kernel/linux.git/net/rds, branch v7.1.6

rds: tcp: unregister sysctl before tearing down listen socket

2026-08-03T09:25:37+00:00

[ Upstream commit 167e54c703ccd4fa028feb568b0d1002020cff86 ] rds_tcp_exit_net() frees the per-netns RDS TCP listen socket via rds_tcp_kill_sock() before unregistering the per-netns sysctl table. Since rds_tcp_skbuf_handler() derives the netns from rtn->rds_tcp_listen_sock->sk, a concurrent sysctl write can race with netns teardown and dereference the freed socket/sk. KASAN reports the race as: BUG: KASAN: slab-use-after-free in rds_tcp_skbuf_handler+0x2aa/0x2e0 rds_tcp_skbuf_handler net/rds/tcp.c:721 proc_sys_call_handler fs/proc/proc_sysctl.c vfs_write fs/read_write.c __x64_sys_pwrite64 fs/read_write.c Fix this by unregistering the RDS TCP sysctl table before calling rds_tcp_kill_sock(). unregister_net_sysctl_table() prevents new sysctl handlers from starting and waits for in-flight handlers to finish, so the listen socket can then be released safely. The fix was tested against the linked reproducer. Fixes: 7f5611cbc487 ("rds: sysctl: rds_tcp_{rcv,snd}buf: avoid using current->nsproxy") Reported-by: AutonomousCodeSecurity@microsoft.com Link: https://lore.kernel.org/all/20260719203718.9680-1-blbllhy@gmail.com Reviewed-by: Allison Henderson Signed-off-by: Cen Zhang (Microsoft) Link: https://patch.msgid.link/20260719210357.10179-1-blbllhy@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

rds: Fix inet6_addr_lst NULL dereference when IPv6 is disabled

2026-08-03T09:25:32+00:00

[ Upstream commit 9c805e592a29be9e4e61ff1bd567da04aa8fd6f9 ] When booting with the 'ipv6.disable=1' parameter, inet6_addr_lst is never initialized because inet6_init() exits before addrconf_init() is called to initialize it. An attempt to bind an RDS socket to an ipv6 address results in a crash in __ipv6_chk_addr_and_flags() KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] RIP: 0010:__ipv6_chk_addr_and_flags+0x1df/0x7e0 Call Trace: ipv6_chk_addr+0x3b/0x50 rds_tcp_laddr_check+0x155/0x3b0 [rds_tcp] rds_trans_get_preferred+0x15d/0x2d0 [rds] ? trace_hardirqs_on+0x2d/0x110 rds_bind+0x1433/0x1d60 [rds] ? rds_remove_bound+0xd50/0xd50 [rds] ? aa_af_perm+0x250/0x250 ? __might_fault+0xde/0x190 ? __sys_bind+0x1dc/0x210 __sys_bind+0x1dc/0x210 ? __ia32_sys_socketpair+0x100/0x100 ? restore_fpregs_from_fpstate+0x53/0x100 __x64_sys_bind+0x73/0xb0 ? syscall_enter_from_user_mode+0x1c/0x50 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 RIP: 0033:0x7f47f8269ea9 The following code reproduces the issue: struct sockaddr_in6 addr; s = socket(PF_RDS, SOCK_SEQPACKET, 0); memset(&addr, 0, sizeof(addr)); inet_pton(AF_INET6, ADDRESS, &addr.sin6_addr); addr.sin6_family = AF_INET6; addr.sin6_port = htons(PORT); bind(s, &addr, sizeof(addr)); Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: eee2fa6ab322 ("rds: Changing IP address internal representation to struct in6_addr") Fixes: 1e2b44e78eea ("rds: Enable RDS IPv6 support") Signed-off-by: Ilia Gavrilov Reviewed-by: Allison Henderson Link: https://patch.msgid.link/20260709162723.367523-1-Ilia.Gavrilov@infotecs.ru Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

