Vulnerabilities (CVE)

In Docker Desktop before v4.29.0, an attacker who has gained access to the Docker Desktop VM through a container breakout can further escape to the host by passing extensions and dashboard related IPC messages. Docker Desktop v4.29.0 https://docs.docker.com/desktop/release-notes/#4290 fixes the issue on MacOS, Linux and Windows with Hyper-V backend. As exploitation requires "Allow only extensions distributed through the Docker Marketplace" to be disabled, Docker Desktop  v4.31.0 https://docs ... In Docker Desktop before v4.29.0, an attacker who has gained access to the Docker Desktop VM through a container breakout can further escape to the host by passing extensions and dashboard related IPC messages. Docker Desktop v4.29.0 https://docs.docker.com/desktop/release-notes/#4290 fixes the issue on MacOS, Linux and Windows with Hyper-V backend. As exploitation requires "Allow only extensions distributed through the Docker Marketplace" to be disabled, Docker Desktop  v4.31.0 https://docs.docker.com/desktop/release-notes/#4310  additionally changes the default configuration to enable this setting by default.

Show More

In the Linux kernel, the following vulnerability has been resolved: btrfs: zoned: fix calc_available_free_space() for zoned mode calc_available_free_space() returns the total size of metadata (or system) block groups, which can be allocated from unallocated disk space. The logic is wrong on zoned mode in two places. First, the calculation of data_chunk_size is wrong. We always allocate one zone as one chunk, and no partial allocation of a zone. So, we should use zone_size (= data_sinfo->chunk ... In the Linux kernel, the following vulnerability has been resolved: btrfs: zoned: fix calc_available_free_space() for zoned mode calc_available_free_space() returns the total size of metadata (or system) block groups, which can be allocated from unallocated disk space. The logic is wrong on zoned mode in two places. First, the calculation of data_chunk_size is wrong. We always allocate one zone as one chunk, and no partial allocation of a zone. So, we should use zone_size (= data_sinfo->chunk_size) as it is. Second, the result "avail" may not be zone aligned. Since we always allocate one zone as one chunk on zoned mode, returning non-zone size aligned bytes will result in less pressure on the async metadata reclaim process. This is serious for the nearly full state with a large zone size device. Allowing over-commit too much will result in less async reclaim work and end up in ENOSPC. We can align down to the zone size to avoid that.

Show More

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix overlapping copy within dml_core_mode_programming [WHY] &mode_lib->mp.Watermark and &locals->Watermark are the same address. memcpy may lead to unexpected behavior. [HOW] memmove should be used.

In the Linux kernel, the following vulnerability has been resolved: gve: Account for stopped queues when reading NIC stats We now account for the fact that the NIC might send us stats for a subset of queues. Without this change, gve_get_ethtool_stats might make an invalid access on the priv->stats_report->stats array.

In the Linux kernel, the following vulnerability has been resolved: s390/pkey: Use kfree_sensitive() to fix Coccinelle warnings Replace memzero_explicit() and kfree() with kfree_sensitive() to fix warnings reported by Coccinelle: WARNING opportunity for kfree_sensitive/kvfree_sensitive (line 1506) WARNING opportunity for kfree_sensitive/kvfree_sensitive (line 1643) WARNING opportunity for kfree_sensitive/kvfree_sensitive (line 1770)

In the Linux kernel, the following vulnerability has been resolved: s390/pkey: Wipe copies of protected- and secure-keys Although the clear-key of neither protected- nor secure-keys is accessible, this key material should only be visible to the calling process. So wipe all copies of protected- or secure-keys from stack, even in case of an error.

In the Linux kernel, the following vulnerability has been resolved: thermal/drivers/mediatek/lvts_thermal: Check NULL ptr on lvts_data Verify that lvts_data is not NULL before using it.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: fix double free err_addr pointer warnings In amdgpu_umc_bad_page_polling_timeout, the amdgpu_umc_handle_bad_pages will be run many times so that double free err_addr in some special case. So set the err_addr to NULL to avoid the warnings.

In the Linux kernel, the following vulnerability has been resolved: ionic: fix kernel panic due to multi-buffer handling Currently, the ionic_run_xdp() doesn't handle multi-buffer packets properly for XDP_TX and XDP_REDIRECT. When a jumbo frame is received, the ionic_run_xdp() first makes xdp frame with all necessary pages in the rx descriptor. And if the action is either XDP_TX or XDP_REDIRECT, it should unmap dma-mapping and reset page pointer to NULL for all pages, not only the first page. ... In the Linux kernel, the following vulnerability has been resolved: ionic: fix kernel panic due to multi-buffer handling Currently, the ionic_run_xdp() doesn't handle multi-buffer packets properly for XDP_TX and XDP_REDIRECT. When a jumbo frame is received, the ionic_run_xdp() first makes xdp frame with all necessary pages in the rx descriptor. And if the action is either XDP_TX or XDP_REDIRECT, it should unmap dma-mapping and reset page pointer to NULL for all pages, not only the first page. But it doesn't for SG pages. So, SG pages unexpectedly will be reused. It eventually causes kernel panic. Oops: general protection fault, probably for non-canonical address 0x504f4e4dbebc64ff: 0000 [#1] PREEMPT SMP NOPTI CPU: 3 PID: 0 Comm: swapper/3 Not tainted 6.10.0-rc3+ #25 RIP: 0010:xdp_return_frame+0x42/0x90 Code: 01 75 12 5b 4c 89 e6 5d 31 c9 41 5c 31 d2 41 5d e9 73 fd ff ff 44 8b 6b 20 0f b7 43 0a 49 81 ed 68 01 00 00 49 29 c5 49 01 fd <41> 80 7d0 RSP: 0018:ffff99d00122ce08 EFLAGS: 00010202 RAX: 0000000000005453 RBX: ffff8d325f904000 RCX: 0000000000000001 RDX: 00000000670e1000 RSI: 000000011f90d000 RDI: 504f4e4d4c4b4a49 RBP: ffff99d003907740 R08: 0000000000000000 R09: 0000000000000000 R10: 000000011f90d000 R11: 0000000000000000 R12: ffff8d325f904010 R13: 504f4e4dbebc64fd R14: ffff8d3242b070c8 R15: ffff99d0039077c0 FS: 0000000000000000(0000) GS:ffff8d399f780000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f41f6c85e38 CR3: 000000037ac30000 CR4: 00000000007506f0 PKRU: 55555554 Call Trace: <IRQ> ? die_addr+0x33/0x90 ? exc_general_protection+0x251/0x2f0 ? asm_exc_general_protection+0x22/0x30 ? xdp_return_frame+0x42/0x90 ionic_tx_clean+0x211/0x280 [ionic 15881354510e6a9c655c59c54812b319ed2cd015] ionic_tx_cq_service+0xd3/0x210 [ionic 15881354510e6a9c655c59c54812b319ed2cd015] ionic_txrx_napi+0x41/0x1b0 [ionic 15881354510e6a9c655c59c54812b319ed2cd015] __napi_poll.constprop.0+0x29/0x1b0 net_rx_action+0x2c4/0x350 handle_softirqs+0xf4/0x320 irq_exit_rcu+0x78/0xa0 common_interrupt+0x77/0x90

Show More

In the Linux kernel, the following vulnerability has been resolved: drm/xe/xe_devcoredump: Check NULL before assignments Assign 'xe_devcoredump_snapshot *' and 'xe_device *' only if 'coredump' is not NULL. v2 - Fix commit messages. v3 - Define variables before code.(Ashutosh/Jose) v4 - Drop return check for coredump_to_xe. (Jose/Rodrigo) v5 - Modify misleading commit message. (Matt)

In the Linux kernel, the following vulnerability has been resolved: nfsd: initialise nfsd_info.mutex early. nfsd_info.mutex can be dereferenced by svc_pool_stats_start() immediately after the new netns is created. Currently this can trigger an oops. Move the initialisation earlier before it can possibly be dereferenced.

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix remap of arena. The bpf arena logic didn't account for mremap operation. Add a refcnt for multiple mmap events to prevent use-after-free in arena_vm_close.

