From c1521811a03c5829a9133781237711428f50daa7 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Apr 20 2023 11:00:35 +0000 Subject: net: qrtr: Fix an uninit variable access bug in qrtr_tx_resume() (bsc#1012628). --- diff --git a/patches.kernel.org/6.2.12-067-net-qrtr-Fix-an-uninit-variable-access-bug-in-.patch b/patches.kernel.org/6.2.12-067-net-qrtr-Fix-an-uninit-variable-access-bug-in-.patch new file mode 100644 index 0000000..03f288d --- /dev/null +++ b/patches.kernel.org/6.2.12-067-net-qrtr-Fix-an-uninit-variable-access-bug-in-.patch @@ -0,0 +1,100 @@ +From: Ziyang Xuan +Date: Mon, 10 Apr 2023 09:23:52 +0800 +Subject: [PATCH] net: qrtr: Fix an uninit variable access bug in + qrtr_tx_resume() +References: bsc#1012628 +Patch-mainline: 6.2.12 +Git-commit: 6417070918de3bcdbe0646e7256dae58fd8083ba + +[ Upstream commit 6417070918de3bcdbe0646e7256dae58fd8083ba ] + +Syzbot reported a bug as following: + +===================================================== +BUG: KMSAN: uninit-value in qrtr_tx_resume+0x185/0x1f0 net/qrtr/af_qrtr.c:230 + qrtr_tx_resume+0x185/0x1f0 net/qrtr/af_qrtr.c:230 + qrtr_endpoint_post+0xf85/0x11b0 net/qrtr/af_qrtr.c:519 + qrtr_tun_write_iter+0x270/0x400 net/qrtr/tun.c:108 + call_write_iter include/linux/fs.h:2189 [inline] + aio_write+0x63a/0x950 fs/aio.c:1600 + io_submit_one+0x1d1c/0x3bf0 fs/aio.c:2019 + __do_sys_io_submit fs/aio.c:2078 [inline] + __se_sys_io_submit+0x293/0x770 fs/aio.c:2048 + __x64_sys_io_submit+0x92/0xd0 fs/aio.c:2048 + do_syscall_x64 arch/x86/entry/common.c:50 [inline] + do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 + entry_SYSCALL_64_after_hwframe+0x63/0xcd + +Uninit was created at: + slab_post_alloc_hook mm/slab.h:766 [inline] + slab_alloc_node mm/slub.c:3452 [inline] + __kmem_cache_alloc_node+0x71f/0xce0 mm/slub.c:3491 + __do_kmalloc_node mm/slab_common.c:967 [inline] + __kmalloc_node_track_caller+0x114/0x3b0 mm/slab_common.c:988 + kmalloc_reserve net/core/skbuff.c:492 [inline] + __alloc_skb+0x3af/0x8f0 net/core/skbuff.c:565 + __netdev_alloc_skb+0x120/0x7d0 net/core/skbuff.c:630 + qrtr_endpoint_post+0xbd/0x11b0 net/qrtr/af_qrtr.c:446 + qrtr_tun_write_iter+0x270/0x400 net/qrtr/tun.c:108 + call_write_iter include/linux/fs.h:2189 [inline] + aio_write+0x63a/0x950 fs/aio.c:1600 + io_submit_one+0x1d1c/0x3bf0 fs/aio.c:2019 + __do_sys_io_submit fs/aio.c:2078 [inline] + __se_sys_io_submit+0x293/0x770 fs/aio.c:2048 + __x64_sys_io_submit+0x92/0xd0 fs/aio.c:2048 + do_syscall_x64 arch/x86/entry/common.c:50 [inline] + do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 + entry_SYSCALL_64_after_hwframe+0x63/0xcd + +It is because that skb->len requires at least sizeof(struct qrtr_ctrl_pkt) +in qrtr_tx_resume(). And skb->len equals to size in qrtr_endpoint_post(). +But size is less than sizeof(struct qrtr_ctrl_pkt) when qrtr_cb->type +equals to QRTR_TYPE_RESUME_TX in qrtr_endpoint_post() under the syzbot +scenario. This triggers the uninit variable access bug. + +Add size check when qrtr_cb->type equals to QRTR_TYPE_RESUME_TX in +qrtr_endpoint_post() to fix the bug. + +Fixes: 5fdeb0d372ab ("net: qrtr: Implement outgoing flow control") +Reported-by: syzbot+4436c9630a45820fda76@syzkaller.appspotmail.com +Link: https://syzkaller.appspot.com/bug?id=c14607f0963d27d5a3d5f4c8639b500909e43540 +Suggested-by: Manivannan Sadhasivam +Signed-off-by: Ziyang Xuan +Reviewed-by: Simon Horman +Link: https://lore.kernel.org/r/20230410012352.3997823-1-william.xuanziyang@huawei.com +Signed-off-by: Paolo Abeni +Signed-off-by: Sasha Levin +Signed-off-by: Jiri Slaby +--- + net/qrtr/af_qrtr.c | 8 +++++--- + 1 file changed, 5 insertions(+), 3 deletions(-) + +diff --git a/net/qrtr/af_qrtr.c b/net/qrtr/af_qrtr.c +index 3a70255c..76f0434d 100644 +--- a/net/qrtr/af_qrtr.c ++++ b/net/qrtr/af_qrtr.c +@@ -498,6 +498,11 @@ int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len) + if (!size || len != ALIGN(size, 4) + hdrlen) + goto err; + ++ if ((cb->type == QRTR_TYPE_NEW_SERVER || ++ cb->type == QRTR_TYPE_RESUME_TX) && ++ size < sizeof(struct qrtr_ctrl_pkt)) ++ goto err; ++ + if (cb->dst_port != QRTR_PORT_CTRL && cb->type != QRTR_TYPE_DATA && + cb->type != QRTR_TYPE_RESUME_TX) + goto err; +@@ -510,9 +515,6 @@ int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len) + /* Remote node endpoint can bridge other distant nodes */ + const struct qrtr_ctrl_pkt *pkt; + +- if (size < sizeof(*pkt)) +- goto err; +- + pkt = data + hdrlen; + qrtr_node_assign(node, le32_to_cpu(pkt->server.node)); + } +-- +2.35.3 + diff --git a/series.conf b/series.conf index 596bd1d..6d56aed 100644 --- a/series.conf +++ b/series.conf @@ -2294,6 +2294,7 @@ patches.kernel.org/6.2.12-064-net-wwan-iosm-Fix-error-handling-path-in-ipc_p.patch patches.kernel.org/6.2.12-065-cgroup-freezer-hold-cpu_hotplug_lock-before-fr.patch patches.kernel.org/6.2.12-066-rtnetlink-Restore-RTM_NEW-DELLINK-notification.patch + patches.kernel.org/6.2.12-067-net-qrtr-Fix-an-uninit-variable-access-bug-in-.patch ######################################################## # Build fixes that apply to the vanilla kernel too.