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 652CF3AE701; Thu, 15 Jan 2026 17:32:26 +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=1768498346; cv=none; b=mZId6K9p+/ZfPy/Yb393llpqc8XuK0ds59neL6eWXLHuybJQCWgQgyr4vs2dFnt19LeDVgF6czw+uPy+2OH46Vjf9ZCg+G23afk/sSPOT2AV1p8AlQQtUKfxFe7IwDMKOutdxrpei2u627VlmMGWoQPfpNZANL6jnMbr63knMxI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768498346; c=relaxed/simple; bh=E3YrMA/K0L9PWHWIs3q7YAo/Od2mjte7BYqidaClNFk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=JfLnPoy0XQUcK0uOGR1/qwX5F7V9LwCIr7VpBQGXnj3TqRPC27rPdrI/5Wq+lGx2eH5JOAsBHtx6YpmkwExRQn1Mi4/mLg+3pfFCKxQGrawgPglrshcqOzw8v/TX9Nt+naasGUDZWmeticVHHoPpg6WuJS1ICBYomu/DbHM/IVo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=pVaWzBoI; 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="pVaWzBoI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DFFC6C116D0; Thu, 15 Jan 2026 17:32:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1768498346; bh=E3YrMA/K0L9PWHWIs3q7YAo/Od2mjte7BYqidaClNFk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pVaWzBoI6dnUbSZfeuW3CdploZYK7vf5SYaqnH9DHoCQpghXshU+VMkEYeMo6il3D 4d0oWO9oiV001zbFLT2TquVGRXCJCPK94HGXBxjV7yLCIWlZadfAwaWVoJdv6U+QEL /yUaBGd6u9jPkMWOpUS553X+wHT7Fuoi1SARoXps= 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 5.15 400/554] idr: fix idr_alloc() returning an ID out of range Date: Thu, 15 Jan 2026 17:47:46 +0100 Message-ID: <20260115164300.713421499@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260115164246.225995385@linuxfoundation.org> References: <20260115164246.225995385@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 5.15-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);