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Author SHA1 Message Date
Inochi Amaoto
621e3634df net: ethernet: litex: use device pointer to simplify code.
As there is already a device pointer in the probe function, replace
all "&pdev->dev" pattern with this predefined device pointer.

Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20260227003351.752934-3-inochiama@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 19:25:16 -08:00
Inochi Amaoto
97c55c1298 net: ethernet: litex: use devm_register_netdev() to register netdev
Use devm_register_netdev to avoid unnecessary remove() callback in
platform_driver structure.

Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20260227003351.752934-2-inochiama@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 19:25:15 -08:00
Leon Kral
57cc8ab3e9 net/handshake: Fixed grammar mistake
The word "a" was used instead of "an" which is grammatically incorrect.
Fixed by changing from "a" to "an". This improves readability of the
documentation.

Signed-off-by: Leon Kral <leon.j.kral@protonmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Link: https://patch.msgid.link/20260227001151.41610-1-leon.j.kral@protonmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 19:24:08 -08:00
Randy Dunlap
2164242c50 NFC: fix header file kernel-doc warnings
Repair some of the comments:
- use the correct enum names
- don't use "/**" for a non-kernel-doc comment

to fix these warnings:

Warning: include/uapi/linux/nfc.h:127 Excess enum value
 '@NFC_EVENT_DEVICE_DEACTIVATED' description in 'nfc_commands'
Warning: include/uapi/linux/nfc.h:204 Excess enum value
 '@NFC_ATTR_APDU' description in 'nfc_attrs'
Warning: include/uapi/linux/nfc.h:302 expecting prototype for Pseudo().
 Prototype was for NFC_RAW_HEADER_SIZE() instead

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://patch.msgid.link/20260226221004.1037909-1-rdunlap@infradead.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 19:21:56 -08:00
Eric Dumazet
6466441a5e net: inline skb_add_rx_frag_netmem()
This critical helper (via skb_add_rx_frag()) is mostly used
from drivers rx fast path.

It is time to inline it, this actually saves space in vmlinux:

size vmlinux.old vmlinux
   text    data     bss     dec     hex filename
37350766        23092977        4846992 65290735        3e441ef vmlinux.old
37350600        23092977        4846992 65290569        3e44149 vmlinux

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260226041213.1892561-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 19:20:34 -08:00
Fernando Fernandez Mancera
9ff2d2a983 ipv6: discard fragment queue earlier if there is malformed datagram
Currently the kernel IPv6 implementation is not dicarding the fragment
queue upon receiving a IPv6 fragment that is not 8 bytes aligned. It
relies on queue expiration to free the queue.

While RFC 8200 section 4.5 does not explicitly mention that the rest of
fragments must be discarded, it does not make sense to keep them. The
parameter problem message is sent regardless that. In addition, if the
sender is able to re-compose the datagram so it is 8 bytes aligned it
would qualify as a new whole datagram not fitting into the same fragment
queue.

The same situation happens if segment end is exceeding the IPv6 maximum
packet length. The sooner we can free resources the better during
reassembly, the better.

Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Link: https://patch.msgid.link/20260225133758.4553-1-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 19:08:54 -08:00
Victor Nogueira
b14e82abf7 selftests/tc-testing: Create tests to exercise act_ct binding restrictions
Add 4 test cases to exercise new act_ct binding restrictions:

- Try to attach act_ct to an ets qdisc
- Attach act_ct to an ingress qdisc
- Attach act_ct to a clsact/egress qdisc
- Attach act_ct to a shared block

Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20260225134349.1287037-2-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 19:06:21 -08:00
Victor Nogueira
11cb63b0d1 net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks
As Paolo said earlier [1]:

"Since the blamed commit below, classify can return TC_ACT_CONSUMED while
the current skb being held by the defragmentation engine. As reported by
GangMin Kim, if such packet is that may cause a UaF when the defrag engine
later on tries to tuch again such packet."

act_ct was never meant to be used in the egress path, however some users
are attaching it to egress today [2]. Attempting to reach a middle
ground, we noticed that, while most qdiscs are not handling
TC_ACT_CONSUMED, clsact/ingress qdiscs are. With that in mind, we
address the issue by only allowing act_ct to bind to clsact/ingress
qdiscs and shared blocks. That way it's still possible to attach act_ct to
egress (albeit only with clsact).

[1] https://lore.kernel.org/netdev/674b8cbfc385c6f37fb29a1de08d8fe5c2b0fbee.1771321118.git.pabeni@redhat.com/
[2] https://lore.kernel.org/netdev/cc6bfb4a-4a2b-42d8-b9ce-7ef6644fb22b@ovn.org/

Reported-by: GangMin Kim <km.kim1503@gmail.com>
Fixes: 3f14b377d0 ("net/sched: act_ct: fix skb leak and crash on ooo frags")
CC: stable@vger.kernel.org
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20260225134349.1287037-1-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 19:06:21 -08:00
Colin Ian King
e6eb3a0584 ntfs: Fix spelling mistake "initiailized" -> "initialized"
There is a spelling mistake in an ntfs_debug message. Fix it.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-02-28 12:04:17 +09:00
Birger Koblitz
e8e83b6796 r8152: Add 2500baseT EEE status/configuration support
The r8152 driver supports the RTL8156, which is a 2.5Gbit Ethernet controller for
USB 3.0, for which support is added for configuring and displaying the EEE
advertisement status for 2.5GBit connections.

The patch also corrects the determination of whether EEE is active to include
the 2.5GBit connection status and make the determination dependent not on the
desired speed configuration (tp->speed), but on the actual speed used by
the controller. For consistency, this is corrected also for the RTL8152/3.

This was tested on an Edimax EU-4307 V1.0 USB-Ethernet adapter with RTL8156,
and a SECOMP Value 12.99.1115 USB-C 3.1 Ethernet converter with RTL8153.

Signed-off-by: Birger Koblitz <mail@birger-koblitz.de>
Link: https://patch.msgid.link/20260224-b4-eee2g5-v2-1-cf5c83df036e@birger-koblitz.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 18:42:22 -08:00
Florian Westphal
ba14798653 selftests: netfilter: nft_queue.sh: avoid flakes on debug kernels
Jakub reports test flakes on debug kernels:
 FAIL: test_udp_gro_ct: Expected software segmentation to occur, had 23 and 17

This test assumes that the kernels nfnetlink_queue module sees N GSO
packets, segments them into M skbs and queues them to userspace for
reinjection.

Hence, if M >= N, no segmentation occurred.

However, its possible that this happens:
- nfnetlink_queue gets GSO packet
- segments that into n skbs
- userspace buffer is full, kernel drops the segmented skbs

-> "toqueue" counter incremented by 1, "fromqueue" is unchanged.

If this happens often enough in a single run, M >= N check triggers
incorrectly.

To solve this, allow the nf_queue.c test program to set the FAIL_OPEN
flag so that the segmented skbs bypass the queueing step in the kernel
if the receive buffer is full.

Also, reduce number of sending socat instances, decrease their priority
and increase nice value for the nf_queue program itself to reduce the
probability of overruns happening in the first place.

Fixes: 59ecffa399 ("selftests: netfilter: nft_queue.sh: add udp fraglist gro test case")
Reported-by: Jakub Kicinski <kuba@kernel.org>
Closes: https://lore.kernel.org/netdev/20260218184114.0b405b72@kernel.org/
Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://patch.msgid.link/20260226161920.1205-1-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 18:36:59 -08:00
Aaron Tomlin
c31770c493 vmxnet3: Suppress page allocation warning for massive Rx Data ring
The vmxnet3 driver supports an Rx Data ring (rx-mini) to optimise the
processing of small packets. The size of this ring's DMA-coherent memory
allocation is determined by the product of the primary Rx ring size and
the data ring descriptor size:

    sz = rq->rx_ring[0].size * rq->data_ring.desc_size;

When a user configures the maximum supported parameters via ethtool
(rx_ring[0].size = 4096, data_ring.desc_size = 2048), the required
contiguous memory allocation reaches 8 MB (8,388,608 bytes).

