This is a note to let you know that I've just added the patch titled
reset: Fix crash when freeing non-existent optional resets
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
reset-fix-crash-when-freeing-non-existent-optional-r.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ee854c1285102b29dbfab8d1cf2c4cc6c87f5bee
Author: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Date: Wed Nov 29 17:55:33 2023 +0100
reset: Fix crash when freeing non-existent optional resets
[ Upstream commit 4a6756f56bcf8e64c87144a626ce53aea4899c0e ]
When obtaining one or more optional resets, non-existent resets are
stored as NULL pointers, and all related error and cleanup paths need to
take this into account.
Currently only reset_control_put() and reset_control_bulk_put()
get this right. All of __reset_control_bulk_get(),
of_reset_control_array_get(), and reset_control_array_put() lack the
proper checking, causing NULL pointer dereferences on failure or
release.
Fix this by moving the existing check from reset_control_bulk_put() to
__reset_control_put_internal(), so it applies to all callers.
The double check in reset_control_put() doesn't hurt.
Fixes: 17c82e206d2a3cd8 ("reset: Add APIs to manage array of resets")
Fixes: 48d71395896d54ee ("reset: Add reset_control_bulk API")
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Link: https://lore.kernel.org/r/2440edae7ca8534628cdbaf559ded288f2998178.1701276806.git.geert+renesas@xxxxxxxxx
Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index ccb97f4e31c38..1680d27040c9b 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -459,6 +459,9 @@ static void __reset_control_put_internal(struct reset_control *rstc)
{
lockdep_assert_held(&reset_list_mutex);
+ if (IS_ERR_OR_NULL(rstc))
+ return;
+
kref_put(&rstc->refcnt, __reset_control_release);
}
