[PATCH AUTOSEL 5.4 075/109] staging: rts5208: Fix get_ms_information() heap buffer size

From: Sasha Levin
Date: Thu Sep 09 2021 - 09:07:44 EST


From: Kees Cook <keescook@xxxxxxxxxxxx>

[ Upstream commit cbe34165cc1b7d1110b268ba8b9f30843c941639 ]

Fix buf allocation size (it needs to be 2 bytes larger). Found when
__alloc_size() annotations were added to kmalloc() interfaces.

In file included from ./include/linux/string.h:253,
from ./include/linux/bitmap.h:10,
from ./include/linux/cpumask.h:12,
from ./arch/x86/include/asm/paravirt.h:17,
from ./arch/x86/include/asm/irqflags.h:63,
from ./include/linux/irqflags.h:16,
from ./include/linux/rcupdate.h:26,
from ./include/linux/rculist.h:11,
from ./include/linux/pid.h:5,
from ./include/linux/sched.h:14,
from ./include/linux/blkdev.h:5,
from drivers/staging/rts5208/rtsx_scsi.c:12:
In function 'get_ms_information',
inlined from 'ms_sp_cmnd' at drivers/staging/rts5208/rtsx_scsi.c:2877:12,
inlined from 'rtsx_scsi_handler' at drivers/staging/rts5208/rtsx_scsi.c:3247:12:
./include/linux/fortify-string.h:54:29: warning: '__builtin_memcpy' forming offset [106, 107] is out
of the bounds [0, 106] [-Warray-bounds]
54 | #define __underlying_memcpy __builtin_memcpy
| ^
./include/linux/fortify-string.h:417:2: note: in expansion of macro '__underlying_memcpy'
417 | __underlying_##op(p, q, __fortify_size); \
| ^~~~~~~~~~~~~
./include/linux/fortify-string.h:463:26: note: in expansion of macro '__fortify_memcpy_chk'
463 | #define memcpy(p, q, s) __fortify_memcpy_chk(p, q, s, \
| ^~~~~~~~~~~~~~~~~~~~
drivers/staging/rts5208/rtsx_scsi.c:2851:3: note: in expansion of macro 'memcpy'
2851 | memcpy(buf + i, ms_card->raw_sys_info, 96);
| ^~~~~~

Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: linux-staging@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210818044252.1533634-1-keescook@xxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/staging/rts5208/rtsx_scsi.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/staging/rts5208/rtsx_scsi.c b/drivers/staging/rts5208/rtsx_scsi.c
index 1deb74112ad4..11d9d9155eef 100644
--- a/drivers/staging/rts5208/rtsx_scsi.c
+++ b/drivers/staging/rts5208/rtsx_scsi.c
@@ -2802,10 +2802,10 @@ static int get_ms_information(struct scsi_cmnd *srb, struct rtsx_chip *chip)
}

if (dev_info_id == 0x15) {
- buf_len = 0x3A;
+ buf_len = 0x3C;
data_len = 0x3A;
} else {
- buf_len = 0x6A;
+ buf_len = 0x6C;
data_len = 0x6A;
}

@@ -2855,11 +2855,7 @@ static int get_ms_information(struct scsi_cmnd *srb, struct rtsx_chip *chip)
}

rtsx_stor_set_xfer_buf(buf, buf_len, srb);
-
- if (dev_info_id == 0x15)
- scsi_set_resid(srb, scsi_bufflen(srb) - 0x3C);
- else
- scsi_set_resid(srb, scsi_bufflen(srb) - 0x6C);
+ scsi_set_resid(srb, scsi_bufflen(srb) - buf_len);

kfree(buf);
return STATUS_SUCCESS;
--
2.30.2