kernel/linux.git/net/rds, branch v6.18.44

rds: tcp: hold the RCU lock across ipv6_chk_addr() in rds_tcp_laddr_check()

2026-08-09T18:25:02+00:00

[ Upstream commit 78f75d632f74b8de0f081a128588f7c37d0d1164 ] rds_tcp_laddr_check() looks up a scoped IPv6 interface with dev_get_by_index_rcu(), drops the RCU read-side lock, and only then passes the bare struct net_device * into ipv6_chk_addr(). dev_get_by_index_rcu() only keeps the device alive within the same RCU read-side section. After rcu_read_unlock(), a concurrent RTM_DELLINK can free the net_device; ipv6_chk_addr() then dereferences the stale pointer in __ipv6_chk_addr_and_flags() (e.g. l3mdev_master_dev_rcu(dev)), reading freed memory. Keep the RCU read-side lock held across the ipv6_chk_addr() call instead of dropping it right after the lookup, so the device cannot be freed while it is in use. BUG: KASAN: slab-use-after-free in __ipv6_chk_addr_and_flags (... net/ipv6/addrconf.c:1998) Read of size 8 at addr ffff8880106ec000 by task exploit/153 Call Trace: ... kasan_report (mm/kasan/report.c:595) __ipv6_chk_addr_and_flags (... net/ipv6/addrconf.c:1998) ipv6_chk_addr (net/ipv6/addrconf.c:2031 net/ipv6/addrconf.c:1972) rds_tcp_laddr_check (net/rds/tcp.c:370) rds_bind (net/rds/bind.c:248) __sys_bind (net/socket.c:1920) __x64_sys_bind (net/socket.c:1956) do_syscall_64 (arch/x86/entry/syscall_64.c:63) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) Fixes: eee2fa6ab322 ("rds: Changing IP address internal representation to struct in6_addr") Reported-by: Weiming Shi Signed-off-by: Xiang Mei Reviewed-by: Allison Henderson Link: https://patch.msgid.link/20260722210203.565803-1-xmei5@asu.edu Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

rds: Fix inet6_addr_lst NULL dereference when IPv6 is disabled

2026-08-09T18:25:01+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 Stable-dep-of: 78f75d632f74 ("rds: tcp: hold the RCU lock across ipv6_chk_addr() in rds_tcp_laddr_check()") Signed-off-by: Sasha Levin

rds: tcp: unregister sysctl before tearing down listen socket

2026-08-03T09:21:47+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: drop incoming messages that cross network namespace boundaries

2026-08-03T09:21:40+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

net: rds: clear i_sends on setup unwind

2026-06-19T11:44:09+00:00

commit 20cf0fb715c41111469577e85e35d15f099473e0 upstream. 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 Signed-off-by: Greg Kroah-Hartman

rds: mark snapshot pages dirty in rds_info_getsockopt()

2026-06-19T11:44:00+00:00

[ Upstream commit 512db8267b73a220a64180d95ab5eebe7c4964a8 ] 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 Signed-off-by: Sasha Levin

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

2026-06-19T11:43:59+00:00

[ Upstream commit 34080db3e70ddf94c38512ad2331e3c3afca6cc1 ] 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 Signed-off-by: Sasha Levin

net/rds: reset op_nents when zerocopy page pin fails

2026-05-23T11:07:20+00:00

commit e174929793195e0cd6a4adb0cad731b39f9019b4 upstream. 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 Signed-off-by: Greg Kroah-Hartman

net/rds: zero per-item info buffer before handing it to visitors

2026-05-23T11:07:03+00:00

[ Upstream commit c88eb7e8d8397a8c1db59c425332c5a30b2a1682 ] rds_for_each_conn_info() and rds_walk_conn_path_info() both hand a caller-allocated on-stack u64 buffer to a per-connection visitor and then copy the full item_len bytes back to user space via rds_info_copy() regardless of how much of the buffer the visitor actually wrote. rds_ib_conn_info_visitor() and rds6_ib_conn_info_visitor() only write a subset of their output struct when the underlying rds_connection is not in state RDS_CONN_UP (src/dst addr, tos, sl and the two GIDs via explicit memsets). Several u32 fields (max_send_wr, max_recv_wr, max_send_sge, rdma_mr_max, rdma_mr_size, cache_allocs) and the 2-byte alignment hole between sl and cache_allocs remain as whatever stack contents preceded the visitor call and are then memcpy_to_user()'d out to user space. struct rds_info_rdma_connection and struct rds6_info_rdma_connection are the only rds_info_* structs in include/uapi/linux/rds.h that are not marked __attribute__((packed)), so they have a real alignment hole. The other info visitors (rds_conn_info_visitor, rds6_conn_info_visitor, rds_tcp_tc_info, ...) write all fields of their packed output struct today and are not known to be vulnerable, but a future visitor that adds a conditional write-path would have the same bug. Reproduction on a kernel built without CONFIG_INIT_STACK_ALL_ZERO=y: a local unprivileged user opens AF_RDS, sets SO_RDS_TRANSPORT=IB, binds to a local address on an RDMA-capable netdev (rxe soft-RoCE on any netdev is sufficient), sendto()'s any peer on the same subnet (fails cleanly but installs an rds_connection in the global hash in RDS_CONN_CONNECTING), then calls getsockopt(SOL_RDS, RDS_INFO_IB_CONNECTIONS). The returned 68-byte item contains 26 bytes of stack garbage including kernel text/data pointers: 0..7 0a 63 00 01 0a 63 00 02 src=10.99.0.1 dst=10.99.0.2 8..39 00 ... gids (memset-zeroed) 40..47 e0 92 a3 81 ff ff ff ff kernel pointer (max_send_wr) 48..55 7f 37 b5 81 ff ff ff ff kernel pointer (rdma_mr_max) 56..59 01 00 08 00 rdma_mr_size (garbage) 60..61 00 00 tos, sl 62..63 00 00 alignment padding 64..67 18 00 00 00 cache_allocs (garbage) Fix by zeroing the per-item buffer in both rds_for_each_conn_info() and rds_walk_conn_path_info() before invoking the visitor. This covers the IPv4/IPv6 IB visitors and hardens all current and future visitors against the same class of bug. No functional change for visitors that fully populate their output. Changes in v2: - retarget at the net tree (subject prefix "[PATCH net v2]", net/rds: prefix in the title) - pick up Reviewed-by tags from Sharath Srinivasan and Allison Henderson Fixes: ec16227e1414 ("RDS/IB: Infiniband transport") Signed-off-by: Michael Bommarito Reviewed-by: Sharath Srinivasan Reviewed-by: Allison Henderson Assisted-by: Claude:claude-opus-4-7 Link: https://patch.msgid.link/20260418141047.3398203-1-michael.bommarito@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net/rds: Restrict use of RDS/IB to the initial network namespace

2026-05-23T11:06:32+00:00

[ Upstream commit ebf71dd4aff46e8e421d455db3e231ba43d2fa8a ] Prevent using RDS/IB in network namespaces other than the initial one. The existing RDS/IB code will not work properly in non-initial network namespaces. Fixes: d5a8ac28a7ff ("RDS-TCP: Make RDS-TCP work correctly when it is set up in a netns other than init_net") Reported-by: syzbot+da8e060735ae02c8f3d1@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=da8e060735ae02c8f3d1 Signed-off-by: Greg Jumper Signed-off-by: Allison Henderson Link: https://patch.msgid.link/20260408080420.540032-3-achender@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin