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| author | Lai Jiangshan <laijs@cn.fujitsu.com> | 2014-06-06 14:37:11 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-06 16:08:12 -0700 |
| commit | 8f9f665a707721146f24a892b1a0da1ab4da1d58 (patch) | |
| tree | 75850b4a284ac671b7f1b563c985b959181aa70d /lib | |
| parent | 3afb69cb5572b3c8c898c00880803cf1a49852c4 (diff) | |
| download | linux-8f9f665a707721146f24a892b1a0da1ab4da1d58.tar.bz2 | |
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@cn.fujitsu.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/idr.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/lib/idr.c b/lib/idr.c index 4df67928816e..c4afd94bdf69 100644 --- a/lib/idr.c +++ b/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; |