kernel/git/stable/linux-stable.git/net, branch linux-5.10.y

Bluetooth: L2CAP: Fix send LE flow credits in ACL link

2026-09-14T11:19:19+00:00

[ Upstream commit f39f905e55f529b036321220af1ba4f4085564a5 ] When the L2CAP channel mode is L2CAP_MODE_ERTM/L2CAP_MODE_STREAMING, l2cap_publish_rx_avail will be called and le flow credits will be sent in l2cap_chan_rx_avail, even though the link type is ACL. The logs in question as follows: > ACL Data RX: Handle 129 flags 0x02 dlen 12 L2CAP: Unknown (0x16) ident 4 len 4 40 00 ed 05 < ACL Data TX: Handle 129 flags 0x00 dlen 10 L2CAP: Command Reject (0x01) ident 4 len 2 Reason: Command not understood (0x0000) Bluetooth: Unknown BR/EDR signaling command 0x16 Bluetooth: Wrong link type (-22) Fixes: ce60b9231b66 ("Bluetooth: compute LE flow credits based on recvbuf space") Signed-off-by: Zhang Chen Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin

tcp: fix corruption of urgent data on multi-segment retransmit

2026-09-14T11:19:19+00:00

[ Upstream commit ce2b807f42ed5e55567b8864ab72963f90779270 ] On the normal xmit path, while in urgent mode we refuse to build a multi-segment TSO packet, so every segment gets its own urg_ptr: /* tcp_write_xmit() */ limit = mss_now; if (tso_segs > 1 && !tcp_urg_mode(tp)) limit = tcp_mss_split_point(...); The retransmit path has no such guard. __tcp_retransmit_skb() builds a segs > 1 skb and hands it to the GSO layer, which only advances th->seq per segment and copies urg_ptr verbatim: /* __tcp_retransmit_skb() */ len = cur_mss * segs; /* segs > 1, no urg_mode check */ ... /* tcp_gso_segment(): bumps seq only, urg_ptr is copied */ urg_ptr is an offset from the segment's own seq, so a copied value points at a different place on each segment. The receiver rebuilds the absolute urgent seq as seg.seq + urg_ptr, so it walks a moving urgent point instead of the one OOB byte: seg1 seq 1 urg_ptr 5001 -> urgent @ 5001 (ok) seg2 seq 1001 urg_ptr 5001 -> urgent @ 6001 (wrong, +MSS) seg3 seq 2001 urg_ptr 5001 -> urgent @ 7001 (wrong, +2*MSS) The real OOB byte is never pointed at, so the receiver stops splicing it out and delivers it as normal in-band data, corrupting the stream. Guard the retransmit length like the xmit path: keep segs = 1 while in urgent mode. Fixes: 10d3be569243 ("tcp-tso: do not split TSO packets at retransmit time") Signed-off-by: Jiayuan Chen Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260826141145.67823-1-jiayuan.chen@linux.dev Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net/sched: bound qdisc_pkt_len to prevent qdisc soft lockup

2026-09-14T11:19:18+00:00

[ Upstream commit 8f735d64382dcf162f4276d6699d03ad2f859c0b ] qdisc_get_stab() accepts a user-supplied size table, and __qdisc_calculate_pkt_len() amplifies qdisc_pkt_len() through the overhead, the size-table data (u16), and size_log (up to STAB_SIZE_LOG_MAX). A crafted stab can therefore set qdisc_pkt_len() to ~1 GiB for an ordinary skb. Per-flow deficit schedulers such as DRR and ETS replenish one quantum per loop iteration; with a tiny quantum (1) they spin billions of times under the qdisc lock, producing a soft lockup / RCU stall as illustrated by vega@nebusec.ai. Cap the final qdisc_pkt_len() to QDISC_PKT_LEN_MAX so the size-table amplification cannot drive deficit schedulers into an unbounded loop. A legitimate size table (e.g. qfq's overhead 999999999, which is handled by dropping) is still accepted. Introduce cap QDISC_PKT_LEN_MAX (1 << 20) = 1 MiB which is well above any legitimate single-skb wire length: the largest current skb->len is GSO_MAX_SIZE (524280), and an ATM-style size table (53/48 cell tax) amplifies that to ~578 KB, both comfortably below 1 MiB. At the same time, 1 MiB bounds the deficit refill loop to ~1M iterations per packet with quantum=1, which completes in a few milliseconds well under the demonstrated softlockup threshold (~10^9 iterations). Conditions to recreate the bug: - CONFIG_NET_SCHED=y, CONFIG_NET_SCH_DRR=y (or CONFIG_NET_SCH_ETS=y). - Attach a DRR (or ETS) root qdisc with a crafted TCA_STAB that amplifies qdisc_pkt_len to ~1 GiB (e.g. size_log=15, data=[32768]). - Add a class with a tiny quantum of 1 and send one small packet; the deficit loop spins billions of times under the qdisc lock and trips the softlockup detector (panic with kernel.softlockup_panic=1). - Reachable as root or from an unprivileged user in a fresh user+net namespace (unshare -Urn) with namespace-local CAP_NET_ADMIN. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: vega@nebusec.ai Tested-by: Victor Nogueira Signed-off-by: Jamal Hadi Salim Link: https://patch.msgid.link/20260825081403.133992-1-jhs@mojatatu.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

netfilter: x_tables: replace pr_{info,err}() by pr_info_ratelimited()

2026-09-14T11:19:18+00:00

[ Upstream commit 793d9eda4821f75b5f7cc9e6a870b72a58b44c2b ] Several xtables extension still use pr_err() or pr_info() without ratelimit. For xt_cgroup, while at this, remove redundant "xt_cgroup:" prefix since pr_fmt is already set on. Fixes: c38c4597e4bf ("netfilter: implement xt_cgroup cgroup2 path match") Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: xt_HL: add pr_fmt and checkentry validation

2026-09-14T11:19:18+00:00

[ Upstream commit 24bd5c2679caf8a228d90cafa221da4b47fd6642 ] Add pr_fmt to prefix log messages with the module name for easier debugging in dmesg. Add checkentry functions for IPv4 (ttl_mt_check) and IPv6 (hl_mt6_check) to validate the match mode at rule registration time, rejecting invalid modes with -EINVAL. The evaluation function returns false in case the mode is unknown, so this is a cleanup, not a bug fix. Signed-off-by: Marino Dzalto Signed-off-by: Florian Westphal Stable-dep-of: 793d9eda4821 ("netfilter: x_tables: replace pr_{info,err}() by pr_info_ratelimited()") Signed-off-by: Sasha Levin

netfilter: xt_cgroup: Make it independent from net_cls

2026-09-14T11:19:18+00:00

[ Upstream commit 3ba0032afea888d0edebf5ece3c6b36417189b63 ] The xt_group matching supports the default hierarchy since commit c38c4597e4bf3 ("netfilter: implement xt_cgroup cgroup2 path match"). The cgroup v1 matching (based on clsid) and cgroup v2 matching (based on path) are rather independent. Downgrade the Kconfig dependency to mere CONFIG_SOCK_GROUP_DATA so that xt_group can be built even without CONFIG_NET_CLS_CGROUP for path matching. Also add a message for users when they attempt to specify any clsid. Link: https://lists.opensuse.org/archives/list/kernel@lists.opensuse.org/thread/S23NOILB7MUIRHSKPBOQKJHVSK26GP6X/ Cc: Jan Engelhardt Cc: Florian Westphal Signed-off-by: Michal Koutný Signed-off-by: Pablo Neira Ayuso Stable-dep-of: 793d9eda4821 ("netfilter: x_tables: replace pr_{info,err}() by pr_info_ratelimited()") Signed-off-by: Sasha Levin

