intel/iwlwifi/fw/dbg.c b/drivers/net/wireless/intel/iwlwifi/fw/dbg.c index a31a42e673c46..37657e999ff8b 100644 --- a/drivers/net/wireless/intel/iwlwifi/fw/dbg.c +++ b/drivers/net/wireless/intel/iwlwifi/fw/dbg.c @@ -824,7 +824,7 @@ void iwl_fw_error_dump(struct iwl_fw_runtime *fwrt) }
/* We only dump the FIFOs if the FW is in error state */ - if (test_bit(STATUS_FW_ERROR, &fwrt->trans->status)) { + if (fifo_data_len) { iwl_fw_dump_fifos(fwrt, &dump_data); if (radio_len) iwl_read_radio_regs(fwrt, &dump_data);