Pull bpf fixes from Kumar Kartikeya Dwivedi: - Fix a UAF in socket clone early bailout paths (Matt Bobrowski) - Reject unhashed UDP sockets on sockmap update to prevent refcount leaks (Michal Luczaj) - Account for receive queue data in FIONREAD on sockmap sockets without a verdict program (Mattia Meleleo) - Reject negative constant offsets for verifier buffer pointers (Sun Jian) - Fix for tracing of kfuncs with implicit arguments (Ihor Solodrai) * tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: selftests/bpf: Cover tracing implicit kfunc args bpf: Fix tracing of kfuncs with implicit args selftests/bpf: Cover negative buffer pointer offsets bpf: Reject negative const offsets for buffer pointers selftests/bpf: Test FIONREAD on a sockmap socket without a verdict program bpf, sockmap: Account for receive queue in FIONREAD without a verdict program selftests/bpf: Fail unbound UDP on sockmap update selftests/bpf: Adapt sockmap update error handling bpf, sockmap: Reject unhashed UDP sockets on sockmap update selftests/bpf: Ensure UDP sockets are bound bpf: Fix UAF in sock clone early bailouts
UDP sockets get SOCK_RCU_FREE set when (auto-)bound. This means
sk_is_refcounted(unbound) = true, while sk_is_refcounted(bound) = false.
Because sockmap accepts unbound UDP sockets, a BPF program can increment a
socket's refcount via lookup. If the socket is subsequently bound, the
transition from unbound to bound causes bpf_sk_release() to skip the
decrement of the refcount, causing a memory leak.
unreferenced object 0xffff88810bc2eb40 (size 1984):
comm "test_progs", pid 2451, jiffies 4295320596
hex dump (first 32 bytes):
7f 00 00 01 7f 00 00 01 d2 04 1b b7 04 d2 00 00 ................
02 00 01 40 00 00 00 00 00 00 00 00 00 00 00 00 ...@............
backtrace (crc bdee079d):
kmem_cache_alloc_noprof+0x557/0x660
sk_prot_alloc+0x69/0x240
sk_alloc+0x30/0x460
inet_create+0x2ce/0xf80
__sock_create+0x25b/0x5c0
__sys_socket+0x119/0x1d0
__x64_sys_socket+0x72/0xd0
do_syscall_64+0xa1/0x5f0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Instead of special-casing for refcounted sockets, reject unhashed UDP
sockets during sockmap updates, as there is no benefit to supporting those.
This effectively reverts the commit under Fixes, with two exceptions:
1. sock_map_sk_state_allowed() maintains a fall-through `return true`.
2. In the spirit of commit b8b8315e39ff ("bpf, sockmap: Remove unhash
handler for BPF sockmap usage"), the proto::unhash BPF handler is not
reintroduced.
Historical note: this issue is related to commit 67312adc96b5 ("bpf: reject
unhashed sockets in bpf_sk_assign").
Fixes: 0c48eefae712 ("sock_map: Lift socket state restriction for datagram sockets")
Suggested-by: Kuniyuki Iwashima <kuniyu@google.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20260707-sockmap-lookup-udp-leak-v4-2-f878346f27ab@rbox.co
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Steffen Klassert says:
====================
pull request (net): ipsec 2026-07-10
1) xfrm: propagate -EINPROGRESS from validate_xmit_xfrm()
Return -EINPROGRESS from xfrm_output_one when validate_xmit_xfrm
requeues the packet asynchronously, so the caller doesn't treat it
as a real error and free the skb.
2) xfrm: fix stale skb->prev after async crypto steals a GSO segment
Re-derive skb->prev from the fragment list after async crypto splits
a GSO skb, keeping the linked-list pointers validi.
3) xfrm: nat_keepalive: avoid double free on send error
Hold a state ref while the nat_keepalive timer is active and drop the
timer before freeing the state, preventing a re-entered free on send
error.
4) xfrm: fix sk_dst_cache double-free in xfrm_user_policy()
Null the skb dst cache before freeing the policy so a later skb
destructor doesn't double-free it.
5) xfrm: cache the offload ifindex for netlink dumps
Cache the device ifindex at state-add time and use it for netlink
dumps instead of dereferencing dst->dev, which may have changed by
the time the dump runs.
6) xfrm: reject optional IPTFS templates in outbound policies
Reject outbound policies with an optional IPTFS template,
IPTFS must always be used if configured.
7) xfrm: clear mode callbacks after failed mode setup
Clear the mode->init_flags and init_state callbacks on the error path
after xfrm_init_mode fails, so a partially-initialised mode isn't
reused in xfrm_state_construct.
8) xfrm: iptfs: propagate SKBFL_SHARED_FRAG in iptfs_skb_add_frags()
Propagate SKBFL_SHARED_FRAG from the original skb to fragments
allocated by iptfs_skb_add_frags, keeping shared-fragment accounting
correct after IPTFS reassembly.
9) xfrm6: clear dst.dev on error to avoid double netdev_put in xfrm6_fill_dst()
Clear dst->dev on the error path of xfrm6_fill_dst() so the caller
doesn't release the netdev reference twice via dst_release.
10) xfrm: policy: preallocate inexact bins before xfrm_hash_rebuild reinsert
Preallocate all inexact hash bins before existing entries are
reinserted during xfrm_hash_rebuild, so reinsertion always hits an
existing bin.
Please pull or let me know if there are problems.
ipsec-2026-07-10
* tag 'ipsec-2026-07-10' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec:
xfrm: policy: preallocate inexact bins before xfrm_hash_rebuild reinsert
xfrm6: clear dst.dev on error to avoid double netdev_put in xfrm6_fill_dst()
xfrm: iptfs: propagate SKBFL_SHARED_FRAG in iptfs_skb_add_frags()
xfrm: clear mode callbacks after failed mode setup
xfrm: reject optional IPTFS templates in outbound policies
xfrm: cache the offload ifindex for netlink dumps
xfrm: fix sk_dst_cache double-free in xfrm_user_policy()
xfrm: nat_keepalive: avoid double free on send error
xfrm: fix stale skb->prev after async crypto steals a GSO segment
xfrm: propagate -EINPROGRESS from validate_xmit_xfrm()
====================
Link: https://patch.msgid.link/20260710090349.343389-1-steffen.klassert@secunet.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Similar to recent commit 9b51a6155d14 ("bpf,fork: wipe ->bpf_storage
before bailouts that access it"), sk_clone() performs an initial
shallow copy of the socket field ->sk_bpf_storage via sock_copy()
for the cloned socket newsk.
If sk_clone() bails out early (e.g. if sk_filter_charge() fails) prior
to calling bpf_sk_storage_clone(), newsk->sk_bpf_storage still points
to the parent socket's BPF local storage. When newsk is subsequently
freed via sk_free(), the deallocation path (__sk_destruct() ->
bpf_sk_storage_free()) destroys the parent socket's BPF local storage,
leading to a use-after-free (UAF) on the parent socket.
Fix this by resetting newsk->sk_bpf_storage to NULL immediately after
sock_copy() in sk_clone(), and remove the now redundant initialization
from bpf_sk_storage_clone().
