lkml.org 
[lkml]   [2022]   [Nov]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH AUTOSEL 5.15 05/31] tools: iio: iio_generic_buffer: Fix read size
Date
From: Matti Vaittinen <mazziesaccount@gmail.com>

[ Upstream commit 7c919b619bcc68158921b1bd968f0e704549bbb6 ]

When noevents is true and small buffer is used the allocated memory for
holding the data may be smaller than the hard-coded 64 bytes. This can
cause the iio_generic_buffer to crash.

Following was recorded on beagle bone black with v6.0 kernel and the
digit fix patch:
https://lore.kernel.org/all/Y0f+tKCz+ZAIoroQ@dc75zzyyyyyyyyyyyyycy-3.rev.dnainternet.fi/
using valgrind;

==339== Using Valgrind-3.18.1 and LibVEX; rerun with -h for copyright info
==339== Command: /iio_generic_buffer -n kx022-accel -T0 -e -l 10 -a -w 2000000
==339== Parent PID: 307
==339==
==339== Syscall param read(buf) points to unaddressable byte(s)
==339== at 0x496BFA4: read (read.c:26)
==339== by 0x11699: main (iio_generic_buffer.c:724)
==339== Address 0x4ab3518 is 0 bytes after a block of size 160 alloc'd
==339== at 0x4864B70: malloc (vg_replace_malloc.c:381)
==339== by 0x115BB: main (iio_generic_buffer.c:677)

Fix this by always using the same size for reading as was used for
data storage allocation.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Link: https://lore.kernel.org/r/Y0kMh0t5qUXJw3nQ@dc75zzyyyyyyyyyyyyycy-3.rev.dnainternet.fi
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/iio/iio_generic_buffer.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/iio/iio_generic_buffer.c b/tools/iio/iio_generic_buffer.c
index 2491c54a5e4f..f8deae4e26a1 100644
--- a/tools/iio/iio_generic_buffer.c
+++ b/tools/iio/iio_generic_buffer.c
@@ -715,12 +715,12 @@ int main(int argc, char **argv)
continue;
}

- toread = buf_len;
} else {
usleep(timedelay);
- toread = 64;
}

+ toread = buf_len;
+
read_size = read(buf_fd, data, toread * scan_size);
if (read_size < 0) {
if (errno == EAGAIN) {
--
2.35.1
\
 
 \ /
  Last update: 2022-11-23 13:48    [W:1.449 / U:0.056 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site