From 7b07c2bc5547b5f4b35eda35b6754faf10b5ccc7 Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Mon, 3 Sep 2012 17:12:29 +0300 Subject: [PATCH] UBI: fix a horrible memory deallocation bug 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(-) diff --git a/drivers/mtd/ubi/vtbl.c b/drivers/mtd/ubi/vtbl.c index 890754c9f327..95b29f5ddfac 100644 --- 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; -- 2.39.2