In environments lacking Contiguous Memory Allocator (CMA),
dma_alloc_coherent() falls back to the standard zone buddy allocator. An
8 MB allocation translates to a page order of 11, which strictly exceeds
the default MAX_PAGE_ORDER (10) on most architectures.

Consequently, __alloc_pages_noprof() catches the oversize request and
triggers a loud kernel warning stack trace:

    WARN_ON_ONCE_GFP(order > MAX_PAGE_ORDER, gfp)

This warning is unnecessary and alarming to system administrators because
the vmxnet3 driver already handles this allocation failure gracefully.
If dma_alloc_coherent() returns NULL, the driver safely disables the
Rx Data ring (adapter->rxdataring_enabled = false) and falls back to
standard, streaming DMA packet processing.

To resolve this, append the __GFP_NOWARN flag to the dma_alloc_coherent()
gfp_mask. This instructs the page allocator to silently fail the
allocation if it exceeds order limits or memory is too fragmented,
preventing the spurious warning stack trace.

Furthermore, enhance the subsequent netdev_err() fallback message to
include the requested allocation size. This provides critical debugging
context to the administrator (e.g., revealing that an 8 MB allocation
was attempted and failed) without making hardcoded assumptions about
the state of the system's configurations.

Reviewed-by: Jijie Shao <shaojijie@huawei.com>
Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
Link: https://patch.msgid.link/20260226163121.4045808-1-atomlin@atomlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 18:36:45 -08:00
Joris Vaisvila
9a04d3b2f0 net: ethernet: mtk_eth_soc: avoid writing to ESW registers on MT7628
The MT7628 has a fixed-link PHY and does not expose MAC control
registers. Writes to these registers only corrupt the ESW VLAN
configuration.

This patch explicitly registers no-op phylink_mac_ops for MT7628, as
after removing the invalid register accesses, the existing
phylink_mac_ops effectively become no-ops.

This code was introduced by commit 296c912075
("net: ethernet: mediatek: Add MT7628/88 SoC support")

Signed-off-by: Joris Vaisvila <joey@tinyisr.com>
Reviewed-by: Daniel Golle <daniel@makrotpia.org>
Reviewed-by: Stefan Roese <stefan.roese@mailbox.org>
Link: https://patch.msgid.link/20260226154547.68553-1-joey@tinyisr.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 18:36:21 -08:00
Sabrina Dubroca
da89f2e312 tls: don't select STREAM_PARSER
ktls was converted to its own stream parser in commit
84c61fe1a7 ("tls: rx: do not use the standard strparser"), but the
Kconfig dependency was left. The only part of the original strparser
that's shared with ktls are a few structs (strp_msg, sk_skb_cb) and
the strp_msg helper, those don't require building the net/strparser
code.

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://patch.msgid.link/cb41e513a30eeaac0b419284cc87433f049b2ee0.1771871995.git.sd@queasysnail.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 18:36:13 -08:00
Jakub Kicinski
71347b9d8c Merge branch 'net-sched-sch_cake-fixes-for-cake_mq'
Jonas Köppeler says:

====================
net/sched: sch_cake: fixes for cake_mq

This patch contains two fixes for cake_mq:
- do not sync when bandwidth is unlimited
- adjust the rates for all tins during sync
====================

Link: https://patch.msgid.link/20260226-cake-mq-skip-sync-bandwidth-unlimited-v1-0-01830bb4db87@tu-berlin.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 18:35:42 -08:00
Jonas Köppeler
15c2715a52 net/sched: sch_cake: fixup cake_mq rate adjustment for diffserv config
cake_mq's rate adjustment during the sync periods did not adjust the
rates for every tin in a diffserv config. This lead to inconsistencies
of rates between the tins. Fix this by setting the rates for all tins
during synchronization.

Fixes: 1bddd758ba ("net/sched: sch_cake: share shaper state across sub-instances of cake_mq")
Signed-off-by: Jonas Köppeler <j.koeppeler@tu-berlin.de>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Link: https://patch.msgid.link/20260226-cake-mq-skip-sync-bandwidth-unlimited-v1-2-01830bb4db87@tu-berlin.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 18:35:40 -08:00
Jonas Köppeler
0b3cd139be net/sched: sch_cake: avoid sync overhead when unlimited
Skip inter-instance sync when no rate limit is configured, as it serves
no purpose and only adds overhead.

Fixes: 1bddd758ba ("net/sched: sch_cake: share shaper state across sub-instances of cake_mq")
Signed-off-by: Jonas Köppeler <j.koeppeler@tu-berlin.de>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Link: https://patch.msgid.link/20260226-cake-mq-skip-sync-bandwidth-unlimited-v1-1-01830bb4db87@tu-berlin.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 18:35:40 -08:00
Eric Dumazet
5151ec54f5 net: use try_cmpxchg() in lock_sock_nested()
Add a fast path in lock_sock_nested(), to avoid acquiring
the socket spinlock only to set @owned to one:

        spin_lock_bh(&sk->sk_lock.slock);
        if (unlikely(sock_owned_by_user_nocheck(sk)))
                __lock_sock(sk);
        sk->sk_lock.owned = 1;
        spin_unlock_bh(&sk->sk_lock.slock);

On x86_64 compiler generates something quite efficient:

00000000000077c0 <lock_sock_nested>:
    77c0:       f3 0f 1e fa                 endbr64
    77c4:       e8 00 00 00 00              call   __fentry__
    77c9:       b9 01 00 00 00              mov    $0x1,%ecx
    77ce:       31 c0                       xor    %eax,%eax
    77d0:       f0 48 0f b1 8f 48 01 00 00  lock cmpxchg %rcx,0x148(%rdi)
    77d9:       75 06                       jne    slow_path
    77db:       2e e9 00 00 00 00           cs jmp __x86_return_thunk-0x4
slow_path:      ...

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://patch.msgid.link/20260226021215.1764237-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 17:25:45 -08:00
Kexin Sun
b99ccb37ed net/hsr: update outdated comments
The function hsr_rcv() was renamed hsr_handle_frame() and moved to
net/hsr/hsr_slave.c by commit 81ba6afd6e ("net/hsr: Switch from
dev_add_pack() to netdev_rx_handler_register()").

Update all remaining references in the comments accordingly.

Signed-off-by: Kexin Sun <kexinsun@smail.nju.edu.cn>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260225145159.2953-1-kexinsun@smail.nju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 17:24:58 -08:00
Jens Emil Schulz Østergaard
11c0663a59 net: phy: micrel: Add support for lan9645x internal phy
LAN9645X is a family of switch chips with 5 internal copper phys. The
internal PHY is based on parts of LAN8832. This is a low-power, single
port triple-speed (10BASE-T/100BASE-TX/1000BASE-T) ethernet physical
layer transceiver (PHY) that supports transmission and reception of data
on standard CAT-5, as well as CAT-5e and CAT-6 Unshielded Twisted
Pair (UTP) cables.

Add support for the internal PHY of the lan9645x chip family.

Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com>
Reviewed-by: Daniel Machon <daniel.machon@microchip.com>
Signed-off-by: Jens Emil Schulz Østergaard <jensemil.schulzostergaard@microchip.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20260226-phy_micrel_add_support_for_lan9645x_internal_phy-v3-1-1fe82379962b@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 17:23:37 -08:00
Eric Dumazet
29252397bc inet: annotate data-races around isk->inet_num
UDP/TCP lookups are using RCU, thus isk->inet_num accesses
should use READ_ONCE() and WRITE_ONCE() where needed.