In the Linux kernel, the following vulnerability has been resolved: ASoC: amd: acp: add a null check for chip_pdev structure When acp platform device creation is skipped, chip->chip_pdev value will remain NULL. Add NULL check for chip->chip_pdev structure in snd_acp_resume() function to avoid null pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: ionic: use dev_consume_skb_any outside of napi If we're not in a NAPI softirq context, we need to be careful about how we call napi_consume_skb(), specifically we need to call it with budget==0 to signal to it that we're not in a safe context. This was found while running some configuration stress testing of traffic and a change queue config loop running, and this curious note popped out: [ 4371.402645] BUG: using smp_proces ... In the Linux kernel, the following vulnerability has been resolved: ionic: use dev_consume_skb_any outside of napi If we're not in a NAPI softirq context, we need to be careful about how we call napi_consume_skb(), specifically we need to call it with budget==0 to signal to it that we're not in a safe context. This was found while running some configuration stress testing of traffic and a change queue config loop running, and this curious note popped out: [ 4371.402645] BUG: using smp_processor_id() in preemptible [00000000] code: ethtool/20545 [ 4371.402897] caller is napi_skb_cache_put+0x16/0x80 [ 4371.403120] CPU: 25 PID: 20545 Comm: ethtool Kdump: loaded Tainted: G OE 6.10.0-rc3-netnext+ #8 [ 4371.403302] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 01/23/2021 [ 4371.403460] Call Trace: [ 4371.403613] <TASK> [ 4371.403758] dump_stack_lvl+0x4f/0x70 [ 4371.403904] check_preemption_disabled+0xc1/0xe0 [ 4371.404051] napi_skb_cache_put+0x16/0x80 [ 4371.404199] ionic_tx_clean+0x18a/0x240 [ionic] [ 4371.404354] ionic_tx_cq_service+0xc4/0x200 [ionic] [ 4371.404505] ionic_tx_flush+0x15/0x70 [ionic] [ 4371.404653] ? ionic_lif_qcq_deinit.isra.23+0x5b/0x70 [ionic] [ 4371.404805] ionic_txrx_deinit+0x71/0x190 [ionic] [ 4371.404956] ionic_reconfigure_queues+0x5f5/0xff0 [ionic] [ 4371.405111] ionic_set_ringparam+0x2e8/0x3e0 [ionic] [ 4371.405265] ethnl_set_rings+0x1f1/0x300 [ 4371.405418] ethnl_default_set_doit+0xbb/0x160 [ 4371.405571] genl_family_rcv_msg_doit+0xff/0x130 [...] I found that ionic_tx_clean() calls napi_consume_skb() which calls napi_skb_cache_put(), but before that last call is the note /* Zero budget indicate non-NAPI context called us, like netpoll */ and DEBUG_NET_WARN_ON_ONCE(!in_softirq()); Those are pretty big hints that we're doing it wrong. We can pass a context hint down through the calls to let ionic_tx_clean() know what we're doing so it can call napi_consume_skb() correctly.

Show More

In the Linux kernel, the following vulnerability has been resolved: drm/xe: Fix potential integer overflow in page size calculation Explicitly cast tbo->page_alignment to u64 before bit-shifting to prevent overflow when assigning to min_page_size.

In the Linux kernel, the following vulnerability has been resolved: drm/xe: Add a NULL check in xe_ttm_stolen_mgr_init Add an explicit check to ensure that the mgr is not NULL.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Skip pipe if the pipe idx not set properly [why] Driver crashes when pipe idx not set properly [how] Add code to skip the pipe that idx not set properly

In the Linux kernel, the following vulnerability has been resolved: drm/fbdev-dma: Only set smem_start is enable per module option Only export struct fb_info.fix.smem_start if that is required by the user and the memory does not come from vmalloc(). Setting struct fb_info.fix.smem_start breaks systems where DMA memory is backed by vmalloc address space. An example error is shown below. [ 3.536043] ------------[ cut here ]------------ [ 3.540716] virt_to_phys used for non-linear address ... In the Linux kernel, the following vulnerability has been resolved: drm/fbdev-dma: Only set smem_start is enable per module option Only export struct fb_info.fix.smem_start if that is required by the user and the memory does not come from vmalloc(). Setting struct fb_info.fix.smem_start breaks systems where DMA memory is backed by vmalloc address space. An example error is shown below. [ 3.536043] ------------[ cut here ]------------ [ 3.540716] virt_to_phys used for non-linear address: 000000007fc4f540 (0xffff800086001000) [ 3.552628] WARNING: CPU: 4 PID: 61 at arch/arm64/mm/physaddr.c:12 __virt_to_phys+0x68/0x98 [ 3.565455] Modules linked in: [ 3.568525] CPU: 4 PID: 61 Comm: kworker/u12:5 Not tainted 6.6.23-06226-g4986cc3e1b75-dirty #250 [ 3.577310] Hardware name: NXP i.MX95 19X19 board (DT) [ 3.582452] Workqueue: events_unbound deferred_probe_work_func [ 3.588291] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 3.595233] pc : __virt_to_phys+0x68/0x98 [ 3.599246] lr : __virt_to_phys+0x68/0x98 [ 3.603276] sp : ffff800083603990 [ 3.677939] Call trace: [ 3.680393] __virt_to_phys+0x68/0x98 [ 3.684067] drm_fbdev_dma_helper_fb_probe+0x138/0x238 [ 3.689214] __drm_fb_helper_initial_config_and_unlock+0x2b0/0x4c0 [ 3.695385] drm_fb_helper_initial_config+0x4c/0x68 [ 3.700264] drm_fbdev_dma_client_hotplug+0x8c/0xe0 [ 3.705161] drm_client_register+0x60/0xb0 [ 3.709269] drm_fbdev_dma_setup+0x94/0x148 Additionally, DMA memory is assumed to by contiguous in physical address space, which is not guaranteed by vmalloc(). Resolve this by checking the module flag drm_leak_fbdev_smem when DRM allocated the instance of struct fb_info. Fbdev-dma then only sets smem_start only if required (via FBINFO_HIDE_SMEM_START). Also guarantee that the framebuffer is not located in vmalloc address space.

