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Before the access to struct batadv_tvlv_mcast_tracker's num_dests, it is
attempted to check whether enough space is actually in the network header.
But instead of using offsetofend() to check for the whole size (2) which
must be accessible, offsetof() of is called. The latter is always returning
0. The comparison with the network header length will always return that
enough data is available - even when only 1 or 0 bytes are accessible.
Instead of using offsetofend(), use the more common check for the whole
header.
Cc: stable@vger.kernel.org
Fixes: 07afe1ba288c ("batman-adv: mcast: implement multicast packet reception and forwarding")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
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If the skb has a frag_list, it must be linearized before it can be split
using skb_split(). But when this step failed, it must not only free the skb
but also take care of the reference to the already found primary_if.
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-bot@kernel.org>
Fixes: a063f2fba3fa ("batman-adv: Don't skb_split skbuffs with frag_list")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
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The caller of batadv_frag_send_packet() assume that the skb provided to the
function are always consumed. But the pre-check for an empty payload or the
zero fragment size returned an error without any further actions.
A failed pre-check must use the same error handling code as the rest of the
function.
Cc: stable@vger.kernel.org
Fixes: ee75ed88879a ("batman-adv: Fragment and send skbs larger than mtu")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
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A TT unicast TVLV contains the number of VLANs stored in it. This number is
an u16 and gets multiplied by the size of the struct
batadv_tvlv_tt_vlan_data (8 bytes). The size can therefore overflow the u16
used to store the tt_vlan_len. All additional safety checks to prevent
out-of-bounds access of the TVLV buffer are invalid due to this overflow.
Using size_t prevents this overflow and ensures that the safety checks
compare against the actual buffer requirements.
Cc: stable@vger.kernel.org
Fixes: 7ea7b4a14275 ("batman-adv: make the TT CRC logic VLAN specific")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
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batadv_send_tt_request() allocates a tt_req_node when none exists for the
destination originator node. This should prevent that a multiple TT
requests are send at the same time to an originator.
But if allocation of the send buffer failed, this request must be cleaned
up again. But indicator for such a failure is "ret == false". But the
actual implementation is checking for "ret == true".
The check must be inverted to not loose the information about the TT
request directly after it was attempted to be sent out. This should avoid
potential request storms.
Cc: stable@vger.kernel.org
Fixes: 335fbe0f5d25 ("batman-adv: tvlv - convert tt query packet to use tvlv unicast packets")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
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When an mesh interface is registered, it creates an untagged struct
batadv_meshif_vlan on top of it via the NETDEV_REGISTER notifier. But in
this process, another receiver of this notification can veto the
registration. The netdev registration will be aborted because of this veto.
The register_netdevice() call will try to clean up the net_device using
unregister_netdevice_queue() - which only uses the .priv_destructor to
free private resources. In this situation, .dellink will not be called.
The cleanup of the untagged batadv_meshif_vlan must thefore be done in the
destructor to avoid a leak of this object.
Cc: stable@vger.kernel.org
Fixes: 5d2c05b21337 ("batman-adv: add per VLAN interface attribute framework")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
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llc_ui_autobind() opens a SAP after choosing a dynamic LSAP.
llc_sap_open() returns a reference owned by the caller, and
llc_sap_add_socket() takes a second reference for the socket's
membership in the SAP hash tables.
llc_ui_bind() drops the caller's reference after adding the socket,
but llc_ui_autobind() keeps it. When the socket is closed,
llc_sap_remove_socket() releases only the socket reference, leaving
the SAP on llc_sap_list with sk_count == 0.
This is user-visible because repeated autobind and close cycles can consume
all dynamic SAP values and make later autobinds fail with -EUSERS.
Drop the caller's reference after a successful autobind, matching
llc_ui_bind()'s ownership model.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Shuangpeng Bai <shuangpeng.kernel@gmail.com>
Link: https://patch.msgid.link/20260630194856.1036497-1-shuangpeng.kernel@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Queue wake, stop, and disable paths walk local->interfaces under RCU.
The bulk hardware teardown path removes entries with list_del(), so an
asynchronous transmit completion can follow a poisoned list node in
ieee802154_wake_queue().
Use list_del_rcu() as in the single-interface removal path. The following
unregister_netdevice() waits for in-flight RCU readers before freeing the
netdevice, so no separate grace-period wait is needed.
Fixes: 592dfbfc72f5 ("mac820154: move interface unregistration into iface")
Reported-by: syzbot+36256deb69a588e9290e@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=36256deb69a588e9290e
Cc: stable@vger.kernel.org
Signed-off-by: Yousef Alhouseen <alhouseenyousef@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://patch.msgid.link/20260701164222.9094-1-alhouseenyousef@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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This is a followup based on sashiko comments [1] on commit e5b811fe7931
("net/sched: sch_teql: Introduce slaves_lock to avoid race condition and UAF")
Use plain rcu_read_lock()/spin_lock() in teql_master_xmit() instead of the
_bh variants, since ndo_start_xmit is already invoked with BH disabled
by the core stack and the _bh primitives can warn in_hardirq() when xmit
is reached through netpoll or a softirq xmit path with hard IRQs disabled.
Moves rcu_read_lock() after restart: label + adds rcu_read_unlock() before
goto restart (fixes the unbounded RCU hold across retries)
[1] https://sashiko.dev/#/patchset/20260628111229.669751-1-jhs%40mojatatu.com
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Fixes: e5b811fe7931 ("net/sched: sch_teql: Introduce slaves_lock to avoid race condition and UAF")
Link: https://patch.msgid.link/20260630150922.238714-1-jhs@mojatatu.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Revision 2 of the CONNMARK target accepts user-controlled shift
parameters and applies them to 32-bit mark values in
connmark_tg_shift().
A shift_bits value of 32 or more triggers an undefined-shift bug when
the rule is evaluated. Invalid shift_dir values are also accepted and
silently fall back to the left-shift path.
Reject invalid revision-2 shift parameters in connmark_tg_check() so
malformed rules fail at installation time, before they can reach the
packet path.
Fixes: 472a73e00757 ("netfilter: xt_conntrack: Support bit-shifting for CONNMARK & MARK targets.")
Reported-by: Yuan Tan <yuantan098@gmail.com>
Reported-by: Zhengchuan Liang <zcliangcn@gmail.com>
Reported-by: Xin Liu <dstsmallbird@foxmail.com>
Assisted-by: Codex:GPT-5.4
Signed-off-by: Wyatt Feng <bronzed_45_vested@icloud.com>
Reviewed-by: Ren Wei <enjou1224z@gmail.com>
Reviewed-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>
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Commit 9a05475cebdd ("ipvs: avoid kmem_cache_zalloc in
ip_vs_conn_new") changed ip_vs_conn_new() to allocate an ip_vs_conn
object with kmem_cache_alloc(). The function then initializes many
fields explicitly, but only resets in_seq.delta and out_seq.delta in the
two struct ip_vs_seq members.
That leaves init_seq and previous_delta uninitialized. This is normally
harmless while the corresponding IP_VS_CONN_F_IN_SEQ or
IP_VS_CONN_F_OUT_SEQ flag is clear. For connections learned from a sync
message, however, ip_vs_proc_conn() preserves those flags from
IP_VS_CONN_F_BACKUP_MASK and passes opt=NULL when the message omits
IPVS_OPT_SEQ_DATA. In that case the new connection can be hashed with
SEQ flags set but with the rest of in_seq/out_seq still containing stale
slab data.
When a packet for such a connection is later handled by an IPVS
application helper, vs_fix_seq() and vs_fix_ack_seq() use
previous_delta and init_seq to rewrite TCP sequence numbers. A malformed
sync message can therefore make forwarded packets carry stale slab bytes
in their TCP seq/ack numbers, and can also corrupt the forwarded TCP
flow.
Reset both struct ip_vs_seq members completely before publishing the
connection. This matches the existing "reset struct ip_vs_seq" comment
and keeps the sequence-adjustment gates inactive unless valid sequence
data is installed later.
Fixes: 9a05475cebdd ("ipvs: avoid kmem_cache_zalloc in ip_vs_conn_new")
Cc: stable@vger.kernel.org
Reported-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Reported-by: Yuxiang Yang <yangyx22@mails.tsinghua.edu.cn>
Reported-by: Ao Wang <wangao@seu.edu.cn>
Reported-by: Xuewei Feng <fengxw06@126.com>
Reported-by: Qi Li <qli01@tsinghua.edu.cn>
Reported-by: Ke Xu <xuke@tsinghua.edu.cn>
Assisted-by: Claude-Code:GLM-5.2
Signed-off-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Signed-off-by: Florian Westphal <fw@strlen.de>
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When an ICMP Fragmentation Needed error is received for a tunneled IPVS
connection, ip_vs_in_icmp() recomputes the MTU that the original packet
can use by subtracting the tunnel overhead from the reported next-hop
MTU.
The current code always subtracts sizeof(struct iphdr), which is only
the IPIP overhead. For GUE and GRE tunnels, ipvs_udp_decap() and
ipvs_gre_decap() already compute the additional tunnel header length,
but that value is scoped to the decapsulation block and is lost before
the ICMP_FRAG_NEEDED handling. As a result, the ICMP error sent back to
the client advertises an MTU that is too large, so PMTUD can fail to
converge for GUE/GRE-tunneled real servers.
With a reported next-hop MTU of 1400, a GUE tunnel currently returns
1380 to the client. The correct value is 1368:
1400 - sizeof(struct iphdr) - sizeof(struct udphdr) -
sizeof(struct guehdr)
Hoist the tunnel header length into the main ip_vs_in_icmp() scope and
subtract sizeof(struct iphdr) + ulen in the Fragmentation Needed path.
The IPIP path keeps ulen as 0, so its existing 1400 - 20 = 1380 result
is unchanged.
Fixes: 508f744c0de3 ("ipvs: strip udp tunnel headers from icmp errors")
Cc: stable@vger.kernel.org
Reported-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Reported-by: Yuxiang Yang <yangyx22@mails.tsinghua.edu.cn>
Reported-by: Ao Wang <wangao@seu.edu.cn>
Reported-by: Xuewei Feng <fengxw06@126.com>
Reported-by: Qi Li <qli01@tsinghua.edu.cn>
Reported-by: Ke Xu <xuke@tsinghua.edu.cn>
Assisted-by: Claude-Code:GLM-5.2
Signed-off-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
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The get command on intervals provide partial matches such as subranges
for usability reasons. However, an open interval has no closing end
element. If the closing element matches within the range of the open
internal, ie. its closest match is the start element of the open range,
then, return 0 but offer no matching element to userspace through
netlink as a special case. Userspace provides at least a matching start
element in this case and the closing end element matching the open
interal is ignored.
Another possibility is to report the matching start element of the open
interval for this end interval. However, this results in duplicated
matching being listed in userspace because userspace does not expect a
start element as response to a end element.
Fixes: 2aa34191f06f ("netfilter: nft_set_rbtree: use binary search array in get command")
Reported-by: Melbin K Mathew <mlbnkm1@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
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The ah, hbh and rt matches check that the fixed extension header is
present, then use the header length field to derive the advertised
extension header length for matching.
For the ah match, add the missing advertised-length check. For hbh
and rt, update the existing advertised-length checks. In all three
cases, set hotdrop to true before returning false when the advertised
extension header length exceeds the available skb data.
Returning false treats the packet as a rule mismatch. Set hotdrop to
true and drop malformed packets so they cannot bypass rules intended
to drop packets with these IPv6 extension headers.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Zhixing Chen <running910@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
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master on updates
Really cap it to NF_CT_EXPECT_MAX_CNT (255) on updates.
The commit ("netfilter: nfnetlink_cthelper: cap to maximum number of
expectation per master") only covers creation of helpers, not updates.
Fixes: 397c8300972f ("netfilter: nf_conntrack_helper: cap maximum number of expectation at helper registration")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
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On links faster than ~34 Gbps, where byte rate may exceed 2^32-1
(~ 4.3 GBps), the comparison result becomes incorrect because the
truncated value no longer reflects the actual estimator rate.
Fix by changing the local variables to u64.
Fixes: 1c0d32fde5bd ("net_sched: gen_estimator: complete rewrite of rate estimators")
Signed-off-by: Feng Wu <wufengwufengwufeng@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
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u32_match_it() executes rule-supplied shift operands on a 32-bit
value. A malformed u32 rule can provide a shift count of 32 or more,
triggering an undefined shift out-of-bounds during packet evaluation.
Validate XT_U32_LEFTSH and XT_U32_RIGHTSH operands in
u32_mt_checkentry() and reject malformed rules before they reach the
packet path.
Fixes: 1b50b8a371e9 ("[NETFILTER]: Add u32 match")
Reported-by: Yuan Tan <yuantan098@gmail.com>
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Reported-by: Zhengchuan Liang <zcliangcn@gmail.com>
Reported-by: Xin Liu <bird@lzu.edu.cn>
Assisted-by: Codex:GPT-5.4
Signed-off-by: Wyatt Feng <bronzed_45_vested@icloud.com>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
Signed-off-by: Florian Westphal <fw@strlen.de>
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quoting sashiko:
------------------------------------------------------------------------
[..] noticed a potential memory bug and header corruption involving the
SIP NAT helper.
In net/netfilter/nf_nat_sip.c:nf_nat_sip():
if (skb_ensure_writable(skb, skb->len)) {
nf_ct_helper_log(skb, ct, "cannot mangle packet");
return NF_DROP;
}
uh = (void *)skb->data + protoff;
uh->dest = ct_sip_info->forced_dport;
if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, protoff,
0, 0, NULL, 0)) {
If a cloned or fragmented SKB is reallocated by skb_ensure_writable(), the
old data buffer is freed. However, nf_nat_sip() fails to update *dptr to
point to the new buffer.
It also appears to use nf_nat_mangle_udp_packet() on what could be a TCP
packet, which would overwrite the sequence number with a checksum update.
------------------------------------------------------------------------
nf_conntrack_sip linerizes skbs, hence no fragmented skb can be seen.
But clones are possible, so rebuild dptr.
Disable nf_nat_mangle_udp_packet() branch for TCP streams.
It doesn't look like this can ever happen, else we should have received
bug reports about this, so just check the conntrack is UDP and drop
otherwise.
The calling conntrack_sip set ->forced_dport for SIP_HDR_VIA_UDP messages,
so I don't think this is ever expected to be true for a TCP stream.
Fixes: 7266507d8999 ("netfilter: nf_ct_sip: support Cisco 7941/7945 IP phones")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-sonnet-4-6
Signed-off-by: Florian Westphal <fw@strlen.de>
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git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux
Pull mod_devicetable.h header split from Uwe Kleine-König:
"Split <linux/mod_devicetable.h> in per subsystem headers
<linux/mod_devicetable.h> is included transitively in nearly every
driver in an x86_64 allmodconfig build of v7.1:
$ find drivers -name \*.o -not -name \*.mod.o | wc -l
21330
$ find drivers -name \*.o.cmd -not -name \*.mod.o.cmd | xargs grep -l mod_devicetable.h | wc -l
17038
The result of this mixture of different and unrelated subsystem
details is that even when touching an obscure device id struct most of
the kernel needs to be recompiled. Given that each driver typically
only needs one or two of these structures, splitting into per
subsystem headers and only including what is really needed reduces the
amount of needed recompilation.
This split is implemented in the first commit and then after some
preparatory work in the following commits, the last two replace
includes of <linux/mod_devicetable.h> by the actually needed more
specific headers.
There are still a few instances left, but the ones with high impact
(that is in headers that are used a lot) and the easy ones (.c files)
are handled. These remaining includes will be addressed during the
next merge window"
* tag 'device-id-rework' of git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux:
Replace <linux/mod_devicetable.h> by more specific <linux/device-id/*.h> (c files)
Replace <linux/mod_devicetable.h> by more specific <linux/device-id/*.h> (headers)
parisc: #include <linux/compiler.h> for unlikely() in <asm/ptrace.h>
media: em28xx: Add include for struct usb_device_id
LoongArch: KVM: Add include defining struct cpu_feature
ALSA: hda/core: Add include defining struct hda_device_id
usb: dwc2: Add include defining struct pci_device_id
platform/x86: int3472: Add include defining struct dmi_system_id
platform/x86: x86-android-tablets: Add include defining struct dmi_system_id
i2c: Let i2c-core.h include <linux/i2c.h>
of: Explicitly include <linux/types.h> and <linux/err.h>
platform/x86: msi-ec: Ensure dmi_system_id is defined
usb: serial: Include <linux/usb.h> in <linux/usb/serial.h>
driver core: platform: Include header for struct platform_device_id
driver: core: Include headers for acpi_device_id and of_device_id for struct device_driver
media: ti: vpe: #include <linux/platform_device.h> explicitly
mod_devicetable.h: Split into per subsystem headers
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files)
Replace the #include of <linux/mod_devicetable.h> by the more specific
<linux/device-id/*.h> where applicable. For most cases the include
can be dropped completely, only a few drivers need one or two headers
added.
Acked-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/1a3f2007c5c5dcf555c09a4035ce3ae8ef1b6c49.1782808461.git.u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
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Pull BPF fixes from Daniel Borkmann:
- Initialize task local storage before fork bails out to free the task
(Jann Horn)
- Fix insn_aux_data leak on verifier error path (KaFai Wan)
- Reject BPF inode storage map creation when BPF LSM is uninitialized
(Matt Bobrowski)
- Mask pseudo pointer values in verifier logs when pointer leaks are
not allowed (Nuoqi Gui)
- Harden BPF JIT against spraying via IBPB flush (Pawan Gupta)
- Reject a skb-modifying SK_SKB stream parser since the latter is only
meant to measure the next message (Sechang Lim)
- Fix bpf_refcount_acquire to reject refcounted allocation arguments
with a non-zero fixed offset (Yiyang Chen)
* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpf: Prefer dirty packs for eBPF allocations
bpf: Prefer packs that won't trigger an IBPB flush on allocation
bpf: Skip redundant IBPB in pack allocator
bpf: Restrict JIT predictor flush to cBPF
x86/bugs: Enable IBPB flush on BPF JIT allocation
bpf: Support for hardening against JIT spraying
bpf: Reject BPF_MAP_TYPE_INODE_STORAGE creation if BPF LSM is uninitialized
bpf,fork: wipe ->bpf_storage before bailouts that access it
bpf: Fix insn_aux_data leak on verifier err_free_env path
selftests/bpf: Cover pseudo-BTF ksym log masking
bpf: Mask pseudo pointer values in verifier logs
selftests/bpf: Cover refcount acquire node offsets
bpf: Reject offset refcount acquire arguments
selftests/bpf: test rejection of a packet-modifying SK_SKB stream parser
bpf, sockmap: reject a packet-modifying SK_SKB stream parser
selftests/bpf: don't modify the skb in the strparser parser prog
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The batadv_skb_set_priority() receives an SKB with the inner ethernet
header at position "offset". When it tries to extract the IPv4 and IPv6
header, it needs to skip the ethernet header to get access to the IP
header.
But for VLAN header, it performs the access with the struct vlan_ethhdr.
This struct contains both both the ethernet header and the VLAN header. It
is therefore incorrect to skip over the whole vlan_ethhdr size to get
access to the vlan_ethhdr.
Cc: stable@vger.kernel.org
Fixes: c54f38c9aa22 ("batman-adv: set skb priority according to content")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Paolo Abeni:
"Including fixes from netfilter and batman-adv.
Current release - new code bugs:
- netfilter: cthelper: cap to maximum number of expectation per master
Previous releases - regressions:
- netpoll: fix a use-after-free on shutdown path
- tcp: restore RCU grace period in tcp_ao_destroy_sock
- ipv6: fix NULL deref in fib6_walk_continiue() on multi-batch dump
- batman-adv: dat: ensure accessible eth_hdr proto field
- eth:
- virtio_net: disable cb when NAPI is busy-polled
- lan743x: Initialize eth_syslock spinlock before use
Previous releases - always broken:
- netfilter:
- nft_set_pipapo: don't leak bad clone into future transaction
- sched:
- sch_teql: Introduce slaves_lock to avoid race condition and UAF
- replace direct dequeue call with peek and qdisc_dequeue_peeked
- sctp: add INIT verification after cookie unpacking
- tipc: fix out-of-bounds read in broadcast Gap ACK blocks
- seg6: validate SRH length before reading fixed fields
- eth:
- mlx5e: fix use-after-free of metadata_dst on RX SC delete
- enetc: check the number of BDs needed for xdp_frame
- fbnic: don't cache shinfo across skb realloc"
* tag 'net-7.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (58 commits)
net/mlx5: HWS, fix matcher leak on resize target setup failure
net/sched: hhf: clear heavy-hitter state on reset
net/sched: dualpi2: clear stale classification on filter miss
net/sched: act_bpf: use rcu_dereference_bh() to read the filter
selftests: drv-net: tso: don't touch dangerous feature bits
cxgb4: Fix decode strings dump for T6 adapters
virtio_net: disable cb when NAPI is busy-polled
sctp: fix addr_wq_timer race in sctp_free_addr_wq()
selftests: net: bump default cmd() timeout to 20 seconds
bridge: stp: Fix a potential use-after-free when deleting a bridge
net/sched: sch_teql: Introduce slaves_lock to avoid race condition and UAF
net: gianfar: dispose irq mappings on probe failure and device removal
net: lan743x: Initialize eth_syslock spinlock before use
net: libwx: fix VMDQ mask for 1-queue mode
net: airoha: fix max receive size configuration
fsl/fman: Free init resources on KeyGen failure in fman_init()
netfilter: nftables: restrict checkum update offset
netfilter: nftables: restrict linklayer and network header writes
netfilter: nfnetlink_queue: restrict writes to network header
netfilter: nft_fib: reject fib expression on the netdev egress hook
...
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As documented in commit 8bd67ebb50c0 ("net: bridge: xmit: make sure we have
at least eth header len bytes"), it is possible by for a local user with
eBPF TC hook access to attach a tc filter which truncates the packet and
redirects to an batadv interface. But the code assumes that at least
ETH_HLEN bytes are available and thus might read outside of the available
buffer.
The batadv_interface_tx() must therefore always check itself if enough data
is available for the ethernet header and don't rely on min_header_len.
Cc: stable@vger.kernel.org
Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
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Simon Wunderlich says:
====================
Here are some batman-adv bugfix, all by Sven Eckelmann:
- fix pointers after potential skb reallocs (5 patches)
- dat: ensure accessible eth_hdr proto field
* tag 'batadv-net-pullrequest-20260630' of https://git.open-mesh.org/batadv:
batman-adv: dat: ensure accessible eth_hdr proto field
batman-adv: bla: reacquire gw address after skb realloc
batman-adv: dat: acquire ARP hw source only after skb realloc
batman-adv: gw: acquire ethernet header only after skb realloc
batman-adv: access unicast_ttvn skb->data only after skb realloc
batman-adv: retrieve ethhdr after potential skb realloc on RX
====================
Link: https://patch.msgid.link/20260630134430.85786-1-sw@simonwunderlich.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf
Florian Westphal says:
====================
netfilter: updates for net
The following patchset contains Netfilter fixes for *net*.
Due to bug volume the plan is to make a second *net* pull request
this Friday.
1) Zero nf_conntrack_expect at allocation to prevent uninitialized data
leaks to userspace. Add missing exp->dir initialization.
2) Prevent out-of-bounds writes in nft_set_pipapo caused by inconsistent
clones during allocation failures. Fail operations if the clone enters an
error state. This was a day-0 bug.
3) Fix use-after-free race between ipset dump and array resizing. Protect
array pointer access with rcu_read_lock(). From Xiang Mei. Bug existed
since v4.20.
4) Validate skb_dst() exists before access in nf_conntrack_sip.
This Prevent crash when called from tc ingress or openvswitch.
From Pablo Neira Ayuso. Bug added in 4.3 when ovs gained support
for conntrack helpers.
5) Cap the maximum number of expectations to NF_CT_EXPECT_MAX_CNT during
userspace helper policy updates. Also from Pablo.
6) Prevent NULL pointer dereference in nft_fib on netdev egress hooks. Add
nft_fib_netdev_validate() to restrict fib expressions to appropriate
netdev hooks. Restrict nft_fib_validate() to IPv4, IPv6, and INET
protocols. From Theodor Arsenij Larionov-Trichkine.
Bug was exposed in v5.16 when egress hooks got added.
7) Restrict nfnetlink_queue writes to network headers. Validate IP/IPv6
header length and disable extension headers or IP option modifications.
Disable bridge modification for now, its unlikely anyone is using this.
8) Restrict arbitrary writes to link-layer and network headers in nftables.
Prevent link-layer modifications from spilling into network headers.
Prevent writes to IP version and length fields.
9) Restrict L3 checksum update offset to IPv4. Else csum offset can be
used to munge arbitrary header offsets, rendering the previous change moot.
These three patches are follow-ups to a 7.1 change that disabled
header rewrite ability in unprivileged network namespaces.
unprivileged netns support is not yet enabled again here.
netfilter pull request nf-26-06-30
* tag 'nf-26-06-30' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
netfilter: nftables: restrict checkum update offset
netfilter: nftables: restrict linklayer and network header writes
netfilter: nfnetlink_queue: restrict writes to network header
netfilter: nft_fib: reject fib expression on the netdev egress hook
netfilter: nfnetlink_cthelper: cap to maximum number of expectation per master
netfilter: nf_conntrack_sip: validate skb_dst() before accessing it
netfilter: ipset: fix race between dump and ip_set_list resize
netfilter: nft_set_pipapo: don't leak bad clone into future transaction
netfilter: nf_conntrack_expect: zero at allocation time
====================
Link: https://patch.msgid.link/20260630045243.2657-1-fw@strlen.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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HHF reset does not clear the classifier state used to identify heavy
hitters. Packets after reset can therefore be scheduled using flow
history from before the reset.
The reset operation should return the qdisc to an empty state.
Clear the heavy-hitter classifier tables when HHF is reset.
Fixes: 10239edf86f1 ("net-qdisc-hhf: Heavy-Hitter Filter (HHF) qdisc")
Assisted-by: Codex:gpt-5.5-cyber-preview
Signed-off-by: Samuel Moelius <sam.moelius@trailofbits.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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DualPI2 leaves previous classification state attached to an skb when
filter classification returns no match. The enqueue path can then act
on stale state from an earlier classification attempt.
A filter miss should fall back to the default class without reusing old
per-packet classification data.
Initialize the classification result to CLASSIC before running the
classifier. Explicit L4S, priority, and successful filter
classification can still override that default.
Fixes: 8f9516daedd6 ("sched: Add enqueue/dequeue of dualpi2 qdisc")
Assisted-by: Codex:gpt-5.5-cyber-preview
Signed-off-by: Samuel Moelius <sam.moelius@trailofbits.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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tcf_bpf_act() can run from the tc egress path, which holds only
rcu_read_lock_bh(), but reads prog->filter with rcu_dereference() and
trips lockdep:
WARNING: suspicious RCU usage
net/sched/act_bpf.c:47 suspicious rcu_dereference_check() usage!
1 lock held by syz.2.1588/12756:
#0: (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit net/core/dev.c:4792
tcf_bpf_act+0x6ae/0x940 net/sched/act_bpf.c:47
tcf_classify+0x6e4/0x1080 net/sched/cls_api.c:1860
sch_handle_egress net/core/dev.c:4545 [inline]
__dev_queue_xmit+0x2185/0x2c00 net/core/dev.c:4808
packet_sendmsg+0x3dfa/0x5120 net/packet/af_packet.c:3114
The other tc actions and cls_bpf already use rcu_dereference_bh() here.
Do the same.
Fixes: 1f211a1b929c ("net, sched: add clsact qdisc")
Signed-off-by: Sechang Lim <rhkrqnwk98@gmail.com>
Reviewed-by: Amery Hung <ameryhung@gmail.com>
Link: https://patch.msgid.link/20260629154112.1164986-1-rhkrqnwk98@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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sctp_free_addr_wq() previously removed addr_wq_timer using timer_delete()
while holding addr_wq_lock. However, timer_delete() does not guarantee that
a currently running timer handler has completed.
This allows a race with sctp_addr_wq_timeout_handler(), where the handler
may still run after addr_waitq has been freed, acquire addr_wq_lock, and
access freed memory, leading to a use-after-free.
Fix this by calling timer_shutdown_sync() before taking addr_wq_lock. This
guarantees that any in-flight timer handler has finished and prevents the
timer from being re-armed during teardown, making subsequent cleanup safe.
Fixes: 4db67e808640 ("sctp: Make the address lists per network namespace")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/5dc95f295bdb5c3f60e880dd9aa5112dc5c071cc.1782757874.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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The three STP timers are not supposed to be armed while the bridge is
administratively down. They are synchronously deactivated when the
bridge is put administratively down and the various call sites check for
'IFF_UP' before arming them.
This check is missing from br_topology_change_detection() and it is
possible to engineer a situation in which the topology change timer is
armed while the bridge is administratively down, resulting in a
use-after-free [1] when the bridge is deleted.
Fix by adding the missing check and for good measures synchronously
shutdown the three timers when the bridge is deleted.
[1]
ODEBUG: free active (active state 0) object: ffff88811662b9b0 object type: timer_list hint: br_topology_change_timer_expired (net/bridge/br_stp_timer.c:120)
WARNING: lib/debugobjects.c:629 at debug_print_object+0x1bc/0x450, CPU#9: ip/359
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Noam Rathaus <noamr@ssd-disclosure.com>
Reported-by: Neil Young <contact@ssd-disclosure.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20260629072117.497959-1-idosch@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
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The teql master->slaves singly linked list is not protected against
multiple writes. It can be mod'ed concurently from teql_master_xmit(),
teql_dequeue(), teql_init() and teql_destroy() without holding any list
lock or RCU protection.
zdi-disclosures@trendmicro.com has demonstrated that the qdisc is freed
after an RCU grace period, but teql_master_xmit() running on another
CPU can still hold a stale pointer into the list, resulting in a
slab-use-after-free:
BUG: KASAN: slab-use-after-free in teql_master_xmit+0xf0f/0x16b0
Read of size 8 at addr ffff888013fb0440 by task poc/332
Freed 512-byte region [ffff888013fb0400, ffff888013fb0600) (kmalloc-512)
The fix?
Add a per-master slaves_lock spinlock that serializes all mutations of
master->slaves and the NEXT_SLAVE() links in teql_destroy() and
teql_qdisc_init(). teql_master_xmit() also takes the same slaves_lock
around those updates.
Annotate master->slaves and the per-slave ->next pointer with __rcu and
use the appropriate RCU accessors everywhere they are touched:
rcu_assign_pointer() on the writer side (under slaves_lock),
rcu_dereference_protected() for the writer-side loads (also under
slaves_lock), rcu_dereference_bh() for the loads in teql_master_xmit() and
rtnl_dereference() for the loads in teql_master_open()/teql_master_mtu(),
which run under RTNL.
Pair this with rcu_read_lock_bh()/rcu_read_unlock_bh() around the list
traversal in teql_master_xmit(), so that readers either observe a fully
linked list or are deferred until the in-flight mutation completes. The two
early-return paths in teql_master_xmit() are updated to release the RCU-bh
read-side critical section before returning, since leaving it held would
disable BH on that CPU for good.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: zdi-disclosures@trendmicro.com
Tested-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20260628111229.669751-1-jhs@mojatatu.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
After previous patch, writes to network header are restricted.
However, there is another way to manipulate the l3 header: The
checksum update function.
Restrict this for network header writes, only the ipv4 header is
allowed. This needs run-time checks because BRIDGE, INET, NETDEV
families can carry l3 headers other than IP.
checksum updates to the udp/tcp (l4) headers are not restricted.
Signed-off-by: Florian Westphal <fw@strlen.de>
|
|
Don't permit arbitrary writes to linklayer and network header data.
Several spots in network stack trust header validation performed in
ipv4/ipv6 before PRE_ROUTING hook.
For linklayer, allow writes for netdev ingress. For other hooks, only
allow link layer writes that do not spill into network header.
For network header, check the offset/length combinations:
- changing dscp requires store at offset 0 for checsum fixups, so
make sure ip version + length field isn't altered.
- ip6 dscp starts directly after the version field, so make sure it
remains 6.
Several of these checks could already be done at rule insertion time.
Risk is that this might cause ruleset load failures for existing
rulesets. With this change such writes are silently skipped and packet
passes unchanged.
Transport and inner header bases are not checked / restricted.
Signed-off-by: Florian Westphal <fw@strlen.de>
|
|
nfnetlink_queue doesn't allow selective replacements of some part of the
payload, only complete replacement.
If the new data is shorter, skb is trimmed, otherwise expanded.
Add minimal validation of the new ip/ipv6 header. Check total len
matches skb length. Disallow ip option modifications.
IPv6 extension headers are also disabled.
IP options and exthdrs could be allowed later after validation pass or
ip option recompile.
Transport header is not checked.
Bridge modifications are rejected. Given userspace doesn't even receive
L2 headers, use is limited and I don't think there are any users of
bridge nfnetlink_queue, let alone users that modifiy payload.
Arp isn't supported at all.
Signed-off-by: Florian Westphal <fw@strlen.de>
|
|
A fib expression in a netdev egress base chain dereferences nft_in(pkt),
NULL on the transmit path, causing a NULL pointer dereference at eval.
nft_fib_validate() masks the hook with NF_INET_* values, but netdev hook
numbers are a separate enum that aliases them (NF_NETDEV_EGRESS ==
NF_INET_LOCAL_IN), so an egress chain passes validation and then faults.
Add nft_fib_netdev_validate() that limits each result/flag to the netdev
hook where the device it reads exists: the input-device cases (OIF,
OIFNAME, ADDRTYPE with F_IIF) to ingress, the output-device case (ADDRTYPE
with F_OIF) to egress, ADDRTYPE with no device flag to both. Also restrict
nft_fib_validate() to NFPROTO_IPV4/IPV6/INET so its NF_INET_* masks are
not applied to another family's hooks.
Fixes: 42df6e1d221d ("netfilter: Introduce egress hook")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/netfilter-devel/ajxsjcDOnwllMfoR@strlen.de/
Signed-off-by: Theodor Arsenij Larionov-Trichkine <theodorlarionov@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
|
|
If userspace helper policy updates sets maximum number of expectation to
zero, cap it to NF_CT_EXPECT_MAX_CNT (255) on updates too.
Fixes: 397c8300972f ("netfilter: nf_conntrack_helper: cap maximum number of expectation at helper registration")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
|
|
tc ingress and openvswitch do not guarantee routing information to be
available. These subsystems use the conntrack helper infrastructure, and
the SIP helper relies on the skb_dst() to be present if
sip_external_media is set to 1 (which is disabled by default as a module
parameter).
This effectively disables the sip_external_media toggle for these
subsystems without resulting in a crash.
Fixes: cae3a2627520 ("openvswitch: Allow attaching helpers to ct action")
Fixes: b57dc7c13ea9 ("net/sched: Introduce action ct")
Cc: stable@vger.kernel.org
Reported-by: Ren Wei <n05ec@lzu.edu.cn>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
|
|
The release path of ip_set_dump_do() and ip_set_dump_done() read
inst->ip_set_list via ip_set_ref_netlink(), a plain rcu_dereference_raw()
of the array pointer. These run from netlink_recvmsg() without the nfnl
mutex and without an RCU read-side critical section.
A concurrent ip_set_create() can grow the array: it publishes the new
array, calls synchronize_net() and then kvfree()s the old one. Since the
dump paths read the array outside any RCU reader, synchronize_net() does
not wait for them and the old array can be freed while they still index
into it, causing a use-after-free.
The dumped set itself stays pinned via set->ref_netlink, so only the
array load needs protecting. Take rcu_read_lock() around it, matching
ip_set_get_byname() and __ip_set_put_byindex().
BUG: KASAN: slab-use-after-free in ip_set_dump_do (net/netfilter/ipset/ip_set_core.c:1697)
Read of size 8 at addr ffff88800b5c4018 by task exploit/150
Call Trace:
...
kasan_report (mm/kasan/report.c:595)
ip_set_dump_do (net/netfilter/ipset/ip_set_core.c:1697)
netlink_dump (net/netlink/af_netlink.c:2325)
netlink_recvmsg (net/netlink/af_netlink.c:1976)
sock_recvmsg (net/socket.c:1159)
__sys_recvfrom (net/socket.c:2315)
...
Oops: general protection fault, probably for non-canonical address ... KASAN NOPTI
KASAN: maybe wild-memory-access in range [0x02d6...d0-0x02d6...d7]
RIP: 0010:ip_set_dump_do (net/netfilter/ipset/ip_set_core.c:1698)
Kernel panic - not syncing: Fatal exception
Fixes: 8a02bdd50b2e ("netfilter: ipset: Fix calling ip_set() macro at dumping")
Cc: stable@vger.kernel.org
Reported-by: Weiming Shi <bestswngs@gmail.com>
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
|
|
On memory allocation failure the cloned nft_pipapo_match can enter a bad
state:
- some fields can have their lookup tables resized while others did
not
- bits might have been toggled
- scratch map can be undersized which also means m->bsize_max can be
lower than what is required
This means that the next insertion in the same batch can trigger
out-of-bounds writes.
Furthermore, a failure in the first can result in the bad clone to
leak into the next transaction because the abort callback is never
executed in this case (the upper layer saw an error and no attempt to
allocate a transactional request was made).
Record a state for the nft_pipapo_match structure:
- NEW (pristine clone)
- MOD (modified clone with good state)
- ERR (potentially bogus content)
Then make it so that deletes and insertions fail when the clone
entered ERR state.
In case the very first insert attempt results in an error, free the
clone right away.
Fixes: 3c4287f62044 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Cc: stable@vger.kernel.org
Reported-and-tested-by: Seesee <cjc000013@gmail.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
|
|
There are occasional LLM hints wrt. leaking uninitialized data to
userspace via ctnetlink. Just zero at allocation time,
expectations are not frequently used these days.
Intentionally keeps _init as-is because we could theoretically
support re-init, so add the missing exp->dir there.
Signed-off-by: Florian Westphal <fw@strlen.de>
|
|
inet6_dump_fib() saves its progress in cb->args[1] as a positional
index within the current hash chain. Between batches, a concurrent
fib6_new_table() can insert a new table at the chain head, shifting
all existing entries. The saved index then lands on a different
table, causing fib6_dump_table() to set w->root to the wrong table
while w->node still points into the previous one.
fib6_walk_continue() dereferences w->node->parent (NULL) and panics:
BUG: kernel NULL pointer dereference, address: 0000000000000008
RIP: 0010:fib6_walk_continue+0x6e/0x170
Call Trace:
<TASK>
fib6_dump_table.isra.0+0xc5/0x240
inet6_dump_fib+0xf6/0x420
rtnl_dumpit+0x30/0xa0
netlink_dump+0x15b/0x460
netlink_recvmsg+0x1d6/0x2a0
____sys_recvmsg+0x17a/0x190
Fix by storing tb->tb6_id in cb->args[1] instead of a positional
index. On resume, skip entries until the id matches; a concurrent
head-insert can never match the saved id, so the walker always
resumes on the correct table.
Fixes: 1b43af5480c3 ("[IPV6]: Increase number of possible routing tables to 2^32")
Signed-off-by: Pengfei Zhang <zhangfeionline@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260625070517.965597-1-zhangfeionline@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
In case of early freeing an unwanted TCP-MD5 key on TCP-AO connect(),
md5sig_info is freed right away (and set to NULL). Later, at
the moment of socket destruction, the static branch counter
is not getting decremented.
Add a missing decrement for TCP-MD5 static branch.
Reported-by: Qihang <q.h.hack.winter@gmail.com>
Fixes: 0aadc73995d0 ("net/tcp: Prevent TCP-MD5 with TCP-AO being set")
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://patch.msgid.link/20260625-tcp-md5-connect-v3-3-1fd313d6c1e0@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
The md5+ao reconciliation in tcp_connect() (net/ipv4/tcp_output.c)
has two symmetric branches:
if (needs_md5) {
tcp_ao_destroy_sock(sk, false);
} else if (needs_ao) {
tcp_clear_md5_list(sk);
kfree(rcu_replace_pointer(tp->md5sig_info, NULL, ...));
}
Both branches free a per-socket auth-info object while the socket is
in TCP_SYN_SENT and is already on the inet ehash (inserted by
inet_hash_connect() in tcp_v4_connect()). Both branches are reachable
by softirq RX-path readers that load the corresponding info pointer
via implicit RCU before bh_lock_sock_nested() is taken.
The needs_md5 branch is fixed in the prior patch by re-introducing
the call_rcu() free in tcp_ao_destroy_sock(): the equivalent per-key
loop runs inside tcp_ao_info_free_rcu(), the RCU callback, so by the
time it frees each tcp_ao_key all softirq readers that captured the
container have already completed rcu_read_unlock().
The needs_ao branch is not symmetric in the same way. The container
free can be deferred via kfree_rcu(md5sig, rcu) -- struct
tcp_md5sig_info already has the required rcu member
(include/net/tcp.h:1999-2002), and the rest of the tree already does
this in the tcp_md5sig_info_add() rollback paths
(net/ipv4/tcp_ipv4.c:1410, 1436). But the per-key teardown is done
by tcp_clear_md5_list() in process context BEFORE the container's
RCU grace period: it walks &md5sig->head and frees each
tcp_md5sig_key with bare hlist_del + kfree. A concurrent softirq
reader in __tcp_md5_do_lookup() / __tcp_md5_do_lookup_exact()
(tcp_ipv4.c:1253, 1298) walks the same list via
hlist_for_each_entry_rcu() and races with that bare kfree on the
keys themselves -- a per-key slab use-after-free of the same class
as the TCP-AO bug, on the same race window.
Fix this in two halves:
1. Convert the bare kfree() in tcp_connect() to kfree_rcu() so the
md5sig_info container joins the rest of the md5sig lifecycle.
The local-variable lift is mechanical and required because
kfree_rcu() is a macro that expects an lvalue.
2. Make tcp_clear_md5_list() RCU-safe by replacing hlist_del +
kfree(key) with hlist_del_rcu + kfree_rcu(key, rcu). struct
tcp_md5sig_key already carries the rcu member
(include/net/tcp.h:1995) and tcp_md5_do_del()
(net/ipv4/tcp_ipv4.c:1456) already uses kfree_rcu, so this
restores the lifecycle invariant the rest of the file follows
rather than introducing a one-off.
The other caller of tcp_clear_md5_list() is tcp_md5_destruct_sock()
(net/ipv4/tcp.c:412), which runs from the sock destructor when the
socket is already unhashed and unreachable; the extra grace period
there is unnecessary but harmless. Making the helper unconditionally
RCU-safe is the cleaner contract.
The needs_ao branch is not reachable by the userns reproducer used
to demonstrate the AO-side splat (the repro installs both keys but
ends up in the needs_md5 branch because the connect peer matches
the MD5 key, not the AO key); however the symmetric race exists
and a maintainer touching this code should not have to think about
which branch escapes RCU and which one does not.
Fixes: 51e547e8c89c ("tcp: Free TCP-AO/TCP-MD5 info/keys without RCU")
Cc: stable@vger.kernel.org # v6.18+
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Reviewed-by: Dmitry Safonov <dima@arista.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
[also credits to Qihang, who found that this races with tcp-diag]
Reported-by: Qihang <q.h.hack.winter@gmail.com>
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://patch.msgid.link/20260625-tcp-md5-connect-v3-2-1fd313d6c1e0@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Commit 51e547e8c89c ("tcp: Free TCP-AO/TCP-MD5 info/keys without RCU")
removed the call_rcu() callback from tcp_ao_destroy_sock(), arguing that
"the destruction of info/keys is delayed until the socket destructor"
and therefore "no one can discover it anymore".
That argument does not hold for the call site in tcp_connect()
(net/ipv4/tcp_output.c:4327-4332). At that point the socket is in
TCP_SYN_SENT, has already been inserted into the inet ehash by
inet_hash_connect() in tcp_v4_connect(), and is therefore very much
discoverable: any softirq running tcp_v4_rcv() on another CPU can take
the socket out of the ehash, walk into tcp_inbound_hash(), and load
tp->ao_info via implicit RCU before bh_lock_sock_nested() is taken on
the destroying CPU.
The reader path then enters __tcp_ao_do_lookup() (net/ipv4/tcp_ao.c:208)
which re-loads tp->ao_info via rcu_dereference_check(); the re-load can
still observe the (about-to-be-freed) pointer because there is no
synchronize_rcu() between rcu_assign_pointer(tp->ao_info, NULL) and
tcp_ao_info_free() in tcp_ao_destroy_sock(). The captured pointer is
then walked at line 223:
hlist_for_each_entry_rcu(key, &ao->head, node, ...)
The writer's synchronous kfree() is free to complete between the line
218 re-fetch and the line 223 hlist iteration. The slab is reused
(or simply LIST_POISON1-stamped if not yet reused) and the iteration
walks attacker-controlled or poison memory in softirq context.
Reproducer (no debug shim, stock x86_64 v7.1-rc2 SMP+KASAN, QEMU+KVM):
an unprivileged uid=1000 process inside CLONE_NEWUSER|CLONE_NEWNET
installs TCP_MD5SIG + TCP_AO_ADD_KEY on a TCP socket, sprays forged
TCP-AO segments toward its eventual 4-tuple via raw sockets, then
calls connect(). The md5-wins reconciliation in tcp_connect() fires
tcp_ao_destroy_sock(); the softirq backlog reader on the loopback
NAPI path crashes on the freed ao->head.first walk:
Oops: general protection fault, probably for non-canonical
address 0xfbd59c000000002f
KASAN: maybe wild-memory-access in range
[0xdead000000000178-0xdead00000000017f]
CPU: 0 UID: 1000 PID: 100 Comm: repro_userns
RIP: 0010:__tcp_ao_do_lookup+0x107/0x1c0
Call Trace: <IRQ>
__tcp_ao_do_lookup+0x107/0x1c0
tcp_ao_inbound_lookup.constprop.0+0x12a/0x200
tcp_inbound_ao_hash+0x5ea/0x1520
tcp_inbound_hash+0x7ce/0x1240
tcp_v4_rcv+0x1e7a/0x3e10
...
Restore the RCU grace period: re-add struct rcu_head to tcp_ao_info
and replace the synchronous tcp_ao_info_free() with a call_rcu()
callback. Readers that captured tp->ao_info before rcu_assign_pointer
NULLed it now see the object remain valid until rcu_read_unlock().
With the patch applied the reproducer runs cleanly for 2000 iterations
on the same kernel build.
Fixes: 51e547e8c89c ("tcp: Free TCP-AO/TCP-MD5 info/keys without RCU")
Cc: stable@vger.kernel.org # v6.18+
Reviewed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://patch.msgid.link/20260625-tcp-md5-connect-v3-1-1fd313d6c1e0@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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A broadcast PROTOCOL/STATE_MSG can carry a Gap ACK blocks record in its
data area. tipc_get_gap_ack_blks() only verifies that the record's len
field is self-consistent with its ugack_cnt/bgack_cnt counts
(sz == struct_size(p, gacks, ugack_cnt + bgack_cnt)); it does not check
that the record actually fits in the message data area, msg_data_sz().
The unicast caller tipc_link_proto_rcv() bounds it ("if (glen > dlen)
break;"), but the broadcast caller tipc_bcast_sync_rcv() discards the
returned size, so tipc_link_advance_transmq() copies the record off the
receive skb with an attacker-controlled count:
this_ga = kmemdup(ga, struct_size(ga, gacks, ga->bgack_cnt),
GFP_ATOMIC);
A TIPC neighbour that negotiated TIPC_GAP_ACK_BLOCK triggers it with one
ordinary broadcast STATE_MSG (msg_bc_ack_invalid() clear), sized so its
data area is short, carrying a Gap ACK record with len = 0x400,
bgack_cnt = 0xff and ugack_cnt = 0. len then equals
struct_size(p, gacks, 255), so the consistency check passes and ga is
non-NULL; kmemdup() reads struct_size(ga, gacks, 255) = 1024 bytes out
of the much smaller skb:
BUG: KASAN: slab-out-of-bounds in kmemdup_noprof+0x48/0x60
Read of size 1024 at addr ffff0000c7030d38 by task poc864/69
Call trace:
kmemdup_noprof+0x48/0x60
tipc_link_advance_transmq+0x86c/0xb80
tipc_link_bc_ack_rcv+0x19c/0x1e0
tipc_bcast_sync_rcv+0x1c4/0x2c4
tipc_rcv+0x85c/0x1340
tipc_l2_rcv_msg+0xac/0x104
The buggy address belongs to the object at ffff0000c7030d00
which belongs to the cache skbuff_small_head of size 704
The buggy address is located 56 bytes inside of
allocated 704-byte region [ffff0000c7030d00, ffff0000c7030fc0)
The copied-out bytes are subsequently consumed as gap/ack values, but
the read is already out of bounds at the kmemdup() regardless of how
they are used.
The unicast STATE path drops such a message: "if (glen > dlen) break;"
skips the rest of STATE_MSG handling and the skb is freed. Make the
broadcast path drop it too. tipc_bcast_sync_rcv() now bounds the record
against msg_data_sz() and, when it does not fit, reports it back through
tipc_node_bc_sync_rcv() to tipc_rcv() so the skb is discarded rather than
processed. ga is not cleared on this path: ga == NULL already means
"legacy peer without Selective ACK", a distinct legitimate state.
Fixes: d7626b5acff9 ("tipc: introduce Gap ACK blocks for broadcast link")
Cc: stable@vger.kernel.org
Signed-off-by: Samuel Page <sam@bynar.io>
Reviewed-by: Tung Nguyen <tung.quang.nguyen@est.tech>
Link: https://patch.msgid.link/20260625143815.1525412-1-sam@bynar.io
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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When batadv_get_vid() accesses the proto field of the ethernet header, it
is not checking if the data itself is accessible. The caller is responsible
for it. But in contrast to other call sites, batadv_dat_get_vid() and its
caller didn't make sure this is true. This could have caused an
out-of-bounds access.
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-bot@kernel.org>
Fixes: be1db4f6615b ("batman-adv: make the Distributed ARP Table vlan aware")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
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The pskb_may_pull() called by batadv_bla_is_backbone_gw() could reallocate
the buffer behind the skb. Variables which were pointing to the old buffer
need to be reassigned to avoid an use-after-free.
Cc: stable@vger.kernel.org
Fixes: 9e794b6bf4a2 ("batman-adv: drop unicast packets from other backbone gw")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
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The pskb_may_pull() called by batadv_get_vid() could reallocate the buffer
behind the skb. Variables which were pointing to the old buffer need to be
reassigned to avoid an use-after-free.
Cc: stable@vger.kernel.org
Fixes: b61ec31c8575 ("batman-adv: Snoop DHCPACKs for DAT")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
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The pskb_may_pull() called by batadv_get_vid() could reallocate the buffer
behind the skb. Variables which were pointing to the old buffer need to be
reassigned to avoid an use-after-free.
Cc: stable@vger.kernel.org
Fixes: 6c413b1c22a2 ("batman-adv: send every DHCP packet as bat-unicast")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
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