From 889d916b6f8a48b8c9489fffcad3b78eedd01a51 Mon Sep 17 00:00:00 2001 From: Shay Drory Date: Tue, 11 May 2021 08:48:28 +0300 Subject: [PATCH] RDMA/core: Don't access cm_id after its destruction restrack should only be attached to a cm_id while the ID has a valid device pointer. It is set up when the device is first loaded, but not cleared when the device is removed. There is also two copies of the device pointer, one private and one in the public API, and these were left out of sync. Make everything go to NULL together and manipulate restrack right around the device assignments. Found by syzcaller: BUG: KASAN: wild-memory-access in __list_del include/linux/list.h:112 [inline] BUG: KASAN: wild-memory-access in __list_del_entry include/linux/list.h:135 [inline] BUG: KASAN: wild-memory-access in list_del include/linux/list.h:146 [inline] BUG: KASAN: wild-memory-access in cma_cancel_listens drivers/infiniband/core/cma.c:1767 [inline] BUG: KASAN: wild-memory-access in cma_cancel_operation drivers/infiniband/core/cma.c:1795 [inline] BUG: KASAN: wild-memory-access in cma_cancel_operation+0x1f4/0x4b0 drivers/infiniband/core/cma.c:1783 Write of size 8 at addr dead000000000108 by task syz-executor716/334 CPU: 0 PID: 334 Comm: syz-executor716 Not tainted 5.11.0+ #271 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0xbe/0xf9 lib/dump_stack.c:120 __kasan_report mm/kasan/report.c:400 [inline] kasan_report.cold+0x5f/0xd5 mm/kasan/report.c:413 __list_del include/linux/list.h:112 [inline] __list_del_entry include/linux/list.h:135 [inline] list_del include/linux/list.h:146 [inline] cma_cancel_listens drivers/infiniband/core/cma.c:1767 [inline] cma_cancel_operation drivers/infiniband/core/cma.c:1795 [inline] cma_cancel_operation+0x1f4/0x4b0 drivers/infiniband/core/cma.c:1783 _destroy_id+0x29/0x460 drivers/infiniband/core/cma.c:1862 ucma_close_id+0x36/0x50 drivers/infiniband/core/ucma.c:185 ucma_destroy_private_ctx+0x58d/0x5b0 drivers/infiniband/core/ucma.c:576 ucma_close+0x91/0xd0 drivers/infiniband/core/ucma.c:1797 __fput+0x169/0x540 fs/file_table.c:280 task_work_run+0xb7/0x100 kernel/task_work.c:140 exit_task_work include/linux/task_work.h:30 [inline] do_exit+0x7da/0x17f0 kernel/exit.c:825 do_group_exit+0x9e/0x190 kernel/exit.c:922 __do_sys_exit_group kernel/exit.c:933 [inline] __se_sys_exit_group kernel/exit.c:931 [inline] __x64_sys_exit_group+0x2d/0x30 kernel/exit.c:931 do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: 255d0c14b375 ("RDMA/cma: rdma_bind_addr() leaks a cma_dev reference count") Link: https://lore.kernel.org/r/3352ee288fe34f2b44220457a29bfc0548686363.1620711734.git.leonro@nvidia.com Signed-off-by: Shay Drory Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe --- drivers/infiniband/core/cma.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index 2b9ffc21cbc4..ab148a696c0c 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -473,6 +473,7 @@ static void cma_release_dev(struct rdma_id_private *id_priv) list_del(&id_priv->list); cma_dev_put(id_priv->cma_dev); id_priv->cma_dev = NULL; + id_priv->id.device = NULL; if (id_priv->id.route.addr.dev_addr.sgid_attr) { rdma_put_gid_attr(id_priv->id.route.addr.dev_addr.sgid_attr); id_priv->id.route.addr.dev_addr.sgid_attr = NULL; @@ -1860,6 +1861,7 @@ static void _destroy_id(struct rdma_id_private *id_priv, iw_destroy_cm_id(id_priv->cm_id.iw); } cma_leave_mc_groups(id_priv); + rdma_restrack_del(&id_priv->res); cma_release_dev(id_priv); } @@ -1873,7 +1875,6 @@ static void _destroy_id(struct rdma_id_private *id_priv, kfree(id_priv->id.route.path_rec); put_net(id_priv->id.route.addr.dev_addr.net); - rdma_restrack_del(&id_priv->res); kfree(id_priv); } @@ -3774,7 +3775,7 @@ int rdma_listen(struct rdma_cm_id *id, int backlog) } id_priv->backlog = backlog; - if (id->device) { + if (id_priv->cma_dev) { if (rdma_cap_ib_cm(id->device, 1)) { ret = cma_ib_listen(id_priv); if (ret)