From: Andrew Morton <akpm@linux-foundation.org>
To: Josh Law <hlcj1234567@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>,
linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, Josh Law <objecting@objecting.org>
Subject: Re: [PATCH v3 1/2] lib/idr: fix infinite loop in idr_get_next()
Date: Thu, 12 Mar 2026 13:55:14 -0700 [thread overview]
Message-ID: <20260312135514.e4fc0fa4c1f50e6fbda2644c@linux-foundation.org> (raw)
In-Reply-To: <20260312181948.20020-2-objecting@objecting.org>
On Thu, 12 Mar 2026 18:19:47 +0000 Josh Law <hlcj1234567@gmail.com> wrote:
> In idr_get_next(), if the returned id from idr_get_next_ul() is greater
> than INT_MAX, the function issues a warning and returns NULL without
> updating the *nextid pointer. This causes a soft lockup for any caller
> iterating over an IDR (e.g. via idr_for_each_entry) because they will
> receive NULL, fail to advance their index, and repeatedly query the same
> state forever.
This assumes that the idr_get_next() caller ignores the NULL return and
just keeps on looping. Isn't that a caller bug and if so, do we need
to defend against it here?
next prev parent reply other threads:[~2026-03-12 20:55 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-12 18:19 [PATCH v3 0/2] lib/idr: Fixes for infinite loop and memory leak Josh Law
2026-03-12 18:19 ` [PATCH v3 1/2] lib/idr: fix infinite loop in idr_get_next() Josh Law
2026-03-12 20:55 ` Andrew Morton [this message]
2026-03-12 20:57 ` Josh Law
2026-03-12 21:15 ` Josh Law
2026-03-12 18:19 ` [PATCH v3 2/2] lib/idr: fix memory leak in ida_alloc_range() error path Josh Law
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