Show More

In the Linux kernel, the following vulnerability has been resolved: cxl/mem: Fix no cxl_nvd during pmem region auto-assembling When CXL subsystem is auto-assembling a pmem region during cxl endpoint port probing, always hit below calltrace. BUG: kernel NULL pointer dereference, address: 0000000000000078 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page RIP: 0010:cxl_pmem_region_probe+0x22e/0x360 [cxl_pmem] Call Trace: <TASK> ? __die+0x24/0x70 ? p ... In the Linux kernel, the following vulnerability has been resolved: cxl/mem: Fix no cxl_nvd during pmem region auto-assembling When CXL subsystem is auto-assembling a pmem region during cxl endpoint port probing, always hit below calltrace. BUG: kernel NULL pointer dereference, address: 0000000000000078 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page RIP: 0010:cxl_pmem_region_probe+0x22e/0x360 [cxl_pmem] Call Trace: <TASK> ? __die+0x24/0x70 ? page_fault_oops+0x82/0x160 ? do_user_addr_fault+0x65/0x6b0 ? exc_page_fault+0x7d/0x170 ? asm_exc_page_fault+0x26/0x30 ? cxl_pmem_region_probe+0x22e/0x360 [cxl_pmem] ? cxl_pmem_region_probe+0x1ac/0x360 [cxl_pmem] cxl_bus_probe+0x1b/0x60 [cxl_core] really_probe+0x173/0x410 ? __pfx___device_attach_driver+0x10/0x10 __driver_probe_device+0x80/0x170 driver_probe_device+0x1e/0x90 __device_attach_driver+0x90/0x120 bus_for_each_drv+0x84/0xe0 __device_attach+0xbc/0x1f0 bus_probe_device+0x90/0xa0 device_add+0x51c/0x710 devm_cxl_add_pmem_region+0x1b5/0x380 [cxl_core] cxl_bus_probe+0x1b/0x60 [cxl_core] The cxl_nvd of the memdev needs to be available during the pmem region probe. Currently the cxl_nvd is registered after the endpoint port probe. The endpoint probe, in the case of autoassembly of regions, can cause a pmem region probe requiring the not yet available cxl_nvd. Adjust the sequence so this dependency is met. This requires adding a port parameter to cxl_find_nvdimm_bridge() that can be used to query the ancestor root port. The endpoint port is not yet available, but will share a common ancestor with its parent, so start the query from there instead.

Show More

In the Linux kernel, the following vulnerability has been resolved: cxl/region: Avoid null pointer dereference in region lookup cxl_dpa_to_region() looks up a region based on a memdev and DPA. It wrongly assumes an endpoint found mapping the DPA is also of a fully assembled region. When not true it leads to a null pointer dereference looking up the region name. This appears during testing of region lookup after a failure to assemble a BIOS defined region or if the lookup raced with the assemb ... In the Linux kernel, the following vulnerability has been resolved: cxl/region: Avoid null pointer dereference in region lookup cxl_dpa_to_region() looks up a region based on a memdev and DPA. It wrongly assumes an endpoint found mapping the DPA is also of a fully assembled region. When not true it leads to a null pointer dereference looking up the region name. This appears during testing of region lookup after a failure to assemble a BIOS defined region or if the lookup raced with the assembly of the BIOS defined region. Failure to clean up BIOS defined regions that fail assembly is an issue in itself and a fix to that problem will alleviate some of the impact. It will not alleviate the race condition so let's harden this path. The behavior change is that the kernel oops due to a null pointer dereference is replaced with a dev_dbg() message noting that an endpoint was mapped. Additional comments are added so that future users of this function can more clearly understand what it provides.

