From: Rob Herring <robh@kernel.org> To: frowand.list@gmail.com Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>, Michael Ellerman <mpe@ellerman.id.au>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Paul Mackerras <paulus@samba.org>, Alan Tull <atull@kernel.org>, Moritz Fischer <mdf@kernel.org>, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, devicetree@vger.kernel.org, linux-fpga@vger.kernel.org Subject: Re: [PATCH v4 02/18] of: overlay: add missing of_node_put() after add new node to changeset Date: Thu, 18 Oct 2018 12:05:02 -0500 [thread overview] Message-ID: <20181018170502.GB15557@bogus> (raw) In-Reply-To: <1539657458-24401-3-git-send-email-frowand.list@gmail.com> On Mon, Oct 15, 2018 at 07:37:22PM -0700, frowand.list@gmail.com wrote: > From: Frank Rowand <frank.rowand@sony.com> > > The refcount of a newly added overlay node decrements to one > (instead of zero) when the overlay changeset is destroyed. This > change will cause the final decrement be to zero. > > After applying this patch, new validation warnings will be > reported from the devicetree unittest during boot due to > a pre-existing devicetree bug. The warnings will be similar to: > > OF: ERROR: memory leak of_node_release() overlay node /testcase-data/overlay-node/test-bus/test-unittest4 before free overlay changeset Same comment on formatting. > > This pre-existing devicetree bug will also trigger a WARN_ONCE() from > refcount_sub_and_test_checked() when an overlay changeset is > destroyed without having first been applied. This scenario occurs > when an error in the overlay is detected during the overlay changeset > creation: > > WARNING: CPU: 0 PID: 1 at lib/refcount.c:187 refcount_sub_and_test_checked+0xa8/0xbc > refcount_t: underflow; use-after-free. > > (unwind_backtrace) from (show_stack+0x10/0x14) > (show_stack) from (dump_stack+0x6c/0x8c) > (dump_stack) from (__warn+0xdc/0x104) > (__warn) from (warn_slowpath_fmt+0x44/0x6c) > (warn_slowpath_fmt) from (refcount_sub_and_test_checked+0xa8/0xbc) > (refcount_sub_and_test_checked) from (kobject_put+0x24/0x208) > (kobject_put) from (of_changeset_destroy+0x2c/0xb4) > (of_changeset_destroy) from (free_overlay_changeset+0x1c/0x9c) > (free_overlay_changeset) from (of_overlay_remove+0x284/0x2cc) > (of_overlay_remove) from (of_unittest_apply_revert_overlay_check.constprop.4+0xf8/0x1e8) > (of_unittest_apply_revert_overlay_check.constprop.4) from (of_unittest_overlay+0x960/0xed8) > (of_unittest_overlay) from (of_unittest+0x1cc4/0x2138) > (of_unittest) from (do_one_initcall+0x4c/0x28c) > (do_one_initcall) from (kernel_init_freeable+0x29c/0x378) > (kernel_init_freeable) from (kernel_init+0x8/0x110) > (kernel_init) from (ret_from_fork+0x14/0x2c) > > Signed-off-by: Frank Rowand <frank.rowand@sony.com> > --- > drivers/of/overlay.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c > index 1176cb4b6e4e..32cfee68f2e3 100644 > --- a/drivers/of/overlay.c > +++ b/drivers/of/overlay.c > @@ -379,7 +379,9 @@ static int add_changeset_node(struct overlay_changeset *ovcs, > if (ret) > return ret; > > - return build_changeset_next_level(ovcs, tchild, node); > + ret = build_changeset_next_level(ovcs, tchild, node); > + of_node_put(tchild); > + return ret; > } > > if (node->phandle && tchild->phandle) > -- > Frank Rowand <frank.rowand@sony.com> >
WARNING: multiple messages have this Message-ID (diff)
