3.19.8-ckt5 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Daniel Axtens <[email protected]> commit 2c069a118fe1d80c47dca84e1561045fc7f3cc9e upstream. The pointer to an AFU in the adapter's list of AFUs can be null if we're in the process of removing AFUs. The afu_list_lock doesn't guard against this. Say we have 2 slices, and we're in the process of removing cxl. - We remove the AFUs in order (see cxl_remove). In cxl_remove_afu for AFU 0, we take the lock, set adapter->afu[0] = NULL, and release the lock. - Then we get an slbia. In cxl_slbia we take the lock, and set afu = adapter->afu[0], which is NULL. - Therefore our attempt to check afu->enabled will blow up. Therefore, check if afu is a null pointer before dereferencing it. Signed-off-by: Daniel Axtens <[email protected]> Acked-by: Michael Neuling <[email protected]> Acked-by: Ian Munsie <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Signed-off-by: Kamal Mostafa <[email protected]> --- drivers/misc/cxl/main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/misc/cxl/main.c b/drivers/misc/cxl/main.c index 4cde9b6..619c7b4 100644 --- a/drivers/misc/cxl/main.c +++ b/drivers/misc/cxl/main.c @@ -71,7 +71,7 @@ static inline void cxl_slbia_core(struct mm_struct *mm) spin_lock(&adapter->afu_list_lock); for (slice = 0; slice < adapter->slices; slice++) { afu = adapter->afu[slice]; - if (!afu->enabled) + if (!afu || !afu->enabled) continue; rcu_read_lock(); idr_for_each_entry(&afu->contexts_idr, ctx, id) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
