All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH v1] drm/nouveau/device: use snprintf() to replace strncpy() to avoid NUL-terminated string loss
@ 2021-03-08  8:32 ` Luo Jiaxing
  0 siblings, 0 replies; 3+ messages in thread
From: Luo Jiaxing @ 2021-03-08  8:32 UTC (permalink / raw)
  To: nouveau, dri-devel, bskeggs
  Cc: linux-kernel, linuxarm, luojiaxing, song.bao.hua

Following warning is found when using W=1 to build kernel:

In function ‘nvkm_udevice_info’,
    inlined from ‘nvkm_udevice_mthd’ at drivers/gpu/drm/nouveau/nvkm/engine/device/user.c:195:10:
drivers/gpu/drm/nouveau/nvkm/engine/device/user.c:164:2: warning: ‘strncpy’ specified bound 16 equals destination size [-Wstringop-truncation]
  164 |  strncpy(args->v0.chip, device->chip->name, sizeof(args->v0.chip));
drivers/gpu/drm/nouveau/nvkm/engine/device/user.c:165:2: warning: ‘strncpy’ specified bound 64 equals destination size [-Wstringop-truncation]
  165 |  strncpy(args->v0.name, device->name, sizeof(args->v0.name));

The reason of this warning is strncpy() does not guarantee that the
destination buffer will be NUL terminated. If the length of source string
is bigger than number we set by third input parameter, only a part of
characters is copied to the destination, and no NUL-terminated string is
automatically added. There are some potential risks.

So use snprintf() to replace strncpy().

Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
---
 drivers/gpu/drm/nouveau/nvkm/engine/device/user.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c b/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c
index fea9d8f..4bf65bb 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c
@@ -161,8 +161,8 @@ nvkm_udevice_info(struct nvkm_udevice *udev, void *data, u32 size)
 	if (imem && args->v0.ram_size > 0)
 		args->v0.ram_user = args->v0.ram_user - imem->reserved;
 
-	strncpy(args->v0.chip, device->chip->name, sizeof(args->v0.chip));
-	strncpy(args->v0.name, device->name, sizeof(args->v0.name));
+	snprintf(args->v0.chip, sizeof(args->v0.chip), "%s", device->chip->name);
+	snprintf(args->v0.name, sizeof(args->v0.name), "%s", device->name);
 	return 0;
 }
 
-- 
2.7.4


^ permalink raw reply related	[flat|nested] 3+ messages in thread
* [Nouveau] [PATCH v1] drm/nouveau/device: use snprintf() to replace strncpy() to avoid NUL-terminated string loss
@ 2021-03-08  8:32 ` Luo Jiaxing
  0 siblings, 0 replies; 3+ messages in thread
From: Luo Jiaxing @ 2021-03-08  8:32 UTC (permalink / raw)
  To: nouveau, dri-devel, bskeggs
  Cc: song.bao.hua, luojiaxing, linux-kernel, linuxarm

Following warning is found when using W=1 to build kernel:

In function ‘nvkm_udevice_info’,
    inlined from ‘nvkm_udevice_mthd’ at drivers/gpu/drm/nouveau/nvkm/engine/device/user.c:195:10:
drivers/gpu/drm/nouveau/nvkm/engine/device/user.c:164:2: warning: ‘strncpy’ specified bound 16 equals destination size [-Wstringop-truncation]
  164 |  strncpy(args->v0.chip, device->chip->name, sizeof(args->v0.chip));
drivers/gpu/drm/nouveau/nvkm/engine/device/user.c:165:2: warning: ‘strncpy’ specified bound 64 equals destination size [-Wstringop-truncation]
  165 |  strncpy(args->v0.name, device->name, sizeof(args->v0.name));

The reason of this warning is strncpy() does not guarantee that the
destination buffer will be NUL terminated. If the length of source string
is bigger than number we set by third input parameter, only a part of
characters is copied to the destination, and no NUL-terminated string is
automatically added. There are some potential risks.

So use snprintf() to replace strncpy().

Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
---
 drivers/gpu/drm/nouveau/nvkm/engine/device/user.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c b/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c
index fea9d8f..4bf65bb 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c
@@ -161,8 +161,8 @@ nvkm_udevice_info(struct nvkm_udevice *udev, void *data, u32 size)
 	if (imem && args->v0.ram_size > 0)
 		args->v0.ram_user = args->v0.ram_user - imem->reserved;
 
-	strncpy(args->v0.chip, device->chip->name, sizeof(args->v0.chip));
-	strncpy(args->v0.name, device->name, sizeof(args->v0.name));
+	snprintf(args->v0.chip, sizeof(args->v0.chip), "%s", device->chip->name);
+	snprintf(args->v0.name, sizeof(args->v0.name), "%s", device->name);
 	return 0;
 }
 
-- 
2.7.4

_______________________________________________
Nouveau mailing list
Nouveau@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/nouveau

^ permalink raw reply related	[flat|nested] 3+ messages in thread
* [PATCH v1] drm/nouveau/device: use snprintf() to replace strncpy() to avoid NUL-terminated string loss
@ 2021-03-08  8:32 ` Luo Jiaxing
  0 siblings, 0 replies; 3+ messages in thread
From: Luo Jiaxing @ 2021-03-08  8:32 UTC (permalink / raw)
  To: nouveau, dri-devel, bskeggs
  Cc: song.bao.hua, luojiaxing, linux-kernel, linuxarm

Following warning is found when using W=1 to build kernel:

In function ‘nvkm_udevice_info’,
    inlined from ‘nvkm_udevice_mthd’ at drivers/gpu/drm/nouveau/nvkm/engine/device/user.c:195:10:
drivers/gpu/drm/nouveau/nvkm/engine/device/user.c:164:2: warning: ‘strncpy’ specified bound 16 equals destination size [-Wstringop-truncation]
  164 |  strncpy(args->v0.chip, device->chip->name, sizeof(args->v0.chip));
drivers/gpu/drm/nouveau/nvkm/engine/device/user.c:165:2: warning: ‘strncpy’ specified bound 64 equals destination size [-Wstringop-truncation]
  165 |  strncpy(args->v0.name, device->name, sizeof(args->v0.name));

The reason of this warning is strncpy() does not guarantee that the
destination buffer will be NUL terminated. If the length of source string
is bigger than number we set by third input parameter, only a part of
characters is copied to the destination, and no NUL-terminated string is
automatically added. There are some potential risks.

So use snprintf() to replace strncpy().

Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
---
 drivers/gpu/drm/nouveau/nvkm/engine/device/user.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c b/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c
index fea9d8f..4bf65bb 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c
@@ -161,8 +161,8 @@ nvkm_udevice_info(struct nvkm_udevice *udev, void *data, u32 size)
 	if (imem && args->v0.ram_size > 0)
 		args->v0.ram_user = args->v0.ram_user - imem->reserved;
 
-	strncpy(args->v0.chip, device->chip->name, sizeof(args->v0.chip));
-	strncpy(args->v0.name, device->name, sizeof(args->v0.name));
+	snprintf(args->v0.chip, sizeof(args->v0.chip), "%s", device->chip->name);
+	snprintf(args->v0.name, sizeof(args->v0.name), "%s", device->name);
 	return 0;
 }
 
-- 
2.7.4

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply related	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-03-08 15:34 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-03-08  8:32 [PATCH v1] drm/nouveau/device: use snprintf() to replace strncpy() to avoid NUL-terminated string loss Luo Jiaxing
2021-03-08  8:32 ` Luo Jiaxing
2021-03-08  8:32 ` [Nouveau] " Luo Jiaxing

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.