kernel/linux.git/drivers/infiniband/core/addr.c, branch linux-7.0.y

IB/core: Fix zero dmac race in neighbor resolution

2026-05-07T04:14:13+00:00

commit 5e6de34d82b49cab9d8a42063e9cd0f22a4f31e5 upstream. dst_fetch_ha() checks nud_state without holding the neighbor lock, then copies ha under the seqlock. A race in __neigh_update() where nud_state is set to NUD_REACHABLE before ha is written allows dst_fetch_ha() to read a zero MAC address while the seqlock reports no concurrent writer. netevent_callback amplifies this by waking ALL pending addr_req workers when ANY neighbor becomes NUD_VALID. At scale (N peers resolving ARP concurrently), the hit probability scales as N^2, making it near-certain for large RDMA workloads. N(A): neigh_update(A) W(A): addr_resolve(A) | [sleep] | write_lock_bh(&A->lock) | | A->nud_state = NUD_REACHABLE | | // A->ha is still 0 | | [woken by netevent_cb() of | another neighbour] | | dst_fetch_ha(A) | | A->nud_state & NUD_VALID | | read_seqbegin(&A->ha_lock) | | snapshot = A->ha /* 0 */ | | read_seqretry(&A->ha_lock) | | return snapshot | seqlock(&A->ha_lock) | A->ha = mac_A /* too late */ | sequnlock(&A->ha_lock) | write_unlock_bh(&A->lock) The incorrect/zero mac is read and programmed in the device QP while it was not yet updated. This causes silent packet loss and eventual RETRY_EXC_ERR. Fix by holding the neighbor read lock across the nud_state check and ha copy in dst_fetch_ha(), ensuring it synchronizes with __neigh_update() which is updating while holding the write lock. Cc: stable@vger.kernel.org Fixes: 92ebb6a0a13a ("IB/cm: Remove now useless rcu_lock in dst_fetch_ha") Link: https://patch.msgid.link/r/20260405-fix-dmac-race-v1-1-cfa1ec2ce54a@nvidia.com Signed-off-by: Chen Zhao Reviewed-by: Parav Pandit Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe Signed-off-by: Greg Kroah-Hartman

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

RDMA/core: Check for the presence of LS_NLA_TYPE_DGID correctly

2025-12-17T01:30:56+00:00

The netlink response for RDMA_NL_LS_OP_IP_RESOLVE should always have a LS_NLA_TYPE_DGID attribute, it is invalid if it does not. Use the nl parsing logic properly and call nla_parse_deprecated() to fill the nlattrs array and then directly index that array to get the data for the DGID. Just fail if it is NULL. Remove the for loop searching for the nla, and squash the validation and parsing into one function. Fixes an uninitialized read from the stack triggered by userspace if it does not provide the DGID to a kernel initiated RDMA_NL_LS_OP_IP_RESOLVE query. BUG: KMSAN: uninit-value in hex_byte_pack include/linux/hex.h:13 [inline] BUG: KMSAN: uninit-value in ip6_string+0xef4/0x13a0 lib/vsprintf.c:1490 hex_byte_pack include/linux/hex.h:13 [inline] ip6_string+0xef4/0x13a0 lib/vsprintf.c:1490 ip6_addr_string+0x18a/0x3e0 lib/vsprintf.c:1509 ip_addr_string+0x245/0xee0 lib/vsprintf.c:1633 pointer+0xc09/0x1bd0 lib/vsprintf.c:2542 vsnprintf+0xf8a/0x1bd0 lib/vsprintf.c:2930 vprintk_store+0x3ae/0x1530 kernel/printk/printk.c:2279 vprintk_emit+0x307/0xcd0 kernel/printk/printk.c:2426 vprintk_default+0x3f/0x50 kernel/printk/printk.c:2465 vprintk+0x36/0x50 kernel/printk/printk_safe.c:82 _printk+0x17e/0x1b0 kernel/printk/printk.c:2475 ib_nl_process_good_ip_rsep drivers/infiniband/core/addr.c:128 [inline] ib_nl_handle_ip_res_resp+0x963/0x9d0 drivers/infiniband/core/addr.c:141 rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:-1 [inline] rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline] rdma_nl_rcv+0xefa/0x11c0 drivers/infiniband/core/netlink.c:259 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0xf04/0x12b0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x10b3/0x1250 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x333/0x3d0 net/socket.c:729 ____sys_sendmsg+0x7e0/0xd80 net/socket.c:2617 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2671 __sys_sendmsg+0x1aa/0x300 net/socket.c:2703 __compat_sys_sendmsg net/compat.c:346 [inline] __do_compat_sys_sendmsg net/compat.c:353 [inline] __se_compat_sys_sendmsg net/compat.c:350 [inline] __ia32_compat_sys_sendmsg+0xa4/0x100 net/compat.c:350 ia32_sys_call+0x3f6c/0x4310 arch/x86/include/generated/asm/syscalls_32.h:371 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xb0/0x150 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x38/0x80 arch/x86/entry/syscall_32.c:331 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:3 Link: https://patch.msgid.link/r/0-v1-3fbaef094271+2cf-rdma_op_ip_rslv_syz_jgg@nvidia.com Cc: stable@vger.kernel.org Fixes: ae43f8286730 ("IB/core: Add IP to GID netlink offload") Reported-by: syzbot+938fcd548c303fe33c1a@syzkaller.appspotmail.com Closes: https://lore.kernel.org/r/68dc3dac.a00a0220.102ee.004f.GAE@google.com Signed-off-by: Jason Gunthorpe