From: Rob Herring <robh@kernel.org> To: frowand.list@gmail.com Cc: devicetree@vger.kernel.org, Alan Tull <atull@kernel.org>, linux-fpga@vger.kernel.org, Pantelis Antoniou <pantelis.antoniou@konsulko.com>, linux-kernel@vger.kernel.org, Moritz Fischer <mdf@kernel.org>, Paul Mackerras <paulus@samba.org>, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH v4 02/18] of: overlay: add missing of_node_put() after add new node to changeset Date: Thu, 18 Oct 2018 12:05:02 -0500 [thread overview] Message-ID: <20181018170502.GB15557@bogus> (raw) In-Reply-To: <1539657458-24401-3-git-send-email-frowand.list@gmail.com> On Mon, Oct 15, 2018 at 07:37:22PM -0700, frowand.list@gmail.com wrote: > From: Frank Rowand <frank.rowand@sony.com> > > The refcount of a newly added overlay node decrements to one > (instead of zero) when the overlay changeset is destroyed. This > change will cause the final decrement be to zero. > > After applying this patch, new validation warnings will be > reported from the devicetree unittest during boot due to > a pre-existing devicetree bug. The warnings will be similar to: > > OF: ERROR: memory leak of_node_release() overlay node /testcase-data/overlay-node/test-bus/test-unittest4 before free overlay changeset Same comment on formatting. > > This pre-existing devicetree bug will also trigger a WARN_ONCE() from > refcount_sub_and_test_checked() when an overlay changeset is > destroyed without having first been applied. This scenario occurs > when an error in the overlay is detected during the overlay changeset > creation: > > WARNING: CPU: 0 PID: 1 at lib/refcount.c:187 refcount_sub_and_test_checked+0xa8/0xbc > refcount_t: underflow; use-after-free. > > (unwind_backtrace) from (show_stack+0x10/0x14) > (show_stack) from (dump_stack+0x6c/0x8c) > (dump_stack) from (__warn+0xdc/0x104) > (__warn) from (warn_slowpath_fmt+0x44/0x6c) > (warn_slowpath_fmt) from (refcount_sub_and_test_checked+0xa8/0xbc) > (refcount_sub_and_test_checked) from (kobject_put+0x24/0x208) > (kobject_put) from (of_changeset_destroy+0x2c/0xb4) > (of_changeset_destroy) from (free_overlay_changeset+0x1c/0x9c) > (free_overlay_changeset) from (of_overlay_remove+0x284/0x2cc) > (of_overlay_remove) from (of_unittest_apply_revert_overlay_check.constprop.4+0xf8/0x1e8) > (of_unittest_apply_revert_overlay_check.constprop.4) from (of_unittest_overlay+0x960/0xed8) > (of_unittest_overlay) from (of_unittest+0x1cc4/0x2138) > (of_unittest) from (do_one_initcall+0x4c/0x28c) > (do_one_initcall) from (kernel_init_freeable+0x29c/0x378) > (kernel_init_freeable) from (kernel_init+0x8/0x110) > (kernel_init) from (ret_from_fork+0x14/0x2c) > > Signed-off-by: Frank Rowand <frank.rowand@sony.com> > --- > drivers/of/overlay.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c > index 1176cb4b6e4e..32cfee68f2e3 100644 > --- a/drivers/of/overlay.c > +++ b/drivers/of/overlay.c > @@ -379,7 +379,9 @@ static int add_changeset_node(struct overlay_changeset *ovcs, > if (ret) > return ret; > > - return build_changeset_next_level(ovcs, tchild, node); > + ret = build_changeset_next_level(ovcs, tchild, node); > + of_node_put(tchild); > + return ret; > } > > if (node->phandle && tchild->phandle) > -- > Frank Rowand <frank.rowand@sony.com> >
next prev parent reply other threads:[~2018-10-18 17:05 UTC|newest] Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-10-16 2:37 [PATCH v4 00/18] of: overlay: validation checks, subsequent fixes frowand.list 2018-10-16 2:37 ` frowand.list 2018-10-16 2:37 ` [PATCH v4 01/18] of: overlay: add tests to validate kfrees from overlay removal frowand.list 2018-10-16 2:37 ` frowand.list 2018-10-17 21:30 ` Alan Tull 2018-10-17 21:30 ` Alan Tull 2018-10-17 21:30 ` Alan Tull 2018-10-18 20:24 ` Alan Tull 2018-10-18 20:24 ` Alan Tull 2018-10-18 20:24 ` Alan Tull 2018-10-18 17:03 ` Rob Herring 2018-10-18 17:03 ` Rob Herring 2018-10-18 19:01 ` Frank Rowand 2018-10-18 19:01 ` Frank Rowand 2018-10-16 2:37 ` [PATCH v4 02/18] of: overlay: add missing of_node_put() after add new node to changeset frowand.list 2018-10-16 2:37 ` frowand.list 2018-10-18 17:05 ` Rob Herring [this message] 2018-10-18 17:05 ` Rob Herring 2018-10-18 19:02 ` Frank Rowand 2018-10-18 19:02 ` Frank Rowand 2018-10-16 2:37 ` [PATCH v4 03/18] of: overlay: add missing of_node_get() in __of_attach_node_sysfs frowand.list 2018-10-16 2:37 ` frowand.list 2018-10-16 2:37 ` [PATCH v4 04/18] powerpc/pseries: add of_node_put() in dlpar_detach_node() frowand.list 2018-10-16 2:37 ` frowand.list 2018-10-18 17:09 ` Rob Herring 2018-10-18 17:09 ` Rob Herring 2018-10-18 19:09 ` Frank Rowand 2018-10-18 19:09 ` Frank Rowand 2018-10-19 16:10 ` Rob Herring 2018-10-19 16:10 ` Rob Herring 2018-10-16 2:37 ` [PATCH v4 05/18] of: overlay: use prop add changeset entry for property in new nodes frowand.list 2018-10-16 2:37 ` frowand.list 2018-10-16 2:37 ` [PATCH v4 06/18] of: overlay: do not duplicate properties from overlay for " frowand.list 2018-10-16 2:37 ` frowand.list 2018-10-16 2:37 ` [PATCH v4 07/18] of: dynamic: change type of of_{at,de}tach_node() to void frowand.list 2018-10-16 2:37 ` [PATCH v4 07/18] of: dynamic: change type of of_{at, de}tach_node() " frowand.list 2018-10-16 2:37 ` [PATCH v4 08/18] of: overlay: reorder fields in struct fragment frowand.list 2018-10-16 2:37 ` frowand.list 2018-10-16 2:37 ` [PATCH v4 09/18] of: overlay: validate overlay properties #address-cells and #size-cells frowand.list 2018-10-16 2:37 ` frowand.list 2018-10-18 18:13 ` Rob Herring 2018-10-18 18:13 ` Rob Herring 2018-10-18 19:13 ` Frank Rowand 2018-10-18 19:13 ` Frank Rowand 2018-10-16 2:37 ` [PATCH v4 10/18] of: overlay: make all pr_debug() and pr_err() messages unique frowand.list 2018-10-16 2:37 ` frowand.list 2018-10-16 2:37 ` [PATCH v4 11/18] of: overlay: test case of two fragments adding same node frowand.list 2018-10-16 2:37 ` frowand.list 2018-10-16 2:37 ` [PATCH v4 12/18] of: overlay: check prevents multiple fragments add or delete " frowand.list 2018-10-16 2:37 ` frowand.list 2018-10-16 2:37 ` [PATCH v4 13/18] of: overlay: check prevents multiple fragments touching same property frowand.list 2018-10-16 2:37 ` frowand.list 2018-10-16 2:37 ` [PATCH v4 14/18] of: unittest: remove unused of_unittest_apply_overlay() argument frowand.list 2018-10-16 2:37 ` frowand.list 2018-10-16 2:37 ` [PATCH v4 15/18] of: overlay: set node fields from properties when add new overlay node frowand.list 2018-10-16 2:37 ` frowand.list 2018-10-16 2:37 ` [PATCH v4 16/18] of: unittest: allow base devicetree to have symbol metadata frowand.list 2018-10-16 2:37 ` frowand.list 2018-10-16 2:37 ` [PATCH v4 17/18] of: unittest: find overlays[] entry by name instead of index frowand.list 2018-10-16 2:37 ` frowand.list 2018-10-16 2:37 ` [PATCH v4 18/18] of: unittest: initialize args before calling of_*parse_*() frowand.list 2018-10-16 2:37 ` frowand.list 2018-10-16 9:47 ` [PATCH v4 00/18] of: overlay: validation checks, subsequent fixes Michael Ellerman 2018-10-16 9:47 ` Michael Ellerman 2018-10-17 3:08 ` Frank Rowand 2018-10-17 3:08 ` Frank Rowand 2018-10-17 21:16 ` Alan Tull 2018-10-17 21:16 ` Alan Tull 2018-10-17 21:16 ` Alan Tull
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20181018170502.GB15557@bogus \ --to=robh@kernel.org \ --cc=atull@kernel.org \ --cc=benh@kernel.crashing.org \ --cc=devicetree@vger.kernel.org \ --cc=frowand.list@gmail.com \ --cc=linux-fpga@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linuxppc-dev@lists.ozlabs.org \ --cc=mdf@kernel.org \ --cc=mpe@ellerman.id.au \ --cc=pantelis.antoniou@konsulko.com \ --cc=paulus@samba.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.