From 699ec4d5b306dfe446ec394916b7c392b205561f Mon Sep 17 00:00:00 2001 From: Ekansh Gupta Date: Fri, 10 Jan 2025 21:42:39 +0800 Subject: [PATCH] misc: fastrpc: Fix copy buffer page size ANBZ: #19148 commit e966eae72762ecfdbdb82627e2cda48845b9dd66 upstream. 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 Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20250110134239.123603-4-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman Fixes: CVE-2025-21734 Signed-off-by: Xiao Long --- drivers/misc/fastrpc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c index 65f24b6150aa..848767855301 100644 --- a/drivers/misc/fastrpc.c +++ b/drivers/misc/fastrpc.c @@ -844,8 +844,8 @@ 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; -- Gitee