From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754841Ab2IQAvj (ORCPT ); Sun, 16 Sep 2012 20:51:39 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33977 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754809Ab2IQAvh (ORCPT ); Sun, 16 Sep 2012 20:51:37 -0400 Message-Id: <20120917003630.419920585@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 17 Sep 2012 01:36:55 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Artem Bityutskiy , Richard Genoud Subject: [ 030/135] UBI: fix a horrible memory deallocation bug In-Reply-To: <20120917003625.784119135@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Artem Bityutskiy commit 78b495c39add820ab66ab897af9bd77a5f2e91f6 upstream. UBI was mistakingly using 'kfree()' instead of 'kmem_cache_free()' when freeing "attach eraseblock" structures in vtbl.c. Thankfully, this happened only when we were doing auto-format, so many systems were unaffected. However, there are still many users affected. It is strange, but the system did not crash and nothing bad happened when the SLUB memory allocator was used. However, in case of SLOB we observed an crash right away. This problem was introduced in 2.6.39 by commit "6c1e875 UBI: add slab cache for ubi_scan_leb objects" A note for stable trees: Because variable were renamed, this won't cleanly apply to older kernels. Changing names like this should help: 1. ai -> si 2. aeb_slab_cache -> seb_slab_cache 3. new_aeb -> new_seb Reported-by: Richard Genoud Tested-by: Richard Genoud Tested-by: Artem Bityutskiy Signed-off-by: Artem Bityutskiy [bwh: Backported to 3.2: aeb_slab_cache was actually named scan_leb_slab] Signed-off-by: Ben Hutchings --- drivers/mtd/ubi/vtbl.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/mtd/ubi/vtbl.c +++ b/drivers/mtd/ubi/vtbl.c @@ -346,7 +346,7 @@ retry: */ err = ubi_scan_add_used(ubi, si, new_seb->pnum, new_seb->ec, vid_hdr, 0); - kfree(new_seb); + kmem_cache_free(si->scan_leb_slab, new_seb); ubi_free_vid_hdr(ubi, vid_hdr); return err; @@ -359,7 +359,7 @@ write_error: list_add(&new_seb->u.list, &si->erase); goto retry; } - kfree(new_seb); + kmem_cache_free(si->scan_leb_slab, new_seb); out_free: ubi_free_vid_hdr(ubi, vid_hdr); return err;