| 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-2024-41065: powerpc/pseries: Whitelist dtl slub object for copying to userspace |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| powerpc/pseries: Whitelist dtl slub object for copying to userspace |
| |
| Reading the dispatch trace log from /sys/kernel/debug/powerpc/dtl/cpu-* |
| results in a BUG() when the config CONFIG_HARDENED_USERCOPY is enabled as |
| shown below. |
| |
| kernel BUG at mm/usercopy.c:102! |
| Oops: Exception in kernel mode, sig: 5 [#1] |
| LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries |
| Modules linked in: xfs libcrc32c dm_service_time sd_mod t10_pi sg ibmvfc |
| scsi_transport_fc ibmveth pseries_wdt dm_multipath dm_mirror dm_region_hash dm_log dm_mod fuse |
| CPU: 27 PID: 1815 Comm: python3 Not tainted 6.10.0-rc3 #85 |
| Hardware name: IBM,9040-MRX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NM1060_042) hv:phyp pSeries |
| NIP: c0000000005d23d4 LR: c0000000005d23d0 CTR: 00000000006ee6f8 |
| REGS: c000000120c078c0 TRAP: 0700 Not tainted (6.10.0-rc3) |
| MSR: 8000000000029033 <SF,EE,ME,IR,DR,RI,LE> CR: 2828220f XER: 0000000e |
| CFAR: c0000000001fdc80 IRQMASK: 0 |
| [ ... GPRs omitted ... ] |
| NIP [c0000000005d23d4] usercopy_abort+0x78/0xb0 |
| LR [c0000000005d23d0] usercopy_abort+0x74/0xb0 |
| Call Trace: |
| usercopy_abort+0x74/0xb0 (unreliable) |
| __check_heap_object+0xf8/0x120 |
| check_heap_object+0x218/0x240 |
| __check_object_size+0x84/0x1a4 |
| dtl_file_read+0x17c/0x2c4 |
| full_proxy_read+0x8c/0x110 |
| vfs_read+0xdc/0x3a0 |
| ksys_read+0x84/0x144 |
| system_call_exception+0x124/0x330 |
| system_call_vectored_common+0x15c/0x2ec |
| --- interrupt: 3000 at 0x7fff81f3ab34 |
| |
| Commit 6d07d1cd300f ("usercopy: Restrict non-usercopy caches to size 0") |
| requires that only whitelisted areas in slab/slub objects can be copied to |
| userspace when usercopy hardening is enabled using CONFIG_HARDENED_USERCOPY. |
| Dtl contains hypervisor dispatch events which are expected to be read by |
| privileged users. Hence mark this safe for user access. |
| Specify useroffset=0 and usersize=DISPATCH_LOG_BYTES to whitelist the |
| entire object. |
| |
| The Linux kernel CVE team has assigned CVE-2024-41065 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 5.4.281 with commit a7b952941ce07e1e7a2cafd08c64a98e14f553e6 |
| Fixed in 5.10.223 with commit 6b16098148ea58a67430d90e20476be2377c3acd |
| Fixed in 5.15.164 with commit e59822f9d700349cd17968d22c979db23a2d347f |
| Fixed in 6.1.101 with commit 1ee68686d1e2a5da35d5650be0be1ce06fe2ceb2 |
| Fixed in 6.6.42 with commit e512a59b472684d8585125101ab03b86c2c1348a |
| Fixed in 6.9.11 with commit 0f5892212c27be31792ef1daa89c8dac1b3047e4 |
| Fixed in 6.10 with commit 1a14150e1656f7a332a943154fc486504db4d586 |
| |
| 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-2024-41065 |
| 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: |
| arch/powerpc/platforms/pseries/setup.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/a7b952941ce07e1e7a2cafd08c64a98e14f553e6 |
| https://git.kernel.org/stable/c/6b16098148ea58a67430d90e20476be2377c3acd |
| https://git.kernel.org/stable/c/e59822f9d700349cd17968d22c979db23a2d347f |
| https://git.kernel.org/stable/c/1ee68686d1e2a5da35d5650be0be1ce06fe2ceb2 |
| https://git.kernel.org/stable/c/e512a59b472684d8585125101ab03b86c2c1348a |
| https://git.kernel.org/stable/c/0f5892212c27be31792ef1daa89c8dac1b3047e4 |
| https://git.kernel.org/stable/c/1a14150e1656f7a332a943154fc486504db4d586 |
