From nobody Fri Sep 25 06:02:54 2026 Received: from mta0.migadu.com (out-154.mta0.migadu.com [91.218.175.154]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3626644C662 for ; Wed, 16 Sep 2026 08:25:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.154 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789547153; cv=none; b=IzSspU6DePfL+joApyhN0WQ+UjB5BLf5QGH4v8GVcoYmqJnSv8b+e1sZvN+zBCqxOsmltStNDJLYZzQyd3Vi91a3r7jboq5weFh8Qu4A1TiGkPa9I/5kN04nKqj3tbQ+llL4SCRWljiQ8ndHiOoMn8Ns8rbhJhN1FUgOuG5zqGQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789547153; c=relaxed/simple; bh=TgBqgmk/OGkiRG4oFsrkPk1fFb54WBL3zueWiSKqe7I=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=f+h5s5DmK8Xw8Qa8RFHxHL7N9tYoyXicMr/683PKsHjSg8kHoAZ4Ny60H1uswe0a/b58UYw4NhV2JpRmW7hUQ4rcVSB9tC6TLykv9KDkxPNf7oNCle921uUBVyrPqOc7+8LKeLh5lN8T+hg/8mHgm8etmBKLWPcTxZpAr+TbRd4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=mxWZ3a5S; arc=none smtp.client-ip=91.218.175.154 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="mxWZ3a5S" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=TgBqgmk/OGkiRG4oFsrkPk1fFb54WBL3zueWiSKqe7I=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1789547141; v=1; x=1790151941; b=mxWZ3a5S60Wa5HGuVt5Xpgegd0w934B026RhIHea/bfbbzJ5TR8xkFXpoch98392Bhy/qz2e TNAsCgDySYfWU7PdPwsVIo5bVmZMuD/DEBE1jPe6Ok+Y0i5YC7Ji0WL0jrcSapwE1Mh4FV/nLUt 5uzORfZMaQHJsXWk1VK9ZUhg= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 440f386aa9fdf0d8; Wed, 16 Sep 2026 08:25:41 +0000 X-Mizu-Trace-ID: 440f386aa9fdf0d8 X-Migadu-Flow: FLOW_OUT From: Ye Liu Date: Wed, 16 Sep 2026 16:25:28 +0800 Subject: [PATCH 1/3] mm/vmalloc: fix vmalloc_dump_obj address alignment for last-page lookups 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 Message-Id: <20260916-vmalloc_dump_obj-v1-1-7aa402d224df@linux.dev> References: <20260916-vmalloc_dump_obj-v1-0-7aa402d224df@linux.dev> In-Reply-To: <20260916-vmalloc_dump_obj-v1-0-7aa402d224df@linux.dev> To: Andrew Morton , Uladzislau Rezki Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Ye Liu X-Mailer: b4 0.14.3 From: Ye Liu vmalloc_dump_obj() uses PAGE_ALIGN() to normalize the input address before looking it up in the per-node busy tree. PAGE_ALIGN() rounds up, which can push an address in the last page of a vmalloc allocation to va_end -- outside the [va_start, va_end) range that __find_vmap_area() searches. This causes the lookup to miss the VA and return false, degrading diagnostic output in OOM dumps and KASAN reports to the less informative "vmalloc memory" fallback. The upward alignment can also change the addr_to_node() mapping when the page boundary crosses a vmap zone boundary, causing the search to hit the wrong node entirely. Use PAGE_ALIGN_DOWN() instead, which rounds down to the page containing the address. This keeps the address within the VA range and preserves the correct node mapping. Signed-off-by: Ye Liu --- mm/vmalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 859e6d2d57a3..df42d8a6f058 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -5277,7 +5277,7 @@ bool vmalloc_dump_obj(void *object) unsigned long addr; unsigned long nr_pages; =20 - addr =3D PAGE_ALIGN((unsigned long) object); + addr =3D PAGE_ALIGN_DOWN((unsigned long) object); vn =3D addr_to_node(addr); =20 if (!spin_trylock(&vn->busy.lock)) --=20 2.25.1 