netfilter: nf_tables: move hardware offload step after building the chain blob

2026-09-14T11:19:18+00:00

[ Upstream commit b1881d362e1924b66f6016c3efd28807032b41bf ] Allocate the chain blob before the ruleset offload to reduce chances of entering an inconsistent state where the offloaded ruleset in the nic and the software ruleset differ. Fixes: c9626a2cbdb2 ("netfilter: nf_tables: add hardware offload support") Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

net/sched: sch_teql: restore skb->dev on the slave failure path

2026-09-14T11:19:17+00:00

[ Upstream commit dc4b95b8fee95113587e93ca116356032d271371 ] teql_master_xmit() sets skb->dev = slave before calling the slave's ndo_start_xmit(), but never restores it when that transmit fails. The skb then walks on to the next slave still pointing at the previous one. If a later slave has no resolved neighbour, teql_resolve() hands the skb to neigh_event_send(), which queues it on that neighbour's arp_queue with the stale skb->dev. skb->dev holds no reference, so deleting the previous slave frees the net_device while the skb is still queued. Whatever runs next on that skb - arp_error_report() on timeout, or neigh_direct_output() -> dev_queue_xmit() once the neighbour resolves - causes a UAF like the one below: BUG: KASAN: slab-use-after-free in __icmp_send (net/ipv4/icmp.c:914 (discriminator 2)) Read of size 4 at addr ffff888106e100b0 by task flood_packet/527 CPU: 0 UID: 0 PID: 527 Comm: flood_packet Not tainted 7.2.0-rc6-g594d90519502 #1 PREEMPT(lazy) Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: dump_stack_lvl (lib/dump_stack.c:94 lib/dump_stack.c:120) print_report (mm/kasan/report.c:378 mm/kasan/report.c:482) ? __pfx__raw_spin_lock_irqsave (./include/asm-generic/qrwlock.h:122 (discriminator 4)) ? __icmp_send (net/ipv4/icmp.c:914 (discriminator 2)) kasan_report (mm/kasan/report.c:595) ? __icmp_send (net/ipv4/icmp.c:914 (discriminator 2)) __icmp_send (net/ipv4/icmp.c:914 (discriminator 2)) [...] ipv4_link_failure (net/ipv4/route.c:1251 net/ipv4/route.c:1258) ? __pfx_ipv4_link_failure (./include/linux/skbuff.h:4327) ? _raw_write_lock (./include/linux/instrumented.h:55 ./include/linux/atomic/atomic-instrumented.h:1301 ./include/asm-generic/qrwlock.h:98 ./include/linux/rwlock_api_smp.h:230 kernel/locking/spinlock.c:304) ? __pfx__raw_write_lock (kernel/locking/spinlock.c:175) arp_error_report (./include/net/dst.h:438 net/ipv4/arp.c:296) neigh_invalidate (net/core/neighbour.c:1077) neigh_timer_handler (net/core/neighbour.c:1169) [...] Allocated by task 505: kasan_save_stack (mm/kasan/common.c:57) kasan_save_track (mm/kasan/common.c:78) __kasan_kmalloc (mm/kasan/common.c:398 mm/kasan/common.c:415) __kvmalloc_node_noprof (./include/linux/kasan.h:263 mm/slub.c:5334 mm/slub.c:6905) alloc_netdev_mqs (net/core/dev.c:12055 (discriminator 2)) rtnl_create_link (net/core/rtnetlink.c:3721) rtnl_newlink (net/core/rtnetlink.c:3903 net/core/rtnetlink.c:4044 net/core/rtnetlink.c:4159) rtnetlink_rcv_msg (net/core/rtnetlink.c:7076) [...] Freed by task 536: kasan_save_stack (mm/kasan/common.c:57) kasan_save_track (mm/kasan/common.c:78) kasan_save_free_info (mm/kasan/generic.c:584) __kasan_slab_free (mm/kasan/common.c:253 mm/kasan/common.c:285) kfree (./include/linux/kasan.h:235 mm/slub.c:2677 mm/slub.c:6377 mm/slub.c:6692) device_release (drivers/base/core.c:2636) kobject_put (lib/kobject.c:689 lib/kobject.c:720 ./include/linux/kref.h:65 lib/kobject.c:737) netdev_run_todo (net/core/dev.c:11756) rtnl_dellink (net/core/rtnetlink.c:157 ./include/linux/rtnetlink.h:135 net/core/rtnetlink.c:3651) rtnetlink_rcv_msg (net/core/rtnetlink.c:7076) [...] Fix this by restoring skb->dev to the master at the end of each slave's iteration. Fixes: 0cc0c2e661af ("net/sched: teql: fix NULL pointer dereference in iptunnel_xmit on TEQL slave xmit") Reported-by: Vega Acked-by: Jamal Hadi Salim Signed-off-by: Victor Nogueira Link: https://patch.msgid.link/20260824115928.4099988-1-victor@mojatatu.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net/sched: sfq: clamp quantum to avoid signed overflow soft lockup