Fixes: 3ab5aee7fe ("net: Convert TCP & DCCP hash tables to use RCU / hlist_nulls")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260225203545.1512417-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 17:16:59 -08:00
Alexei Starovoitov
b9c0a5c483 Merge branch 'fix-invariant-violation-for-single-value-tnums'
Paul Chaignon says:

====================
Fix invariant violation for single-value tnums

We're hitting an invariant violation in Cilium that sometimes leads to
BPF programs being rejected and Cilium failing to start [1]. As far as
I know this is the first case of invariant violation found in a real
program (i.e., not by a fuzzer). The following extract from verifier
logs shows what's happening:

  from 201 to 236: R1=0 R6=ctx() R7=1 R9=scalar(smin=umin=smin32=umin32=3584,smax=umax=smax32=umax32=3840,var_off=(0xe00; 0x100)) R10=fp0
  236: R1=0 R6=ctx() R7=1 R9=scalar(smin=umin=smin32=umin32=3584,smax=umax=smax32=umax32=3840,var_off=(0xe00; 0x100)) R10=fp0
  ; if (magic == MARK_MAGIC_HOST || magic == MARK_MAGIC_OVERLAY || magic == MARK_MAGIC_ENCRYPT) @ bpf_host.c:1337
  236: (16) if w9 == 0xe00 goto pc+45   ; R9=scalar(smin=umin=smin32=umin32=3585,smax=umax=smax32=umax32=3840,var_off=(0xe00; 0x100))
  237: (16) if w9 == 0xf00 goto pc+1
  verifier bug: REG INVARIANTS VIOLATION (false_reg1): range bounds violation u64=[0xe01, 0xe00] s64=[0xe01, 0xe00] u32=[0xe01, 0xe00] s32=[0xe01, 0xe00] var_off=(0xe00, 0x0)

More details are given in the second patch, but in short, the verifier
should be able to detect that the false branch of instruction 237 is
never true. After instruction 236, the u64 range and the tnum overlap
in a single value, 0xf00.

The long-term solution to invariant violation is likely to rely on the
refinement + invariant violation check to detect dead branches, as
started by Eduard. To fix the current issue, we need something with
less refactoring that we can backport to affected kernels.

The solution implemented in the second patch is to improve the bounds
refinement to avoid this case. It relies on a new tnum helper,
tnum_step, first sent as an RFC in [2]. The last two patches extend and
update the selftests.

Link: https://github.com/cilium/cilium/issues/44216 [1]
Link: https://lore.kernel.org/bpf/20251107192328.2190680-2-harishankar.vishwanathan@gmail.com/ [2]

Changes in v3:
  - Fix commit description error spotted by AI bot.
  - Simplify constants in first two tests (Eduard).
  - Rework comment on third test (Eduard).
  - Add two new negative test cases (Eduard).
  - Rebased.
Changes in v2:
  - Add guard suggested by Hari in tnum_step, to avoid undefined
    behavior spotted by AI code review.
  - Add explanation diagrams in code as suggested by Eduard.
  - Rework conditions for readability as suggested by Eduard.
  - Updated reference to SMT formula.
  - Rebased.
====================

Link: https://patch.msgid.link/cover.1772225741.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-02-27 16:11:50 -08:00
Paul Chaignon
024cea2d64 selftests/bpf: Avoid simplification of crafted bounds test
The reg_bounds_crafted tests validate the verifier's range analysis
logic. They focus on the actual ranges and thus ignore the tnum. As a
consequence, they carry the assumption that the tested cases can be
reproduced in userspace without using the tnum information.

Unfortunately, the previous change the refinement logic breaks that
assumption for one test case:

  (u64)2147483648 (u32)<op> [4294967294; 0x100000000]

The tested bytecode is shown below. Without our previous improvement, on
the false branch of the condition, R7 is only known to have u64 range
[0xfffffffe; 0x100000000]. With our improvement, and using the tnum
information, we can deduce that R7 equals 0x100000000.

  19: (bc) w0 = w6                ; R6=0x80000000
  20: (bc) w0 = w7                ; R7=scalar(smin=umin=0xfffffffe,smax=umax=0x100000000,smin32=-2,smax32=0,var_off=(0x0; 0x1ffffffff))
  21: (be) if w6 <= w7 goto pc+3  ; R6=0x80000000 R7=0x100000000

R7's tnum is (0; 0x1ffffffff). On the false branch, regs_refine_cond_op
refines R7's u32 range to [0; 0x7fffffff]. Then, __reg32_deduce_bounds
refines the s32 range to 0 using u32 and finally also sets u32=0.
From this, __reg_bound_offset improves the tnum to (0; 0x100000000).
Finally, our previous patch uses this new tnum to deduce that it only
intersect with u64=[0xfffffffe; 0x100000000] in a single value:
0x100000000.

Because the verifier uses the tnum to reach this constant value, the
selftest is unable to reproduce it by only simulating ranges. The
solution implemented in this patch is to change the test case such that
there is more than one overlap value between u64 and the tnum. The max.
u64 value is thus changed from 0x100000000 to 0x300000000.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/50641c6a7ef39520595dcafa605692427c1006ec.1772225741.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-02-27 16:11:50 -08:00
Paul Chaignon
e6ad477d1b selftests/bpf: Test refinement of single-value tnum
This patch introduces selftests to cover the new bounds refinement
logic introduced in the previous patch. Without the previous patch,
the first two tests fail because of the invariant violation they
trigger. The last test fails because the R10 access is not detected as
dead code. In addition, all three tests fail because of R0 having a
non-constant value in the verifier logs.

In addition, the last two cases are covering the negative cases: when we
shouldn't refine the bounds because the u64 and tnum overlap in at least
two values.

Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/90d880c8cf587b9f7dc715d8961cd1b8111d01a8.1772225741.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-02-27 16:11:50 -08:00
Paul Chaignon
efc11a6678 bpf: Improve bounds when tnum has a single possible value
We're hitting an invariant violation in Cilium that sometimes leads to
BPF programs being rejected and Cilium failing to start [1]. The
following extract from verifier logs shows what's happening:

  from 201 to 236: R1=0 R6=ctx() R7=1 R9=scalar(smin=umin=smin32=umin32=3584,smax=umax=smax32=umax32=3840,var_off=(0xe00; 0x100)) R10=fp0
  236: R1=0 R6=ctx() R7=1 R9=scalar(smin=umin=smin32=umin32=3584,smax=umax=smax32=umax32=3840,var_off=(0xe00; 0x100)) R10=fp0
  ; if (magic == MARK_MAGIC_HOST || magic == MARK_MAGIC_OVERLAY || magic == MARK_MAGIC_ENCRYPT) @ bpf_host.c:1337
  236: (16) if w9 == 0xe00 goto pc+45   ; R9=scalar(smin=umin=smin32=umin32=3585,smax=umax=smax32=umax32=3840,var_off=(0xe00; 0x100))
  237: (16) if w9 == 0xf00 goto pc+1
  verifier bug: REG INVARIANTS VIOLATION (false_reg1): range bounds violation u64=[0xe01, 0xe00] s64=[0xe01, 0xe00] u32=[0xe01, 0xe00] s32=[0xe01, 0xe00] var_off=(0xe00, 0x0)

We reach instruction 236 with two possible values for R9, 0xe00 and
0xf00. This is perfectly reflected in the tnum, but of course the ranges
are less accurate and cover [0xe00; 0xf00]. Taking the fallthrough path
at instruction 236 allows the verifier to reduce the range to
[0xe01; 0xf00]. The tnum is however not updated.

With these ranges, at instruction 237, the verifier is not able to
deduce that R9 is always equal to 0xf00. Hence the fallthrough pass is
explored first, the verifier refines the bounds using the assumption
that R9 != 0xf00, and ends up with an invariant violation.

This pattern of impossible branch + bounds refinement is common to all
invariant violations seen so far. The long-term solution is likely to
rely on the refinement + invariant violation check to detect dead
branches, as started by Eduard. To fix the current issue, we need
something with less refactoring that we can backport.

This patch uses the tnum_step helper introduced in the previous patch to
detect the above situation. In particular, three cases are now detected
in the bounds refinement:

1. The u64 range and the tnum only overlap in umin.
   u64:  ---[xxxxxx]-----
   tnum: --xx----------x-

2. The u64 range and the tnum only overlap in the maximum value
   represented by the tnum, called tmax.
   u64:  ---[xxxxxx]-----
   tnum: xx-----x--------

3. The u64 range and the tnum only overlap in between umin (excluded)
   and umax.
   u64:  ---[xxxxxx]-----
   tnum: xx----x-------x-

To detect these three cases, we call tnum_step(tnum, umin), which
returns the smallest member of the tnum greater than umin, called
tnum_next here. We're in case (1) if umin is part of the tnum and
tnum_next is greater than umax. We're in case (2) if umin is not part of
the tnum and tnum_next is equal to tmax. Finally, we're in case (3) if
umin is not part of the tnum, tnum_next is inferior or equal to umax,
and calling tnum_step a second time gives us a value past umax.