From nobody Fri Sep 25 06:02:54 2026 Received: from mta0.migadu.com (out-157.mta0.migadu.com [91.218.175.157]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0A2253ACA7F for ; Wed, 16 Sep 2026 08:25:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.157 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789547154; cv=none; b=ILJEM9h488uFwZM87SrhgmdpGSPww24aGZz2LXFJ61hrEpUkzMaZOhsEXxePTfTQdcCMoC4xTIZ2fyQZD8w9Vjf42Qcdyi6lMpPfCLu4vfeBRMFzxdUK26YFrgm+2YkhQTu2Jy1Uk/9M9LEZOyKAG6BjO9TLvziCORt7OqkIDaM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789547154; c=relaxed/simple; bh=ueVOpPzYnMeot+dswpS82YrnsBHSSPYd5K+PQjCvvaY=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=pWu8KItnOm+M1qgMnt4nr/Xq2BckBhB3kqrYS8wSiRfAGW/rYt+NheE6FvRgailvJDOnfhDV0TXxbsWtt9RlVPaExk7Cdrpkx/5NaPS09ii/SV9ntgQfYL26gfK6xsJVoUi3yxBdCEyuatlMGOebn0fV8TbYzTQoRgVOsbvKKnY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=oWEsdVD5; arc=none smtp.client-ip=91.218.175.157 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="oWEsdVD5" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=ueVOpPzYnMeot+dswpS82YrnsBHSSPYd5K+PQjCvvaY=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1789547147; v=1; x=1790151947; b=oWEsdVD5I+8FD3wHIoHvy0lk7QLXJiwhTLBv5CfLEmQv4uFhZZ4kUbz2ufNXhrfcbYQN0wpd EIO0R1ct+nS13l/HKk4hkDEQ+WKBMjIv8HgLW+C7EL7nacr8sf/OfjS/iMb8V+sHFN0Ky5ID2d/ txZc01I48G0CBx+OhkhYG6S8= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 3414f8a749aa3b67; Wed, 16 Sep 2026 08:25:46 +0000 X-Mizu-Trace-ID: 3414f8a749aa3b67 X-Migadu-Flow: FLOW_OUT From: Ye Liu Date: Wed, 16 Sep 2026 16:25:29 +0800 Subject: [PATCH 2/3] mm/vmalloc: fix vmalloc_dump_obj cross-zone VA lookup 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 Message-Id: <20260916-vmalloc_dump_obj-v1-2-7aa402d224df@linux.dev> References: <20260916-vmalloc_dump_obj-v1-0-7aa402d224df@linux.dev> In-Reply-To: <20260916-vmalloc_dump_obj-v1-0-7aa402d224df@linux.dev> To: Andrew Morton , Uladzislau Rezki Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Ye Liu X-Mailer: b4 0.14.3 From: Ye Liu vmalloc_dump_obj() searches only one vmap node (addr_to_node(addr)), but a vmalloc allocation may span multiple vmap zones. The VA is stored in only one node's rb-tree (addr_to_node(va_start)), so an object pointer in a different zone than va_start maps to a different node and the search misses. This affects any allocation larger than vmap_zone_size (64 KiB) on multi-CPU systems. Iterate all vmap nodes using for_each_vmap_node, like find_vmap_area() does, but with spin_trylock instead of spin_lock as this function can be called from atomic dump contexts (OOM, KASAN, RCU). Signed-off-by: Ye Liu --- mm/vmalloc.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index df42d8a6f058..30c610f678dc 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -5278,17 +5278,29 @@ bool vmalloc_dump_obj(void *object) unsigned long nr_pages; =20 addr =3D PAGE_ALIGN_DOWN((unsigned long) object); - vn =3D addr_to_node(addr); =20 - if (!spin_trylock(&vn->busy.lock)) - return false; + /* + * A vmalloc allocation may span multiple vmap zones, so the + * node whose rb-tree holds the VA may differ from the node + * the address maps to. Search all nodes. Use trylock as + * this function can be called from atomic dump contexts. + */ + va =3D NULL; + for_each_vmap_node(vn) { + if (!spin_trylock(&vn->busy.lock)) + continue; + + va =3D __find_vmap_area(addr, &vn->busy.root); + if (va && va->vm) + break; =20 - va =3D __find_vmap_area(addr, &vn->busy.root); - if (!va || !va->vm) { spin_unlock(&vn->busy.lock); - return false; + va =3D NULL; } =20 + if (!va) + return false; + vm =3D va->vm; addr =3D (unsigned long) vm->addr; caller =3D vm->caller; --=20 2.25.1 From nobody Fri Sep 25 06:02:54 2026 Received: from mta0.migadu.com (out-163.mta0.migadu.com [91.218.175.163]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 061D840F743 for ; Wed, 16 Sep 2026 08:25:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.163 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789547163; cv=none; b=If633Rc/yYJsqVn572qGjSV2ha7n2k8cC2h7YMUMPEjEX9GUaSAv2aQ8NLWx0Eg9pgNIlFPQUEIL8sioQiuo3nN5Zs6vjH2L3fWnfag5liLuXY/ObdUOG/xwiVY1xSMcEM1iHuQeN47ndXcHZT+Az1tCbnTqnerLzMoytbr7sso= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789547163; c=relaxed/simple; bh=jFgYLuMhSLSQE34QZ7YWi1qBRpOmgxt6A18X041cY7s=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=kEc+y5nq+mr/MHg1jn3OAcV1zVUyoMF8rip84BMDnWFvGFil0iAs85RWH2ZLgRvwMKv9QQn6LIqE4t8U9pXhFWOjBfhACDUiERoTyqgKs4Qm3cHH1iM9Zvx270xSAyfRWWiKbokt5SiNfl12+cOovBjRd+PITEl8v2+L9LW2pfo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=ACNpOlIz; arc=none smtp.client-ip=91.218.175.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="ACNpOlIz" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=jFgYLuMhSLSQE34QZ7YWi1qBRpOmgxt6A18X041cY7s=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1789547152; v=1; x=1790151952; b=ACNpOlIziJcMJjVV9bgvUAjoiPUr5hhT/e+mnH4Aj2rGohMGrWaSh8nOrIxFAcU+1lmoZxEW 9pAvzI4Nhu+KbjVCzY/TBzU3wLJnNl79CeHuw3/is7OSmOWtMX4F9tN5pkHmNUAhUUVguVXyo28 p7ytLlGQmIOTrc6bx8DyL888= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id ee530d7fdc31aba6; Wed, 16 Sep 2026 08:25:52 +0000 X-Mizu-Trace-ID: ee530d7fdc31aba6 X-Migadu-Flow: FLOW_OUT From: Ye Liu Date: Wed, 16 Sep 2026 16:25:30 +0800 Subject: [PATCH 3/3] mm/vmalloc: skip vmalloc_dump_obj for non-vmalloc addresses 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 Message-Id: <20260916-vmalloc_dump_obj-v1-3-7aa402d224df@linux.dev> References: <20260916-vmalloc_dump_obj-v1-0-7aa402d224df@linux.dev> In-Reply-To: <20260916-vmalloc_dump_obj-v1-0-7aa402d224df@linux.dev> To: Andrew Morton , Uladzislau Rezki Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Ye Liu X-Mailer: b4 0.14.3 From: Ye Liu vmalloc_dump_obj() unconditionally searches all vmap nodes even when called with a non-vmalloc address (e.g. a slab or stack pointer from mem_dump_obj()). Add an is_vmalloc_addr() check at the entry to avoid the unnecessary per-node trylock and rb-tree traversal. The KASAN caller already gates on is_vmalloc_addr(), but mem_dump_obj() calls vmalloc_dump_obj() before the fallback type check, so the guard in the callee covers both paths without requiring caller changes. Signed-off-by: Ye Liu --- mm/vmalloc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 30c610f678dc..b3e706fde202 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -5277,6 +5277,9 @@ bool vmalloc_dump_obj(void *object) unsigned long addr; unsigned long nr_pages; =20 + if (!is_vmalloc_addr(object)) + return false; + addr =3D PAGE_ALIGN_DOWN((unsigned long) object); =20 /* --=20 2.25.1