kernel/linux.git/net/rds/connection.c, branch v6.18.33

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: Clear reconnect pending bit

2026-03-04T12:20:26+00:00

[ Upstream commit b89fc7c2523b2b0750d91840f4e52521270d70ed ] When canceling the reconnect worker, care must be taken to reset the reconnect-pending bit. If the reconnect worker has not yet been scheduled before it is canceled, the reconnect-pending bit will stay on forever. Signed-off-by: Håkon Bugge Signed-off-by: Allison Henderson Link: https://patch.msgid.link/20260203055723.1085751-6-achender@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net/rds: No shortcut out of RDS_CONN_ERROR

2026-03-04T12:20:21+00:00

[ Upstream commit ad22d24be635c6beab6a1fdd3f8b1f3c478d15da ] RDS connections carry a state "rds_conn_path::cp_state" and transitions from one state to another and are conditional upon an expected state: "rds_conn_path_transition." There is one exception to this conditionality, which is "RDS_CONN_ERROR" that can be enforced by "rds_conn_path_drop" regardless of what state the condition is currently in. But as soon as a connection enters state "RDS_CONN_ERROR", the connection handling code expects it to go through the shutdown-path. The RDS/TCP multipath changes added a shortcut out of "RDS_CONN_ERROR" straight back to "RDS_CONN_CONNECTING" via "rds_tcp_accept_one_path" (e.g. after "rds_tcp_state_change"). A subsequent "rds_tcp_reset_callbacks" can then transition the state to "RDS_CONN_RESETTING" with a shutdown-worker queued. That'll trip up "rds_conn_init_shutdown", which was never adjusted to handle "RDS_CONN_RESETTING" and subsequently drops the connection with the dreaded "DR_INV_CONN_STATE", which leaves "RDS_SHUTDOWN_WORK_QUEUED" on forever. So we do two things here: a) Don't shortcut "RDS_CONN_ERROR", but take the longer path through the shutdown code. b) Add "RDS_CONN_RESETTING" to the expected states in "rds_conn_init_shutdown" so that we won't error out and get stuck, if we ever hit weird state transitions like this again." Signed-off-by: Gerd Rausch Signed-off-by: Allison Henderson Link: https://patch.msgid.link/20260122055213.83608-2-achender@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

rds: Fix endianness annotation of jhash wrappers

2025-08-22T23:44:34+00:00

__ipv6_addr_jhash (wrapper around jhash2()) and __inet_ehashfn (wrapper around jhash_3words()) work with u32 (host endian) values but accept big endian inputs. Declare the local variables as big endian to avoid unnecessary casts. Flagged by Sparse. Signed-off-by: Ujwal Kundur Reviewed-by: Allison Henderson Link: https://patch.msgid.link/20250820175550.498-3-ujwal.kundur@gmail.com Signed-off-by: Jakub Kicinski

replace strncpy with strscpy_pad

2025-05-26T20:28:44+00:00

The strncpy() function is actively dangerous to use since it may not NULL-terminate the destination string, resulting in potential memory content exposures, unbounded reads, or crashes. Link: https://github.com/KSPP/linux/issues/90 In addition, strscpy_pad is more appropriate because it also zero-fills any remaining space in the destination if the source is shorter than the provided buffer size. Signed-off-by: Baris Can Goral Reviewed-by: Allison Henderson Link: https://patch.msgid.link/20250521161036.14489-1-goralbaris@gmail.com Signed-off-by: Paolo Abeni

net: rds: Simplify the allocation of slab caches in rds_conn_init

2024-01-31T01:08:19+00:00

Use the new KMEM_CACHE() macro instead of direct kmem_cache_create to simplify the creation of SLAB caches. Signed-off-by: Kunwu Chan Link: https://lore.kernel.org/r/20240124075801.471330-1-chentao@kylinos.cn Signed-off-by: Jakub Kicinski

rds: memory leak in __rds_conn_create()

2021-12-14T12:51:52+00:00

__rds_conn_create() did not release conn->c_path when loop_trans != 0 and trans->t_prefer_loopback != 0 and is_outgoing == 0. Fixes: aced3ce57cd3 ("RDS tcp loopback connection can hang") Signed-off-by: Hangyu Hua Reviewed-by: Sharath Srinivasan Signed-off-by: David S. Miller

RDS tcp loopback connection can hang

2021-05-21T21:46:59+00:00

When TCP is used as transport and a program on the system connects to RDS port 16385, connection is accepted but denied per the rules of RDS. However, RDS connections object is left in the list. Next loopback connection will select that connection object as it is at the head of list. The connection attempt will hang as the connection object is set to connect over TCP which is not allowed The issue can be reproduced easily, use rds-ping to ping a local IP address. After that use any program like ncat to connect to the same IP address and port 16385. This will hang so ctrl-c out. Now try rds-ping, it will hang. To fix the issue this patch adds checks to disallow the connection object creation and destroys the connection object. Signed-off-by: Rao Shoaib Signed-off-by: David S. Miller

rds: If one path needs re-connection, check all and re-connect

2020-07-02T00:35:17+00:00

In testing with mprds enabled, Oracle Cluster nodes after reboot were not able to communicate with others nodes and so failed to rejoin the cluster. Peers with lower IP address initiated connection but the node could not respond as it choose a different path and could not initiate a connection as it had a higher IP address. With this patch, when a node sends out a packet and the selected path is down, all other paths are also checked and any down paths are re-connected. Reviewed-by: Ka-cheong Poon Reviewed-by: David Edmondson Signed-off-by: Somasundaram Krishnasamy Signed-off-by: Rao Shoaib Signed-off-by: David S. Miller

rds: Return proper "tos" value to user-space

2019-07-10T04:45:42+00:00

The proper "tos" value needs to be returned to user-space (sockopt RDS_INFO_CONNECTIONS). Fixes: 3eb450367d08 ("rds: add type of service(tos) infrastructure") Signed-off-by: Gerd Rausch Reviewed-by: Zhu Yanjun Signed-off-by: Santosh Shilimkar