Subject: [merged] idr-fix-unexpected-id-removal-when-idr_removeunallocated_id.patch removed from -mm tree To: laijs@xxxxxxxxxxxxxx,tj@xxxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Mon, 09 Jun 2014 12:35:02 -0700 The patch titled Subject: idr: fix unexpected ID-removal when idr_remove(unallocated_id) has been removed from the -mm tree. Its filename was idr-fix-unexpected-id-removal-when-idr_removeunallocated_id.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ 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 origin.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