On Fri, 14 Nov 2008 19:05:31 +0100 (CET) Julia Lawall <julia@xxxxxxx> wrote: > From: Julia Lawall <julia@xxxxxxx> > > Error handling code following a kzalloc should free the allocated data. > > The semantic match that finds the problem is as follows: > (http://www.emn.fr/x-info/coccinelle/) > > // <smpl> > @r exists@ > local idexpression x; > statement S; > expression E; > identifier f,l; > position p1,p2; > expression *ptr != NULL; > @@ > > ( > if ((x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...)) == NULL) S > | > x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...); > ... > if (x == NULL) S > ) > <... when != x > when != if (...) { <+...x...+> } > x->f = E > ...> > ( > return \(0\|<+...x...+>\|ptr\); > | > return@p2 ...; > ) > > @script:python@ > p1 << r.p1; > p2 << r.p2; > @@ > > print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line) > // </smpl> > > Signed-off-by: Julia Lawall <julia@xxxxxxx> > --- > kernel/trace/trace.c | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index 697eda3..d86e325 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -1936,6 +1936,7 @@ __tracing_open(struct inode *inode, struct file *file, int *ret) > ring_buffer_read_finish(iter->buffer_iter[cpu]); > } > mutex_unlock(&trace_types_lock); > + kfree(iter); > > return ERR_PTR(-ENOMEM); > } Nobody seems to have applied this to anything yet? That function really needs help. Sometimes it will return NULL and will set *ret. Other times it will return ERR_PTR(-ENOMEM) and will fail to write anything to *ret. One caller (tracing_open) ignores the return value. Another caller (tracing_lt_open) tests the possibly-uninitialised `ret' and then blindly dereferences the possibly-IS_ERR return value. Or something like that. I looked at it long enough to convince myself that it needs fixing ;) -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
