The patch below does not apply to the v4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

Thanks, Sasha

------------------ original commit in Linus's tree ------------------

From 4adf613e01bf99e1739f6ff3e162ad5b7d578d1a Mon Sep 17 00:00:00 2001 From: Alexander Usyskin alexander.usyskin@intel.com Date: Tue, 15 Oct 2024 15:31:57 +0300 Subject: [PATCH] mei: use kvmalloc for read buffer

Read buffer is allocated according to max message size, reported by the firmware and may reach 64K in systems with pxp client. Contiguous 64k allocation may fail under memory pressure. Read buffer is used as in-driver message storage and not required to be contiguous. Use kvmalloc to allow kernel to allocate non-contiguous memory.

Fixes: 3030dc056459 ("mei: add wrapper for queuing control commands.") Cc: stable stable@kernel.org Reported-by: Rohit Agarwal rohiagar@chromium.org Closes: https://lore.kernel.org/all/20240813084542.2921300-1-rohiagar@chromium.org/ Tested-by: Brian Geffon bgeffon@google.com Signed-off-by: Alexander Usyskin alexander.usyskin@intel.com Acked-by: Tomas Winkler tomasw@gmail.com Link: https://lore.kernel.org/r/20241015123157.2337026-1-alexander.usyskin@intel.c... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/misc/mei/client.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c index 9d090fa07516f..be011cef12e5d 100644 --- a/drivers/misc/mei/client.c +++ b/drivers/misc/mei/client.c @@ -321,7 +321,7 @@ void mei_io_cb_free(struct mei_cl_cb *cb) return;

list_del(&cb->list); - kfree(cb->buf.data); + kvfree(cb->buf.data); kfree(cb->ext_hdr); kfree(cb); } @@ -497,7 +497,7 @@ struct mei_cl_cb *mei_cl_alloc_cb(struct mei_cl *cl, size_t length, if (length == 0) return cb;

- cb->buf.data = kmalloc(roundup(length, MEI_SLOT_SIZE), GFP_KERNEL); + cb->buf.data = kvmalloc(roundup(length, MEI_SLOT_SIZE), GFP_KERNEL); if (!cb->buf.data) { mei_io_cb_free(cb); return NULL;