kernel/linux.git/net/core, branch v5.10.268

net: pktgen: fix proc entry use-after-free

2026-08-23T12:16:27+00:00

[ Upstream commit 817ff6efdb7f484ea547218e11e17d8e43daa3b4 ] pktgen_change_name() replaces pkt_dev->entry while holding t->if_lock. pktgen_remove_device() removes the same entry before _rem_dev_from_if_list() takes that lock. This allows the following interleaving: CPU 0 (NETDEV_CHANGENAME) CPU 1 (kpktgend) if_lock(t) proc_remove(pkt_dev->entry) proc_remove(pkt_dev->entry) pkt_dev->entry = proc_create_data(...) if_unlock(t) The kthread can pass the stale proc_dir_entry to proc_remove() after the rename path has freed it. A reproducer with a widened race window reports: BUG: KASAN: slab-use-after-free in proc_remove+0x78/0x80 Read of size 8 at addr ffff8881478fea70 by task kpktgend_0/67 Call Trace: proc_remove+0x78/0x80 pktgen_remove_device.isra.0+0x11c/0x4c0 pktgen_thread_worker+0x1214/0x6bc0 kthread+0x2c6/0x3b0 Allocated by task 95: __proc_create+0x204/0x790 proc_create_data+0x72/0xe0 pktgen_thread_write+0xd61/0x1510 Freed by task 28: kmem_cache_free+0xcb/0x3d0 proc_free_inode+0x5b/0x80 rcu_core+0x50a/0x1850 The buggy address belongs to the object at ffff8881478fea00 which belongs to the cache proc_dir_entry of size 192 Move proc_remove() into the if_lock-protected list removal helper. Keep it before list_del_rcu() to preserve the ordering required by add_device(). The rename path must then finish replacing the entry before removal, or it observes that the device is no longer on the list. Fixes: 39df232f1a9b ("[PKTGEN]: fix device name handling") Cc: stable@vger.kernel.org Signed-off-by: Chengfeng Ye Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260719145740.2888967-1-nicoyip.dev@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

net: pktgen: fix code style (WARNING: Block comments)

2026-08-23T12:16:27+00:00

[ Upstream commit 870b856cb478bc02fffe4d89897e62c692efb09a ] Fix checkpatch code style warnings: WARNING: Block comments use a trailing */ on a separate line + * removal by worker thread */ WARNING: Block comments use * on subsequent lines + __u8 tos; /* six MSB of (former) IPv4 TOS + are for dscp codepoint */ WARNING: Block comments use a trailing */ on a separate line + are for dscp codepoint */ WARNING: Block comments use * on subsequent lines + __u8 traffic_class; /* ditto for the (former) Traffic Class in IPv6 + (see RFC 3260, sec. 4) */ WARNING: Block comments use a trailing */ on a separate line + (see RFC 3260, sec. 4) */ WARNING: Block comments use * on subsequent lines + /* = { + 0x00, 0x80, 0xC8, 0x79, 0xB3, 0xCB, WARNING: Block comments use * on subsequent lines + /* Field for thread to receive "posted" events terminate, + stop ifs etc. */ WARNING: Block comments use a trailing */ on a separate line + stop ifs etc. */ WARNING: Block comments should align the * on each line + * we go look for it ... +*/ WARNING: Block comments use a trailing */ on a separate line + * we resolve the dst issue */ WARNING: Block comments use a trailing */ on a separate line + * with proc_create_data() */ Signed-off-by: Peter Seiderer Reviewed-by: Toke Høiland-Jørgensen Signed-off-by: Jakub Kicinski Stable-dep-of: 817ff6efdb7f ("net: pktgen: fix proc entry use-after-free") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

skbuff: introduce skb_pull_data

2026-08-23T12:16:27+00:00

[ Upstream commit 13244cccc2b61ec715f0ac583d3037497004d4a5 ] Like skb_pull but returns the original data pointer before pulling the data after performing a check against sbk->len. This allows to change code that does "struct foo *p = (void *)skb->data;" which is hard to audit and error prone, to: p = skb_pull_data(skb, sizeof(*p)); if (!p) return; Which is both safer and cleaner. Acked-by: Jakub Kicinski Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Dan Carpenter Signed-off-by: Marcel Holtmann Stable-dep-of: 47778d2c2087 ("Bluetooth: HIDP: reject frames without a transaction header") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

