The patch below does not apply to the 5.4-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.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x e966eae72762ecfdbdb82627e2cda48845b9dd66 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025021134-kissing-enjoyer-5d7e@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e966eae72762ecfdbdb82627e2cda48845b9dd66 Mon Sep 17 00:00:00 2001 From: Ekansh Gupta quic_ekangupt@quicinc.com Date: Fri, 10 Jan 2025 13:42:39 +0000 Subject: [PATCH] misc: fastrpc: Fix copy buffer page size
For non-registered buffer, fastrpc driver copies the buffer and pass it to the remote subsystem. There is a problem with current implementation of page size calculation which is not considering the offset in the calculation. This might lead to passing of improper and out-of-bounds page size which could result in memory issue. Calculate page start and page end using the offset adjusted address instead of absolute address.
Fixes: 02b45b47fbe8 ("misc: fastrpc: fix remote page size calculation") Cc: stable@kernel.org Signed-off-by: Ekansh Gupta quic_ekangupt@quicinc.com Signed-off-by: Srinivas Kandagatla srinivas.kandagatla@linaro.org Link: https://lore.kernel.org/r/20250110134239.123603-4-srinivas.kandagatla@linaro... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c index 56dc3b3a8940..7b7a22c91fe4 100644 --- a/drivers/misc/fastrpc.c +++ b/drivers/misc/fastrpc.c @@ -1019,8 +1019,8 @@ static int fastrpc_get_args(u32 kernel, struct fastrpc_invoke_ctx *ctx) (pkt_size - rlen); pages[i].addr = pages[i].addr & PAGE_MASK;
- pg_start = (args & PAGE_MASK) >> PAGE_SHIFT; - pg_end = ((args + len - 1) & PAGE_MASK) >> PAGE_SHIFT; + pg_start = (rpra[i].buf.pv & PAGE_MASK) >> PAGE_SHIFT; + pg_end = ((rpra[i].buf.pv + len - 1) & PAGE_MASK) >> PAGE_SHIFT; pages[i].size = (pg_end - pg_start + 1) * PAGE_SIZE; args = args + mlen; rlen -= mlen;