This change implements these three cases. With it, the above bytecode
looks as follows:

  0: (85) call bpf_get_prandom_u32#7    ; R0=scalar()
  1: (47) r0 |= 3584                    ; R0=scalar(smin=0x8000000000000e00,umin=umin32=3584,smin32=0x80000e00,var_off=(0xe00; 0xfffffffffffff1ff))
  2: (57) r0 &= 3840                    ; R0=scalar(smin=umin=smin32=umin32=3584,smax=umax=smax32=umax32=3840,var_off=(0xe00; 0x100))
  3: (15) if r0 == 0xe00 goto pc+2      ; R0=3840
  4: (15) if r0 == 0xf00 goto pc+1
  4: R0=3840
  6: (95) exit

In addition to the new selftests, this change was also verified with
Agni [3]. For the record, the raw SMT is available at [4]. The property
it verifies is that: If a concrete value x is contained in all input
abstract values, after __update_reg_bounds, it will continue to be
contained in all output abstract values.

Link: https://github.com/cilium/cilium/issues/44216 [1]
Link: https://pchaigno.github.io/test-verifier-complexity.html [2]
Link: https://github.com/bpfverif/agni [3]
Link: https://pastebin.com/raw/naCfaqNx [4]
Fixes: 0df1a55afa ("bpf: Warn on internal verifier errors")
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Tested-by: Marco Schirrmeister <mschirrmeister@gmail.com>
Co-developed-by: Harishankar Vishwanathan <harishankar.vishwanathan@gmail.com>
Signed-off-by: Harishankar Vishwanathan <harishankar.vishwanathan@gmail.com>
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/ef254c4f68be19bd393d450188946821c588565d.1772225741.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-02-27 16:11:50 -08:00
Harishankar Vishwanathan
76e954155b bpf: Introduce tnum_step to step through tnum's members
This commit introduces tnum_step(), a function that, when given t, and a
number z returns the smallest member of t larger than z. The number z
must be greater or equal to the smallest member of t and less than the
largest member of t.

The first step is to compute j, a number that keeps all of t's known
bits, and matches all unknown bits to z's bits. Since j is a member of
the t, it is already a candidate for result. However, we want our result
to be (minimally) greater than z.

There are only two possible cases:

(1) Case j <= z. In this case, we want to increase the value of j and
make it > z.
(2) Case j > z. In this case, we want to decrease the value of j while
keeping it > z.

(Case 1) j <= z

t = xx11x0x0
z = 10111101 (189)
j = 10111000 (184)
         ^
         k

(Case 1.1) Let's first consider the case where j < z. We will address j
== z later.

Since z > j, there had to be a bit position that was 1 in z and a 0 in
j, beyond which all positions of higher significance are equal in j and
z. Further, this position could not have been unknown in a, because the
unknown positions of a match z. This position had to be a 1 in z and
known 0 in t.

Let k be position of the most significant 1-to-0 flip. In our example, k
= 3 (starting the count at 1 at the least significant bit).  Setting (to
1) the unknown bits of t in positions of significance smaller than
k will not produce a result > z. Hence, we must set/unset the unknown
bits at positions of significance higher than k. Specifically, we look
for the next larger combination of 1s and 0s to place in those
positions, relative to the combination that exists in z. We can achieve
this by concatenating bits at unknown positions of t into an integer,
adding 1, and writing the bits of that result back into the
corresponding bit positions previously extracted from z.

>From our example, considering only positions of significance greater
than k:

t =  xx..x
z =  10..1
    +    1
     -----
     11..0

This is the exact combination 1s and 0s we need at the unknown bits of t
in positions of significance greater than k. Further, our result must
only increase the value minimally above z. Hence, unknown bits in
positions of significance smaller than k should remain 0. We finally
have,

result = 11110000 (240)

(Case 1.2) Now consider the case when j = z, for example

t = 1x1x0xxx
z = 10110100 (180)
j = 10110100 (180)

Matching the unknown bits of the t to the bits of z yielded exactly z.
To produce a number greater than z, we must set/unset the unknown bits
in t, and *all* the unknown bits of t candidates for being set/unset. We
can do this similar to Case 1.1, by adding 1 to the bits extracted from
the masked bit positions of z. Essentially, this case is equivalent to
Case 1.1, with k = 0.

t =  1x1x0xxx
z =  .0.1.100
    +       1
    ---------
     .0.1.101

This is the exact combination of bits needed in the unknown positions of
t. After recalling the known positions of t, we get

result = 10110101 (181)

(Case 2) j > z

t = x00010x1
z = 10000010 (130)
j = 10001011 (139)
	^
	k

Since j > z, there had to be a bit position which was 0 in z, and a 1 in
j, beyond which all positions of higher significance are equal in j and
z. This position had to be a 0 in z and known 1 in t. Let k be the
position of the most significant 0-to-1 flip. In our example, k = 4.

Because of the 0-to-1 flip at position k, a member of t can become
greater than z if the bits in positions greater than k are themselves >=
to z. To make that member *minimally* greater than z, the bits in
positions greater than k must be exactly = z. Hence, we simply match all
of t's unknown bits in positions more significant than k to z's bits. In
positions less significant than k, we set all t's unknown bits to 0
to retain minimality.

In our example, in positions of greater significance than k (=4),
t=x000. These positions are matched with z (1000) to produce 1000. In
positions of lower significance than k, t=10x1. All unknown bits are set
to 0 to produce 1001. The final result is:

result = 10001001 (137)

This concludes the computation for a result > z that is a member of t.

The procedure for tnum_step() in this commit implements the idea
described above. As a proof of correctness, we verified the algorithm
against a logical specification of tnum_step. The specification asserts
the following about the inputs t, z and output res that:

1. res is a member of t, and
2. res is strictly greater than z, and
3. there does not exist another value res2 such that
	3a. res2 is also a member of t, and
	3b. res2 is greater than z
	3c. res2 is smaller than res

We checked the implementation against this logical specification using
an SMT solver. The verification formula in SMTLIB format is available
at [1]. The verification returned an "unsat": indicating that no input
assignment exists for which the implementation and the specification
produce different outputs.

In addition, we also automatically generated the logical encoding of the
C implementation using Agni [2] and verified it against the same
specification. This verification also returned an "unsat", confirming
that the implementation is equivalent to the specification. The formula
for this check is also available at [3].

Link: https://pastebin.com/raw/2eRWbiit [1]
Link: https://github.com/bpfverif/agni [2]
Link: https://pastebin.com/raw/EztVbBJ2 [3]
Co-developed-by: Srinivas Narayana <srinivas.narayana@rutgers.edu>
Signed-off-by: Srinivas Narayana <srinivas.narayana@rutgers.edu>
Co-developed-by: Santosh Nagarakatte <santosh.nagarakatte@rutgers.edu>
Signed-off-by: Santosh Nagarakatte <santosh.nagarakatte@rutgers.edu>
Signed-off-by: Harishankar Vishwanathan <harishankar.vishwanathan@gmail.com>
Link: https://lore.kernel.org/r/93fdf71910411c0f19e282ba6d03b4c65f9c5d73.1772225741.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-02-27 16:11:50 -08:00
Paul Moses
62413a9c3c net/sched: act_gate: snapshot parameters with RCU on replace
The gate action can be replaced while the hrtimer callback or dump path is
walking the schedule list.

Convert the parameters to an RCU-protected snapshot and swap updates under
tcf_lock, freeing the previous snapshot via call_rcu(). When REPLACE omits
the entry list, preserve the existing schedule so the effective state is
unchanged.

Fixes: a51c328df3 ("net: qos: introduce a gate control flow action")
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moses <p@1g4.org>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20260223150512.2251594-2-p@1g4.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-27 16:10:36 -08:00
Alexei Starovoitov
8c0d9e178d Merge branch 'bpf-cpumap-devmap-fix-per-cpu-bulk-queue-races-on-preempt_rt'
Jiayuan Chen says:

====================
bpf: Fix per-CPU bulk queue races on PREEMPT_RT

On PREEMPT_RT kernels, local_bh_disable() only calls migrate_disable()
(when PREEMPT_RT_NEEDS_BH_LOCK is not set) and does not disable
preemption. This means CFS scheduling can preempt a task inside the
per-CPU bulk queue (bq) operations in cpumap and devmap, allowing
another task on the same CPU to concurrently access the same bq,
leading to use-after-free, list corruption, and kernel panics.

Patch 1 fixes the cpumap race in bq_flush_to_queue(), originally
reported by syzbot [1].

Patch 2 fixes the same class of race in devmap's bq_xmit_all(),
identified by code inspection after Sebastian Andrzej Siewior pointed
out that devmap has the same per-CPU bulk queue pattern [2].

Both patches use local_lock_nested_bh() to serialize access to the
per-CPU bq. On non-RT this is a pure lockdep annotation with no
overhead; on PREEMPT_RT it provides a per-CPU sleeping lock.

To reproduce the devmap race, insert an mdelay(100) in bq_xmit_all()
after "cnt = bq->count" and before the actual transmit loop. Then pin
two threads to the same CPU, each running BPF_PROG_TEST_RUN with an XDP
program that redirects to a DEVMAP entry (e.g. a veth pair). CFS
timeslicing during the mdelay window causes interleaving. Without the
fix, KASAN reports null-ptr-deref due to operating on freed frames:

  BUG: KASAN: null-ptr-deref in __build_skb_around+0x22d/0x340
  Write of size 32 at addr 0000000000000d50 by task devmap_race_rep/449

  CPU: 0 UID: 0 PID: 449 Comm: devmap_race_rep Not tainted 6.19.0+ #31 PREEMPT_RT
  Call Trace:
   <TASK>
   __build_skb_around+0x22d/0x340
   build_skb_around+0x25/0x260
   __xdp_build_skb_from_frame+0x103/0x860
   veth_xdp_rcv_bulk_skb.isra.0+0x162/0x320
   veth_xdp_rcv.constprop.0+0x61e/0xbb0
   veth_poll+0x280/0xb50
   __napi_poll.constprop.0+0xa5/0x590
   net_rx_action+0x4b0/0xea0
   handle_softirqs.isra.0+0x1b3/0x780
   __local_bh_enable_ip+0x12a/0x240
   xdp_test_run_batch.constprop.0+0xedd/0x1f60
   bpf_test_run_xdp_live+0x304/0x640
   bpf_prog_test_run_xdp+0xd24/0x1b70
   __sys_bpf+0x61c/0x3e00
   </TASK>

  Kernel panic - not syncing: Fatal exception in interrupt

[1] https://lore.kernel.org/all/69369331.a70a0220.38f243.009d.GAE@google.com/T/
[2] https://lore.kernel.org/bpf/20260212023634.366343-1-jiayuan.chen@linux.dev/

v3 -> v4: https://lore.kernel.org/all/20260213034018.284146-1-jiayuan.chen@linux.dev/
- Move panic trace to cover letter. (Sebastian Andrzej Siewior)
- Add Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> to both patches
  from cover letter.

v2 -> v3: https://lore.kernel.org/bpf/20260212023634.366343-1-jiayuan.chen@linux.dev/
- Fix commit message: remove incorrect "spin_lock() becomes rt_mutex"
claim, the per-CPU bq has no spin_lock at all. (Sebastian Andrzej Siewior)
- Fix commit message: accurately describe local_lock_nested_bh()
behavior instead of referencing local_lock(). (Sebastian Andrzej Siewior)
- Remove incomplete discussion of snapshot alternative.
(Sebastian Andrzej Siewior)
- Remove panic trace from commit message. (Sebastian Andrzej Siewior)
- Add patch 2/2 for devmap, same race pattern. (Sebastian Andrzej Siewior)

v1 -> v2: https://lore.kernel.org/bpf/20260211064417.196401-1-jiayuan.chen@linux.dev/
- Use local_lock_nested_bh()/local_unlock_nested_bh() instead of
local_lock()/local_unlock(), since these paths already run under
local_bh_disable(). (Sebastian Andrzej Siewior)
- Replace "Caller must hold bq->bq_lock" comment with
lockdep_assert_held() in bq_flush_to_queue(). (Sebastian Andrzej Siewior)
- Fix Fixes tag to 3253cb49cb ("softirq: Allow to drop the
softirq-BKL lock on PREEMPT_RT") which is the actual commit that
makes the race possible. (Sebastian Andrzej Siewior)
====================

Link: https://patch.msgid.link/20260225121459.183121-1-jiayuan.chen@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-02-27 16:08:34 -08:00
Jiayuan Chen
1872e75375 bpf: Fix race in devmap on PREEMPT_RT
On PREEMPT_RT kernels, the per-CPU xdp_dev_bulk_queue (bq) can be
accessed concurrently by multiple preemptible tasks on the same CPU.

The original code assumes bq_enqueue() and __dev_flush() run atomically
with respect to each other on the same CPU, relying on
local_bh_disable() to prevent preemption. However, on PREEMPT_RT,
local_bh_disable() only calls migrate_disable() (when
PREEMPT_RT_NEEDS_BH_LOCK is not set) and does not disable
preemption, which allows CFS scheduling to preempt a task during
bq_xmit_all(), enabling another task on the same CPU to enter
bq_enqueue() and operate on the same per-CPU bq concurrently.

This leads to several races:

1. Double-free / use-after-free on bq->q[]: bq_xmit_all() snapshots
   cnt = bq->count, then iterates bq->q[0..cnt-1] to transmit frames.
   If preempted after the snapshot, a second task can call bq_enqueue()
   -> bq_xmit_all() on the same bq, transmitting (and freeing) the
   same frames. When the first task resumes, it operates on stale
   pointers in bq->q[], causing use-after-free.

2. bq->count and bq->q[] corruption: concurrent bq_enqueue() modifying
   bq->count and bq->q[] while bq_xmit_all() is reading them.

3. dev_rx/xdp_prog teardown race: __dev_flush() clears bq->dev_rx and
   bq->xdp_prog after bq_xmit_all(). If preempted between
   bq_xmit_all() return and bq->dev_rx = NULL, a preempting
   bq_enqueue() sees dev_rx still set (non-NULL), skips adding bq to
   the flush_list, and enqueues a frame. When __dev_flush() resumes,
   it clears dev_rx and removes bq from the flush_list, orphaning the
   newly enqueued frame.

4. __list_del_clearprev() on flush_node: similar to the cpumap race,
   both tasks can call __list_del_clearprev() on the same flush_node,
   the second dereferences the prev pointer already set to NULL.

The race between task A (__dev_flush -> bq_xmit_all) and task B
(bq_enqueue -> bq_xmit_all) on the same CPU:

  Task A (xdp_do_flush)          Task B (ndo_xdp_xmit redirect)
  ----------------------         --------------------------------
  __dev_flush(flush_list)
    bq_xmit_all(bq)
      cnt = bq->count  /* e.g. 16 */
      /* start iterating bq->q[] */
    <-- CFS preempts Task A -->
                                   bq_enqueue(dev, xdpf)
                                     bq->count == DEV_MAP_BULK_SIZE
                                     bq_xmit_all(bq, 0)
                                       cnt = bq->count  /* same 16! */
                                       ndo_xdp_xmit(bq->q[])
                                       /* frames freed by driver */
                                       bq->count = 0
    <-- Task A resumes -->
      ndo_xdp_xmit(bq->q[])
      /* use-after-free: frames already freed! */

Fix this by adding a local_lock_t to xdp_dev_bulk_queue and acquiring
it in bq_enqueue() and __dev_flush(). These paths already run under
local_bh_disable(), so use local_lock_nested_bh() which on non-RT is
a pure annotation with no overhead, and on PREEMPT_RT provides a
per-CPU sleeping lock that serializes access to the bq.

Fixes: 3253cb49cb ("softirq: Allow to drop the softirq-BKL lock on PREEMPT_RT")
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Jiayuan Chen <jiayuan.chen@shopee.com>
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Link: https://lore.kernel.org/r/20260225121459.183121-3-jiayuan.chen@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-02-27 16:08:10 -08:00
Jiayuan Chen
869c63d597 bpf: Fix race in cpumap on PREEMPT_RT
On PREEMPT_RT kernels, the per-CPU xdp_bulk_queue (bq) can be accessed
concurrently by multiple preemptible tasks on the same CPU.

The original code assumes bq_enqueue() and __cpu_map_flush() run
atomically with respect to each other on the same CPU, relying on
local_bh_disable() to prevent preemption. However, on PREEMPT_RT,
local_bh_disable() only calls migrate_disable() (when
PREEMPT_RT_NEEDS_BH_LOCK is not set) and does not disable
preemption, which allows CFS scheduling to preempt a task during
bq_flush_to_queue(), enabling another task on the same CPU to enter
bq_enqueue() and operate on the same per-CPU bq concurrently.

This leads to several races:

1. Double __list_del_clearprev(): after bq->count is reset in
   bq_flush_to_queue(), a preempting task can call bq_enqueue() ->
   bq_flush_to_queue() on the same bq when bq->count reaches
   CPU_MAP_BULK_SIZE. Both tasks then call __list_del_clearprev()
   on the same bq->flush_node, the second call dereferences the
   prev pointer that was already set to NULL by the first.

2. bq->count and bq->q[] races: concurrent bq_enqueue() can corrupt
   the packet queue while bq_flush_to_queue() is processing it.

The race between task A (__cpu_map_flush -> bq_flush_to_queue) and
task B (bq_enqueue -> bq_flush_to_queue) on the same CPU:

  Task A (xdp_do_flush)          Task B (cpu_map_enqueue)
  ----------------------         ------------------------
  bq_flush_to_queue(bq)
    spin_lock(&q->producer_lock)
    /* flush bq->q[] to ptr_ring */
    bq->count = 0
    spin_unlock(&q->producer_lock)
                                   bq_enqueue(rcpu, xdpf)
    <-- CFS preempts Task A -->      bq->q[bq->count++] = xdpf
                                     /* ... more enqueues until full ... */
                                     bq_flush_to_queue(bq)
                                       spin_lock(&q->producer_lock)
                                       /* flush to ptr_ring */
                                       spin_unlock(&q->producer_lock)
                                       __list_del_clearprev(flush_node)
                                         /* sets flush_node.prev = NULL */
    <-- Task A resumes -->
    __list_del_clearprev(flush_node)
      flush_node.prev->next = ...
      /* prev is NULL -> kernel oops */

Fix this by adding a local_lock_t to xdp_bulk_queue and acquiring it
in bq_enqueue() and __cpu_map_flush(). These paths already run under
local_bh_disable(), so use local_lock_nested_bh() which on non-RT is
a pure annotation with no overhead, and on PREEMPT_RT provides a
per-CPU sleeping lock that serializes access to the bq.

To reproduce, insert an mdelay(100) between bq->count = 0 and
__list_del_clearprev() in bq_flush_to_queue(), then run reproducer
provided by syzkaller.

Fixes: 3253cb49cb ("softirq: Allow to drop the softirq-BKL lock on PREEMPT_RT")
Reported-by: syzbot+2b3391f44313b3983e91@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/69369331.a70a0220.38f243.009d.GAE@google.com/T/
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Jiayuan Chen <jiayuan.chen@shopee.com>
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Link: https://lore.kernel.org/r/20260225121459.183121-2-jiayuan.chen@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-02-27 16:07:14 -08:00
Song Hongyi
60477d7897 of: property: fix typo in kernel-doc return description
Fix the spelling of "success" in the return value description
of the kernel-doc comment to improve documentation quality.

Signed-off-by: Song Hongyi <szpcq123@gmail.com>
Link: https://patch.msgid.link/20260225093814.124735-1-szpcq123@gmail.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
2026-02-27 17:49:54 -06:00
Kenny Cheng
28f060c4b0 of: fix incorrect device creation for reserved memory nodes
The current global search for nodes in reserved_mem_matches can find
nodes outside "/reserved-memory". These nodes might not have actual
memory reserved (via memblock), leading to drivers (e.g., ramoops)
accessing unreserved memory and causing memory corruption.

Restrict the scan to the "/reserved-memory" node to ensure created
devices are correctly backed by reserved memory. This enforces
specification compliance and avoids dangerous probing.

Signed-off-by: Kenny Cheng <chao.shun.cheng.tw@gmail.com>
Link: https://patch.msgid.link/20260222234715.1748302-1-chao.shun.cheng.tw@gmail.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
2026-02-27 17:49:31 -06:00
Alexei Starovoitov
5263e30fff Merge branch 'close-race-in-freeing-special-fields-and-map-value'
Kumar Kartikeya Dwivedi says:

====================
Close race in freeing special fields and map value

There exists a race across various map types where the freeing of
special fields (tw, timer, wq, kptr, etc.) can be done eagerly when a
logical delete operation is done on a map value, such that the program
which continues to have access to such a map value can recreate the
fields and cause them to leak.

The set contains fixes for this case. It is a continuation of Mykyta's
previous attempt in [0], but applies to all fields. A test is included
which reproduces the bug reliably in absence of the fixes.

Local Storage Benchmarks
------------------------
Evaluation Setup: Benchmarked on a dual-socket Intel Xeon Gold 6348 (Ice
Lake) @ 2.60GHz (56 cores / 112 threads), with the CPU governor set to
performance. Bench was pinned to a single NUMA node throughout the test.

Benchmark comes from [1] using the following command:
./bench -p 1 local-storage-create --storage-type <socket,task> --batch-size <16,32,64>

Before the test, 10 runs of all cases ([socket|task] x 3 batch sizes x 7
iterations per batch size) are done to warm up and prime the machine.

Then, 3 runs of all cases are done (with and without the patch, across
reboots).

For each comparison, we have 21 samples, i.e. per batch size (e.g.
socket 16) of a given local storage, we have 3 runs x 7 iterations.

The statistics (mean, median, stddev) and t-test is done for each
scenario (local storage and batch size pair) individually (21 samples
for either case). All values are for local storage creations in thousand
creations / sec (k/s).

	       Baseline (without patch)               With patch                       Delta
     Case      Median        Mean   Std. Dev.   Median        Mean   Std. Dev.   Median       %
---------------------------------------------------------------------------------------------------
socket 16     432.026     431.941    1.047     431.347     431.953    1.635      -0.679    -0.16%
socket 32     432.641     432.818    1.535     432.488     432.302    1.508      -0.153    -0.04%
socket 64     431.504     431.996    1.337     429.145     430.326    2.469      -2.359    -0.55%
  task 16      38.816      39.382    1.456      39.657      39.337    1.831      +0.841    +2.17%
  task 32      38.815      39.644    2.690      38.721      39.122    1.636      -0.094    -0.24%
  task 64      37.562      38.080    1.701      39.554      38.563    1.689      +1.992    +5.30%

The cases for socket are within the range of noise, and improvements in task
local storage are due to high variance (CV ~4%-6% across batch sizes). The only
statistically significant case worth mentioning is socket with batch size 64
with p-value from t-test < 0.05, but the absolute difference is small (~2k/s).

TL;DR there doesn't appear to be any significant regression or improvement.

