This is a note to let you know that I've just added the patch titled misc: fastrpc: Fix incorrect DMA mapping unmap request to the 6.5-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: misc-fastrpc-fix-incorrect-dma-mapping-unmap-request.patch and it can be found in the queue-6.5 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a2cb9cd6a3949a3804ad9fd7da234892ce6719ec Mon Sep 17 00:00:00 2001 From: Ekansh Gupta <quic_ekangupt@xxxxxxxxxxx> Date: Fri, 11 Aug 2023 12:56:42 +0100 Subject: misc: fastrpc: Fix incorrect DMA mapping unmap request From: Ekansh Gupta <quic_ekangupt@xxxxxxxxxxx> commit a2cb9cd6a3949a3804ad9fd7da234892ce6719ec upstream. Scatterlist table is obtained during map create request and the same table is used for DMA mapping unmap. In case there is any failure while getting the sg_table, ERR_PTR is returned instead of sg_table. When the map is getting freed, there is only a non-NULL check of sg_table which will also be true in case failure was returned instead of sg_table. This would result in improper unmap request. Add proper check before setting map table to avoid bad unmap request. Fixes: c68cfb718c8f ("misc: fastrpc: Add support for context Invoke method") Cc: stable <stable@xxxxxxxxxx> Signed-off-by: Ekansh Gupta <quic_ekangupt@xxxxxxxxxxx> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx> Link: https://lore.kernel.org/r/20230811115643.38578-3-srinivas.kandagatla@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/misc/fastrpc.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/drivers/misc/fastrpc.c +++ b/drivers/misc/fastrpc.c @@ -756,6 +756,7 @@ static int fastrpc_map_create(struct fas { struct fastrpc_session_ctx *sess = fl->sctx; struct fastrpc_map *map = NULL; + struct sg_table *table; int err = 0; if (!fastrpc_map_lookup(fl, fd, ppmap, true)) @@ -783,11 +784,12 @@ static int fastrpc_map_create(struct fas goto attach_err; } - map->table = dma_buf_map_attachment_unlocked(map->attach, DMA_BIDIRECTIONAL); - if (IS_ERR(map->table)) { - err = PTR_ERR(map->table); + table = dma_buf_map_attachment_unlocked(map->attach, DMA_BIDIRECTIONAL); + if (IS_ERR(table)) { + err = PTR_ERR(table); goto map_err; } + map->table = table; if (attr & FASTRPC_ATTR_SECUREMAP) { map->phys = sg_phys(map->table->sgl); Patches currently in stable-queue which might be from quic_ekangupt@xxxxxxxxxxx are queue-6.5/misc-fastrpc-fix-remote-heap-allocation-request.patch queue-6.5/misc-fastrpc-fix-incorrect-dma-mapping-unmap-request.patch