RDMA/core: Use route entry flag to decide on loopback traffic

2025-09-18T09:20:35+00:00

addr_resolve() considers a destination to be local if the next-hop device of the resolved route for the destination is the loopback netdevice. This fails when the source and destination IP addresses belong to a netdev enslaved to a VRF netdev. In this case the next-hop device is the VRF itself: $ ip link add name myvrf up type vrf table 100 $ ip link set ens2f0np0 master myvrf up $ ip addr add 192.168.1.1/24 dev ens2f0np0 $ ip route get 192.168.1.1 oif myvrf local 192.168.1.1 dev myvrf table 100 src 192.168.1.1 uid 0 cache This results in packets being generated with an incorrect destination MAC of the VRF netdevice and ib_write_bw failing with timeout. Solve this by determining if a destination is local or not based on the resolved route's type rather than based on its next-hop netdevice loopback flag. This enables to resolve loopback traffic with and without VRF configurations in a uniform way. Signed-off-by: Parav Pandit Reviewed-by: Vlad Dumitrescu Signed-off-by: Edward Srouji Link: https://patch.msgid.link/20250916111103.84069-4-edwards@nvidia.com Signed-off-by: Leon Romanovsky

RDMA/core: Resolve MAC of next-hop device without ARP support

2025-09-18T09:20:20+00:00

Currently, if the next-hop netdevice does not support ARP resolution, the destination MAC address is silently set to zero without reporting an error. This leads to incorrect behavior and may result in packet transmission failures. Fix this by deferring MAC resolution to the IP stack via neighbour lookup, allowing proper resolution or error reporting as appropriate. Fixes: 7025fcd36bd6 ("IB: address translation to map IP toIB addresses (GIDs)") Signed-off-by: Parav Pandit Reviewed-by: Vlad Dumitrescu Signed-off-by: Edward Srouji Link: https://patch.msgid.link/20250916111103.84069-3-edwards@nvidia.com Signed-off-by: Leon Romanovsky

RDMA/core: Squash a single user static function

2025-09-18T09:15:39+00:00

To reduce dependencies in IFF_LOOPBACK in route and neighbour resolution steps, squash the static function to its single caller and simplify the code. Until now, network field was set even when neighbour resolution failed. With this change, dev_addr output fields are valid only when resolution is successful. Signed-off-by: Parav Pandit Reviewed-by: Vlad Dumitrescu Signed-off-by: Edward Srouji Link: https://patch.msgid.link/20250916111103.84069-2-edwards@nvidia.com Signed-off-by: Leon Romanovsky

Revert "RDMA/core: Fix ENODEV error for iWARP test over vlan"

2024-11-12T14:53:11+00:00

The citied commit in Fixes line caused to regression for udaddy [1] application. It doesn't work over VLANs anymore. Client: ifconfig eth2 1.1.1.1 ip link add link eth2 name p0.3597 type vlan protocol 802.1Q id 3597 ip link set dev p0.3597 up ip addr add 2.2.2.2/16 dev p0.3597 udaddy -S 847 -C 220 -c 2 -t 0 -s 2.2.2.3 -b 2.2.2.2 Server: ifconfig eth2 1.1.1.3 ip link add link eth2 name p0.3597 type vlan protocol 802.1Q id 3597 ip link set dev p0.3597 up ip addr add 2.2.2.3/16 dev p0.3597 udaddy -S 847 -C 220 -c 2 -t 0 -b 2.2.2.3 [1] https://github.com/linux-rdma/rdma-core/blob/master/librdmacm/examples/udaddy.c Fixes: 5069d7e202f6 ("RDMA/core: Fix ENODEV error for iWARP test over vlan") Reported-by: Leon Romanovsky Closes: https://lore.kernel.org/all/20241110130746.GA48891@unreal Link: https://patch.msgid.link/bb9d403419b2b9566da5b8bf0761fa8377927e49.1731401658.git.leon@kernel.org Signed-off-by: Leon Romanovsky

RDMA/core: Fix ENODEV error for iWARP test over vlan

2024-10-08T12:07:41+00:00

If traffic is over vlan, cma_validate_port() fails to match vlan net_device ifindex with bound_if_index and results in ENODEV error. It is because rdma_copy_src_l2_addr() always assigns bound_if_index with real net_device ifindex. This patch fixes the issue by assigning bound_if_index with vlan net_device index if traffic is over vlan. Fixes: f8ef1be816bf ("RDMA/cma: Avoid GID lookups on iWARP devices") Signed-off-by: Anumula Murali Mohan Reddy Signed-off-by: Potnuri Bharat Teja Link: https://patch.msgid.link/20241008114334.146702-1-anumula@chelsio.com Signed-off-by: Leon Romanovsky

inet: introduce dst_rtable() helper

2024-05-01T01:32:38+00:00

I added dst_rt6_info() in commit e8dfd42c17fa ("ipv6: introduce dst_rt6_info() helper") This patch does a similar change for IPv4. Instead of (struct rtable *)dst casts, we can use : #define dst_rtable(_ptr) \ container_of_const(_ptr, struct rtable, dst) Patch is smaller than IPv6 one, because IPv4 has skb_rtable() helper. Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Reviewed-by: Sabrina Dubroca Link: https://lore.kernel.org/r/20240429133009.1227754-1-edumazet@google.com Signed-off-by: Jakub Kicinski