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
| ||
|
Message-ID: <2025070422-CVE-2025-38211-215a@gregkh> Date: Fri, 4 Jul 2025 15:37:40 +0200 From: Greg Kroah-Hartman <gregkh@...uxfoundation.org> To: linux-cve-announce@...r.kernel.org Cc: Greg Kroah-Hartman <gregkh@...nel.org> Subject: CVE-2025-38211: RDMA/iwcm: Fix use-after-free of work objects after cm_id destruction From: Greg Kroah-Hartman <gregkh@...nel.org> Description =========== In the Linux kernel, the following vulnerability has been resolved: RDMA/iwcm: Fix use-after-free of work objects after cm_id destruction The commit 59c68ac31e15 ("iw_cm: free cm_id resources on the last deref") simplified cm_id resource management by freeing cm_id once all references to the cm_id were removed. The references are removed either upon completion of iw_cm event handlers or when the application destroys the cm_id. This commit introduced the use-after-free condition where cm_id_private object could still be in use by event handler works during the destruction of cm_id. The commit aee2424246f9 ("RDMA/iwcm: Fix a use-after-free related to destroying CM IDs") addressed this use-after- free by flushing all pending works at the cm_id destruction. However, still another use-after-free possibility remained. It happens with the work objects allocated for each cm_id_priv within alloc_work_entries() during cm_id creation, and subsequently freed in dealloc_work_entries() once all references to the cm_id are removed. If the cm_id's last reference is decremented in the event handler work, the work object for the work itself gets removed, and causes the use- after-free BUG below: BUG: KASAN: slab-use-after-free in __pwq_activate_work+0x1ff/0x250 Read of size 8 at addr ffff88811f9cf800 by task kworker/u16:1/147091 CPU: 2 UID: 0 PID: 147091 Comm: kworker/u16:1 Not tainted 6.15.0-rc2+ #27 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014 Workqueue: 0x0 (iw_cm_wq) Call Trace: <TASK> dump_stack_lvl+0x6a/0x90 print_report+0x174/0x554 ? __virt_addr_valid+0x208/0x430 ? __pwq_activate_work+0x1ff/0x250 kasan_report+0xae/0x170 ? __pwq_activate_work+0x1ff/0x250 __pwq_activate_work+0x1ff/0x250 pwq_dec_nr_in_flight+0x8c5/0xfb0 process_one_work+0xc11/0x1460 ? __pfx_process_one_work+0x10/0x10 ? assign_work+0x16c/0x240 worker_thread+0x5ef/0xfd0 ? __pfx_worker_thread+0x10/0x10 kthread+0x3b0/0x770 ? __pfx_kthread+0x10/0x10 ? rcu_is_watching+0x11/0xb0 ? _raw_spin_unlock_irq+0x24/0x50 ? rcu_is_watching+0x11/0xb0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x30/0x70 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Allocated by task 147416: kasan_save_stack+0x2c/0x50 kasan_save_track+0x10/0x30 __kasan_kmalloc+0xa6/0xb0 alloc_work_entries+0xa9/0x260 [iw_cm] iw_cm_connect+0x23/0x4a0 [iw_cm] rdma_connect_locked+0xbfd/0x1920 [rdma_cm] nvme_rdma_cm_handler+0x8e5/0x1b60 [nvme_rdma] cma_cm_event_handler+0xae/0x320 [rdma_cm] cma_work_handler+0x106/0x1b0 [rdma_cm] process_one_work+0x84f/0x1460 worker_thread+0x5ef/0xfd0 kthread+0x3b0/0x770 ret_from_fork+0x30/0x70 ret_from_fork_asm+0x1a/0x30 Freed by task 147091: kasan_save_stack+0x2c/0x50 kasan_save_track+0x10/0x30 kasan_save_free_info+0x37/0x60 __kasan_slab_free+0x4b/0x70 kfree+0x13a/0x4b0 dealloc_work_entries+0x125/0x1f0 [iw_cm] iwcm_deref_id+0x6f/0xa0 [iw_cm] cm_work_handler+0x136/0x1ba0 [iw_cm] process_one_work+0x84f/0x1460 worker_thread+0x5ef/0xfd0 kthread+0x3b0/0x770 ret_from_fork+0x30/0x70 ret_from_fork_asm+0x1a/0x30 Last potentially related work creation: kasan_save_stack+0x2c/0x50 kasan_record_aux_stack+0xa3/0xb0 __queue_work+0x2ff/0x1390 queue_work_on+0x67/0xc0 cm_event_handler+0x46a/0x820 [iw_cm] siw_cm_upcall+0x330/0x650 [siw] siw_cm_work_handler+0x6b9/0x2b20 [siw] process_one_work+0x84f/0x1460 worker_thread+0x5ef/0xfd0 kthread+0x3b0/0x770 ret_from_fork+0x30/0x70 ret_from_fork_asm+0x1a/0x30 This BUG is reproducible by repeating the blktests test case nvme/061 for the rdma transport and the siw driver. To avoid the use-after-free of cm_id_private work objects, ensure that the last reference to the cm_id is decremented not in the event handler works, but in the cm_id destruction context. For that purpose, move iwcm_deref_id() call from destroy_cm_id() to the callers of destroy_cm_id(). In iw_destroy_cm_id(), call iwcm_deref_id() after flushing the pending works. During the fix work, I noticed that iw_destroy_cm_id() is called from cm_work_handler() and process_event() context. However, the comment of iw_destroy_cm_id() notes that the function "cannot be called by the event thread". Drop the false comment. The Linux kernel CVE team has assigned CVE-2025-38211 to this issue. Affected and fixed versions =========================== Issue introduced in 4.8 with commit 59c68ac31e15ad09d2cb04734e3c8c544a95f8d4 and fixed in 5.15.186 with commit 3b4a50d733acad6831f6bd9288a76a80f70650ac Issue introduced in 4.8 with commit 59c68ac31e15ad09d2cb04734e3c8c544a95f8d4 and fixed in 6.1.142 with commit 78381dc8a6b61c9bb9987d37b4d671b99767c4a1 Issue introduced in 4.8 with commit 59c68ac31e15ad09d2cb04734e3c8c544a95f8d4 and fixed in 6.6.95 with commit 23a707bbcbea468eedb398832eeb7e8e0ceafd21 Issue introduced in 4.8 with commit 59c68ac31e15ad09d2cb04734e3c8c544a95f8d4 and fixed in 6.12.35 with commit 764c9f69beabef8bdc651a7746c59f7a340d104f Issue introduced in 4.8 with commit 59c68ac31e15ad09d2cb04734e3c8c544a95f8d4 and fixed in 6.15.4 with commit fd960b5ddf4faf00da43babdd3acda68842e1f6a Issue introduced in 4.8 with commit 59c68ac31e15ad09d2cb04734e3c8c544a95f8d4 and fixed in 6.16-rc1 with commit 6883b680e703c6b2efddb4e7a8d891ce1803d06b 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-2025-38211 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/iwcm.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/3b4a50d733acad6831f6bd9288a76a80f70650ac https://git.kernel.org/stable/c/78381dc8a6b61c9bb9987d37b4d671b99767c4a1 https://git.kernel.org/stable/c/23a707bbcbea468eedb398832eeb7e8e0ceafd21 https://git.kernel.org/stable/c/764c9f69beabef8bdc651a7746c59f7a340d104f https://git.kernel.org/stable/c/fd960b5ddf4faf00da43babdd3acda68842e1f6a https://git.kernel.org/stable/c/6883b680e703c6b2efddb4e7a8d891ce1803d06b
Powered by blists - more mailing lists