From c079194c1d2fe7190fcf04fea544f3b3a25f1741 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Tue, 5 Feb 2019 13:05:20 +1100 Subject: [PATCH] drivers/media/platform/sti/delta/delta-ipc.c: fix read buffer overflow The single caller passes a string to delta_ipc_open, which copies with a fixed size larger than the string. So it copies some random data after the original string the ro segment. If the string was at the end of a page it may fault. Just copy the string with a normal strcpy after clearing the field. Found by a LTO build (which errors out) because the compiler inlines the functions and can resolve the string sizes and triggers the compile time checks in memcpy. In function `memcpy', inlined from `delta_ipc_open.constprop' at linux/drivers/media/platform/sti/delta/delta-ipc.c:178:0, inlined from `delta_mjpeg_ipc_open' at linux/drivers/media/platform/sti/delta/delta-mjpeg-dec.c:227:0, inlined from `delta_mjpeg_decode' at linux/drivers/media/platform/sti/delta/delta-mjpeg-dec.c:403:0: /home/andi/lsrc/linux/include/linux/string.h:337:0: error: call to `__read_overflow2' declared with attribute error: detected read beyond size of object passed as 2nd parameter __read_overflow2(); Link: http://lkml.kernel.org/r/20171222001212.1850-1-andi@firstfloor.org Signed-off-by: Andi Kleen Cc: Hugues FRUCHET Signed-off-by: Andrew Morton Signed-off-by: Stephen Rothwell --- drivers/media/platform/sti/delta/delta-ipc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/media/platform/sti/delta/delta-ipc.c b/drivers/media/platform/sti/delta/delta-ipc.c index a4603d573c34a7..bd1bbbeedec373 100644 --- a/drivers/media/platform/sti/delta/delta-ipc.c +++ b/drivers/media/platform/sti/delta/delta-ipc.c @@ -175,8 +175,8 @@ int delta_ipc_open(struct delta_ctx *pctx, const char *name, msg.ipc_buf_size = ipc_buf_size; msg.ipc_buf_paddr = ctx->ipc_buf->paddr; - memcpy(msg.name, name, sizeof(msg.name)); - msg.name[sizeof(msg.name) - 1] = 0; + memset(msg.name, 0, sizeof(msg.name)); + strcpy(msg.name, name); msg.param_size = param->size; memcpy(ctx->ipc_buf->vaddr, param->data, msg.param_size);