| Message ID | 1381471493-6464-1-git-send-email-famz@redhat.com |
|---|---|
| State | New |
| Headers | show |
Am 11.10.2013 um 08:04 hat Fam Zheng geschrieben: > An extra 'p++' after while loop when *p == '\n' will move p to unknown > data position, risking parsing junk data or memory access violation. > > Cc: qemu-stable@nongnu.org > Signed-off-by: Fam Zheng <famz@redhat.com> > --- > block/vmdk.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/block/vmdk.c b/block/vmdk.c > index 5d56e31..f2dda21 100644 > --- a/block/vmdk.c > +++ b/block/vmdk.c > @@ -760,10 +760,13 @@ static int vmdk_parse_extents(const char *desc, BlockDriverState *bs, > } > next_line: > /* move to next line */ > - while (*p && *p != '\n') { > + while (*p) { > p++; If the first not yet parsed character is \n, you're missing a line break now, aren't you? > + if (*p == '\n') { > + p++; > + break; > + } > } > - p++; > } > return 0; > } Kevin
On Fri, 10/11 13:23, Kevin Wolf wrote: > Am 11.10.2013 um 08:04 hat Fam Zheng geschrieben: > > An extra 'p++' after while loop when *p == '\n' will move p to unknown > > data position, risking parsing junk data or memory access violation. > > > > Cc: qemu-stable@nongnu.org > > Signed-off-by: Fam Zheng <famz@redhat.com> > > --- > > block/vmdk.c | 7 +++++-- > > 1 file changed, 5 insertions(+), 2 deletions(-) > > > > diff --git a/block/vmdk.c b/block/vmdk.c > > index 5d56e31..f2dda21 100644 > > --- a/block/vmdk.c > > +++ b/block/vmdk.c > > @@ -760,10 +760,13 @@ static int vmdk_parse_extents(const char *desc, BlockDriverState *bs, > > } > > next_line: > > /* move to next line */ > > - while (*p && *p != '\n') { > > + while (*p) { > > p++; > > If the first not yet parsed character is \n, you're missing a line break > now, aren't you? > Yes. This case it can miss a whole line following an empty line. Will fix. Thanks. Fam
diff --git a/block/vmdk.c b/block/vmdk.c index 5d56e31..f2dda21 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -760,10 +760,13 @@ static int vmdk_parse_extents(const char *desc, BlockDriverState *bs, } next_line: /* move to next line */ - while (*p && *p != '\n') { + while (*p) { p++; + if (*p == '\n') { + p++; + break; + } } - p++; } return 0; }
An extra 'p++' after while loop when *p == '\n' will move p to unknown data position, risking parsing junk data or memory access violation. Cc: qemu-stable@nongnu.org Signed-off-by: Fam Zheng <famz@redhat.com> --- block/vmdk.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)