Fixes: 6ac99e8f23d4 ("bpf: Introduce bpf sk local storage")
Fixes: f12dd75959b0 ("bpf: net: Set sk_bpf_storage back to NULL for cloned sk")
Signed-off-by: Matt Bobrowski <mattbobrowski@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20260709025316.999913-1-mattbobrowski@google.com
Pull BPF fixes from Daniel Borkmann: - Initialize task local storage before fork bails out to free the task (Jann Horn) - Fix insn_aux_data leak on verifier error path (KaFai Wan) - Reject BPF inode storage map creation when BPF LSM is uninitialized (Matt Bobrowski) - Mask pseudo pointer values in verifier logs when pointer leaks are not allowed (Nuoqi Gui) - Harden BPF JIT against spraying via IBPB flush (Pawan Gupta) - Reject a skb-modifying SK_SKB stream parser since the latter is only meant to measure the next message (Sechang Lim) - Fix bpf_refcount_acquire to reject refcounted allocation arguments with a non-zero fixed offset (Yiyang Chen) * tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: bpf: Prefer dirty packs for eBPF allocations bpf: Prefer packs that won't trigger an IBPB flush on allocation bpf: Skip redundant IBPB in pack allocator bpf: Restrict JIT predictor flush to cBPF x86/bugs: Enable IBPB flush on BPF JIT allocation bpf: Support for hardening against JIT spraying bpf: Reject BPF_MAP_TYPE_INODE_STORAGE creation if BPF LSM is uninitialized bpf,fork: wipe ->bpf_storage before bailouts that access it bpf: Fix insn_aux_data leak on verifier err_free_env path selftests/bpf: Cover pseudo-BTF ksym log masking bpf: Mask pseudo pointer values in verifier logs selftests/bpf: Cover refcount acquire node offsets bpf: Reject offset refcount acquire arguments selftests/bpf: test rejection of a packet-modifying SK_SKB stream parser bpf, sockmap: reject a packet-modifying SK_SKB stream parser selftests/bpf: don't modify the skb in the strparser parser prog
Pull networking fixes from Paolo Abeni:
"Including fixes from netfilter and batman-adv.
Current release - new code bugs:
- netfilter: cthelper: cap to maximum number of expectation per master
Previous releases - regressions:
- netpoll: fix a use-after-free on shutdown path
- tcp: restore RCU grace period in tcp_ao_destroy_sock
- ipv6: fix NULL deref in fib6_walk_continiue() on multi-batch dump
- batman-adv: dat: ensure accessible eth_hdr proto field
- eth:
- virtio_net: disable cb when NAPI is busy-polled
- lan743x: Initialize eth_syslock spinlock before use
Previous releases - always broken:
- netfilter:
- nft_set_pipapo: don't leak bad clone into future transaction
- sched:
- sch_teql: Introduce slaves_lock to avoid race condition and UAF
- replace direct dequeue call with peek and qdisc_dequeue_peeked
- sctp: add INIT verification after cookie unpacking
- tipc: fix out-of-bounds read in broadcast Gap ACK blocks
- seg6: validate SRH length before reading fixed fields
- eth:
- mlx5e: fix use-after-free of metadata_dst on RX SC delete
- enetc: check the number of BDs needed for xdp_frame
- fbnic: don't cache shinfo across skb realloc"
* tag 'net-7.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (58 commits)
net/mlx5: HWS, fix matcher leak on resize target setup failure
net/sched: hhf: clear heavy-hitter state on reset
net/sched: dualpi2: clear stale classification on filter miss
net/sched: act_bpf: use rcu_dereference_bh() to read the filter
selftests: drv-net: tso: don't touch dangerous feature bits
cxgb4: Fix decode strings dump for T6 adapters
virtio_net: disable cb when NAPI is busy-polled
sctp: fix addr_wq_timer race in sctp_free_addr_wq()
selftests: net: bump default cmd() timeout to 20 seconds
bridge: stp: Fix a potential use-after-free when deleting a bridge
net/sched: sch_teql: Introduce slaves_lock to avoid race condition and UAF
net: gianfar: dispose irq mappings on probe failure and device removal
net: lan743x: Initialize eth_syslock spinlock before use
net: libwx: fix VMDQ mask for 1-queue mode
net: airoha: fix max receive size configuration
fsl/fman: Free init resources on KeyGen failure in fman_init()
netfilter: nftables: restrict checkum update offset
netfilter: nftables: restrict linklayer and network header writes
netfilter: nfnetlink_queue: restrict writes to network header
netfilter: nft_fib: reject fib expression on the netdev egress hook
...
There is a use-after-free error on netpoll, which is clearly detected by
KASAN.
BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x3b/0x80
Read of size 1 at addr ... by task kworker/9:1
Workqueue: events queue_process
Call Trace:
skb_dequeue+0x1e/0xb0
queue_process+0x2c/0x600
process_scheduled_works+0x4b6/0x850
worker_thread+0x414/0x5a0
Allocated by task 242:
__netpoll_setup+0x201/0x4a0
netpoll_setup+0x249/0x550
enabled_store+0x32f/0x380
Freed by task 0:
kfree+0x1b7/0x540
rcu_core+0x3f8/0x7a0
The problem happens when there is a pending TX worker running in
parallel with the cleanup path.
