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 --- net/ceph/auth_none.c | 146 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 146 insertions(+) create mode 100644 net/ceph/auth_none.c (limited to 'net/ceph/auth_none.c') diff --git a/net/ceph/auth_none.c b/net/ceph/auth_none.c new file mode 100644 index 000000000..99e1f3e10 --- /dev/null +++ b/net/ceph/auth_none.c @@ -0,0 +1,146 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +#include +#include +#include +#include + +#include +#include + +#include "auth_none.h" + +static void reset(struct ceph_auth_client *ac) +{ + struct ceph_auth_none_info *xi = ac->private; + + xi->starting = true; +} + +static void destroy(struct ceph_auth_client *ac) +{ + kfree(ac->private); + ac->private = NULL; +} + +static int is_authenticated(struct ceph_auth_client *ac) +{ + struct ceph_auth_none_info *xi = ac->private; + + return !xi->starting; +} + +static int should_authenticate(struct ceph_auth_client *ac) +{ + struct ceph_auth_none_info *xi = ac->private; + + return xi->starting; +} + +static int ceph_auth_none_build_authorizer(struct ceph_auth_client *ac, + struct ceph_none_authorizer *au) +{ + void *p = au->buf; + void *const end = p + sizeof(au->buf); + int ret; + + ceph_encode_8_safe(&p, end, 1, e_range); + ret = ceph_auth_entity_name_encode(ac->name, &p, end); + if (ret < 0) + return ret; + + ceph_encode_64_safe(&p, end, ac->global_id, e_range); + au->buf_len = p - (void *)au->buf; + dout("%s built authorizer len %d\n", __func__, au->buf_len); + return 0; + +e_range: + return -ERANGE; +} + +static int build_request(struct ceph_auth_client *ac, void *buf, void *end) +{ + return 0; +} + +/* + * the generic auth code decode the global_id, and we carry no actual + * authenticate state, so nothing happens here. + */ +static int handle_reply(struct ceph_auth_client *ac, u64 global_id, + void *buf, void *end, u8 *session_key, + int *session_key_len, u8 *con_secret, + int *con_secret_len) +{ + struct ceph_auth_none_info *xi = ac->private; + + xi->starting = false; + ceph_auth_set_global_id(ac, global_id); + return 0; +} + +static void ceph_auth_none_destroy_authorizer(struct ceph_authorizer *a) +{ + kfree(a); +} + +/* + * build an 'authorizer' with our entity_name and global_id. it is + * identical for all services we connect to. + */ +static int ceph_auth_none_create_authorizer( + struct ceph_auth_client *ac, int peer_type, + struct ceph_auth_handshake *auth) +{ + struct ceph_none_authorizer *au; + int ret; + + au = kmalloc_obj(*au, GFP_NOFS); + if (!au) + return -ENOMEM; + + au->base.destroy = ceph_auth_none_destroy_authorizer; + + ret = ceph_auth_none_build_authorizer(ac, au); + if (ret) { + kfree(au); + return ret; + } + + auth->authorizer = (struct ceph_authorizer *) au; + auth->authorizer_buf = au->buf; + auth->authorizer_buf_len = au->buf_len; + auth->authorizer_reply_buf = NULL; + auth->authorizer_reply_buf_len = 0; + + return 0; +} + +static const struct ceph_auth_client_ops ceph_auth_none_ops = { + .reset = reset, + .destroy = destroy, + .is_authenticated = is_authenticated, + .should_authenticate = should_authenticate, + .build_request = build_request, + .handle_reply = handle_reply, + .create_authorizer = ceph_auth_none_create_authorizer, +}; + +int ceph_auth_none_init(struct ceph_auth_client *ac) +{ + struct ceph_auth_none_info *xi; + + dout("ceph_auth_none_init %p\n", ac); + xi = kzalloc_obj(*xi, GFP_NOFS); + if (!xi) + return -ENOMEM; + + xi->starting = true; + + ac->protocol = CEPH_AUTH_NONE; + ac->private = xi; + ac->ops = &ceph_auth_none_ops; + return 0; +} -- cgit v1.3.1