| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2024-57891: sched_ext: Fix invalid irq restore in scx_ops_bypass() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| sched_ext: Fix invalid irq restore in scx_ops_bypass() |
| |
| While adding outer irqsave/restore locking, 0e7ffff1b811 ("scx: Fix raciness |
| in scx_ops_bypass()") forgot to convert an inner rq_unlock_irqrestore() to |
| rq_unlock() which could re-enable IRQ prematurely leading to the following |
| warning: |
| |
| raw_local_irq_restore() called with IRQs enabled |
| WARNING: CPU: 1 PID: 96 at kernel/locking/irqflag-debug.c:10 warn_bogus_irq_restore+0x30/0x40 |
| ... |
| Sched_ext: create_dsq (enabling) |
| pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) |
| pc : warn_bogus_irq_restore+0x30/0x40 |
| lr : warn_bogus_irq_restore+0x30/0x40 |
| ... |
| Call trace: |
| warn_bogus_irq_restore+0x30/0x40 (P) |
| warn_bogus_irq_restore+0x30/0x40 (L) |
| scx_ops_bypass+0x224/0x3b8 |
| scx_ops_enable.isra.0+0x2c8/0xaa8 |
| bpf_scx_reg+0x18/0x30 |
| ... |
| irq event stamp: 33739 |
| hardirqs last enabled at (33739): [<ffff8000800b699c>] scx_ops_bypass+0x174/0x3b8 |
| hardirqs last disabled at (33738): [<ffff800080d48ad4>] _raw_spin_lock_irqsave+0xb4/0xd8 |
| |
| Drop the stray _irqrestore(). |
| |
| The Linux kernel CVE team has assigned CVE-2024-57891 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.12 with commit 0e7ffff1b8117b05635c87d3c9099f6aa9c9b689 and fixed in 6.12.9 with commit 786362ce60d79967875f43e0ba55ad7a5376c133 |
| Issue introduced in 6.12 with commit 0e7ffff1b8117b05635c87d3c9099f6aa9c9b689 and fixed in 6.13 with commit 18b2093f4598d8ee67a8153badc93f0fa7686b8a |
| |
| 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-2024-57891 |
| 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: |
| kernel/sched/ext.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/786362ce60d79967875f43e0ba55ad7a5376c133 |
| https://git.kernel.org/stable/c/18b2093f4598d8ee67a8153badc93f0fa7686b8a |
