| Message ID | 20230602113602.1271695-1-sukrut.bellary@linux.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] misc: fastrpc: Fix double free of 'buf' in error path | expand |
On Fri, 02 Jun 2023 04:36:02 -0700, Sukrut Bellary wrote: > 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. > > [...] Applied, thanks! [1/1] misc: fastrpc: Fix double free of 'buf' in error path commit: 5b3006fffce89706a12741d7f657869ca2be1640 Best regards,
diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c index f48466960f1b..b3b520fcfb75 100644 --- a/drivers/misc/fastrpc.c +++ b/drivers/misc/fastrpc.c @@ -1882,7 +1882,8 @@ 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 */ @@ -1922,8 +1923,6 @@ 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; }
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 <skhan@linuxfoundation.org> Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Sukrut Bellary <sukrut.bellary@linux.com> --- This is based on static analysis. Compilation tested. --- Changes in v2: - Fixed the commit message. - Addressed the review comment about deleting buf from the list before freeing. - Link to v1: https://lore.kernel.org/all/20230518100829.515143-1-sukrut.bellary@linux.com/ --- drivers/misc/fastrpc.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)