Messages in this thread | | | Date | Mon, 6 Mar 2006 21:20:53 -0500 | From | "Latchesar Ionkov" <> | Subject | Re: 9pfs double kfree |
| |
We can't allocate it on the outermost caller's stack. The memory pointed by v9fs_fcall strucures has variable size and depends on the incoming 9P messages.
Thanks, Lucho
On 3/6/06, Andrew Morton <akpm@osdl.org> wrote: > Dave Jones <davej@redhat.com> wrote: > > > > Probably the first of many found with Coverity. > > > > This is kfree'd outside of both arms of the if condition already, > > so fall through and free it just once. > > > > Second variant is double-nasty, it deref's the free'd fcall > > before it tries to free it a second time. > > > > (I wish we had a kfree variant that NULL'd the target when it was free'd) > > > > Coverity bugs: 987, 986 > > > > Signed-off-by: Dave Jones <davej@redhat.com> > > > > > > --- linux-2.6.15.noarch/fs/9p/vfs_super.c~ 2006-03-06 01:53:38.000000000 -0500 > > +++ linux-2.6.15.noarch/fs/9p/vfs_super.c 2006-03-06 01:54:36.000000000 -0500 > > @@ -156,7 +156,6 @@ static struct super_block *v9fs_get_sb(s > > stat_result = v9fs_t_stat(v9ses, newfid, &fcall); > > if (stat_result < 0) { > > dprintk(DEBUG_ERROR, "stat error\n"); > > - kfree(fcall); > > v9fs_t_clunk(v9ses, newfid); > > } else { > > /* Setup the Root Inode */ > > --- linux-2.6.15.noarch/fs/9p/vfs_inode.c~ 2006-03-06 01:57:05.000000000 -0500 > > +++ linux-2.6.15.noarch/fs/9p/vfs_inode.c 2006-03-06 01:58:05.000000000 -0500 > > @@ -274,7 +274,6 @@ v9fs_create(struct v9fs_session_info *v9 > > PRINT_FCALL_ERROR("clone error", fcall); > > goto error; > > } > > - kfree(fcall); > > > > err = v9fs_t_create(v9ses, fid, name, perm, mode, &fcall); > > if (err < 0) { > > The second hunk is probably right and I guess the first one has to be right > as well, but it's all rather obscure, complex and (naturally) comment-free. > > So I'll duck on this - Eric, could you please handle it? Consider doing > away with the dynamically-allocated thing altogether and just allocating it > on the outermost caller's stack. > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |