From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 94AAE5695; Tue, 6 Jan 2026 17:38:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767721116; cv=none; b=gWU6sIfSczw/Ni/p89jG1y2xFHXiXha4j0SJZyNJYfjq2a6cAOeLZrADBvkno9eFhB1Qq6Px/lsumYwovD0tsXgJ2BNaa+LWIh/dPZMg8JPViE7PnTFCl0FBHFmHjYo0pbqkZrejXIqiUslrQbVthf6daMoQmfHpDHnvhcgDqZE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767721116; c=relaxed/simple; bh=Yc3/l/ahcD0PQfkVEp5B/KdsB8CjGXUdtRU9HVUIXRk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=BvY4M6Hj19Y/rtyt9MxepyUGY5GOjQnkpLpaSmCn0NQZ4hckJ2eWuMuEOE0qBvgIAy14aK40DS42nhEzs6DSZRavuceUW3Sl/3N0pvVtjh49BomLvfTkiqjQGZDUf8gVC26CAZWuQwJST8iWFGNNBOlsSSNcp5IWkN5YlyPuL6c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=qkWWfbkA; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="qkWWfbkA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CBAC3C16AAE; Tue, 6 Jan 2026 17:38:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1767721116; bh=Yc3/l/ahcD0PQfkVEp5B/KdsB8CjGXUdtRU9HVUIXRk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qkWWfbkA0E53fdTMJBoBqMKx9mrWOiVWjhvMkWUHVvbtVCDR0W/cig7mE+wCjFIcF ZQPhBZejtBUcA35egvqJ9ymy1z2+IKVxNQVQpJIvK0bK9o/NbJl+hDNnjNJEuyHSQI TFaIj6uToIllF8h4/b6NB/AlKKHiujlkYeVbbRXE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Matthew Wilcox (Oracle)" , Jan Sokolowski , Koen Koning , Peter Senna Tschudin , =?UTF-8?q?Christian=20K=C3=B6nig?= , Andrew Morton Subject: [PATCH 6.12 440/567] idr: fix idr_alloc() returning an ID out of range Date: Tue, 6 Jan 2026 18:03:42 +0100 Message-ID: <20260106170507.629956873@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260106170451.332875001@linuxfoundation.org> References: <20260106170451.332875001@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Matthew Wilcox (Oracle) commit c6e8e595a0798ad67da0f7bebaf69c31ef70dfff upstream. If you use an IDR with a non-zero base, and specify a range that lies entirely below the base, 'max - base' becomes very large and idr_get_free() can return an ID that lies outside of the requested range. Link: https://lkml.kernel.org/r/20251128161853.3200058-1-willy@infradead.org Fixes: 6ce711f27500 ("idr: Make 1-based IDRs more efficient") Signed-off-by: Matthew Wilcox (Oracle) Reported-by: Jan Sokolowski Reported-by: Koen Koning Reported-by: Peter Senna Tschudin Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/6449 Reviewed-by: Christian König Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- lib/idr.c | 2 ++ tools/testing/radix-tree/idr-test.c | 21 +++++++++++++++++++++ 2 files changed, 23 insertions(+) --- a/lib/idr.c +++ b/lib/idr.c @@ -40,6 +40,8 @@ int idr_alloc_u32(struct idr *idr, void if (WARN_ON_ONCE(!(idr->idr_rt.xa_flags & ROOT_IS_IDR))) idr->idr_rt.xa_flags |= IDR_RT_MARKER; + if (max < base) + return -ENOSPC; id = (id < base) ? 0 : id - base; radix_tree_iter_init(&iter, id); --- a/tools/testing/radix-tree/idr-test.c +++ b/tools/testing/radix-tree/idr-test.c @@ -57,6 +57,26 @@ void idr_alloc_test(void) idr_destroy(&idr); } +void idr_alloc2_test(void) +{ + int id; + struct idr idr = IDR_INIT_BASE(idr, 1); + + id = idr_alloc(&idr, idr_alloc2_test, 0, 1, GFP_KERNEL); + assert(id == -ENOSPC); + + id = idr_alloc(&idr, idr_alloc2_test, 1, 2, GFP_KERNEL); + assert(id == 1); + + id = idr_alloc(&idr, idr_alloc2_test, 0, 1, GFP_KERNEL); + assert(id == -ENOSPC); + + id = idr_alloc(&idr, idr_alloc2_test, 0, 2, GFP_KERNEL); + assert(id == -ENOSPC); + + idr_destroy(&idr); +} + void idr_replace_test(void) { DEFINE_IDR(idr); @@ -409,6 +429,7 @@ void idr_checks(void) idr_replace_test(); idr_alloc_test(); + idr_alloc2_test(); idr_null_test(); idr_nowait_test(); idr_get_next_test(0);