linux-stable.git/net, branch v6.18.39 Linux kernel stable tree Bluetooth: 6lowpan: Fix using chan->conn as indication to no remote netdev 2026-07-18T14:53:36+00:00 Luiz Augusto von Dentz luiz.von.dentz@intel.com 2026-06-12T14:21:09+00:00 1c56c46519353112005c248982a7074c63da4926 commit d38eaf611839b85ade3dd3db309dbc8aaaaf0095 upstream. b66774b48dd9 ("Bluetooth: L2CAP: Fix UAF in channel timeout by holding conn ref") don't reset the chan->conn to NULL anymore making the bt# netdev not be remove once the last l2cap_chan_del is removed. Instead of restoring the original behavior this remove the logic of keeping the interface after the last channel is removed because it never worked as intended and the l2cap_chan_del always detach its l2cap_conn which results in always removing the channel anyway. Fixes: b66774b48dd9 ("Bluetooth: L2CAP: Fix UAF in channel timeout by holding conn ref") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d38eaf611839b85ade3dd3db309dbc8aaaaf0095 upstream.

b66774b48dd9 ("Bluetooth: L2CAP: Fix UAF in channel timeout by holding
conn ref") don't reset the chan->conn to NULL anymore making the bt#
netdev not be remove once the last l2cap_chan_del is removed.

Instead of restoring the original behavior this remove the logic of
keeping the interface after the last channel is removed because it
never worked as intended and the l2cap_chan_del always detach its
l2cap_conn which results in always removing the channel anyway.

Fixes: b66774b48dd9 ("Bluetooth: L2CAP: Fix UAF in channel timeout by holding conn ref")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bluetooth: L2CAP: validate option length before reading conf opt value 2026-07-18T14:53:17+00:00 Muhammad Bilal meatuni001@gmail.com 2026-06-20T19:56:35+00:00 73abbaf91aa33da87c008fb62c148ade561bb606 commit 687617555cedfb74c9e3cb85d759b908dcb17856 upstream. l2cap_get_conf_opt() derives the option length from the attacker-controlled opt->len field and immediately dereferences opt->val (as u8, get_unaligned_le16() or get_unaligned_le32(), or a raw pointer for the default case) before any caller has confirmed that opt->len bytes are present in the buffer. The callers (l2cap_parse_conf_req(), l2cap_parse_conf_rsp() and l2cap_conf_rfc_get()) only detect a malformed option afterwards, once the running length has gone negative, by which point the out-of-bounds read has already executed. An existing post-hoc length check keeps the garbage value from being consumed, so this is not a data leak in the current control flow. It is still a validate-after-use ordering bug: up to 4 bytes are read past the end of the buffer before it is known to contain them, and it is fragile to future changes in the callers. Fix it at the source. Pass the end of the buffer into l2cap_get_conf_opt() and refuse to touch opt->val unless the full option (header + value) fits. Each caller computes an end pointer once before the loop and checks the return value directly instead of inferring the error from a negative length. Fixes: 7c9cbd0b5e38 ("Bluetooth: Verify that l2cap_get_conf_opt provides large enough buffer") Cc: stable@vger.kernel.org Signed-off-by: Muhammad Bilal <meatuni001@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 687617555cedfb74c9e3cb85d759b908dcb17856 upstream.

l2cap_get_conf_opt() derives the option length from the
attacker-controlled opt->len field and immediately dereferences
opt->val (as u8, get_unaligned_le16() or get_unaligned_le32(), or a
raw pointer for the default case) before any caller has confirmed
that opt->len bytes are present in the buffer. The callers
(l2cap_parse_conf_req(), l2cap_parse_conf_rsp() and
l2cap_conf_rfc_get()) only detect a malformed option afterwards, once
the running length has gone negative, by which point the
out-of-bounds read has already executed.

An existing post-hoc length check keeps the garbage value from being
consumed, so this is not a data leak in the current control flow. It
is still a validate-after-use ordering bug: up to 4 bytes are read
past the end of the buffer before it is known to contain them, and it
is fragile to future changes in the callers.

Fix it at the source. Pass the end of the buffer into
l2cap_get_conf_opt() and refuse to touch opt->val unless the full
option (header + value) fits. Each caller computes an end pointer
once before the loop and checks the return value directly instead of
inferring the error from a negative length.

Fixes: 7c9cbd0b5e38 ("Bluetooth: Verify that l2cap_get_conf_opt provides large enough buffer")
Cc: stable@vger.kernel.org
Signed-off-by: Muhammad Bilal <meatuni001@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bluetooth: L2CAP: cancel pending_rx_work before taking conn->lock 2026-07-18T14:53:17+00:00 Runyu Xiao runyu.xiao@seu.edu.cn 2026-06-17T15:36:13+00:00 d5616beb3355b5fca2280d796c1cf7ada4ee6551 commit 2641a9e0a1dd4af2e21995470a21d55dd35e5203 upstream. l2cap_conn_del() takes conn->lock and then calls cancel_work_sync() for pending_rx_work. process_pending_rx() takes the same mutex, so teardown can deadlock against the worker it is flushing. This issue was found by our static analysis tool and then manually reviewed against the current tree. The grounded PoC kept the l2cap_conn_ready() -> queue_work(..., &conn->pending_rx_work) submit path, the l2cap_conn_del() -> cancel_work_sync(&conn->pending_rx_work) teardown path, and the process_pending_rx() -> mutex_lock(&conn->lock) worker edge. Lockdep reported: WARNING: possible circular locking dependency detected process_pending_rx+0x21/0x2a [vuln_msv] l2cap_conn_del.constprop.0+0x3f/0x4e [vuln_msv] *** DEADLOCK *** Cancel pending_rx_work before taking conn->lock, matching the existing lock-before-drain ordering used for the two delayed works in the same teardown path. The pending_rx queue is still purged after the work has been cancelled and conn->lock has been acquired. Fixes: 7ab56c3a6ecc ("Bluetooth: Fix deadlock in l2cap_conn_del()") Cc: stable@vger.kernel.org Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2641a9e0a1dd4af2e21995470a21d55dd35e5203 upstream.

l2cap_conn_del() takes conn->lock and then calls cancel_work_sync() for
pending_rx_work.  process_pending_rx() takes the same mutex, so teardown
can deadlock against the worker it is flushing.

This issue was found by our static analysis tool and then manually
reviewed against the current tree.

The grounded PoC kept the l2cap_conn_ready() -> queue_work(...,
&conn->pending_rx_work) submit path, the l2cap_conn_del() ->
cancel_work_sync(&conn->pending_rx_work) teardown path, and the
process_pending_rx() -> mutex_lock(&conn->lock) worker edge.  Lockdep
reported:

  WARNING: possible circular locking dependency detected
  process_pending_rx+0x21/0x2a [vuln_msv]
  l2cap_conn_del.constprop.0+0x3f/0x4e [vuln_msv]
  *** DEADLOCK ***

Cancel pending_rx_work before taking conn->lock, matching the existing
lock-before-drain ordering used for the two delayed works in the same
teardown path.  The pending_rx queue is still purged after the work has
been cancelled and conn->lock has been acquired.

Fixes: 7ab56c3a6ecc ("Bluetooth: Fix deadlock in l2cap_conn_del()")
Cc: stable@vger.kernel.org
Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bluetooth: ISO: avoid NULL deref of conn in iso_conn_big_sync() 2026-07-18T14:53:17+00:00 Muhammad Bilal meatuni001@gmail.com 2026-06-21T16:23:05+00:00 b84eeb7636d6962dd882d5e0b31475e4f404313c commit d5541eb148da72d5e0a1bca8ecd171f9fc8b366f upstream. iso_conn_big_sync() drops the socket lock to call hci_get_route() and then re-acquires it, but dereferences iso_pi(sk)->conn->hcon afterwards without re-checking that conn is still valid. While the lock is dropped, the connection can be torn down under the same socket lock: iso_disconn_cfm() -> iso_conn_del() -> iso_chan_del() sets iso_pi(sk)->conn to NULL (and the broadcast teardown path can also clear conn->hcon on its own). When iso_conn_big_sync() re-acquires the lock and reads conn->hcon, conn may be NULL, causing a NULL pointer dereference (hcon is the first member of struct iso_conn). This path is reached from iso_sock_recvmsg() for a PA-sync broadcast sink socket (BT_SK_DEFER_SETUP | BT_SK_PA_SYNC), so the dropped-lock window can race with connection teardown driven by controller events. Re-validate iso_pi(sk)->conn and its hcon after re-acquiring the socket lock and bail out if the connection went away, as already done in the sibling iso_sock_rebind_bc(). Fixes: 7a17308c17880d ("Bluetooth: iso: Fix circular lock in iso_conn_big_sync") Cc: stable@vger.kernel.org Signed-off-by: Muhammad Bilal <meatuni001@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d5541eb148da72d5e0a1bca8ecd171f9fc8b366f upstream.

iso_conn_big_sync() drops the socket lock to call hci_get_route() and
then re-acquires it, but dereferences iso_pi(sk)->conn->hcon afterwards
without re-checking that conn is still valid.

While the lock is dropped, the connection can be torn down under the
same socket lock: iso_disconn_cfm() -> iso_conn_del() -> iso_chan_del()
sets iso_pi(sk)->conn to NULL (and the broadcast teardown path can also
clear conn->hcon on its own). When iso_conn_big_sync() re-acquires the
lock and reads conn->hcon, conn may be NULL, causing a NULL pointer
dereference (hcon is the first member of struct iso_conn).

This path is reached from iso_sock_recvmsg() for a PA-sync broadcast
sink socket (BT_SK_DEFER_SETUP | BT_SK_PA_SYNC), so the dropped-lock
window can race with connection teardown driven by controller events.

Re-validate iso_pi(sk)->conn and its hcon after re-acquiring the socket
lock and bail out if the connection went away, as already done in the
sibling iso_sock_rebind_bc().

Fixes: 7a17308c17880d ("Bluetooth: iso: Fix circular lock in iso_conn_big_sync")
Cc: stable@vger.kernel.org
Signed-off-by: Muhammad Bilal <meatuni001@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bluetooth: hci_conn: Fix null ptr deref in hci_abort_conn() 2026-07-18T14:53:17+00:00 Siwei Zhang oss@fourdim.xyz 2026-06-15T15:33:05+00:00 61701912c58a05f6a043f097cc177a964abef348 commit 12917f591cea1af36087dba5b9ec888652f0b42a upstream. hci_abort_conn() read hci_skb_event(hdev->sent_cmd) when a connection was pending, but hdev->sent_cmd can be NULL while req_status is still HCI_REQ_PEND, leading to a NULL pointer dereference and a general protection fault from the hci_rx_work() receive path. Instead of inspecting hdev->sent_cmd, track the in-flight create connection command with a new per-connection HCI_CONN_CREATE flag and route all cancellation through hci_cancel_connect_sync(), which dispatches to a dedicated per-type cancel function. The create command is in exactly one of two states: still queued, or in flight. The cancel function holds cmd_sync_work_lock across the whole decision: the worker takes this lock to dequeue every entry, so while it is held a queued command cannot start running and an in-flight command cannot complete and let the next command become pending. This keeps the flag test and hci_cmd_sync_cancel() atomic with respect to the worker, so a queued command is simply dequeued, and an in-flight command owned by this connection is cancelled without the risk of cancelling an unrelated command that became pending in the meantime. CIS uses the same flag mechanism via HCI_CONN_CREATE_CIS but cannot be dequeued per-connection. hci_acl_create_conn_sync() and hci_le_create_conn_sync() clear HCI_CONN_CREATE after the create command completes, but the command status handler can free conn via hci_conn_del() (for example when the controller rejects the connection) while the worker is still blocked on the connection complete event. Hold a reference on conn across the create command so the flag can be cleared without a use-after-free. Fixes: a13f316e90fd ("Bluetooth: hci_conn: Consolidate code for aborting connections") Cc: stable@vger.kernel.org Suggested-by: XIAO WU <xiaowu.417@qq.com> Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Siwei Zhang <oss@fourdim.xyz> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 12917f591cea1af36087dba5b9ec888652f0b42a upstream.

hci_abort_conn() read hci_skb_event(hdev->sent_cmd) when a connection
was pending, but hdev->sent_cmd can be NULL while req_status is still
HCI_REQ_PEND, leading to a NULL pointer dereference and a general
protection fault from the hci_rx_work() receive path.

Instead of inspecting hdev->sent_cmd, track the in-flight create
connection command with a new per-connection HCI_CONN_CREATE flag and
route all cancellation through hci_cancel_connect_sync(), which
dispatches to a dedicated per-type cancel function. The create command
is in exactly one of two states: still queued, or in flight. The cancel
function holds cmd_sync_work_lock across the whole decision: the worker
takes this lock to dequeue every entry, so while it is held a queued
command cannot start running and an in-flight command cannot complete
and let the next command become pending. This keeps the flag test and
hci_cmd_sync_cancel() atomic with respect to the worker, so a queued
command is simply dequeued, and an in-flight command owned by this
connection is cancelled without the risk of cancelling an unrelated
command that became pending in the meantime. CIS uses the same flag
mechanism via HCI_CONN_CREATE_CIS but cannot be dequeued per-connection.

hci_acl_create_conn_sync() and hci_le_create_conn_sync() clear
HCI_CONN_CREATE after the create command completes, but the command
status handler can free conn via hci_conn_del() (for example when the
controller rejects the connection) while the worker is still blocked on
the connection complete event. Hold a reference on conn across the
create command so the flag can be cleared without a use-after-free.

Fixes: a13f316e90fd ("Bluetooth: hci_conn: Consolidate code for aborting connections")
Cc: stable@vger.kernel.org
Suggested-by: XIAO WU <xiaowu.417@qq.com>
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Siwei Zhang <oss@fourdim.xyz>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bluetooth: fix UAF in bt_accept_dequeue() 2026-07-18T14:53:17+00:00 Yousef Alhouseen alhouseenyousef@gmail.com 2026-06-28T00:23:05+00:00 26168db1ce5a9766cde021b18e590a101c056614 commit 4bd0b274054f2679f28b70222b607bb0afc3ab9a upstream. bt_accept_get() takes a temporary reference before dropping the accept queue lock. bt_accept_dequeue() currently drops that reference before bt_accept_unlink(), leaving only the queue reference. bt_accept_unlink() drops the queue reference. The subsequent sock_hold() therefore accesses freed memory if it was the final reference, as observed by KASAN during listening L2CAP socket cleanup. Retain the temporary queue-walk reference through unlink and hand it to the caller on success. Drop it explicitly on the closed and not-yet-connected paths. Fixes: ab1513597c6c ("Bluetooth: fix UAF in l2cap_sock_cleanup_listen() vs l2cap_conn_del()") Reported-by: syzbot+674ff7e4d7fdfd572afc@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=674ff7e4d7fdfd572afc Cc: stable@vger.kernel.org Signed-off-by: Yousef Alhouseen <alhouseenyousef@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4bd0b274054f2679f28b70222b607bb0afc3ab9a upstream.

bt_accept_get() takes a temporary reference before dropping the accept
queue lock. bt_accept_dequeue() currently drops that reference before
bt_accept_unlink(), leaving only the queue reference.

bt_accept_unlink() drops the queue reference. The subsequent
sock_hold() therefore accesses freed memory if it was the final
reference, as observed by KASAN during listening L2CAP socket cleanup.

Retain the temporary queue-walk reference through unlink and hand it to
the caller on success. Drop it explicitly on the closed and
not-yet-connected paths.

Fixes: ab1513597c6c ("Bluetooth: fix UAF in l2cap_sock_cleanup_listen() vs l2cap_conn_del()")
Reported-by: syzbot+674ff7e4d7fdfd572afc@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=674ff7e4d7fdfd572afc
Cc: stable@vger.kernel.org
Signed-off-by: Yousef Alhouseen <alhouseenyousef@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bluetooth: bnep: pin L2CAP connection during netdev registration 2026-07-18T14:53:17+00:00 Yousef Alhouseen alhouseenyousef@gmail.com 2026-06-28T00:50:58+00:00 a6b22dbd80926556290ad2243be25218d6956a19 commit bb067a99a0356196c0b89a95721985485ebce5a5 upstream. bnep_add_connection() reads the L2CAP connection without holding the channel lock, then passes its HCI device to register_netdev(). Controller teardown can clear and release that connection concurrently, leaving the network device registration path to dereference a freed parent device. Take a reference to the L2CAP connection while holding the channel lock. Retain it until register_netdev() has taken the parent device reference. Fixes: 65f53e9802db ("Bluetooth: Access BNEP session addresses through L2CAP channel") Reported-by: syzbot+fed5dce4553262f3b35c@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=fed5dce4553262f3b35c Cc: stable@vger.kernel.org Signed-off-by: Yousef Alhouseen <alhouseenyousef@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit bb067a99a0356196c0b89a95721985485ebce5a5 upstream.

bnep_add_connection() reads the L2CAP connection without holding the
channel lock, then passes its HCI device to register_netdev(). Controller
teardown can clear and release that connection concurrently, leaving the
network device registration path to dereference a freed parent device.

Take a reference to the L2CAP connection while holding the channel lock.
Retain it until register_netdev() has taken the parent device reference.

Fixes: 65f53e9802db ("Bluetooth: Access BNEP session addresses through L2CAP channel")
Reported-by: syzbot+fed5dce4553262f3b35c@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=fed5dce4553262f3b35c
Cc: stable@vger.kernel.org
Signed-off-by: Yousef Alhouseen <alhouseenyousef@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netfilter: flowtable: fix offloaded ct timeout never being extended 2026-07-18T14:53:17+00:00 Adrian Bente adibente@gmail.com 2026-05-28T07:08:51+00:00 81a5971cbe18b474b49c651e32f2194b2fb171fe commit 53b3e60edb674b442b2b3bbdba484667b0f47a5d upstream. OpenWrt has recently migrated many platforms to kernel 6.18. On the MediaTek platform, which supports hardware network offloading, WiFi connections accelerated via the WED path were observed to drop after roughly 300 seconds. After several debugging sessions, assisted by the Claude LLM, the problem was narrowed down as follows: nf_flow_table_extend_ct_timeout() extends ct->timeout for offloaded flows using: cmpxchg(&ct->timeout, expires, new_timeout); 'expires' comes from nf_ct_expires(ct) and is a relative value, while ct->timeout holds an absolute timestamp. The two are never equal, so the cmpxchg always fails and the timeout is never extended. This goes unnoticed for most flows, but a long-lived hardware (WED) offloaded flow on MediaTek MT7986 eventually has ct->timeout decay to zero, the conntrack entry is reaped and the connection breaks. Open-code the relative value from a single READ_ONCE(ct->timeout) snapshot and compare against that same absolute snapshot in the cmpxchg, so the timeout extension actually takes effect while the datapath remains authoritative if it updates ct->timeout concurrently. Fixes: 03428ca5cee9 ("netfilter: conntrack: rework offload nf_conn timeout extension logic") Cc: stable@vger.kernel.org Suggested-by: Florian Westphal <fw@strlen.de> Signed-off-by: Adrian Bente <adibente@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 53b3e60edb674b442b2b3bbdba484667b0f47a5d upstream.

OpenWrt has recently migrated many platforms to kernel 6.18. On the
MediaTek platform, which supports hardware network offloading, WiFi
connections accelerated via the WED path were observed to drop after
roughly 300 seconds.

After several debugging sessions, assisted by the Claude LLM, the
problem was narrowed down as follows:

nf_flow_table_extend_ct_timeout() extends ct->timeout for offloaded
flows using:

	cmpxchg(&ct->timeout, expires, new_timeout);

'expires' comes from nf_ct_expires(ct) and is a relative value, while
ct->timeout holds an absolute timestamp. The two are never equal, so
the cmpxchg always fails and the timeout is never extended.

This goes unnoticed for most flows, but a long-lived hardware (WED)
offloaded flow on MediaTek MT7986 eventually has ct->timeout decay to
zero, the conntrack entry is reaped and the connection breaks.

Open-code the relative value from a single READ_ONCE(ct->timeout)
snapshot and compare against that same absolute snapshot in the
cmpxchg, so the timeout extension actually takes effect while the
datapath remains authoritative if it updates ct->timeout concurrently.

Fixes: 03428ca5cee9 ("netfilter: conntrack: rework offload nf_conn timeout extension logic")
Cc: stable@vger.kernel.org
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Adrian Bente <adibente@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netfilter: ebtables: terminate table name before find_table_lock() 2026-07-18T14:53:17+00:00 Xiang Mei xmei5@asu.edu 2026-07-05T21:58:00+00:00 6fe8d3cecd20bfaaaf440db3a06ba674d2f2e322 commit a622d2e9608c9dff47fc2e5759ac7aa3a836b45d upstream. update_counters() and compat_update_counters() forward a user-supplied 32-byte table name to find_table_lock() without NUL-terminating it. On a lookup miss, find_inlist_lock() calls try_then_request_module(..., "%s%s", "ebtable_", name), and vsnprintf() reads past the name field and the stack object until it hits a zero byte. BUG: KASAN: stack-out-of-bounds in string (lib/vsprintf.c:648 lib/vsprintf.c:730) Read of size 1 at addr ffff8880119dfb20 by task exploit/147 Call Trace: ... string (lib/vsprintf.c:648 lib/vsprintf.c:730) vsnprintf (lib/vsprintf.c:2945) __request_module (kernel/module/kmod.c:150) do_update_counters.isra.0 (net/bridge/netfilter/ebtables.c:371 net/bridge/netfilter/ebtables.c:380) update_counters (net/bridge/netfilter/ebtables.c:1440) do_ebt_set_ctl (net/bridge/netfilter/ebtables.c:2573) nf_setsockopt (net/netfilter/nf_sockopt.c:101) ip_setsockopt (net/ipv4/ip_sockglue.c:1424) raw_setsockopt (net/ipv4/raw.c:847) __sys_setsockopt (net/socket.c:2393) ... compat_do_replace() shares the same unterminated name via compat_copy_ebt_replace_from_user(); terminate it there too so all find_table_lock() callers behave alike. The other callers already terminate the name after the copy. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Fixes: 81e675c227ec ("netfilter: ebtables: add CONFIG_COMPAT support") 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> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit a622d2e9608c9dff47fc2e5759ac7aa3a836b45d upstream.

update_counters() and compat_update_counters() forward a user-supplied
32-byte table name to find_table_lock() without NUL-terminating it. On a
lookup miss, find_inlist_lock() calls try_then_request_module(..., "%s%s",
"ebtable_", name), and vsnprintf() reads past the name field and the
stack object until it hits a zero byte.

  BUG: KASAN: stack-out-of-bounds in string (lib/vsprintf.c:648 lib/vsprintf.c:730)
  Read of size 1 at addr ffff8880119dfb20 by task exploit/147
  Call Trace:
  ...
   string (lib/vsprintf.c:648 lib/vsprintf.c:730)
   vsnprintf (lib/vsprintf.c:2945)
   __request_module (kernel/module/kmod.c:150)
   do_update_counters.isra.0 (net/bridge/netfilter/ebtables.c:371 net/bridge/netfilter/ebtables.c:380)
   update_counters (net/bridge/netfilter/ebtables.c:1440)
   do_ebt_set_ctl (net/bridge/netfilter/ebtables.c:2573)
   nf_setsockopt (net/netfilter/nf_sockopt.c:101)
   ip_setsockopt (net/ipv4/ip_sockglue.c:1424)
   raw_setsockopt (net/ipv4/raw.c:847)
   __sys_setsockopt (net/socket.c:2393)
  ...

compat_do_replace() shares the same unterminated name via
compat_copy_ebt_replace_from_user(); terminate it there too so all
find_table_lock() callers behave alike. The other callers already
terminate the name after the copy.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Fixes: 81e675c227ec ("netfilter: ebtables: add CONFIG_COMPAT support")
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>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netfilter: ebtables: module names must be null-terminated 2026-07-18T14:53:16+00:00 Florian Westphal fw@strlen.de 2026-07-04T10:05:15+00:00 13a5f532e3a4fc75c33060a026def1572c208643 commit 084d23f818321390509e9738a0b08bbf46df6425 upstream. We need to explicitly check the length, else we may pass non-null terminated string to request_module(). Cc: stable@vger.kernel.org Fixes: bcf493428840 ("netfilter: ebtables: Fix extension lookup with identical name") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 084d23f818321390509e9738a0b08bbf46df6425 upstream.

We need to explicitly check the length, else we may pass non-null
terminated string to request_module().

Cc: stable@vger.kernel.org
Fixes: bcf493428840 ("netfilter: ebtables: Fix extension lookup with identical name")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>