{"id":"DEBIAN-CVE-2023-52587","details":"In the Linux kernel, the following vulnerability has been resolved:  IB/ipoib: Fix mcast list locking  Releasing the `priv-\u003elock` while iterating the `priv-\u003emulticast_list` in `ipoib_mcast_join_task()` opens a window for `ipoib_mcast_dev_flush()` to remove the items while in the middle of iteration. If the mcast is removed while the lock was dropped, the for loop spins forever resulting in a hard lockup (as was reported on RHEL 4.18.0-372.75.1.el8_6 kernel):      Task A (kworker/u72:2 below)       | Task B (kworker/u72:0 below)     -----------------------------------+-----------------------------------     ipoib_mcast_join_task(work)        | ipoib_ib_dev_flush_light(work)       spin_lock_irq(&priv-\u003elock)       | __ipoib_ib_dev_flush(priv, ...)       list_for_each_entry(mcast,       | ipoib_mcast_dev_flush(dev = priv-\u003edev)           &priv-\u003emulticast_list, list) |         ipoib_mcast_join(dev, mcast)   |           spin_unlock_irq(&priv-\u003elock) |                                        |   spin_lock_irqsave(&priv-\u003elock, flags)                                        |   list_for_each_entry_safe(mcast, tmcast,                                        |                  &priv-\u003emulticast_list, list)                                        |     list_del(&mcast-\u003elist);                                        |     list_add_tail(&mcast-\u003elist, &remove_list)                                        |   spin_unlock_irqrestore(&priv-\u003elock, flags)           spin_lock_irq(&priv-\u003elock)   |                                        |   ipoib_mcast_remove_list(&remove_list)    (Here, `mcast` is no longer on the  |     list_for_each_entry_safe(mcast, tmcast,     `priv-\u003emulticast_list` and we keep |                            remove_list, list)     spinning on the `remove_list` of   |  \u003e\u003e\u003e  wait_for_completion(&mcast-\u003edone)     the other thread which is blocked  |     and the list is still valid on     |     it's stack.)  Fix this by keeping the lock held and changing to GFP_ATOMIC to prevent eventual sleeps. Unfortunately we could not reproduce the lockup and confirm this fix but based on the code review I think this fix should address such lockups.  crash\u003e bc 31 PID: 747      TASK: ff1c6a1a007e8000  CPU: 31   COMMAND: \"kworker/u72:2\" --     [exception RIP: ipoib_mcast_join_task+0x1b1]     RIP: ffffffffc0944ac1  RSP: ff646f199a8c7e00  RFLAGS: 00000002     RAX: 0000000000000000  RBX: ff1c6a1a04dc82f8  RCX: 0000000000000000                                   work (&priv-\u003emcast_task{,.work})     RDX: ff1c6a192d60ac68  RSI: 0000000000000286  RDI: ff1c6a1a04dc8000            &mcast-\u003elist     RBP: ff646f199a8c7e90   R8: ff1c699980019420   R9: ff1c6a1920c9a000     R10: ff646f199a8c7e00  R11: ff1c6a191a7d9800  R12: ff1c6a192d60ac00                                                          mcast     R13: ff1c6a1d82200000  R14: ff1c6a1a04dc8000  R15: ff1c6a1a04dc82d8            dev                    priv (&priv-\u003elock)     &priv-\u003emulticast_list (aka head)     ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018 --- \u003cNMI exception stack\u003e ---  #5 [ff646f199a8c7e00] ipoib_mcast_join_task+0x1b1 at ffffffffc0944ac1 [ib_ipoib]  #6 [ff646f199a8c7e98] process_one_work+0x1a7 at ffffffff9bf10967  crash\u003e rx ff646f199a8c7e68 ff646f199a8c7e68:  ff1c6a1a04dc82f8 \u003c\u003c\u003c work = &priv-\u003emcast_task.work  crash\u003e list -hO ipoib_dev_priv.multicast_list ff1c6a1a04dc8000 (empty)  crash\u003e ipoib_dev_priv.mcast_task.work.func,mcast_mutex.owner.counter ff1c6a1a04dc8000   mcast_task.work.func = 0xffffffffc0944910 \u003cipoib_mcast_join_task\u003e,   mcast_mutex.owner.counter = 0xff1c69998efec000  crash\u003e b 8 PID: 8        TASK: ff1c69998efec000  CPU: 33   COMMAND: \"kworker/u72:0\" --  #3 [ff646f1980153d50] wait_for_completion+0x96 at ffffffff9c7d7646  #4 [ff646f1980153d90] ipoib_mcast_remove_list+0x56 at ffffffffc0944dc6 [ib_ipoib]  #5 [ff646f1980153de8] ipoib_mcast_dev_flush+0x1a7 at ffffffffc09455a7 [ib_ipoib]  #6 [ff646f1980153e58] __ipoib_ib_dev_flush+0x1a4 at ffffffffc09431a4 [ib_ipoib]  #7 [ff ---truncated---","modified":"2026-09-01T20:05:12.476342763Z","published":"2024-03-06T07:15:07.633Z","upstream":["CVE-2023-52587"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2023-52587"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.82-1"}]}],"versions":["6.1.27-1","6.1.37-1","6.1.38-1","6.1.38-2","6.1.38-2~bpo11+1","6.1.38-3","6.1.38-4","6.1.38-4~bpo11+1","6.1.52-1","6.1.55-1","6.1.55-1~bpo11+1","6.1.64-1","6.1.66-1","6.1.67-1","6.1.69-1","6.1.69-1~bpo11+1","6.1.76-1","6.1.76-1~bpo11+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2023-52587.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.7.7-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2023-52587.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.7.7-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2023-52587.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}