Subject: + idr-fix-unexpected-id-removal-when-idr_removeunallocated_id.patch added to -mm tree To: laijs@xxxxxxxxxxxxxx,tj@xxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Tue, 22 Apr 2014 12:40:44 -0700 The patch titled Subject: idr: fix unexpected ID-removal when idr_remove(unallocated_id) has been added to the -mm tree. Its filename is idr-fix-unexpected-id-removal-when-idr_removeunallocated_id.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/idr-fix-unexpected-id-removal-when-idr_removeunallocated_id.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/idr-fix-unexpected-id-removal-when-idr_removeunallocated_id.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Lai Jiangshan <laijs@xxxxxxxxxxxxxx> Subject: idr: fix unexpected ID-removal when idr_remove(unallocated_id) If unallocated_id = (ANY * idr_max(idp->layers) + existing_id) is passed to idr_remove(). The existing_id will be removed unexpectedly. The following test shows this unexpected id-removal: static void test4(void) { int id; DEFINE_IDR(test_idr); printk(KERN_INFO "Start test4\n"); id = idr_alloc(&test_idr, (void *)1, 42, 43, GFP_KERNEL); BUG_ON(id != 42); idr_remove(&test_idr, 42 + IDR_SIZE); TEST_BUG_ON(idr_find(&test_idr, 42) != (void *)1); idr_destroy(&test_idr); printk(KERN_INFO "End of test4\n"); } ida_remove() shares the similar problem. It happens only when the caller tries to free an unallocated ID which is the caller's fault. It is not a bug. But it is better to add the proper check and complain rather than removing an existing_id silently. Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxx> Acked-by: Tejun Heo <tj@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- lib/idr.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff -puN lib/idr.c~idr-fix-unexpected-id-removal-when-idr_removeunallocated_id lib/idr.c --- a/lib/idr.c~idr-fix-unexpected-id-removal-when-idr_removeunallocated_id +++ a/lib/idr.c @@ -562,6 +562,11 @@ void idr_remove(struct idr *idp, int id) if (id < 0) return; + if (id > idr_max(idp->layers)) { + idr_remove_warning(id); + return; + } + sub_remove(idp, (idp->layers - 1) * IDR_BITS, id); if (idp->top && idp->top->count == 1 && (idp->layers > 1) && idp->top->ary[0]) { @@ -1025,6 +1030,9 @@ void ida_remove(struct ida *ida, int id) int n; struct ida_bitmap *bitmap; + if (idr_id > idr_max(ida->idr.layers)) + goto err; + /* clear full bits while looking up the leaf idr_layer */ while ((shift > 0) && p) { n = (idr_id >> shift) & IDR_MASK; _ Patches currently in -mm which might be from laijs@xxxxxxxxxxxxxx are mem-hotplug-implement-get-put_online_mems.patch slab-get_online_mems-for-kmem_cache_createdestroyshrink.patch idr-fix-overflow-bug-during-maximum-id-calculation-at-maximum-height.patch idr-fix-unexpected-id-removal-when-idr_removeunallocated_id.patch idr-fix-null-pointer-dereference-when-ida_removeunallocated_id.patch idr-fix-idr_replaces-returned-error-code.patch idr-dont-need-to-shink-the-free-list-when-idr_remove.patch idr-reduce-the-unneeded-check-in-free_layer.patch linux-next.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html