linux-cve-announce - CVE-2024-50095: RDMA/mad: Improve handling of timed out WRs of mad agent

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [day] [month] [year] [list]
Message-ID: <2024110551-CVE-2024-50095-7abe@gregkh>
Date: Tue,  5 Nov 2024 18:04:55 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: CVE-2024-50095: RDMA/mad: Improve handling of timed out WRs of mad agent

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

RDMA/mad: Improve handling of timed out WRs of mad agent

Current timeout handler of mad agent acquires/releases mad_agent_priv
lock for every timed out WRs. This causes heavy locking contention
when higher no. of WRs are to be handled inside timeout handler.

This leads to softlockup with below trace in some use cases where
rdma-cm path is used to establish connection between peer nodes

Trace:
-----
 BUG: soft lockup - CPU#4 stuck for 26s! [kworker/u128:3:19767]
 CPU: 4 PID: 19767 Comm: kworker/u128:3 Kdump: loaded Tainted: G OE
     -------  ---  5.14.0-427.13.1.el9_4.x86_64 #1
 Hardware name: Dell Inc. PowerEdge R740/01YM03, BIOS 2.4.8 11/26/2019
 Workqueue: ib_mad1 timeout_sends [ib_core]
 RIP: 0010:__do_softirq+0x78/0x2ac
 RSP: 0018:ffffb253449e4f98 EFLAGS: 00000246
 RAX: 00000000ffffffff RBX: 0000000000000000 RCX: 000000000000001f
 RDX: 000000000000001d RSI: 000000003d1879ab RDI: fff363b66fd3a86b
 RBP: ffffb253604cbcd8 R08: 0000009065635f3b R09: 0000000000000000
 R10: 0000000000000040 R11: ffffb253449e4ff8 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000040
 FS:  0000000000000000(0000) GS:ffff8caa1fc80000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007fd9ec9db900 CR3: 0000000891934006 CR4: 00000000007706e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 PKRU: 55555554
 Call Trace:
  <IRQ>
  ? show_trace_log_lvl+0x1c4/0x2df
  ? show_trace_log_lvl+0x1c4/0x2df
  ? __irq_exit_rcu+0xa1/0xc0
  ? watchdog_timer_fn+0x1b2/0x210
  ? __pfx_watchdog_timer_fn+0x10/0x10
  ? __hrtimer_run_queues+0x127/0x2c0
  ? hrtimer_interrupt+0xfc/0x210
  ? __sysvec_apic_timer_interrupt+0x5c/0x110
  ? sysvec_apic_timer_interrupt+0x37/0x90
  ? asm_sysvec_apic_timer_interrupt+0x16/0x20
  ? __do_softirq+0x78/0x2ac
  ? __do_softirq+0x60/0x2ac
  __irq_exit_rcu+0xa1/0xc0
  sysvec_call_function_single+0x72/0x90
  </IRQ>
  <TASK>
  asm_sysvec_call_function_single+0x16/0x20
 RIP: 0010:_raw_spin_unlock_irq+0x14/0x30
 RSP: 0018:ffffb253604cbd88 EFLAGS: 00000247
 RAX: 000000000001960d RBX: 0000000000000002 RCX: ffff8cad2a064800
 RDX: 000000008020001b RSI: 0000000000000001 RDI: ffff8cad5d39f66c
 RBP: ffff8cad5d39f600 R08: 0000000000000001 R09: 0000000000000000
 R10: ffff8caa443e0c00 R11: ffffb253604cbcd8 R12: ffff8cacb8682538
 R13: 0000000000000005 R14: ffffb253604cbd90 R15: ffff8cad5d39f66c
  cm_process_send_error+0x122/0x1d0 [ib_cm]
  timeout_sends+0x1dd/0x270 [ib_core]
  process_one_work+0x1e2/0x3b0
  ? __pfx_worker_thread+0x10/0x10
  worker_thread+0x50/0x3a0
  ? __pfx_worker_thread+0x10/0x10
  kthread+0xdd/0x100
  ? __pfx_kthread+0x10/0x10
  ret_from_fork+0x29/0x50
  </TASK>

Simplified timeout handler by creating local list of timed out WRs
and invoke send handler post creating the list. The new method acquires/
releases lock once to fetch the list and hence helps to reduce locking
contetiong when processing higher no. of WRs

The Linux kernel CVE team has assigned CVE-2024-50095 to this issue.


Affected and fixed versions
===========================

	Fixed in 5.10.227 with commit 713adaf0ecfc
	Fixed in 5.15.168 with commit 7022a517bf1c
	Fixed in 6.1.113 with commit e80eadb3604a
	Fixed in 6.6.57 with commit a195a42dd25c
	Fixed in 6.11.4 with commit 3e799fa46350
	Fixed in 6.12-rc1 with commit 2a777679b8cc

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2024-50095
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/infiniband/core/mad.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/713adaf0ecfc49405f6e5d9e409d984f628de818
	https://git.kernel.org/stable/c/7022a517bf1ca37ef5a474365bcc5eafd345a13a
	https://git.kernel.org/stable/c/e80eadb3604a92d2d086e956b8b2692b699d4d0a
	https://git.kernel.org/stable/c/a195a42dd25ca4f12489687065d00be64939409f
	https://git.kernel.org/stable/c/3e799fa463508abe7a738ce5d0f62a8dfd05262a
	https://git.kernel.org/stable/c/2a777679b8ccd09a9a65ea0716ef10365179caac