[PATCH AUTOSEL 5.4 028/187] efi/gop: Fix memory leak in __gop_query32/64()

Sasha Levin
2019-12-27T17:58:10Z

From: Arvind Sankar <nivedita@alum.mit.edu>

[ Upstream commit ff397be685e410a59c34b21ce0c55d4daa466bb7 ]

efi_graphics_output_protocol::query_mode() returns info in
callee-allocated memory which must be freed by the caller, which
we aren't doing.

We don't actually need to call query_mode() in order to obtain the
info for the current graphics mode, which is already there in
gop->mode->info, so just access it directly in the setup_gop32/64()
functions.

Also nothing uses the size of the info structure, so don't update the
passed-in size (which is the size of the gop_handle table in bytes)
unnecessarily.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191206165542.31469-5-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/firmware/efi/libstub/gop.c | 66 ++++++------------------------
1 file changed, 12 insertions(+), 54 deletions(-)

diff --git a/drivers/firmware/efi/libstub/gop.c b/drivers/firmware/efi/libstub/gop.c
index 69b2b019a1d0..b7bf1e993b8b 100644
--- a/drivers/firmware/efi/libstub/gop.c
+++ b/drivers/firmware/efi/libstub/gop.c
@@ -83,30 +83,6 @@ setup_pixel_info(struct screen_info *si, u32 pixels_per_scan_line,
}
}

-static efi_status_t
-__gop_query32(efi_system_table_t *sys_table_arg,
- struct efi_graphics_output_protocol_32 *gop32,
- struct efi_graphics_output_mode_info **info,
- unsigned long *size, u64 *fb_base)
-{
- struct efi_graphics_output_protocol_mode_32 *mode;
- efi_graphics_output_protocol_query_mode query_mode;
- efi_status_t status;
- unsigned long m;
-
- m = gop32->mode;
- mode = (struct efi_graphics_output_protocol_mode_32 *)m;
- query_mode = (void *)(unsigned long)gop32->query_mode;
-
- status = __efi_call_early(query_mode, (void *)gop32, mode->mode, size,
- info);
- if (status != EFI_SUCCESS)
- return status;
-
- *fb_base = mode->frame_buffer_base;
- return status;
-}
-
static efi_status_t
setup_gop32(efi_system_table_t *sys_table_arg, struct screen_info *si,
efi_guid_t *proto, unsigned long size, void **gop_handle)
@@ -128,6 +104,7 @@ setup_gop32(efi_system_table_t *sys_table_arg, struct screen_info *si,

nr_gops = size / sizeof(u32);
for (i = 0; i < nr_gops; i++) {
+ struct efi_graphics_output_protocol_mode_32 *mode;
struct efi_graphics_output_mode_info *info = NULL;
efi_guid_t conout_proto = EFI_CONSOLE_OUT_DEVICE_GUID;
bool conout_found = false;
@@ -145,9 +122,11 @@ setup_gop32(efi_system_table_t *sys_table_arg, struct screen_info *si,
if (status == EFI_SUCCESS)
conout_found = true;

- status = __gop_query32(sys_table_arg, gop32, &info, &size,
- &current_fb_base);
- if (status == EFI_SUCCESS && (!first_gop || conout_found) &&
+ mode = (void *)(unsigned long)gop32->mode;
+ info = (void *)(unsigned long)mode->info;
+ current_fb_base = mode->frame_buffer_base;
+
+ if ((!first_gop || conout_found) &&
info->pixel_format != PIXEL_BLT_ONLY) {
/*
* Systems that use the UEFI Console Splitter may
@@ -201,30 +180,6 @@ setup_gop32(efi_system_table_t *sys_table_arg, struct screen_info *si,
return EFI_SUCCESS;
}

-static efi_status_t
-__gop_query64(efi_system_table_t *sys_table_arg,
- struct efi_graphics_output_protocol_64 *gop64,
- struct efi_graphics_output_mode_info **info,
- unsigned long *size, u64 *fb_base)
-{
- struct efi_graphics_output_protocol_mode_64 *mode;
- efi_graphics_output_protocol_query_mode query_mode;
- efi_status_t status;
- unsigned long m;
-
- m = gop64->mode;
- mode = (struct efi_graphics_output_protocol_mode_64 *)m;
- query_mode = (void *)(unsigned long)gop64->query_mode;
-
- status = __efi_call_early(query_mode, (void *)gop64, mode->mode, size,
- info);
- if (status != EFI_SUCCESS)
- return status;
-
- *fb_base = mode->frame_buffer_base;
- return status;
-}
-
static efi_status_t
setup_gop64(efi_system_table_t *sys_table_arg, struct screen_info *si,
efi_guid_t *proto, unsigned long size, void **gop_handle)
@@ -246,6 +201,7 @@ setup_gop64(efi_system_table_t *sys_table_arg, struct screen_info *si,

nr_gops = size / sizeof(u64);
for (i = 0; i < nr_gops; i++) {
+ struct efi_graphics_output_protocol_mode_64 *mode;
struct efi_graphics_output_mode_info *info = NULL;
efi_guid_t conout_proto = EFI_CONSOLE_OUT_DEVICE_GUID;
bool conout_found = false;
@@ -263,9 +219,11 @@ setup_gop64(efi_system_table_t *sys_table_arg, struct screen_info *si,
if (status == EFI_SUCCESS)
conout_found = true;

- status = __gop_query64(sys_table_arg, gop64, &info, &size,
- &current_fb_base);
- if (status == EFI_SUCCESS && (!first_gop || conout_found) &&
+ mode = (void *)(unsigned long)gop64->mode;
+ info = (void *)(unsigned long)mode->info;
+ current_fb_base = mode->frame_buffer_base;
+
+ if ((!first_gop || conout_found) &&
info->pixel_format != PIXEL_BLT_ONLY) {
/*
* Systems that use the UEFI Console Splitter may
--
2.20.1