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Thu, 12 Mar 2026 10:28:50 -0700 (PDT) Date: Thu, 12 Mar 2026 17:28:48 +0000 From: Josh Law To: Matthew Wilcox Cc: Andrew Morton , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Josh Law Message-ID: <40767ecf-7e25-48f5-a604-c43b835b6b66@gmail.com> In-Reply-To: References: <20260312171238.7961-1-objecting@objecting.org> Subject: Re: [PATCH v2] lib/idr: fix infinite loop in idr_get_next() Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Correlation-ID: <40767ecf-7e25-48f5-a604-c43b835b6b66@gmail.com> 12 Mar 2026 17:26:44 Matthew Wilcox : > On Thu, Mar 12, 2026 at 05:12:38PM +0000, Josh Law wrote: >> From: Josh Law >> >> 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?=C2=A0 And the IDA patch you also sent? Lmao you and your test cases, absolutely ill add some test cases