On Thu, 03 Feb 2011 04:18:58 +0900 "J. R. Okajima" <hooanon05@xxxxxxxxxxx> wrote: > > commit e1ddf5b0dd3e8234581c78c3cadd6e2adfe6e2d4 > Author: J. R. Okajima <hooanon05@xxxxxxxxxxx> > Date: Thu Feb 3 03:38:12 2011 +0900 > > fix filp_cachep memory corruption > > By the commit > 31e6b01 2011-01-07 fs: rcu-walk for path lookup > the condition "-ESTALE && !LOOKUP_REVAL" is added to "goto reval" in > do_filp_open(), and it lookup again with LOOKUP_REVAL _after_ > release_open_intent(). Since release_open_intent() is called by > do_last() and finish_open() too, add the same condition to all of them. > > Signed-off-by: J. R. Okajima <hooanon05@xxxxxxxxxxx> > > diff --git a/fs/namei.c b/fs/namei.c > index 084be4d..1f62d6a 100644 > --- a/fs/namei.c > +++ b/fs/namei.c > @@ -2269,7 +2269,8 @@ static struct file *finish_open(struct nameidata *nd, > return filp; > > exit: > - if (!IS_ERR(nd->intent.open.file)) > + if (!(error == -ESTALE && !(nd->flags & LOOKUP_REVAL)) > + && !IS_ERR(nd->intent.open.file)) > release_open_intent(nd); > path_put(&nd->path); > return ERR_PTR(error); > @@ -2393,7 +2394,8 @@ exit_mutex_unlock: > exit_dput: > path_put_conditional(path, nd); > exit: > - if (!IS_ERR(nd->intent.open.file)) > + if (!(error == -ESTALE && !(nd->flags & LOOKUP_REVAL)) > + && !IS_ERR(nd->intent.open.file)) > release_open_intent(nd); > path_put(&nd->path); > return ERR_PTR(error); > @@ -2564,7 +2566,8 @@ exit_dput: > out_path: > path_put(&nd.path); > out_filp: > - if (!IS_ERR(nd.intent.open.file)) > + if (!(error == -ESTALE && !(flags & LOOKUP_REVAL)) > + && !IS_ERR(nd.intent.open.file)) > release_open_intent(&nd); > filp = ERR_PTR(error); > goto out; The patch is pretty ugly. It would be much nicer if we had a well-named and documented helper function to replace that repeated open-coded test. Not just because the code looks better - a standalone function is an opportunity to explain to readers what the code is trying to do. Anyway, as Nick appears to have done a dump-and-run on the kernel project, I shall send your fix into Linus as-is. Perhaps you or Nick could look into cleaning things up later on? -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