net: gro: fix double aggregation of flush-marked skbs

2026-08-23T12:16:27+00:00

[ Upstream commit e751256486d0ded20f5a9f9863467f1dce65142f ] Commit 0ab03f353d36 ("net-gro: Fix GRO flush when receiving a GSO packet.") added a flush check to skb_gro_receive(), but skb_gro_receive_list() lacks the same validation. As a result, packets marked with NAPI_GRO_CB(skb)->flush may still be re-aggregated. This allows already-GRO'd packets with existing frag_list to be re-aggregated into a new GRO session, corrupting the frag_list chain structure. When skb_segment() attempts to unpack these malformed packets, it encounters invalid state and triggers a kernel panic. Scenario (Tethering/Device forwarding): 1. Driver: Generated aggregated packet P1 via LRO with frag_list 2. Dev A: Receives aggregated fraglist packet and flush flag set 3. Dev A: Re-enters GRO, skb_gro_receive_list() is called 4. Missing flush check allows re-aggregation despite flush flag 5. Frag_list chain becomes corrupted (loops or dangling refs) 6. Dev B: TX path calls skb_segment(), crashes on corrupted frag_list Root cause in skb_segment(): The check at line ~4891: if (hsize <= 0 && i >= nfrags && skb_headlen(list_skb) && (skb_headlen(list_skb) == len || sg)) { When frag_list is corrupted by double aggregation, when list_skb is a NULL pointer from skb->next, skb_headlen(list_skb) dereference NULL/corrupted pointers occurs. Call Trace: skb_headlen(NULL skb) skb_segment tcp_gso_segment tcp4_gso_segment inet_gso_segment skb_mac_gso_segment __skb_gso_segment skb_gso_segment validate_xmit_skb validate_xmit_skb_list sch_direct_xmit qdisc_restart __qdisc_run qdisc_run net_tx_action Fix: Add NAPI_GRO_CB(skb)->flush validation to the early-return check in skb_gro_receive_list(), matching the defensive programming pattern of skb_gro_receive(). Fixes: 3a1296a38d0c ("net: Support GRO/GSO fraglist chaining.") Cc: stable@vger.kernel.org Signed-off-by: Shiming Cheng Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20260709014704.3625-1-shiming.cheng@mediatek.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

net: remove WARN_ON_ONCE() from sk_mc_loop()

2026-08-19T15:12:12+00:00

[ Upstream commit b8a39a09ae4eaae04309e1e38ed6a1101d967496 ] sk_mc_loop() can be called for sockets that are neither AF_INET nor AF_INET6 (e.g. AF_PACKET sockets when sending packets via raw/packet socket over virtual devices such as VRF or ipvlan). In such cases, sk_family is not AF_INET/AF_INET6 and sk_mc_loop() falls through the switch statement and triggers WARN_ON_ONCE(1). Non-INET sockets do not support IP_MULTICAST_LOOP or IPV6_MULTICAST_LOOP options, so loopback should default to true without generating a warning. Fixes: f60e5990d9c1 ("ipv6: protect skb->sk accesses from recursive dereference inside the stack") Reported-by: syzbot+22c3218a6fa219e47321@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6a72024c.13623e66.bdc14.0019.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20260804152048.2134341-1-edumazet@google.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

bpf: lwt: Fix dst reference leak on reroute failure

2026-08-19T15:12:07+00:00

commit 88c17de85ddb459c3fe1e3c65d61fa366b1cf0a8 upstream. bpf_lwt_xmit_reroute() obtains a referenced dst from the route lookup. When skb_cow_head() fails before that dst is installed on the skb, the error path only frees the skb. The skb still owns its previous dst, so the newly looked up dst reference is leaked. Release the new dst reference before freeing the skb on this error path. Fixes: 3bd0b15281af ("bpf: add handling of BPF_LWT_REROUTE to lwt_bpf.c") Cc: stable@vger.kernel.org Signed-off-by: Xuanqiang Luo Link: https://patch.msgid.link/20260723060445.21926-1-xuanqiang.luo@linux.dev Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

