diff options
| author | Gustavo A. R. Silva <gustavoars@kernel.org> | 2021-04-19 18:43:32 -0500 |
|---|---|---|
| committer | Gustavo A. R. Silva <gustavoars@kernel.org> | 2021-07-19 19:33:46 -0500 |
| commit | 8d4abca95ecc82fc8c41912fa0085281f19cc29f (patch) | |
| tree | bb4305f0e26bee8bb3bf80d419e0581fbaf3ce57 | |
| parent | 2734d6c1b1a089fb593ef6a23d4b70903526fe0c (diff) | |
media: ngene: Fix out-of-bounds bug in ngene_command_config_free_buf()
Fix an 11-year old bug in ngene_command_config_free_buf() while
addressing the following warnings caught with -Warray-bounds:
arch/alpha/include/asm/string.h:22:16: warning: '__builtin_memcpy' offset [12, 16] from the object at 'com' is out of the bounds of referenced subobject 'config' with type 'unsigned char' at offset 10 [-Warray-bounds]
arch/x86/include/asm/string_32.h:182:25: warning: '__builtin_memcpy' offset [12, 16] from the object at 'com' is out of the bounds of referenced subobject 'config' with type 'unsigned char' at offset 10 [-Warray-bounds]
The problem is that the original code is trying to copy 6 bytes of
data into a one-byte size member _config_ of the wrong structue
FW_CONFIGURE_BUFFERS, in a single call to memcpy(). This causes a
legitimate compiler warning because memcpy() overruns the length
of &com.cmd.ConfigureBuffers.config. It seems that the right
structure is FW_CONFIGURE_FREE_BUFFERS, instead, because it contains
6 more members apart from the header _hdr_. Also, the name of
the function ngene_command_config_free_buf() suggests that the actual
intention is to ConfigureFreeBuffers, instead of ConfigureBuffers
(which takes place in the function ngene_command_config_buf(), above).
Fix this by enclosing those 6 members of struct FW_CONFIGURE_FREE_BUFFERS
into new struct config, and use &com.cmd.ConfigureFreeBuffers.config as
the destination address, instead of &com.cmd.ConfigureBuffers.config,
when calling memcpy().
This also helps with the ongoing efforts to globally enable
-Warray-bounds and get us closer to being able to tighten the
FORTIFY_SOURCE routines on memcpy().
Link: https://github.com/KSPP/linux/issues/109
Fixes: dae52d009fc9 ("V4L/DVB: ngene: Initial check-in")
Cc: stable@vger.kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/linux-hardening/20210420001631.GA45456@embeddedor/
| -rw-r--r-- | drivers/media/pci/ngene/ngene-core.c | 2 | ||||
| -rw-r--r-- | drivers/media/pci/ngene/ngene.h | 14 |
2 files changed, 9 insertions, 7 deletions
diff --git a/drivers/media/pci/ngene/ngene-core.c b/drivers/media/pci/ngene/ngene-core.c index 07f342db6701..7481f553f959 100644 --- a/drivers/media/pci/ngene/ngene-core.c +++ b/drivers/media/pci/ngene/ngene-core.c @@ -385,7 +385,7 @@ static int ngene_command_config_free_buf(struct ngene *dev, u8 *config) com.cmd.hdr.Opcode = CMD_CONFIGURE_FREE_BUFFER; com.cmd.hdr.Length = 6; - memcpy(&com.cmd.ConfigureBuffers.config, config, 6); + memcpy(&com.cmd.ConfigureFreeBuffers.config, config, 6); com.in_len = 6; com.out_len = 0; diff --git a/drivers/media/pci/ngene/ngene.h b/drivers/media/pci/ngene/ngene.h index 84f04e0e0cb9..3d296f1998a1 100644 --- a/drivers/media/pci/ngene/ngene.h +++ b/drivers/media/pci/ngene/ngene.h @@ -407,12 +407,14 @@ enum _BUFFER_CONFIGS { struct FW_CONFIGURE_FREE_BUFFERS { struct FW_HEADER hdr; - u8 UVI1_BufferLength; - u8 UVI2_BufferLength; - u8 TVO_BufferLength; - u8 AUD1_BufferLength; - u8 AUD2_BufferLength; - u8 TVA_BufferLength; + struct { + u8 UVI1_BufferLength; + u8 UVI2_BufferLength; + u8 TVO_BufferLength; + u8 AUD1_BufferLength; + u8 AUD2_BufferLength; + u8 TVA_BufferLength; + } __packed config; } __attribute__ ((__packed__)); struct FW_CONFIGURE_UART { |