From: Matthew Wilcox <willy@infradead.org>
To: Josh Law <hlcj1234567@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, Josh Law <objecting@objecting.org>
Subject: Re: [PATCH v2] lib/idr: fix infinite loop in idr_get_next()
Date: Thu, 12 Mar 2026 17:26:43 +0000 [thread overview]
Message-ID: <abL3U3xm9c4oSbKM@casper.infradead.org> (raw)
In-Reply-To: <20260312171238.7961-1-objecting@objecting.org>
On Thu, Mar 12, 2026 at 05:12:38PM +0000, Josh Law wrote:
> From: Josh Law <objecting@objecting.org>
>
> 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.
>
> Fix this by setting *nextid to INT_MAX when the bounds check fails,
> ensuring the caller's iteration will terminate.
Can you add a test-case for this? And the IDA patch you also sent?
next prev parent reply other threads:[~2026-03-12 17:26 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-12 17:12 Josh Law
2026-03-12 17:26 ` Matthew Wilcox [this message]
2026-03-12 17:28 ` Josh Law
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