bpf, sockmap: fix integer overflow in bpf_msg_pop_data() bounds check

2026-07-24T13:49:00+00:00

[ Upstream commit a48802fb2cd2d1e23651989f8ff4d15e9d5dad54 ] start and len are u32, so u64 last = start + len; evaluates start + len in 32-bit and wraps before storing it in last. The bounds check if (start >= offset + l || last > msg->sg.size) return -EINVAL; can then be passed with an out-of-range start/len, after which the pop loop runs off the end of the scatterlist and sk_msg_shift_left() calls put_page() on the empty msg->sg.end slot: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] RIP: 0010:sk_msg_shift_left net/core/filter.c:2957 [inline] RIP: 0010:____bpf_msg_pop_data net/core/filter.c:3103 [inline] RIP: 0010:bpf_msg_pop_data+0x753/0x1a10 net/core/filter.c:2984 Call Trace: bpf_prog_4cc92c278f4d5d56+0x1b1/0x1e8 bpf_prog_run_pin_on_cpu+0x107/0x320 include/linux/filter.h:746 sk_psock_msg_verdict+0x357/0x7f0 net/core/skmsg.c:934 tcp_bpf_send_verdict net/ipv4/tcp_bpf.c:420 [inline] tcp_bpf_sendmsg+0x766/0x1ae0 net/ipv4/tcp_bpf.c:583 __sock_sendmsg+0x153/0x1c0 net/socket.c:802 __sys_sendto+0x326/0x430 net/socket.c:2265 __x64_sys_sendto+0xe3/0x100 net/socket.c:2268 do_syscall_64+0x14c/0x480 entry_SYSCALL_64_after_hwframe+0x77/0x7f Widen the addition with a (u64) cast so the bound is evaluated in 64-bit and a len near U32_MAX no longer wraps below msg->sg.size. While here, change pop from int to u32. It counts bytes against the unsigned scatterlist lengths and can never be negative, so the signed type only invites sign-confusion in the pop loop. Fixes: 7246d8ed4dcc ("bpf: helper to pop data from messages") Reviewed-by: Jiayuan Chen Reviewed-by: Emil Tsalapatis Reviewed-by: Kuniyuki Iwashima Signed-off-by: Sechang Lim Signed-off-by: Jiayuan Chen Link: https://lore.kernel.org/r/20260615021959.140010-6-jiayuan.chen@linux.dev Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

bpf, sockmap: reject overflowing copy + len in bpf_msg_push_data()

2026-07-24T13:49:00+00:00

[ Upstream commit 0c0a8ed85349dae298712d79cb276acfeb794d82 ] When the scatterlist ring is full or nearly full, bpf_msg_push_data() enters a copy fallback path and computes copy + len for the page allocation size. Since len comes from BPF with arg3_type = ARG_ANYTHING and both are u32, a crafted len can wrap the sum to a small value, causing an undersized allocation followed by an out-of-bounds memcpy. BUG: unable to handle page fault for address: ffffed104089a402 Oops: Oops: 0000 [#1] SMP KASAN NOPTI Call Trace: __asan_memcpy (mm/kasan/shadow.c:105) bpf_msg_push_data (net/core/filter.c:2852 net/core/filter.c:2788) bpf_prog_9ed8b5711920a7d7+0x2e/0x36 sk_psock_msg_verdict (net/core/skmsg.c:934) tcp_bpf_sendmsg (net/ipv4/tcp_bpf.c:421 net/ipv4/tcp_bpf.c:584) __sys_sendto (net/socket.c:2206) do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Add an overflow check before the allocation. Link: https://lore.kernel.org/all/20260424155913.A19FDC19425@smtp.kernel.org Fixes: 6fff607e2f14 ("bpf: sk_msg program helper bpf_msg_push_data") Tested-by: Xiang Mei Tested-by: Xinyu Ma Reviewed-by: Jiayuan Chen Reviewed-by: Emil Tsalapatis Reviewed-by: Kuniyuki Iwashima Signed-off-by: Weiming Shi Signed-off-by: Jiayuan Chen Link: https://lore.kernel.org/r/20260615021959.140010-2-jiayuan.chen@linux.dev Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

net: fib_rules: Don't dump dying fib_rule in fib_rules_dump().

2026-07-24T13:49:00+00:00

[ Upstream commit 2821e85c058f81c9948a2fb1a634f7b47457d51c ] rocker_router_fib_event() calls fib_rule_get() during RCU dump. If the fib_rule is dying, refcount_inc() will complain about it. Let's call refcount_inc_not_zero() in fib_rules_dump(). Fixes: 5d7bfd141924 ("ipv4: fib_rules: Dump FIB rules when registering FIB notifier") Signed-off-by: Kuniyuki Iwashima Reviewed-by: Ido Schimmel Reviewed-by: David Ahern Link: https://patch.msgid.link/20260610061744.2030996-3-kuniyu@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

bpf: Update transport_header when encapsulating UDP tunnel in lwt

2026-07-24T13:48:58+00:00

[ Upstream commit 82d7d0adbc678064543e9d254864f6b4ea4a388c ] Currently, bpf_lwt_push_ip_encap() does not update skb->transport_header. When a driver, e.g. ice, reuses the stale skb->transport_header to offload checksum computation to NIC hardware, VxLAN packets encapsulated by bpf_lwt_push_encap() helper may be dropped due to incorrect checksum. Update skb->transport_header in bpf_lwt_push_ip_encap() whenever the encapsulated packet uses UDP, so checksum offload works correctly. Fixes: 52f278774e79 ("bpf: implement BPF_LWT_ENCAP_IP mode in bpf_lwt_push_encap") Cc: Leon Hwang Signed-off-by: Leon Hwang Link: https://lore.kernel.org/r/20260602150931.49629-2-leon.hwang@linux.dev Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin