From e873c74132f0c5f1452816cd9bb26208f0bba1e1 Mon Sep 17 00:00:00 2001 From: Shivank Garg Date: Sat, 22 Aug 2026 19:22:05 +0000 Subject: dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel() When dma_device_put() drops the last reference on chan->device->ref, dma_device_release() runs and may free the dma_device along with its channels. dma_chan_put() then still reads chan->device->owner via dma_chan_to_owner() for the trailing module_put(). KASAN catches it: slab-use-after-free in dma_chan_put+0x3e6/0x4c0 Read of size 8 by task insmod/6319 Freed by task 6319: kfree+0x225/0x470 dma_chan_put+0x395/0x4c0 dmaengine_put+0xf8/0x160 Cache the module owner in dma_chan_put() before the put so the trailing module_put() does not need chan->device. Fixes: 8ad342a86359 ("dmaengine: Add reference counting to dma_device struct") Suggested-by: Sashiko Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com Reviewed-by: Frank Li Reviewed-by: Logan Gunthorpe Signed-off-by: Shivank Garg Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com Signed-off-by: Vinod Koul --- fs/lockd/netlink.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 fs/lockd/netlink.c (limited to 'fs/lockd/netlink.c') diff --git a/fs/lockd/netlink.c b/fs/lockd/netlink.c new file mode 100644 index 000000000..880c42b4f --- /dev/null +++ b/fs/lockd/netlink.c @@ -0,0 +1,45 @@ +// SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) +/* Do not edit directly, auto-generated from: */ +/* Documentation/netlink/specs/lockd.yaml */ +/* YNL-GEN kernel source */ +/* To regenerate run: tools/net/ynl/ynl-regen.sh */ + +#include +#include + +#include "netlink.h" + +#include + +/* LOCKD_CMD_SERVER_SET - do */ +static const struct nla_policy lockd_server_set_nl_policy[LOCKD_A_SERVER_UDP_PORT + 1] = { + [LOCKD_A_SERVER_GRACETIME] = { .type = NLA_U32, }, + [LOCKD_A_SERVER_TCP_PORT] = { .type = NLA_U16, }, + [LOCKD_A_SERVER_UDP_PORT] = { .type = NLA_U16, }, +}; + +/* Ops table for lockd */ +static const struct genl_split_ops lockd_nl_ops[] = { + { + .cmd = LOCKD_CMD_SERVER_SET, + .doit = lockd_nl_server_set_doit, + .policy = lockd_server_set_nl_policy, + .maxattr = LOCKD_A_SERVER_UDP_PORT, + .flags = GENL_ADMIN_PERM | GENL_CMD_CAP_DO, + }, + { + .cmd = LOCKD_CMD_SERVER_GET, + .doit = lockd_nl_server_get_doit, + .flags = GENL_CMD_CAP_DO, + }, +}; + +struct genl_family lockd_nl_family __ro_after_init = { + .name = LOCKD_FAMILY_NAME, + .version = LOCKD_FAMILY_VERSION, + .netnsok = true, + .parallel_ops = true, + .module = THIS_MODULE, + .split_ops = lockd_nl_ops, + .n_split_ops = ARRAY_SIZE(lockd_nl_ops), +}; -- cgit v1.3.1