2026-09-14T11:19:17+00:00

[ Upstream commit 816e90057ab1879562a5b7cc688e35bb9027ae97 ] sfq_init() sets q->quantum = psched_mtu(qdisc_dev(sch)) (unsigned). A device with a huge MTU (e.g. dummy with max_mtu == 0 accepting MTU 2147483634) makes psched_mtu() return 0x80000000, so slot->allot = INT_MIN and INT_MIN + INT_MIN toggles between INT_MIN and 0 forever, spinning sfq_dequeue() under the qdisc lock. Clamp the quantum to [256, 1 << 20] so the refill loop terminates. The lower bound also covers q->quantum == 0 (psched_mtu() returning 0), which spins sfq_dequeue() identically. sfq_change() already rejects a negative quantum, so only the init path was exposed. Conditions to recreate the bug: a device whose MTU (plus hard_header_len) wraps psched_mtu() into the sign bit (e.g. a dummy device with max_mtu == 0 accepting MTU 2147483634). Requires CAP_NET_ADMIN in a user namespace. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: vega@nebusec.ai Tested-by: Victor Nogueira Signed-off-by: Jamal Hadi Salim Link: https://patch.msgid.link/20260822195509.112717-7-jhs@mojatatu.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net/sched: hhf: clamp quantum before hhf_change() to avoid overflow

2026-09-14T11:19:17+00:00

[ Upstream commit 2164b512b97bb053e8ce4d6e95576f11bed6a005 ] hhf_init() sets q->quantum = psched_mtu(qdisc_dev(sch)) with no overflow check. A device with a huge MTU (e.g. dummy with max_mtu == 0 accepting MTU 2147483634) makes weight * quantum overflow the signed deficit in hhf_dequeue(), spinning forever. Clamp q->quantum before hhf_change() so both the opt and !opt paths see a sane quantum. Without this, bare "tc qdisc add ... hhf" succeeds with a clamped quantum but "tc qdisc add ... hhf limit 1000" (any option present) fails with -EINVAL because hhf_change() re-validates the unclamped default (sch_hhf.c:559). 256 matches fq_codel's floor and is a sane minimum for a DRR quantum. Conditions to recreate the bug: a device whose MTU (plus hard_header_len) wraps psched_mtu() into the sign bit (e.g. a dummy device with max_mtu == 0 accepting MTU 2147483634). Requires CAP_NET_ADMIN in a user namespace. Fixes: 10239edf86f1 ("net-qdisc-hhf: Heavy-Hitter Filter (HHF) qdisc") Reported-by: vega@nebusec.ai Tested-by: Victor Nogueira Signed-off-by: Jamal Hadi Salim Link: https://patch.msgid.link/20260822195509.112717-6-jhs@mojatatu.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin