In the Linux kernel, the following vulnerability has been resolved: RDMA/bnxt_re: Fix the page details for the srq created by kernel consumers While using nvme target with use_srq on, below kernel panic is noticed. [ 549.698111] bnxt_en 0000:41:00.0 enp65s0np0: FEC autoneg off encoding: Clause 91 RS(544,514) [ 566.393619] Oops: divide error: 0000 [#1] PREEMPT SMP NOPTI .. [ 566.393799] <TASK> [ 566.393807] ? __die_body+0x1a/0x60 [ 566.393823] ? die+0x38/0x60 [ 566.393835] ? do_trap+0xe4/0x110 [ 566.393847] ? bnxt_qplib_alloc_init_hwq+0x1d4/0x580 [bnxt_re] [ 566.393867] ? bnxt_qplib_alloc_init_hwq+0x1d4/0x580 [bnxt_re] [ 566.393881] ? do_error_trap+0x7c/0x120 [ 566.393890] ? bnxt_qplib_alloc_init_hwq+0x1d4/0x580 [bnxt_re] [ 566.393911] ? exc_divide_error+0x34/0x50 [ 566.393923] ? bnxt_qplib_alloc_init_hwq+0x1d4/0x580 [bnxt_re] [ 566.393939] ? asm_exc_divide_error+0x16/0x20 [ 566.393966] ? bnxt_qplib_alloc_init_hwq+0x1d4/0x580 [bnxt_re] [ 566.393997] bnxt_qplib_create_srq+0xc9/0x340 [bnxt_re] [ 566.394040] bnxt_re_create_srq+0x335/0x3b0 [bnxt_re] [ 566.394057] ? srso_return_thunk+0x5/0x5f [ 566.394068] ? __init_swait_queue_head+0x4a/0x60 [ 566.394090] ib_create_srq_user+0xa7/0x150 [ib_core] [ 566.394147] nvmet_rdma_queue_connect+0x7d0/0xbe0 [nvmet_rdma] [ 566.394174] ? lock_release+0x22c/0x3f0 [ 566.394187] ? srso_return_thunk+0x5/0x5f Page size and shift info is set only for the user space SRQs. Set page size and page shift for kernel space SRQs also.
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix WARNING "do not call blocking ops when !TASK_RUNNING" wait_event_timeout() will set the state of the current task to TASK_UNINTERRUPTIBLE, before doing the condition check. This means that ksmbd_durable_scavenger_alive() will try to acquire the mutex while already in a sleeping state. The scheduler warns us by giving the following warning: do not call blocking ops when !TASK_RUNNING; state=2 set at [<0000000061515a6f>] prepare_to_wait_event+0x9f/0x6c0 WARNING: CPU: 2 PID: 4147 at kernel/sched/core.c:10099 __might_sleep+0x12f/0x160 mutex lock is not needed in ksmbd_durable_scavenger_alive().
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix null pointer dereference in destroy_previous_session If client set ->PreviousSessionId on kerberos session setup stage, NULL pointer dereference error will happen. Since sess->user is not set yet, It can pass the user argument as NULL to destroy_previous_session. sess->user will be set in ksmbd_krb5_authenticate(). So this patch move calling destroy_previous_session() after ksmbd_krb5_authenticate().
In the Linux kernel, the following vulnerability has been resolved: nfsd: decrease sc_count directly if fail to queue dl_recall A deadlock warning occurred when invoking nfs4_put_stid following a failed dl_recall queue operation: T1 T2 nfs4_laundromat nfs4_get_client_reaplist nfs4_anylock_blockers __break_lease spin_lock // ctx->flc_lock spin_lock // clp->cl_lock nfs4_lockowner_has_blockers locks_owner_has_blockers spin_lock // flctx->flc_lock nfsd_break_deleg_cb nfsd_break_one_deleg nfs4_put_stid refcount_dec_and_lock spin_lock // clp->cl_lock When a file is opened, an nfs4_delegation is allocated with sc_count initialized to 1, and the file_lease holds a reference to the delegation. The file_lease is then associated with the file through kernel_setlease. The disassociation is performed in nfsd4_delegreturn via the following call chain: nfsd4_delegreturn --> destroy_delegation --> destroy_unhashed_deleg --> nfs4_unlock_deleg_lease --> kernel_setlease --> generic_delete_lease The corresponding sc_count reference will be released after this disassociation. Since nfsd_break_one_deleg executes while holding the flc_lock, the disassociation process becomes blocked when attempting to acquire flc_lock in generic_delete_lease. This means: 1) sc_count in nfsd_break_one_deleg will not be decremented to 0; 2) The nfs4_put_stid called by nfsd_break_one_deleg will not attempt to acquire cl_lock; 3) Consequently, no deadlock condition is created. Given that sc_count in nfsd_break_one_deleg remains non-zero, we can safely perform refcount_dec on sc_count directly. This approach effectively avoids triggering deadlock warnings.
In the Linux kernel, the following vulnerability has been resolved: uio_hv_generic: Let userspace take care of interrupt mask Remove the logic to set interrupt mask by default in uio_hv_generic driver as the interrupt mask value is supposed to be controlled completely by the user space. If the mask bit gets changed by the driver, concurrently with user mode operating on the ring, the mask bit may be set when it is supposed to be clear, and the user-mode driver will miss an interrupt which will cause a hang. For eg- when the driver sets inbound ring buffer interrupt mask to 1, the host does not interrupt the guest on the UIO VMBus channel. However, setting the mask does not prevent the host from putting a message in the inbound ring buffer. So let’s assume that happens, the host puts a message into the ring buffer but does not interrupt. Subsequently, the user space code in the guest sets the inbound ring buffer interrupt mask to 0, saying “Hey, I’m ready for interrupts”. User space code then calls pread() to wait for an interrupt. Then one of two things happens: * The host never sends another message. So the pread() waits forever. * The host does send another message. But because there’s already a message in the ring buffer, it doesn’t generate an interrupt. This is the correct behavior, because the host should only send an interrupt when the inbound ring buffer transitions from empty to not-empty. Adding an additional message to a ring buffer that is not empty is not supposed to generate an interrupt on the guest. Since the guest is waiting in pread() and not removing messages from the ring buffer, the pread() waits forever. This could be easily reproduced in hv_fcopy_uio_daemon if we delay setting interrupt mask to 0. Similarly if hv_uio_channel_cb() sets the interrupt_mask to 1, there’s a race condition. Once user space empties the inbound ring buffer, but before user space sets interrupt_mask to 0, the host could put another message in the ring buffer but it wouldn’t interrupt. Then the next pread() would hang. Fix these by removing all instances where interrupt_mask is changed, while keeping the one in set_event() unchanged to enable userspace control the interrupt mask by writing 0/1 to /dev/uioX.
The igmp_heard_query function in net/ipv4/igmp.c in the Linux kernel before 3.2.1 allows remote attackers to cause a denial of service (divide-by-zero error and panic) via IGMP packets.
The NFSv2/NFSv3 server in the nfsd subsystem in the Linux kernel through 4.10.11 allows remote attackers to cause a denial of service (system crash) via a long RPC reply, related to net/sunrpc/svc.c, fs/nfsd/nfs3xdr.c, and fs/nfsd/nfsxdr.c.
In the Linux kernel, the following vulnerability has been resolved: mptcp: avoid deadlock on fallback while reinjecting Jakub reported an MPTCP deadlock at fallback time: WARNING: possible recursive locking detected 6.18.0-rc7-virtme #1 Not tainted -------------------------------------------- mptcp_connect/20858 is trying to acquire lock: ff1100001da18b60 (&msk->fallback_lock){+.-.}-{3:3}, at: __mptcp_try_fallback+0xd8/0x280 but task is already holding lock: ff1100001da18b60 (&msk->fallback_lock){+.-.}-{3:3}, at: __mptcp_retrans+0x352/0xaa0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&msk->fallback_lock); lock(&msk->fallback_lock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by mptcp_connect/20858: #0: ff1100001da18290 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x114/0x1bc0 #1: ff1100001db40fd0 (k-sk_lock-AF_INET#2){+.+.}-{0:0}, at: __mptcp_retrans+0x2cb/0xaa0 #2: ff1100001da18b60 (&msk->fallback_lock){+.-.}-{3:3}, at: __mptcp_retrans+0x352/0xaa0 stack backtrace: CPU: 0 UID: 0 PID: 20858 Comm: mptcp_connect Not tainted 6.18.0-rc7-virtme #1 PREEMPT(full) Hardware name: Bochs, BIOS Bochs 01/01/2011 Call Trace: <TASK> dump_stack_lvl+0x6f/0xa0 print_deadlock_bug.cold+0xc0/0xcd validate_chain+0x2ff/0x5f0 __lock_acquire+0x34c/0x740 lock_acquire.part.0+0xbc/0x260 _raw_spin_lock_bh+0x38/0x50 __mptcp_try_fallback+0xd8/0x280 mptcp_sendmsg_frag+0x16c2/0x3050 __mptcp_retrans+0x421/0xaa0 mptcp_release_cb+0x5aa/0xa70 release_sock+0xab/0x1d0 mptcp_sendmsg+0xd5b/0x1bc0 sock_write_iter+0x281/0x4d0 new_sync_write+0x3c5/0x6f0 vfs_write+0x65e/0xbb0 ksys_write+0x17e/0x200 do_syscall_64+0xbb/0xfd0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7fa5627cbc5e Code: 4d 89 d8 e8 14 bd 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 <c9> c3 83 e2 39 83 fa 08 75 e7 e8 13 ff ff ff 0f 1f 00 f3 0f 1e fa RSP: 002b:00007fff1fe14700 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fa5627cbc5e RDX: 0000000000001f9c RSI: 00007fff1fe16984 RDI: 0000000000000005 RBP: 00007fff1fe14710 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff1fe16920 R13: 0000000000002000 R14: 0000000000001f9c R15: 0000000000001f9c The packet scheduler could attempt a reinjection after receiving an MP_FAIL and before the infinite map has been transmitted, causing a deadlock since MPTCP needs to do the reinjection atomically from WRT fallback. Address the issue explicitly avoiding the reinjection in the critical scenario. Note that this is the only fallback critical section that could potentially send packets and hit the double-lock.
In the Linux kernel, the following vulnerability has been resolved: flow_dissector: do not dissect PPPoE PFC frames RFC 2516 Section 7 states that Protocol Field Compression (PFC) is NOT RECOMMENDED for PPPoE. In practice, pppd does not support negotiating PFC for PPPoE sessions, and the flow dissector driver has assumed an uncompressed frame until the blamed commit. During the review process of that commit [1], support for PFC is suggested. However, having a compressed (1-byte) protocol field means the subsequent PPP payload is shifted by one byte, causing 4-byte misalignment for the network header and an unaligned access exception on some architectures. The exception can be reproduced by sending a PPPoE PFC frame to an ethernet interface of a MIPS board, with RPS enabled, even if no PPPoE session is active on that interface: $ 0 : 00000000 80c40000 00000000 85144817 $ 4 : 00000008 00000100 80a75758 81dc9bb8 $ 8 : 00000010 8087ae2c 0000003d 00000000 $12 : 000000e0 00000039 00000000 00000000 $16 : 85043240 80a75758 81dc9bb8 00006488 $20 : 0000002f 00000007 85144810 80a70000 $24 : 81d1bda0 00000000 $28 : 81dc8000 81dc9aa8 00000000 805ead08 Hi : 00009d51 Lo : 2163358a epc : 805e91f0 __skb_flow_dissect+0x1b0/0x1b50 ra : 805ead08 __skb_get_hash_net+0x74/0x12c Status: 11000403 KERNEL EXL IE Cause : 40800010 (ExcCode 04) BadVA : 85144817 PrId : 0001992f (MIPS 1004Kc) Call Trace: [<805e91f0>] __skb_flow_dissect+0x1b0/0x1b50 [<805ead08>] __skb_get_hash_net+0x74/0x12c [<805ef330>] get_rps_cpu+0x1b8/0x3fc [<805fca70>] netif_receive_skb_list_internal+0x324/0x364 [<805fd120>] napi_complete_done+0x68/0x2a4 [<8058de5c>] mtk_napi_rx+0x228/0xfec [<805fd398>] __napi_poll+0x3c/0x1c4 [<805fd754>] napi_threaded_poll_loop+0x234/0x29c [<805fd848>] napi_threaded_poll+0x8c/0xb0 [<80053544>] kthread+0x104/0x12c [<80002bd8>] ret_from_kernel_thread+0x14/0x1c Code: 02d51821 1060045b 00000000 <8c640000> 3084000f 2c820005 144001a2 00042080 8e220000 To reduce the attack surface and maintain performance, do not process PPPoE PFC frames. [1] https://lore.kernel.org/r/20220630231016.GA392@debian.home
In the Linux kernel, the following vulnerability has been resolved: btrfs: only release the dirty pages io tree after successful writes [WARNING] With extra warning on dirty extent buffers at umount (aka, the next patch in the series), test case generic/388 can trigger the following warning about dirty extent buffers at unmount time: BTRFS critical (device dm-2 state E): emergency shutdown BTRFS error (device dm-2 state E): error while writing out transaction: -30 BTRFS warning (device dm-2 state E): Skipping commit of aborted transaction. BTRFS error (device dm-2 state EA): Transaction 9 aborted (error -30) BTRFS: error (device dm-2 state EA) in cleanup_transaction:2068: errno=-30 Readonly filesystem BTRFS info (device dm-2 state EA): forced readonly BTRFS info (device dm-2 state EA): last unmount of filesystem 4fbf2e15-f941-49a0-bc7c-716315d2777c ------------[ cut here ]------------ WARNING: disk-io.c:3311 at invalidate_and_check_btree_folios+0xfd/0x1ca [btrfs], CPU#8: umount/914368 CPU: 8 UID: 0 PID: 914368 Comm: umount Tainted: G OE 7.1.0-rc1-custom+ #372 PREEMPT(full) 2de38db8d1deae71fde295430a0ff3ab98ccf596 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022 RIP: 0010:invalidate_and_check_btree_folios+0xfd/0x1ca [btrfs] Call Trace: <TASK> close_ctree+0x52e/0x574 [btrfs d2f0b1cd330d1287e7a9919d112eadfc0e914efd] generic_shutdown_super+0x89/0x1a0 kill_anon_super+0x16/0x40 btrfs_kill_super+0x16/0x20 [btrfs d2f0b1cd330d1287e7a9919d112eadfc0e914efd] deactivate_locked_super+0x2d/0xb0 cleanup_mnt+0xdc/0x140 task_work_run+0x5a/0xa0 exit_to_user_mode_loop+0x123/0x4b0 do_syscall_64+0x243/0x7c0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 </TASK> ---[ end trace 0000000000000000 ]--- BTRFS warning (device dm-2 state EA): unable to release extent buffer 30539776 owner 9 gen 9 refs 2 flags 0x7 BTRFS warning (device dm-2 state EA): unable to release extent buffer 30621696 owner 257 gen 9 refs 2 flags 0x7 BTRFS warning (device dm-2 state EA): unable to release extent buffer 30638080 owner 258 gen 9 refs 2 flags 0x7 BTRFS warning (device dm-2 state EA): unable to release extent buffer 30654464 owner 7 gen 9 refs 2 flags 0x7 BTRFS warning (device dm-2 state EA): unable to release extent buffer 30703616 owner 2 gen 9 refs 2 flags 0x7 BTRFS warning (device dm-2 state EA): unable to release extent buffer 30720000 owner 10 gen 9 refs 2 flags 0x7 BTRFS warning (device dm-2 state EA): unable to release extent buffer 30736384 owner 4 gen 9 refs 2 flags 0x7 BTRFS warning (device dm-2 state EA): unable to release extent buffer 30752768 owner 11 gen 9 refs 2 flags 0x7 I'm using a stripped down version, which seems to trigger the warning more reliably: _fsstress_pid="" workload() { dmesg -C mkfs.btrfs -f -K $dev > /dev/null echo 1 > /sys/kernel/debug/clear_warn_once mount $dev $mnt $fsstress -w -n 1024 -p 4 -d $mnt & _fsstress_pid=$! sleep 0 $godown $mnt pkill --echo -PIPE fsstress > /dev/null wait $_fsstress_pid unset _fsstress_pid umount $mnt if dmesg | grep -q "WARNING"; then fail fi } for (( i = 0; i < $runtime; i++ )); do echo "=== $i/$runtime ===" workload done [CAUSE] Inside btrfs_write_and_wait_transaction(), we first try to write all dirty ebs, then wait for them to finish. After that we call btrfs_extent_io_tree_release() to free all extent states from dirty_pages io tree. However if we hit an error from btrfs_write_marked_extent(), then we still call btrfs_extent_io_tree_release() to clear that dirty_pages io tree, which may contain dirty records that we haven't yet submitted. Furthermore, the later transaction cleanup path will utilize that dirty_pages io tree to properly cleanup those dirty ebs, but since it's already empty, no dirty ebs are properly cleaned up, thus will later trigger the warnings inside invalidate_btree_folios(). ---truncated---
The dma_rx function in drivers/net/wireless/b43/dma.c in the Linux kernel before 2.6.39 does not properly allocate receive buffers, which allows remote attackers to cause a denial of service (system crash) via a crafted frame.
IBM InfoSphere Information Server 11.7.0.0 through 11.7.1.6 could allow a remote attacker to cause a denial of service due to insufficient validation of incoming request resources.
In the Linux kernel, the following vulnerability has been resolved: neigh: let neigh_xmit take skb ownership neigh_xmit always releases the skb, except when no neighbour table is found. But even the first added user of neigh_xmit (mpls) relied on neigh_xmit to release the skb (or queue it for tx). sashiko reported: If neigh_xmit() is called with an uninitialized neighbor table (for example, NEIGH_ND_TABLE when IPv6 is disabled), it returns -EAFNOSUPPORT and bypasses its internal out_kfree_skb error path. Because the return value of neigh_xmit() is ignored here, does this leak the SKB? Assume full ownership and remove the last code path that doesn't xmit or free skb.
The TCP stack in the Linux kernel 3.x does not properly implement a SYN cookie protection mechanism for the case of a fast network connection, which allows remote attackers to cause a denial of service (CPU consumption) by sending many TCP SYN packets, as demonstrated by an attack against the kernel-3.10.0 package in CentOS Linux 7. NOTE: third parties have been unable to discern any relationship between the GitHub Engineering finding and the Trigemini.c attack code.
The IPv6 implementation in the Linux kernel before 6.3 has a net/ipv6/route.c max_size threshold that can be consumed easily, e.g., leading to a denial of service (network is unreachable errors) when IPv6 packets are sent in a loop via a raw socket.
The br_parse_ip_options function in net/bridge/br_netfilter.c in the Linux kernel before 2.6.39 does not properly initialize a certain data structure, which allows remote attackers to cause a denial of service by leveraging connectivity to a network interface that uses an Ethernet bridge device.
In the Linux kernel, the following vulnerability has been resolved: net, bpf: fix null-ptr-deref in xdp_master_redirect() for down master syzkaller reported a kernel panic in bond_rr_gen_slave_id() reached via xdp_master_redirect(). Full decoded trace: https://syzkaller.appspot.com/bug?extid=80e046b8da2820b6ba73 bond_rr_gen_slave_id() dereferences bond->rr_tx_counter, a per-CPU counter that bonding only allocates in bond_open() when the mode is round-robin. If the bond device was never brought up, rr_tx_counter stays NULL. The XDP redirect path can still reach that code on a bond that was never opened: bpf_master_redirect_enabled_key is a global static key, so as soon as any bond device has native XDP attached, the XDP_TX -> xdp_master_redirect() interception is enabled for every slave system-wide. The path xdp_master_redirect() -> bond_xdp_get_xmit_slave() -> bond_xdp_xmit_roundrobin_slave_get() -> bond_rr_gen_slave_id() then runs against a bond that has no rr_tx_counter and crashes. Fix this in the generic xdp_master_redirect() by refusing to call into the master's ->ndo_xdp_get_xmit_slave() when the master device is not up. IFF_UP is only set after ->ndo_open() has successfully returned, so this reliably excludes masters whose XDP state has not been fully initialized. Drop the frame with XDP_ABORTED so the exception is visible via trace_xdp_exception() rather than silently falling through. This is not specific to bonding: any current or future master that defers XDP state allocation to ->ndo_open() is protected.
In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix "scheduling while atomic" in IPsec MAC address query Fix a "scheduling while atomic" bug in mlx5e_ipsec_init_macs() by replacing mlx5_query_mac_address() with ether_addr_copy() to get the local MAC address directly from netdev->dev_addr. The issue occurs because mlx5_query_mac_address() queries the hardware which involves mlx5_cmd_exec() that can sleep, but it is called from the mlx5e_ipsec_handle_event workqueue which runs in atomic context. The MAC address is already available in netdev->dev_addr, so no need to query hardware. This avoids the sleeping call and resolves the bug. Call trace: BUG: scheduling while atomic: kworker/u112:2/69344/0x00000200 __schedule+0x7ab/0xa20 schedule+0x1c/0xb0 schedule_timeout+0x6e/0xf0 __wait_for_common+0x91/0x1b0 cmd_exec+0xa85/0xff0 [mlx5_core] mlx5_cmd_exec+0x1f/0x50 [mlx5_core] mlx5_query_nic_vport_mac_address+0x7b/0xd0 [mlx5_core] mlx5_query_mac_address+0x19/0x30 [mlx5_core] mlx5e_ipsec_init_macs+0xc1/0x720 [mlx5_core] mlx5e_ipsec_build_accel_xfrm_attrs+0x422/0x670 [mlx5_core] mlx5e_ipsec_handle_event+0x2b9/0x460 [mlx5_core] process_one_work+0x178/0x2e0 worker_thread+0x2ea/0x430
In the Linux kernel, the following vulnerability has been resolved: ipv4: route: Prevent rt_bind_exception() from rebinding stale fnhe The sit driver's packet transmission path calls: sit_tunnel_xmit() -> update_or_create_fnhe(), which lead to fnhe_remove_oldest() being called to delete entries exceeding FNHE_RECLAIM_DEPTH+random. The race window is between fnhe_remove_oldest() selecting fnheX for deletion and the subsequent kfree_rcu(). During this time, the concurrent path's __mkroute_output() -> find_exception() can fetch the soon-to-be-deleted fnheX, and rt_bind_exception() then binds it with a new dst using a dst_hold(). When the original fnheX is freed via RCU, the dst reference remains permanently leaked. CPU 0 CPU 1 __mkroute_output() find_exception() [fnheX] update_or_create_fnhe() fnhe_remove_oldest() [fnheX] rt_bind_exception() [bind dst] RCU callback [fnheX freed, dst leak] This issue manifests as a device reference count leak and a warning in dmesg when unregistering the net device: unregister_netdevice: waiting for sitX to become free. Usage count = N Ido Schimmel provided the simple test validation method [1]. The fix clears 'oldest->fnhe_daddr' before calling fnhe_flush_routes(). Since rt_bind_exception() checks this field, setting it to zero prevents the stale fnhe from being reused and bound to a new dst just before it is freed. [1] ip netns add ns1 ip -n ns1 link set dev lo up ip -n ns1 address add 192.0.2.1/32 dev lo ip -n ns1 link add name dummy1 up type dummy ip -n ns1 route add 192.0.2.2/32 dev dummy1 ip -n ns1 link add name gretap1 up arp off type gretap \ local 192.0.2.1 remote 192.0.2.2 ip -n ns1 route add 198.51.0.0/16 dev gretap1 taskset -c 0 ip netns exec ns1 mausezahn gretap1 \ -A 198.51.100.1 -B 198.51.0.0/16 -t udp -p 1000 -c 0 -q & taskset -c 2 ip netns exec ns1 mausezahn gretap1 \ -A 198.51.100.1 -B 198.51.0.0/16 -t udp -p 1000 -c 0 -q & sleep 10 ip netns pids ns1 | xargs kill ip netns del ns1
net/core/net_namespace.c in the Linux kernel 2.6.32 and earlier does not properly handle a high rate of creation and cleanup of network namespaces, which makes it easier for remote attackers to cause a denial of service (memory consumption) via requests to a daemon that requires a separate namespace per connection, as demonstrated by vsftpd.
In the Linux kernel, the following vulnerability has been resolved: jbd2: avoid bug_on in jbd2_journal_get_create_access() when file system corrupted There's issue when file system corrupted: ------------[ cut here ]------------ kernel BUG at fs/jbd2/transaction.c:1289! Oops: invalid opcode: 0000 [#1] SMP KASAN PTI CPU: 5 UID: 0 PID: 2031 Comm: mkdir Not tainted 6.18.0-rc1-next RIP: 0010:jbd2_journal_get_create_access+0x3b6/0x4d0 RSP: 0018:ffff888117aafa30 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffff88811a86b000 RCX: ffffffff89a63534 RDX: 1ffff110200ec602 RSI: 0000000000000004 RDI: ffff888100763010 RBP: ffff888100763000 R08: 0000000000000001 R09: ffff888100763028 R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000000 R13: ffff88812c432000 R14: ffff88812c608000 R15: ffff888120bfc000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f91d6970c99 CR3: 00000001159c4000 CR4: 00000000000006f0 Call Trace: <TASK> __ext4_journal_get_create_access+0x42/0x170 ext4_getblk+0x319/0x6f0 ext4_bread+0x11/0x100 ext4_append+0x1e6/0x4a0 ext4_init_new_dir+0x145/0x1d0 ext4_mkdir+0x326/0x920 vfs_mkdir+0x45c/0x740 do_mkdirat+0x234/0x2f0 __x64_sys_mkdir+0xd6/0x120 do_syscall_64+0x5f/0xfa0 entry_SYSCALL_64_after_hwframe+0x76/0x7e The above issue occurs with us in errors=continue mode when accompanied by storage failures. There have been many inconsistencies in the file system data. In the case of file system data inconsistency, for example, if the block bitmap of a referenced block is not set, it can lead to the situation where a block being committed is allocated and used again. As a result, the following condition will not be satisfied then trigger BUG_ON. Of course, it is entirely possible to construct a problematic image that can trigger this BUG_ON through specific operations. In fact, I have constructed such an image and easily reproduced this issue. Therefore, J_ASSERT() holds true only under ideal conditions, but it may not necessarily be satisfied in exceptional scenarios. Using J_ASSERT() directly in abnormal situations would cause the system to crash, which is clearly not what we want. So here we directly trigger a JBD abort instead of immediately invoking BUG_ON.
In the Linux kernel, the following vulnerability has been resolved: nfsd: avoid leaking pre-allocated openowner on unconfirmed retry race When find_or_alloc_open_stateowner() encounters an unconfirmed owner, it calls release_openowner() and sets oo = NULL. Control then falls through past the `if (oo)` guard -- which would have freed any pre-allocated `new` -- and unconditionally executes `new = alloc_stateowner(...)`. If `new` was already allocated on a prior iteration, the pointer is silently overwritten and the previous allocation (slab object + owner name buffer) is leaked. This requires a race: two NFSv4.0 OPEN threads with the same owner string, where a concurrent thread inserts a new unconfirmed owner into the hash between retry iterations. The window is narrow but repeatable under adversarial conditions. Fix by adding `goto retry` after `oo = NULL` so the already-allocated `new` is reused on the next iteration rather than overwritten.
A certain Red Hat patch to the sctp_sock_migrate function in net/sctp/socket.c in the Linux kernel before 2.6.21, as used in Red Hat Enterprise Linux (RHEL) 5, allows remote attackers to cause a denial of service (NULL pointer dereference and OOPS) via a crafted SCTP packet.
In the Linux kernel, the following vulnerability has been resolved: ethtool: strset: fix message length calculation Outer nest for ETHTOOL_A_STRSET_STRINGSETS is not accounted for. This may result in ETHTOOL_MSG_STRSET_GET producing a warning like: calculated message payload length (684) not sufficient WARNING: CPU: 0 PID: 30967 at net/ethtool/netlink.c:369 ethnl_default_doit+0x87a/0xa20 and a splat. As usually with such warnings three conditions must be met for the warning to trigger: - there must be no skb size rounding up (e.g. reply_size of 684); - string set must be per-device (so that the header gets populated); - the device name must be at least 12 characters long. all in all with current user space it looks like reading priv flags is the only place this could potentially happen. Or with syzbot :)
Integer underflow in the dccp_parse_options function (net/dccp/options.c) in the Linux kernel before 2.6.33.14 allows remote attackers to cause a denial of service via a Datagram Congestion Control Protocol (DCCP) packet with an invalid feature options length, which triggers a buffer over-read.
Certain WithSecure products allow a remote crash of a scanning engine via unpacking of a PE file. This affects WithSecure Client Security 15, WithSecure Server Security 15, WithSecure Email and Server Security 15, WithSecure Elements Endpoint Protection 17 and later, WithSecure Client Security for Mac 15, WithSecure Elements Endpoint Protection for Mac 17 and later, Linux Security 64 12.0 , Linux Protection 12.0, and WithSecure Atlant (formerly F-Secure Atlant) 1.0.35-1.
In the Linux kernel, the following vulnerability has been resolved: net: sched: fix memory leak in tcindex_partial_destroy_work Syzbot reported memory leak in tcindex_set_parms(). The problem was in non-freed perfect hash in tcindex_partial_destroy_work(). In tcindex_set_parms() new tcindex_data is allocated and some fields from old one are copied to new one, but not the perfect hash. Since tcindex_partial_destroy_work() is the destroy function for old tcindex_data, we need to free perfect hash to avoid memory leak.
CAI Content Credentials is affected by an Improper Input Validation vulnerability that could result in an application denial-of-service. An attacker could exploit this vulnerability to crash the application, leading to a denial-of-service condition. Exploitation of this issue does not require user interaction.
Certain WithSecure products allow Denial of Service via the aepack archive unpack handler. This affects WithSecure Client Security 15, WithSecure Server Security 15, WithSecure Email and Server Security 15, WithSecure Elements Endpoint Protection 17 and later, WithSecure Client Security for Mac 15, WithSecure Elements Endpoint Protection for Mac 17 and later, Linux Security 64 12.0 , Linux Protection 12.0, and WithSecure Atlant (formerly F-Secure Atlant) 1.0.35-1.
CAI Content Credentials is affected by an Improper Input Validation vulnerability that could result in an application denial-of-service. An attacker could exploit this vulnerability to crash the application, leading to a denial-of-service condition. Exploitation of this issue does not require user interaction.
Memory leak in the virtio_gpu_object_create function in drivers/gpu/drm/virtio/virtgpu_object.c in the Linux kernel through 4.11.8 allows attackers to cause a denial of service (memory consumption) by triggering object-initialization failures.
The icmp6_send function in net/ipv6/icmp.c in the Linux kernel through 4.8.12 omits a certain check of the dst data structure, which allows remote attackers to cause a denial of service (panic) via a fragmented IPv6 packet.
Allocation of resources without limits or throttling in .NET allows an unauthorized attacker to deny service over a network.
IBM DB2 for Linux, UNIX and Windows (includes Db2 Connect Server) 10.5, 11.1, and 11.5 is vulnerable to denial of service with a specially crafted RUNSTATS command on an 8TB table. IBM X-Force ID: 264809.
The IP stack in the Linux kernel before 4.6 allows remote attackers to cause a denial of service (stack consumption and panic) or possibly have unspecified other impact by triggering use of the GRO path for packets with tunnel stacking, as demonstrated by interleaved IPv4 headers and GRE headers, a related issue to CVE-2016-7039.
In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: RX, Fix XDP multi-buf frag counting for legacy RQ XDP multi-buf programs can modify the layout of the XDP buffer when the program calls bpf_xdp_pull_data() or bpf_xdp_adjust_tail(). The referenced commit in the fixes tag corrected the assumption in the mlx5 driver that the XDP buffer layout doesn't change during a program execution. However, this fix introduced another issue: the dropped fragments still need to be counted on the driver side to avoid page fragment reference counting issues. Such issue can be observed with the test_xdp_native_adjst_tail_shrnk_data selftest when using a payload of 3600 and shrinking by 256 bytes (an upcoming selftest patch): the last fragment gets released by the XDP code but doesn't get tracked by the driver. This results in a negative pp_ref_count during page release and the following splat: WARNING: include/net/page_pool/helpers.h:297 at mlx5e_page_release_fragmented.isra.0+0x4a/0x50 [mlx5_core], CPU#12: ip/3137 Modules linked in: [...] CPU: 12 UID: 0 PID: 3137 Comm: ip Not tainted 6.19.0-rc3+ #12 NONE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 RIP: 0010:mlx5e_page_release_fragmented.isra.0+0x4a/0x50 [mlx5_core] [...] Call Trace: <TASK> mlx5e_dealloc_rx_wqe+0xcb/0x1a0 [mlx5_core] mlx5e_free_rx_descs+0x7f/0x110 [mlx5_core] mlx5e_close_rq+0x50/0x60 [mlx5_core] mlx5e_close_queues+0x36/0x2c0 [mlx5_core] mlx5e_close_channel+0x1c/0x50 [mlx5_core] mlx5e_close_channels+0x45/0x80 [mlx5_core] mlx5e_safe_switch_params+0x1a5/0x230 [mlx5_core] mlx5e_change_mtu+0xf3/0x2f0 [mlx5_core] netif_set_mtu_ext+0xf1/0x230 do_setlink.isra.0+0x219/0x1180 rtnl_newlink+0x79f/0xb60 rtnetlink_rcv_msg+0x213/0x3a0 netlink_rcv_skb+0x48/0xf0 netlink_unicast+0x24a/0x350 netlink_sendmsg+0x1ee/0x410 __sock_sendmsg+0x38/0x60 ____sys_sendmsg+0x232/0x280 ___sys_sendmsg+0x78/0xb0 __sys_sendmsg+0x5f/0xb0 [...] do_syscall_64+0x57/0xc50 This patch fixes the issue by doing page frag counting on all the original XDP buffer fragments for all relevant XDP actions (XDP_TX , XDP_REDIRECT and XDP_PASS). This is basically reverting to the original counting before the commit in the fixes tag. As frag_page is still pointing to the original tail, the nr_frags parameter to xdp_update_skb_frags_info() needs to be calculated in a different way to reflect the new nr_frags.
crypto/ahash.c in the Linux kernel through 4.10.9 allows attackers to cause a denial of service (API operation calling its own callback, and infinite recursion) by triggering EBUSY on a full queue.
In the Linux kernel, the following vulnerability has been resolved: RDMA/hns: Fix WQ_MEM_RECLAIM warning When sunrpc is used, if a reset triggered, our wq may lead the following trace: workqueue: WQ_MEM_RECLAIM xprtiod:xprt_rdma_connect_worker [rpcrdma] is flushing !WQ_MEM_RECLAIM hns_roce_irq_workq:flush_work_handle [hns_roce_hw_v2] WARNING: CPU: 0 PID: 8250 at kernel/workqueue.c:2644 check_flush_dependency+0xe0/0x144 Call trace: check_flush_dependency+0xe0/0x144 start_flush_work.constprop.0+0x1d0/0x2f0 __flush_work.isra.0+0x40/0xb0 flush_work+0x14/0x30 hns_roce_v2_destroy_qp+0xac/0x1e0 [hns_roce_hw_v2] ib_destroy_qp_user+0x9c/0x2b4 rdma_destroy_qp+0x34/0xb0 rpcrdma_ep_destroy+0x28/0xcc [rpcrdma] rpcrdma_ep_put+0x74/0xb4 [rpcrdma] rpcrdma_xprt_disconnect+0x1d8/0x260 [rpcrdma] xprt_rdma_connect_worker+0xc0/0x120 [rpcrdma] process_one_work+0x1cc/0x4d0 worker_thread+0x154/0x414 kthread+0x104/0x144 ret_from_fork+0x10/0x18 Since QP destruction frees memory, this wq should have the WQ_MEM_RECLAIM.
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix recursive locking in RPC handle list access Since commit 305853cce3794 ("ksmbd: Fix race condition in RPC handle list access"), ksmbd_session_rpc_method() attempts to lock sess->rpc_lock. This causes hung connections / tasks when a client attempts to open a named pipe. Using Samba's rpcclient tool: $ rpcclient //192.168.1.254 -U user%password $ rpcclient $> srvinfo <connection hung here> Kernel side: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:0 state:D stack:0 pid:5021 tgid:5021 ppid:2 flags:0x00200000 Workqueue: ksmbd-io handle_ksmbd_work Call trace: __schedule from schedule+0x3c/0x58 schedule from schedule_preempt_disabled+0xc/0x10 schedule_preempt_disabled from rwsem_down_read_slowpath+0x1b0/0x1d8 rwsem_down_read_slowpath from down_read+0x28/0x30 down_read from ksmbd_session_rpc_method+0x18/0x3c ksmbd_session_rpc_method from ksmbd_rpc_open+0x34/0x68 ksmbd_rpc_open from ksmbd_session_rpc_open+0x194/0x228 ksmbd_session_rpc_open from create_smb2_pipe+0x8c/0x2c8 create_smb2_pipe from smb2_open+0x10c/0x27ac smb2_open from handle_ksmbd_work+0x238/0x3dc handle_ksmbd_work from process_scheduled_works+0x160/0x25c process_scheduled_works from worker_thread+0x16c/0x1e8 worker_thread from kthread+0xa8/0xb8 kthread from ret_from_fork+0x14/0x38 Exception stack(0x8529ffb0 to 0x8529fff8) The task deadlocks because the lock is already held: ksmbd_session_rpc_open down_write(&sess->rpc_lock) ksmbd_rpc_open ksmbd_session_rpc_method down_read(&sess->rpc_lock) <-- deadlock Adjust ksmbd_session_rpc_method() callers to take the lock when necessary.
In the Linux kernel, the following vulnerability has been resolved: libceph: Prevent potential null-ptr-deref in ceph_handle_auth_reply() If a message of type CEPH_MSG_AUTH_REPLY contains a zero value for both protocol and result, this is currently not treated as an error. In case of ac->negotiating == true and ac->protocol > 0, this leads to setting ac->protocol = 0 and ac->ops = NULL. Thereafter, the check for ac->protocol != protocol returns false, and init_protocol() is not called. Subsequently, ac->ops->handle_reply() is called, which leads to a null pointer dereference, because ac->ops is still NULL. This patch changes the check for ac->protocol != protocol to !ac->protocol, as this also includes the case when the protocol was set to zero in the message. This causes the message to be treated as containing a bad auth protocol.
Uncontrolled resource consumption in .NET allows an unauthorized attacker to deny service over a network.
The IP stack in the Linux kernel through 4.8.2 allows remote attackers to cause a denial of service (stack consumption and panic) or possibly have unspecified other impact by triggering use of the GRO path for large crafted packets, as demonstrated by packets that contain only VLAN headers, a related issue to CVE-2016-8666.
In the Linux kernel, the following vulnerability has been resolved: nvmet: avoid recursive nvmet-wq flush in nvmet_ctrl_free nvmet_tcp_release_queue_work() runs on nvmet-wq and can drop the final controller reference through nvmet_cq_put(). If that triggers nvmet_ctrl_free(), the teardown path flushes ctrl->async_event_work on the same nvmet-wq. Call chain: nvmet_tcp_schedule_release_queue() kref_put(&queue->kref, nvmet_tcp_release_queue) nvmet_tcp_release_queue() queue_work(nvmet_wq, &queue->release_work) <--- nvmet_wq process_one_work() nvmet_tcp_release_queue_work() nvmet_cq_put(&queue->nvme_cq) nvmet_cq_destroy() nvmet_ctrl_put(cq->ctrl) nvmet_ctrl_free() flush_work(&ctrl->async_event_work) <--- nvmet_wq Previously Scheduled by :- nvmet_add_async_event queue_work(nvmet_wq, &ctrl->async_event_work); This trips lockdep with a possible recursive locking warning. [ 5223.015876] run blktests nvme/003 at 2026-04-07 20:53:55 [ 5223.061801] loop0: detected capacity change from 0 to 2097152 [ 5223.072206] nvmet: adding nsid 1 to subsystem blktests-subsystem-1 [ 5223.088368] nvmet_tcp: enabling port 0 (127.0.0.1:4420) [ 5223.126086] nvmet: Created discovery controller 1 for subsystem nqn.2014-08.org.nvmexpress.discovery for NQN nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349. [ 5223.128453] nvme nvme1: new ctrl: NQN "nqn.2014-08.org.nvmexpress.discovery", addr 127.0.0.1:4420, hostnqn: nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349 [ 5233.199447] nvme nvme1: Removing ctrl: NQN "nqn.2014-08.org.nvmexpress.discovery" [ 5233.227718] ============================================ [ 5233.231283] WARNING: possible recursive locking detected [ 5233.234696] 7.0.0-rc3nvme+ #20 Tainted: G O N [ 5233.238434] -------------------------------------------- [ 5233.241852] kworker/u192:6/2413 is trying to acquire lock: [ 5233.245429] ffff888111632548 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: touch_wq_lockdep_map+0x26/0x90 [ 5233.251438] but task is already holding lock: [ 5233.255254] ffff888111632548 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: process_one_work+0x5cc/0x6e0 [ 5233.261125] other info that might help us debug this: [ 5233.265333] Possible unsafe locking scenario: [ 5233.269217] CPU0 [ 5233.270795] ---- [ 5233.272436] lock((wq_completion)nvmet-wq); [ 5233.275241] lock((wq_completion)nvmet-wq); [ 5233.278020] *** DEADLOCK *** [ 5233.281793] May be due to missing lock nesting notation [ 5233.286195] 3 locks held by kworker/u192:6/2413: [ 5233.289192] #0: ffff888111632548 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: process_one_work+0x5cc/0x6e0 [ 5233.294569] #1: ffffc9000e2a7e40 ((work_completion)(&queue->release_work)){+.+.}-{0:0}, at: process_one_work+0x1c5/0x6e0 [ 5233.300128] #2: ffffffff82d7dc40 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x62/0x530 [ 5233.304290] stack backtrace: [ 5233.306520] CPU: 4 UID: 0 PID: 2413 Comm: kworker/u192:6 Tainted: G O N 7.0.0-rc3nvme+ #20 PREEMPT(full) [ 5233.306524] Tainted: [O]=OOT_MODULE, [N]=TEST [ 5233.306525] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 [ 5233.306527] Workqueue: nvmet-wq nvmet_tcp_release_queue_work [nvmet_tcp] [ 5233.306532] Call Trace: [ 5233.306534] <TASK> [ 5233.306536] dump_stack_lvl+0x73/0xb0 [ 5233.306552] print_deadlock_bug+0x225/0x2f0 [ 5233.306556] __lock_acquire+0x13f0/0x2290 [ 5233.306563] lock_acquire+0xd0/0x300 [ 5233.306565] ? touch_wq_lockdep_map+0x26/0x90 [ 5233.306571] ? __flush_work+0x20b/0x530 [ 5233.306573] ? touch_wq_lockdep_map+0x26/0x90 [ 5233.306577] touch_wq_lockdep_map+0x3b/0x90 [ 5233.306580] ? touch_wq_lockdep_map+0x26/0x90 [ 52 ---truncated---
A flaw was found within the handling of SMB2_READ commands in the kernel ksmbd module. The issue results from not releasing memory after its effective lifetime. An attacker can leverage this to create a denial-of-service condition on affected installations of Linux. Authentication is not required to exploit this vulnerability, but only systems with ksmbd enabled are vulnerable.
In the Linux kernel, the following vulnerability has been resolved: net: ks8851: Reinstate disabling of BHs around IRQ handler If the driver executes ks8851_irq() AND a TX packet has been sent, then the driver enables TX queue via netif_wake_queue() which schedules TX softirq to queue packets for this device. If CONFIG_PREEMPT_RT=y is set AND a packet has also been received by the MAC, then ks8851_rx_pkts() calls netdev_alloc_skb_ip_align() to allocate SKBs for the received packets. If netdev_alloc_skb_ip_align() is called with BH enabled, then local_bh_enable() at the end of netdev_alloc_skb_ip_align() will trigger the pending softirq processing, which may ultimately call the .xmit callback ks8851_start_xmit_par(). The ks8851_start_xmit_par() will try to lock struct ks8851_net_par .lock spinlock, which is already locked by ks8851_irq() from which ks8851_start_xmit_par() was called. This leads to a deadlock, which is reported by the kernel, including a trace listed below. If CONFIG_PREEMPT_RT is not set, then since commit 0913ec336a6c0 ("net: ks8851: Fix deadlock with the SPI chip variant") the deadlock can also be triggered without received packet in the RX FIFO. The pending softirqs will be processed on return from spin_unlock_bh(&ks->statelock) in ks8851_irq(), which triggers the deadlock as well. Fix the problem by disabling BH around critical sections, including the IRQ handler, thus preventing the net_tx_action() softirq from triggering during these critical sections. The net_tx_action() softirq is triggered once BH are re-enabled and at the end of the IRQ handler, once all the other IRQ handler actions have been completed. __schedule from schedule_rtlock+0x1c/0x34 schedule_rtlock from rtlock_slowlock_locked+0x548/0x904 rtlock_slowlock_locked from rt_spin_lock+0x60/0x9c rt_spin_lock from ks8851_start_xmit_par+0x74/0x1a8 ks8851_start_xmit_par from netdev_start_xmit+0x20/0x44 netdev_start_xmit from dev_hard_start_xmit+0xd0/0x188 dev_hard_start_xmit from sch_direct_xmit+0xb8/0x25c sch_direct_xmit from __qdisc_run+0x1f8/0x4ec __qdisc_run from qdisc_run+0x1c/0x28 qdisc_run from net_tx_action+0x1f0/0x268 net_tx_action from handle_softirqs+0x1a4/0x270 handle_softirqs from __local_bh_enable_ip+0xcc/0xe0 __local_bh_enable_ip from __alloc_skb+0xd8/0x128 __alloc_skb from __netdev_alloc_skb+0x3c/0x19c __netdev_alloc_skb from ks8851_irq+0x388/0x4d4 ks8851_irq from irq_thread_fn+0x24/0x64 irq_thread_fn from irq_thread+0x178/0x28c irq_thread from kthread+0x12c/0x138 kthread from ret_from_fork+0x14/0x28
IBM TXSeries for Multiplatforms 8.1, 8.2, and 9.1 is vulnerable to a denial of service, caused by improper enforcement of the timeout on individual read operations. By conducting a slowloris-type attacks, a remote attacker could exploit this vulnerability to cause a denial of service. IBM X-Force ID: 262905.
NVIDIA Triton Inference Server for Windows and Linux contains a vulnerability where an attacker could cause an integer overflow through a specially crafted input. A successful exploit of this vulnerability might lead to denial of service.
The socket implementation in net/core/sock.c in the Linux kernel before 2.6.34 does not properly manage a backlog of received packets, which allows remote attackers to cause a denial of service (memory consumption) by sending a large amount of network traffic, as demonstrated by netperf UDP tests.
NVIDIA Triton Inference Server for Windows and Linux contains a vulnerability where multiple requests could cause a double free when a stream is cancelled before it is processed. A successful exploit of this vulnerability might lead to denial of service.
In the Linux kernel, the following vulnerability has been resolved: ipmi: Add limits to event and receive message requests The driver would just fetch events and receive messages until the BMC said it was done. To avoid issues with BMCs that never say they are done, add a limit of 10 fetches at a time. In addition, an si interface has an attn state it can return from the hardware which is supposed to cause a flag fetch to see if the driver needs to fetch events or message or a few other things. If the attn bit gets stuck, it's a similar problem. So allow messages in between flag fetches so the driver itself doesn't get stuck. This is a more general fix than the previous fix for the specific bad BMC, but should fix the more general issue of a BMC that won't stop saying it has data. This has been there from the beginning of the driver. It's not a bug per-se, but it is accounting for bugs in BMCs.