* [PATCH v5] media: gspca: cpia1: shift-out-of-bounds in set_flicker
@ 2023-08-30 7:44 coolrrsh
[not found] ` <CA+VNjV0pkR7w5Z_z8wS8WxckfSJ43sN8rGkWO6nxzYNHL4U46Q@mail.gmail.com>
0 siblings, 1 reply; 3+ messages in thread
From: coolrrsh @ 2023-08-30 7:44 UTC (permalink / raw)
To: hverkuil, mchehab, slark_xiao, linux-media, linux-kernel
Cc: linux-kernel-mentees, Rajeshwar R Shinde,
syzbot+e27f3dbdab04e43b9f73
From: Rajeshwar R Shinde <coolrrsh@gmail.com>
Syzkaller reported the following issue:
UBSAN: shift-out-of-bounds in drivers/media/usb/gspca/cpia1.c:1031:27
shift exponent 245 is too large for 32-bit type 'int'
When the value of the variable "sd->params.exposure.gain" exceeds the
number of bits in an integer, a shift-out-of-bounds error is reported. It
is triggered because the variable "currentexp" cannot be left-shifted by
more than the number of bits in an integer. In order to avoid invalid
range during left-shift, the conditional expression is added.
Reported-by: syzbot+e27f3dbdab04e43b9f73@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/20230818164522.12806-1-coolrrsh@gmail.com
Link: https://syzkaller.appspot.com/bug?extid=e27f3dbdab04e43b9f73
Signed-off-by: Rajeshwar R Shinde <coolrrsh@gmail.com>
---
v1->v2
Changed the patch. Instead of avoiding shift operation for invalid
input of 'exposure.gain', throw an error for invalid range.
v2->v3
Changed the commit message details
v3->v4
Removed the trailing spaces in commit message
v4->v5
Replaced the hardcoded value with inbuilt macro
---
drivers/media/usb/gspca/cpia1.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/media/usb/gspca/cpia1.c b/drivers/media/usb/gspca/cpia1.c
index 46ed95483e22..5f5fa851ca64 100644
--- a/drivers/media/usb/gspca/cpia1.c
+++ b/drivers/media/usb/gspca/cpia1.c
@@ -18,6 +18,7 @@
#include <linux/input.h>
#include <linux/sched/signal.h>
+#include <linux/bitops.h>
#include "gspca.h"
@@ -1028,6 +1029,8 @@ static int set_flicker(struct gspca_dev *gspca_dev, int on, int apply)
sd->params.exposure.expMode = 2;
sd->exposure_status = EXPOSURE_NORMAL;
}
+ if (sd->params.exposure.gain >= BITS_PER_TYPE(currentexp))
+ return -EINVAL;
currentexp = currentexp << sd->params.exposure.gain;
sd->params.exposure.gain = 0;
/* round down current exposure to nearest value */
--
2.25.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH v5] media: gspca: cpia1: shift-out-of-bounds in set_flicker
@ 2023-08-27 18:53 coolrrsh
0 siblings, 0 replies; 3+ messages in thread
From: coolrrsh @ 2023-08-27 18:53 UTC (permalink / raw)
To: hverkuil, mchehab, slark_xiao, linux-media, linux-kernel
Cc: linux-kernel-mentees, Rajeshwar R Shinde,
syzbot+e27f3dbdab04e43b9f73
From: Rajeshwar R Shinde <coolrrsh@gmail.com>
Syzkaller reported the following issue:
UBSAN: shift-out-of-bounds in drivers/media/usb/gspca/cpia1.c:1031:27
shift exponent 245 is too large for 32-bit type 'int'
When the value of the variable "sd->params.exposure.gain" exceeds the
number of bits in an integer, a shift-out-of-bounds error is reported. It
is triggered because the variable "currentexp" cannot be left-shifted by
more than the number of bits in an integer. In order to avoid invalid
range during left-shift, the conditional expression is added.
Reported-by: syzbot+e27f3dbdab04e43b9f73@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/20230818164522.12806-1-coolrrsh@gmail.com
Link: https://syzkaller.appspot.com/bug?extid=e27f3dbdab04e43b9f73
Signed-off-by: Rajeshwar R Shinde <coolrrsh@gmail.com>
---
v1->v2
Changed the patch. Instead of avoiding shift operation for invalid
input of 'exposure.gain', throw an error for invalid range.
v2->v3
Changed the commit message details
v3->v4
Removed the trailing spaces in commit message
v4->v5
Replaced the hardcoded value with inbuilt macro
---
drivers/media/usb/gspca/cpia1.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/media/usb/gspca/cpia1.c b/drivers/media/usb/gspca/cpia1.c
index 46ed95483e22..5f5fa851ca64 100644
--- a/drivers/media/usb/gspca/cpia1.c
+++ b/drivers/media/usb/gspca/cpia1.c
@@ -18,6 +18,7 @@
#include <linux/input.h>
#include <linux/sched/signal.h>
+#include <linux/bitops.h>
#include "gspca.h"
@@ -1028,6 +1029,8 @@ static int set_flicker(struct gspca_dev *gspca_dev, int on, int apply)
sd->params.exposure.expMode = 2;
sd->exposure_status = EXPOSURE_NORMAL;
}
+ if (sd->params.exposure.gain >= BITS_PER_TYPE(currentexp))
+ return -EINVAL;
currentexp = currentexp << sd->params.exposure.gain;
sd->params.exposure.gain = 0;
/* round down current exposure to nearest value */
--
2.25.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
end of thread, other threads:[~2023-09-04 7:23 UTC | newest]
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2023-08-30 7:44 [PATCH v5] media: gspca: cpia1: shift-out-of-bounds in set_flicker coolrrsh
[not found] ` <CA+VNjV0pkR7w5Z_z8wS8WxckfSJ43sN8rGkWO6nxzYNHL4U46Q@mail.gmail.com>
2023-09-04 7:23 ` Hans Verkuil
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2023-08-27 18:53 coolrrsh
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