This is what happens on netpoll shutdown path:
1) __netpoll_cleanup() is called
2) set dev->npinfo to NULL
3) call_rcu() with rcu_cleanup_netpoll_info()
3.1) rcu_cleanup_netpoll_info() tries to cancel all workers with
cancel_delayed_work(), but doesn't wait for the worker to finish
4) and kfree(npinfo);
Because 3.1) doesn't really cancel the work, as the comment says "we
can't call cancel_delayed_work_sync here, as we are in softirq", the TX
worker can run after 4).
Tl;DR: queue_process() is not an RCU reader, it reaches npinfo through
the work item via container_of().
Use disable_delayed_work_sync() to ensure the worker is completely
stopped and prevent any future re-arming attempts. Once npinfo is set
to NULL, senders will bail out and not queue new work. The disable flag
ensures any in-flight re-arming attempts also fail silently.
In the future, we can do the cleanup inline here without needing the
npinfo->rcu rcu_head, but that is net-next material.
Cc: stable@vger.kernel.org
Fixes: 38e6bc185d95 ("netpoll: make __netpoll_cleanup non-block")
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20260625-netpoll_rcu_fix-v2-1-0748ffac1e98@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
validate_xmit_xfrm() returns NULL both when a packet is dropped and
when it is stolen by async crypto (-EINPROGRESS from ->xmit()).
Callers cannot distinguish the two cases.
f53c723902d1 ("net: Add asynchronous callbacks for xfrm on layer 2.")
changed the semantics of a NULL return from "dropped" to "stolen or
dropped", but __dev_queue_xmit() was not updated. On virtual/bridge
interfaces (noqueue qdisc) __dev_queue_xmit() initialises rc=-ENOMEM
and jumps to out: when skb is NULL, returning -ENOMEM to the caller
even though the packet will be delivered correctly via xfrm_dev_resume().
Return ERR_PTR(-EINPROGRESS) from validate_xmit_xfrm() for the async
case so callers can tell it apart from a real drop. Update
__dev_queue_xmit() to handle ERR_PTR(-EINPROGRESS) from
validate_xmit_skb() correctly. Update validate_xmit_skb_list() to
use IS_ERR_OR_NULL() so that ERR_PTR(-EINPROGRESS) is not mistakenly
added to the transmitted list.
Fixes: f53c723902d1 ("net: Add asynchronous callbacks for xfrm on layer 2.")
Suggested-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Petr Wozniak <petr.wozniak@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
sk_psock_strp_parse() runs the BPF_PROG_TYPE_SK_SKB stream-parser program
to find the length of the next message. strparser assembles a message out
of several received skbs by chaining them onto the head's frag_list and
recording where to append the next one in strp->skb_nextp:
*strp->skb_nextp = skb;
strp->skb_nextp = &skb->next;
and then calls the parser on the head:
len = (*strp->cb.parse_msg)(strp, head);
The parser is only meant to inspect the skb, but the program may call
bpf_skb_change_tail() -- or the sibling bpf_skb_pull_data(),
bpf_skb_change_head(), bpf_skb_adjust_room(), all allowed for SK_SKB.
Once the head carries a frag_list these go
... -> skb_ensure_writable -> pskb_may_pull -> __pskb_pull_tail
and __pskb_pull_tail() frees the frag_list skbs that strparser still
tracks through skb_nextp:
while ((list = skb_shinfo(skb)->frag_list) != insp) {
skb_shinfo(skb)->frag_list = list->next;
consume_skb(list);
}
strp->skb_nextp now points into a freed sk_buff. The next segment of
the same message arrives in __strp_recv(), which links it with
*strp->skb_nextp = skb, an 8-byte write into the freed skb. The free
and the write happen in different __strp_recv() calls, so the message
has to span at least three segments before it triggers.