rds: drop incoming messages that cross network namespace boundaries

2026-08-03T09:25:30+00:00

[ Upstream commit 5521ae71e32a8069ed4ca6e792179dc57bc43ab2 ] rds_find_bound() looks up the destination socket using a global rhashtable keyed solely on (addr, port, scope_id). Network namespaces are not part of the key, so a sender in netns A can deliver an incoming message (inc) to a socket that lives in a different netns B. When this happens, inc->i_conn points to an rds_connection whose c_net is netns A, but the receiving rs lives in netns B. Once the child process that created netns A exits, cleanup_net() calls rds_loop_exit_net() -> rds_loop_kill_conns() -> rds_conn_destroy(), freeing that connection. If the survivor socket in netns B still holds the inc, any subsequent dereference of inc->i_conn is a use-after-free. There are two dangerous sites in rds_clear_recv_queue(): 1. inc->i_conn->c_lcong (offset 88 of freed rds_connection, size 200) read via rds_recv_rcvbuf_delta() -- confirmed by KASAN. 2. inc->i_conn->c_trans->inc_free(inc) (function pointer at offset 80) called via rds_inc_put() when the inc refcount reaches zero -- same race window, potential call-through-freed-object primitive. The bug is reachable from unprivileged user namespaces (CLONE_NEWUSER + CLONE_NEWNET), available since Linux 3.8. Fix this by rejecting the delivery in rds_recv_incoming() when the socket returned by rds_find_bound() belongs to a different network namespace than the connection that carried the message. Use the existing rds_conn_net() / sock_net() helpers and net_eq() for the comparison. Fixes: c809195f5523 ("rds: clean up loopback rds_connections on netns deletion") Signed-off-by: Aldo Ariel Panzardo Reviewed-by: Allison Henderson Tested-by: Allison Henderson Signed-off-by: Allison Henderson Link: https://patch.msgid.link/20260708024314.601139-1-achender@kernel.org Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

rds: mark snapshot pages dirty in rds_info_getsockopt()

2026-06-10T15:18:16+00:00

rds_info_getsockopt() pins the destination user pages with FOLL_WRITE and the RDS_INFO_* producers memcpy the snapshot into them through kmap_atomic(). Because that copy goes through the kernel direct map, the dirty bit on the user PTE is never set, so unpin_user_pages() releases the pages without marking them dirty. A file-backed destination page can then be reclaimed without writeback, silently discarding the copied data. Use unpin_user_pages_dirty_lock() with make_dirty=true so the modified pages are marked dirty before they are unpinned. Fixes: a8c879a7ee98 ("RDS: Info and stats") Signed-off-by: Breno Leitao Reviewed-by: Allison Henderson Link: https://patch.msgid.link/20260608-rds_fix-v1-1-006c88543408@debian.org Signed-off-by: Jakub Kicinski

net/rds: fix NULL deref in rds_ib_send_cqe_handler() on masked atomic completion

2026-06-10T01:32:54+00:00

rds_ib_xmit_atomic() always programs a masked atomic opcode (IB_WR_MASKED_ATOMIC_CMP_AND_SWP or IB_WR_MASKED_ATOMIC_FETCH_AND_ADD) for every RDS atomic cmsg. But the completion-side switch in rds_ib_send_unmap_op() only handles the non-masked opcodes, so a masked atomic completion falls through to default and returns rm == NULL while send->s_op is left set. rds_ib_send_cqe_handler() then dereferences the NULL rm via rm->m_final_op, oopsing in softirq context. An unprivileged AF_RDS sendmsg() of an atomic cmsg over an active RDS/IB connection triggers it; on hardware that natively accepts masked atomics (mlx4, mlx5) no extra setup is needed. RDS/IB: rds_ib_send_unmap_op: unexpected opcode 0xd in WR! Oops: general protection fault [#1] SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000190-0x0000000000000197] RIP: rds_ib_send_cqe_handler+0x25c/0xb10 (net/rds/ib_send.c:282) Call Trace: rds_ib_send_cqe_handler (net/rds/ib_send.c:282) poll_scq (net/rds/ib_cm.c:274) rds_ib_tasklet_fn_send (net/rds/ib_cm.c:294) tasklet_action_common (kernel/softirq.c:943) handle_softirqs (kernel/softirq.c:573) run_ksoftirqd (kernel/softirq.c:479) Kernel panic - not syncing: Fatal exception in interrupt Handle the masked atomic opcodes in the same case as the non-masked ones: they map to the same struct rds_message.atomic union member, so the existing container_of()/rds_ib_send_unmap_atomic() body is correct for them. Fixes: 20c72bd5f5f9 ("RDS: Implement masked atomic operations") Reported-by: Xiang Mei Signed-off-by: Weiming Shi Reviewed-by: Allison Henderson Link: https://patch.msgid.link/20260606192447.1179255-2-bestswngs@gmail.com Signed-off-by: Jakub Kicinski

net: rds: clear i_sends on setup unwind

2026-06-02T20:31:27+00:00

The RDS IB connection teardown path is written so it can run during partial startup and on repeated shutdown attempts. It uses NULL pointers to distinguish resources that are still owned from resources that have already been released. When rds_ib_setup_qp() fails after allocating i_sends but before allocating i_recvs, the sends_out path frees i_sends without clearing the pointer. A later shutdown pass can still treat that stale pointer as a live send ring allocation. Clear i_sends after vfree() in the error unwind path so the existing shutdown logic continues to use the correct ownership state. Fixes: 3b12f73a5c29 ("rds: ib: add error handle") Cc: stable@kernel.org Reported-by: Yuan Tan Reported-by: Zhengchuan Liang Reported-by: Xin Liu Signed-off-by: Yuqi Xu Signed-off-by: Ren Wei Reviewed-by: Allison Henderson Link: https://patch.msgid.link/5a0f7624bb9845a7b67d26166a150b59e7f394ce.1779632468.git.xuyq21@lenovo.com Signed-off-by: Jakub Kicinski

