On Thu, 2018-03-01 at 11:29 -0800, Bart Van Assche wrote:
> Avoid that the strchr() call in this function examines uninitialized
> data on the stack. This patch avoids that Coverity reports the
> following:
>
> CID 173252: Error handling issues (CHECKED_RETURN)
> "read(int, void *, size_t)" returns the number of bytes read, but
> it is ignored.
>
> Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
Reviewed-by: Martin Wilck <mwilck@xxxxxxxx>
> ---
> kpartx/lopart.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/kpartx/lopart.c b/kpartx/lopart.c
> index 02b29e8cf91d..69c1eda1cc5c 100644
> --- a/kpartx/lopart.c
> +++ b/kpartx/lopart.c
> @@ -64,7 +64,7 @@ char *find_loop_by_file(const char *filename)
> DIR *dir;
> struct dirent *dent;
> char dev[64], *found = NULL, *p;
> - int fd;
> + int fd, bytes_read;
> struct stat statbuf;
> struct loop_info loopinfo;
> const char VIRT_BLOCK[] = "/sys/devices/virtual/block";
> @@ -86,14 +86,15 @@ char *find_loop_by_file(const char *filename)
> if (fd < 0)
> continue;
>
> - if (read(fd, dev, sizeof(dev)) <= 0) {
> + bytes_read = read(fd, dev, sizeof(dev) - 1);
> + if (bytes_read <= 0) {
> close(fd);
> continue;
> }
>
> close(fd);
>
> - dev[sizeof(dev)-1] = '\0';
> + dev[bytes_read] = '\0';
> p = strchr(dev, '\n');
> if (p != NULL)
> *p = '\0';
--
Dr. Martin Wilck <mwilck@xxxxxxxx>, Tel. +49 (0)911 74053 2107
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
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