BUG: KASAN: slab-use-after-free in __strp_recv+0x447/0xda0
Write of size 8 at addr ffff88810db86140 by task repro/349
Call Trace:
<IRQ>
__strp_recv+0x447/0xda0
__tcp_read_sock+0x13d/0x590
tcp_bpf_strp_read_sock+0x195/0x320
strp_data_ready+0x267/0x340
sk_psock_strp_data_ready+0x1ce/0x350
tcp_data_queue+0x1364/0x2fd0
tcp_rcv_established+0xe07/0x1640
[...]
Allocated by task 349:
skb_clone+0x17b/0x210
__strp_recv+0x2c3/0xda0
__tcp_read_sock+0x13d/0x590
[...]
Freed by task 349:
kmem_cache_free+0x150/0x570
__pskb_pull_tail+0x57b/0xc20
skb_ensure_writable+0x236/0x260
__bpf_skb_change_tail+0x1d4/0x590
sk_skb_change_tail+0x2a/0x40
bpf_prog_1b285dcd6c41373e+0x27/0x30
bpf_prog_run_pin_on_cpu+0xf3/0x260
sk_psock_strp_parse+0x118/0x1e0
__strp_recv+0x4f6/0xda0
[...]
The same resize also leaves the head's length inconsistent with its
frags, so a later __pskb_pull_tail() can instead hit the
BUG_ON(skb_copy_bits(...)) in net/core/skbuff.c.
A stream parser is only meant to measure the next message, not to modify
the packet. Reject a parser whose program can change packet data
(prog->aux->changes_pkt_data) at attach time. The check is shared by
sock_map_prog_update() and sock_map_link_update_prog(), which between them
cover prog attach, link create and link update. Verdict programs are
unaffected and may still modify the skb.
Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Signed-off-by: Sechang Lim <rhkrqnwk98@gmail.com>
Link: https://lore.kernel.org/r/20260620024423.4141004-3-rhkrqnwk98@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Pull bpf fixes from Alexei Starovoitov: - Fix effective prog array index with BPF_F_PREORDER (Amery Hung) - Zero-initialize the fib lookup flow struct (Avinash Duduskar) - Disable xfrm_decode_session hook attachment (Bradley Morgan) - Allow type tag BTF records to succeed other modifier records (Emil Tsalapatis) - Fix build_id caching in stack_map_get_build_id_offset() (Ihor Solodrai) - Add missing access_ok call to copy_user_syms (Jiri Olsa) - Fix stack slot index in nospec checks (Nuoqi Gui) - Preserve pointer spill metadata during half-slot cleanup (Nuoqi Gui) - Fix partial copy of non-linear test_run output (Sun Jian) - Fix BPF_PROG_ASSOC_STRUCT_OPS last field check (Thiébaud Weksteen) - Reset register bounds before narrowing retval range (Tristan Madani) - Fix vmlinux BTF leak in bpftool cgroup commands (Yichong Chen) - Guard error writes in conntrack kfuncs (Yiyang Chen) * tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: bpf: Disable xfrm_decode_session hook attachment selftests/bpf: Add test for stale bounds on LSM retval context load bpf: Reset register bounds before narrowing retval range in check_mem_access() selftests/bpf: Cover small conntrack opts error writes bpf: Guard conntrack opts error writes selftests/bpf: Cover half-slot cleanup of pointer spills bpf: Preserve pointer spill metadata during half-slot cleanup selftests/bpf: Test cgroup link replace with BPF_F_PREORDER bpf: Fix effective prog array index with BPF_F_PREORDER bpf: Fix BPF_PROG_ASSOC_STRUCT_OPS last field check bpf: zero-initialize the fib lookup flow struct bpftool: Fix vmlinux BTF leak in cgroup commands bpf: Add missing access_ok call to copy_user_syms bpf: Allow type tag BTF records to succeed other modifier records bpf: Emit verbose message when prog-specific btf_struct_access rejects a write bpf: Fix build_id caching in stack_map_get_build_id_offset() bpf: Fix partial copy of non-linear test_run output selftests/bpf: Cover stack nospec slot indexing bpf: Fix stack slot index in nospec checks