rds_tcp: close NULL deref window in rds_tcp_set_callbacks

2026-05-15T00:06:59+00:00

rds_tcp_set_callbacks() links a new rds_tcp_connection onto rds_tcp_tc_list under rds_tcp_tc_list_lock. It releases the lock, then assigns tc->t_sock = sock outside the lock. rds_tcp_tc_info() and rds6_tcp_tc_info() walk rds_tcp_tc_list under the same lock. Both dereference tc->t_sock->sk without a NULL check. A reader can acquire rds_tcp_tc_list_lock between the writer's spin_unlock and the t_sock store. It then sees a list entry whose t_sock is NULL. The dereference of tc->t_sock->sk is a NULL access. Move tc->t_sock = sock inside rds_tcp_tc_list_lock, before list_add_tail. A reader holding the lock then observes the linkage and the t_sock store together. The restore path is safe. rds_tcp_restore_callbacks() does list_del_init inside the lock. The matching tc->t_sock = NULL after unlink is harmless to readers holding the lock. Fixes: 70041088e3b9 ("RDS: Add TCP transport to RDS") Suggested-by: Simon Horman Signed-off-by: Maoyi Xie Reviewed-by: Allison Henderson Link: https://patch.msgid.link/20260512142807.1855619-1-maoyi.xie@ntu.edu.sg Signed-off-by: Jakub Kicinski

net/rds: reset op_nents when zerocopy page pin fails

2026-05-12T00:20:02+00:00

When iov_iter_get_pages2() fails in rds_message_zcopy_from_user(), the pinned pages are released with put_page(), and rm->data.op_mmp_znotifier is cleared. But we fail to properly clear rm->data.op_nents. Later when rds_message_purge() is called from rds_sendmsg() the cleanup loop iterates over the incorrectly non zero number of op_nents and frees them again. Fix this by properly resetting op_nents when it should be in rds_message_zcopy_from_user(). Fixes: 0cebaccef3ac ("rds: zerocopy Tx support.") Signed-off-by: Allison Henderson Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260505234336.2132721-1-achender@kernel.org Signed-off-by: Jakub Kicinski

net/rds: handle zerocopy send cleanup before the message is queued

2026-05-05T13:32:40+00:00

A zerocopy send can fail after user pages have been pinned but before the message is attached to the sending socket. The purge path currently infers zerocopy state from rm->m_rs, so an unqueued message can be cleaned up as if it owned normal payload pages. However, zerocopy ownership is really determined by the presence of op_mmp_znotifier, regardless of whether the message has reached the socket queue. Capture op_mmp_znotifier up front in rds_message_purge() and use it as the cleanup discriminator. If the message is already associated with a socket, keep the existing completion path. Otherwise, drop the pinned page accounting directly and release the notifier before putting the payload pages. This keeps early send failure cleanup consistent with the zerocopy lifetime rules without changing the normal queued completion path. Fixes: 0cebaccef3ac ("rds: zerocopy Tx support.") Cc: stable@kernel.org Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Co-developed-by: Xiao Liu Signed-off-by: Xiao Liu Signed-off-by: Nan Li Signed-off-by: Ren Wei Reviewed-by: Allison Henderson Link: https://patch.msgid.link/d2ea98a6313d5467bac00f7c9fef8c7acddb9258.1777550074.git.tonanli66@gmail.com Signed-off-by: Paolo Abeni

net: rds: fix MR cleanup on copy error

2026-04-23T19:18:08+00:00

__rds_rdma_map() hands sg/pages ownership to the transport after get_mr() succeeds. If copying the generated cookie back to user space fails after that point, the error path must not free those resources again before dropping the MR reference. Remove the duplicate unpin/free from the put_user() failure branch so that MR teardown is handled only through the existing final cleanup path. Fixes: 0d4597c8c5ab ("net/rds: Track user mapped pages through special API") Cc: stable@kernel.org Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Signed-off-by: Ao Zhou Signed-off-by: Ren Wei Reviewed-by: Allison Henderson Link: https://patch.msgid.link/79c8ef73ec8e5844d71038983940cc2943099baf.1776764247.git.draw51280@163.com Signed-off-by: Jakub Kicinski