  [0]: https://lore.kernel.org/bpf/20260216131341.1285427-1-mykyta.yatsenko5@gmail.com
  [1]: https://lore.kernel.org/bpf/20260205222916.1788211-1-ameryhung@gmail.com

Changelog:
----------
v2 -> v3
v2: https://lore.kernel.org/bpf/20260227052031.3988575-1-memxor@gmail.com

 * Add syzbot Tested-by.
 * Add Amery's Reviewed-by.
 * Fix missing rcu_dereference_check() in __bpf_selem_free_rcu. (BPF CI Bot)
 * Remove migrate_disable() in bpf_selem_free_rcu. (Alexei)

v1 -> v2
v1: https://lore.kernel.org/bpf/20260225185121.2057388-1-memxor@gmail.com

 * Add Paul's Reviewed-by.
 * Fix use-after-free in accessing bpf_mem_alloc embedded in map. (syzbot CI)
 * Add benchmark numbers for local storage.
 * Add extra test case for per-cpu hashmap coverage with up to 16 refcount leaks.
 * Target bpf tree.
====================

Link: https://patch.msgid.link/20260227224806.646888-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-02-27 15:39:01 -08:00
Kumar Kartikeya Dwivedi
2939d7b3b0 selftests/bpf: Add tests for special fields races
Add a couple of tests to ensure that the refcount drops to zero when we
exercise the race where creation of a special field succeeds the logical
bpf_obj_free_fields done when deleting an element. Prior to previous
changes, the fields would be freed eagerly and repopulate and end up
leaking, causing the reference to not drop down correctly. Running this
test on a kernel without fixes will cause a hang in delete_module, since
the module reference stays active due to the leaked kptr not dropping
it. After the fixes tests succeed as expected.

Reviewed-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260227224806.646888-6-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-02-27 15:39:00 -08:00
Kumar Kartikeya Dwivedi
baa35b3cb6 bpf: Retire rcu_trace_implies_rcu_gp() from local storage
This assumption will always hold going forward, hence just remove the
various checks and assume it is true with a comment for the uninformed
reader.

Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260227224806.646888-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-02-27 15:39:00 -08:00
Kumar Kartikeya Dwivedi
f41deee082 bpf: Delay freeing fields in local storage
Currently, when use_kmalloc_nolock is false, the freeing of fields for a
local storage selem is done eagerly before waiting for the RCU or RCU
tasks trace grace period to elapse. This opens up a window where the
program which has access to the selem can recreate the fields after the
freeing of fields is done eagerly, causing memory leaks when the element
is finally freed and returned to the kernel.

Make a few changes to address this. First, delay the freeing of fields
until after the grace periods have expired using a __bpf_selem_free_rcu
wrapper which is eventually invoked after transitioning through the
necessary number of grace period waits. Replace usage of the kfree_rcu
with call_rcu to be able to take a custom callback. Finally, care needs
to be taken to extend the rcu barriers for all cases, and not just when
use_kmalloc_nolock is true, as RCU and RCU tasks trace callbacks can be
in flight for either case and access the smap field, which is used to
obtain the BTF record to walk over special fields in the map value.

While we're at it, drop migrate_disable() from bpf_selem_free_rcu, since
migration should be disabled for RCU callbacks already.

Fixes: 9bac675e63 ("bpf: Postpone bpf_obj_free_fields to the rcu callback")
Reviewed-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260227224806.646888-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-02-27 15:39:00 -08:00
Kumar Kartikeya Dwivedi
ae51772b1e bpf: Lose const-ness of map in map_check_btf()
BPF hash map may now use the map_check_btf() callback to decide whether
to set a dtor on its bpf_mem_alloc or not. Unlike C++ where members can
opt out of const-ness using mutable, we must lose the const qualifier on
the callback such that we can avoid the ugly cast. Make the change and
adjust all existing users, and lose the comment in hashtab.c.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260227224806.646888-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-02-27 15:39:00 -08:00
Kumar Kartikeya Dwivedi
1df97a7453 bpf: Register dtor for freeing special fields
There is a race window where BPF hash map elements can leak special
fields if the program with access to the map value recreates these
special fields between the check_and_free_fields done on the map value
and its eventual return to the memory allocator.

Several ways were explored prior to this patch, most notably [0] tried
to use a poison value to reject attempts to recreate special fields for
map values that have been logically deleted but still accessible to BPF
programs (either while sitting in the free list or when reused). While
this approach works well for task work, timers, wq, etc., it is harder
to apply the idea to kptrs, which have a similar race and failure mode.

Instead, we change bpf_mem_alloc to allow registering destructor for
allocated elements, such that when they are returned to the allocator,
any special fields created while they were accessible to programs in the
mean time will be freed. If these values get reused, we do not free the
fields again before handing the element back. The special fields thus
may remain initialized while the map value sits in a free list.

When bpf_mem_alloc is retired in the future, a similar concept can be
introduced to kmalloc_nolock-backed kmem_cache, paired with the existing
idea of a constructor.

Note that the destructor registration happens in map_check_btf, after
the BTF record is populated and (at that point) avaiable for inspection
and duplication. Duplication is necessary since the freeing of embedded
bpf_mem_alloc can be decoupled from actual map lifetime due to logic
introduced to reduce the cost of rcu_barrier()s in mem alloc free path in
9f2c6e96c6 ("bpf: Optimize rcu_barrier usage between hash map and bpf_mem_alloc.").

As such, once all callbacks are done, we must also free the duplicated
record. To remove dependency on the bpf_map itself, also stash the key
size of the map to obtain value from htab_elem long after the map is
gone.

  [0]: https://lore.kernel.org/bpf/20260216131341.1285427-1-mykyta.yatsenko5@gmail.com

Fixes: 14a324f6a6 ("bpf: Wire up freeing of referenced kptr")
Fixes: 1bfbc267ec ("bpf: Enable bpf_timer and bpf_wq in any context")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: syzbot@syzkaller.appspotmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260227224806.646888-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-02-27 15:39:00 -08:00
Linus Torvalds
4d349ee5c7 arm64 fixes for -rc2
- Fix cpufreq warning due to attempting a cross-call with interrupts
   masked when reading local AMU counters.
 
 - Fix DEBUG_PREEMPT warning from the delay loop when it tries to access
   per-cpu errata workaround state for the virtual counter.
 
 - Re-jig and optimise our TLB invalidation errata workarounds in
   preparation for more hardware brokenness.
 
 - Fix GCS mappings to interact properly with PROT_NONE and to avoid
   corrupting the pte on CPUs with FEAT_LPA2.
 
 - Fix ioremap_prot() to extract only the memory attributes from the
   user pte and ignore all the other 'prot' bits.
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:
 "The diffstat is dominated by changes to our TLB invalidation errata
  handling and the introduction of a new GCS selftest to catch one of
  the issues that is fixed here relating to PROT_NONE mappings.

   - Fix cpufreq warning due to attempting a cross-call with interrupts
     masked when reading local AMU counters

   - Fix DEBUG_PREEMPT warning from the delay loop when it tries to
     access per-cpu errata workaround state for the virtual counter

   - Re-jig and optimise our TLB invalidation errata workarounds in
     preparation for more hardware brokenness

   - Fix GCS mappings to interact properly with PROT_NONE and to avoid
     corrupting the pte on CPUs with FEAT_LPA2

   - Fix ioremap_prot() to extract only the memory attributes from the
     user pte and ignore all the other 'prot' bits"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: topology: Fix false warning in counters_read_on_cpu() for same-CPU reads
  arm64: Fix sampling the "stable" virtual counter in preemptible section
  arm64: tlb: Optimize ARM64_WORKAROUND_REPEAT_TLBI
  arm64: tlb: Allow XZR argument to TLBI ops
  kselftest: arm64: Check access to GCS after mprotect(PROT_NONE)
  arm64: gcs: Honour mprotect(PROT_NONE) on shadow stack mappings
  arm64: gcs: Do not set PTE_SHARED on GCS mappings if FEAT_LPA2 is enabled
  arm64: io: Extract user memory type in ioremap_prot()
  arm64: io: Rename ioremap_prot() to __ioremap_prot()
2026-02-27 13:40:30 -08:00
Linus Torvalds
1c63df24be pci-v7.0-fixes-2
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Merge tag 'pci-v7.0-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci

Pull pci fixes from Bjorn Helgaas:

 - Update MAINTAINERS email address (Shawn Guo)

 - Refresh cached Endpoint driver MSI Message Address to fix a v7.0
   regression when kernel changes the address after firmware has
   configured it (Niklas Cassel)

 - Flush Endpoint MSI-X writes so they complete before the outbound ATU
   entry is unmapped (Niklas Cassel)

 - Correct the PCI_CAP_EXP_ENDPOINT_SIZEOF_V2 value, which broke VMM use
   of PCI capabilities (Bjorn Helgaas)

* tag 'pci-v7.0-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
  PCI: Correct PCI_CAP_EXP_ENDPOINT_SIZEOF_V2 value
  PCI: dwc: ep: Flush MSI-X write before unmapping its ATU entry
  PCI: dwc: ep: Refresh MSI Message Address cache on change
  MAINTAINERS: Update Shawn Guo's address for HiSilicon PCIe controller driver
2026-02-27 13:32:52 -08:00
Christian Brauner
10047142d6
Merge patch series "tighten nstree visibility checks"
Christian Brauner <brauner@kernel.org> says:

Listing various namespaces is currently only scoped on owning namespace.
We can make this more fine-grained so that we scope visibility even
tighter. To make it possible to change behavior restrict visibility for
now. This shouldn't be a big deal as there aren't actual large users out
there and paves the way to make this even cleaner in the future.

* patches from https://patch.msgid.link/20260226-work-visibility-fixes-v1-0-d2c2853313bd@kernel.org:
  selftests: fix mntns iteration selftests
  nstree: tighten permission checks for listing
  nsfs: tighten permission checks for handle opening
  nsfs: tighten permission checks for ns iteration ioctls

Link: https://patch.msgid.link/20260226-work-visibility-fixes-v1-0-d2c2853313bd@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-02-27 22:00:19 +01:00
Christian Brauner
4c7b2ec23c
selftests: fix mntns iteration selftests
Now that we changed permission checking make sure that we reflect that
in the selftests.

Link: https://patch.msgid.link/20260226-work-visibility-fixes-v1-4-d2c2853313bd@kernel.org
Fixes: 9d87b10673 ("selftests: add tests for mntns iteration")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Cc: stable@kernel.org # v6.14+
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-02-27 22:00:11 +01:00
Christian Brauner
8d76afe84f
nstree: tighten permission checks for listing
Even privileged services should not necessarily be able to see other
privileged service's namespaces so they can't leak information to each
other. Use may_see_all_namespaces() helper that centralizes this policy
until the nstree adapts.

Link: https://patch.msgid.link/20260226-work-visibility-fixes-v1-3-d2c2853313bd@kernel.org
Fixes: 76b6f5dfb3 ("nstree: add listns()")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Cc: stable@kernel.org # v6.19+
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-02-27 22:00:11 +01:00
Christian Brauner
d2324a9317
nsfs: tighten permission checks for handle opening
Even privileged services should not necessarily be able to see other
privileged service's namespaces so they can't leak information to each
other. Use may_see_all_namespaces() helper that centralizes this policy
until the nstree adapts.

Link: https://patch.msgid.link/20260226-work-visibility-fixes-v1-2-d2c2853313bd@kernel.org
Fixes: 5222470b2f ("nsfs: support file handles")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Cc: stable@kernel.org # v6.18+
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-02-27 22:00:11 +01:00
Christian Brauner
e6b899f080
nsfs: tighten permission checks for ns iteration ioctls
Even privileged services should not necessarily be able to see other
privileged service's namespaces so they can't leak information to each
other. Use may_see_all_namespaces() helper that centralizes this policy
until the nstree adapts.

Link: https://patch.msgid.link/20260226-work-visibility-fixes-v1-1-d2c2853313bd@kernel.org
Fixes: a1d220d9da ("nsfs: iterate through mount namespaces")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Cc: stable@kernel.org # v6.12+
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-02-27 22:00:08 +01:00
Anna Schumaker
4529e00154 NFS: Fix NFS KConfig typos
Two issues were noticed after the NFS v4.0 KConfig changes were merged
upstream. First, the text of CONFIG_NFS_V4 should not encourage people
to select it if they are unsure. Second, the new CONFIG_NFS_V4_0 option
should default to "on" instead of "off" to avoid breaking people's
setups if they are using NFS v4.0.

Reported-by: Niklas Cassel <cassel@kernel.org>
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Fixes: 4e02693525 ("NFS: Add a way to disable NFS v4.0 via KConfig")
Fixes: 7537db2480 ("NFS: Merge CONFIG_NFS_V4_1 with CONFIG_NFS_V4")
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2026-02-27 15:42:14 -05:00
Eric Badger
7b6275c80a xprtrdma: Decrement re_receiving on the early exit paths
In the event that rpcrdma_post_recvs() fails to create a work request
(due to memory allocation failure, say) or otherwise exits early, we
should decrement ep->re_receiving before returning. Otherwise we will
hang in rpcrdma_xprt_drain() as re_receiving will never reach zero and
the completion will never be triggered.

On a system with high memory pressure, this can appear as the following
hung task:

    INFO: task kworker/u385:17:8393 blocked for more than 122 seconds.
          Tainted: G S          E       6.19.0 #3
    "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    task:kworker/u385:17 state:D stack:0     pid:8393  tgid:8393  ppid:2      task_flags:0x4248060 flags:0x00080000
    Workqueue: xprtiod xprt_autoclose [sunrpc]
    Call Trace:
     <TASK>
     __schedule+0x48b/0x18b0
     ? ib_post_send_mad+0x247/0xae0 [ib_core]
     schedule+0x27/0xf0
     schedule_timeout+0x104/0x110
     __wait_for_common+0x98/0x180
     ? __pfx_schedule_timeout+0x10/0x10
     wait_for_completion+0x24/0x40
     rpcrdma_xprt_disconnect+0x444/0x460 [rpcrdma]
     xprt_rdma_close+0x12/0x40 [rpcrdma]
     xprt_autoclose+0x5f/0x120 [sunrpc]
     process_one_work+0x191/0x3e0
     worker_thread+0x2e3/0x420
     ? __pfx_worker_thread+0x10/0x10
     kthread+0x10d/0x230
     ? __pfx_kthread+0x10/0x10
     ret_from_fork+0x273/0x2b0
     ? __pfx_kthread+0x10/0x10
     ret_from_fork_asm+0x1a/0x30

Fixes: 15788d1d10 ("xprtrdma: Do not refresh Receive Queue while it is draining")
Signed-off-by: Eric Badger <ebadger@purestorage.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2026-02-27 15:42:14 -05:00
Armin Wolf
591230c6f2 ACPI: OSL: Poweroff when encountering a fatal ACPI error
The ACPI spec states that the operating system should respond
to a fatal ACPI error by "performing a controlled OS shutdown in
a timely fashion". Comply with the ACPI specification by powering
off the system when ACPICA signals a fatal ACPI error. Users can
still disable this behavior by using the acpi.poweroff_on_fatal
kernel option to work around firmware bugs.

Link: https://uefi.org/specs/ACPI/6.6/19_ASL_Reference.html#fatal-fatal-error-check
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
[ rjw: Dropped the new Kconfig option, adjusted header file inclusions ]
Link: https://patch.msgid.link/20260204212931.3860-1-W_Armin@gmx.de
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2026-02-27 21:24:41 +01:00
Vijay Sundar Selvamani
aef50ed5b2 vfio/qat: extend Kconfig dependencies for 420xx and 6xxx devices
Currently, the QAT VFIO PCI driver can only be configured when the 4xxx
QAT driver (CRYPTO_DEV_QAT_4XXX) is enabled. This is too restrictive as
the VFIO driver also supports VFs from the 420xx and 6xxx device
families, which share a compatible migration interface.

Extends the Kconfig dependencies to allow configuration when any of the
supported QAT device families (4xxx, 420xx, or 6xxx) are enabled.

Signed-off-by: Vijay Sundar Selvamani <vijay.sundar.selvamani@intel.com>
Signed-off-by: Suman Kumar Chakraborty <suman.kumar.chakraborty@intel.com>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Link: https://lore.kernel.org/r/20260213091403.72338-1-suman.kumar.chakraborty@intel.com
Signed-off-by: Alex Williamson <alex@shazbot.org>
2026-02-27 12:52:36 -07:00
Sumit Gupta
856250ba2e cpufreq: CPPC: Add sysfs documentation for perf_limited
Add ABI documentation for the Performance Limited Register sysfs
interface in the cppc_cpufreq driver.

Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Pierre Gondois <pierre.gondois@arm.com>
Reviewed-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Link: https://patch.msgid.link/20260206142658.72583-8-sumitg@nvidia.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2026-02-27 20:50:42 +01:00