From 66b5c2c5e3778a0b6ebd80dc1c9213205e767238 Mon Sep 17 00:00:00 2001 From: Sukrut Bellary Date: Mon, 2 Sep 2024 15:14:09 +0100 Subject: [PATCH] misc: fastrpc: Fix double free of 'buf' in error path BugLink: https://bugs.launchpad.net/bugs/2085849 commit e8c276d4dc0e19ee48385f74426aebc855b49aaf upstream. smatch warning: drivers/misc/fastrpc.c:1926 fastrpc_req_mmap() error: double free of 'buf' In fastrpc_req_mmap() error path, the fastrpc buffer is freed in fastrpc_req_munmap_impl() if unmap is successful. But in the end, there is an unconditional call to fastrpc_buf_free(). So the above case triggers the double free of fastrpc buf. Fixes: 72fa6f7820c4 ("misc: fastrpc: Rework fastrpc_req_munmap") Reviewed-by: Shuah Khan Reviewed-by: Dan Carpenter Reviewed-by: Srinivas Kandagatla Signed-off-by: Sukrut Bellary Signed-off-by: Srinivas Kandagatla Cc: stable Link: https://lore.kernel.org/r/20240902141409.70371-2-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman CVE-2024-46741 Signed-off-by: Manuel Diewald Signed-off-by: Roxana Nicolescu --- drivers/misc/fastrpc.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c index f0626814d56b..4df0d7a0cd11 100644 --- a/drivers/misc/fastrpc.c +++ b/drivers/misc/fastrpc.c @@ -1912,7 +1912,8 @@ static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp) &args[0]); if (err) { dev_err(dev, "mmap error (len 0x%08llx)\n", buf->size); - goto err_invoke; + fastrpc_buf_free(buf); + return err; } /* update the buffer to be able to deallocate the memory on the DSP */ @@ -1950,8 +1951,6 @@ static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp) err_assign: fastrpc_req_munmap_impl(fl, buf); -err_invoke: - fastrpc_buf_free(buf); return err; }