Show More

In the Linux kernel, the following vulnerability has been resolved: netfs: Fix netfs_page_mkwrite() to check folio->mapping is valid Fix netfs_page_mkwrite() to check that folio->mapping is valid once it has taken the folio lock (as filemap_page_mkwrite() does). Without this, generic/247 occasionally oopses with something like the following: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-pre ... In the Linux kernel, the following vulnerability has been resolved: netfs: Fix netfs_page_mkwrite() to check folio->mapping is valid Fix netfs_page_mkwrite() to check that folio->mapping is valid once it has taken the folio lock (as filemap_page_mkwrite() does). Without this, generic/247 occasionally oopses with something like the following: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page RIP: 0010:trace_event_raw_event_netfs_folio+0x61/0xc0 ... Call Trace: <TASK> ? __die_body+0x1a/0x60 ? page_fault_oops+0x6e/0xa0 ? exc_page_fault+0xc2/0xe0 ? asm_exc_page_fault+0x22/0x30 ? trace_event_raw_event_netfs_folio+0x61/0xc0 trace_netfs_folio+0x39/0x40 netfs_page_mkwrite+0x14c/0x1d0 do_page_mkwrite+0x50/0x90 do_pte_missing+0x184/0x200 __handle_mm_fault+0x42d/0x500 handle_mm_fault+0x121/0x1f0 do_user_addr_fault+0x23e/0x3c0 exc_page_fault+0xc2/0xe0 asm_exc_page_fault+0x22/0x30 This is due to the invalidate_inode_pages2_range() issued at the end of the DIO write interfering with the mmap'd writes.

Show More

In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: core: Fix ufshcd_clear_cmd racing issue When ufshcd_clear_cmd is racing with the completion ISR, the completed tag of the request's mq_hctx pointer will be set to NULL by the ISR. And ufshcd_clear_cmd's call to ufshcd_mcq_req_to_hwq will get NULL pointer KE. Return success when the request is completed by ISR because sq does not need cleanup. The racing flow is: Thread A ufshcd_err_handler step 1 ufshcd_try_ ... In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: core: Fix ufshcd_clear_cmd racing issue When ufshcd_clear_cmd is racing with the completion ISR, the completed tag of the request's mq_hctx pointer will be set to NULL by the ISR. And ufshcd_clear_cmd's call to ufshcd_mcq_req_to_hwq will get NULL pointer KE. Return success when the request is completed by ISR because sq does not need cleanup. The racing flow is: Thread A ufshcd_err_handler step 1 ufshcd_try_to_abort_task ufshcd_cmd_inflight(true) step 3 ufshcd_clear_cmd ... ufshcd_mcq_req_to_hwq blk_mq_unique_tag rq->mq_hctx->queue_num step 5 Thread B ufs_mtk_mcq_intr(cq complete ISR) step 2 scsi_done ... __blk_mq_free_request rq->mq_hctx = NULL; step 4 Below is KE back trace: ufshcd_try_to_abort_task: cmd pending in the device. tag = 6 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000194 pc : [0xffffffd589679bf8] blk_mq_unique_tag+0x8/0x14 lr : [0xffffffd5862f95b4] ufshcd_mcq_sq_cleanup+0x6c/0x1cc [ufs_mediatek_mod_ise] Workqueue: ufs_eh_wq_0 ufshcd_err_handler [ufs_mediatek_mod_ise] Call trace: dump_backtrace+0xf8/0x148 show_stack+0x18/0x24 dump_stack_lvl+0x60/0x7c dump_stack+0x18/0x3c mrdump_common_die+0x24c/0x398 [mrdump] ipanic_die+0x20/0x34 [mrdump] notify_die+0x80/0xd8 die+0x94/0x2b8 __do_kernel_fault+0x264/0x298 do_page_fault+0xa4/0x4b8 do_translation_fault+0x38/0x54 do_mem_abort+0x58/0x118 el1_abort+0x3c/0x5c el1h_64_sync_handler+0x54/0x90 el1h_64_sync+0x68/0x6c blk_mq_unique_tag+0x8/0x14 ufshcd_clear_cmd+0x34/0x118 [ufs_mediatek_mod_ise] ufshcd_try_to_abort_task+0x2c8/0x5b4 [ufs_mediatek_mod_ise] ufshcd_err_handler+0xa7c/0xfa8 [ufs_mediatek_mod_ise] process_one_work+0x208/0x4fc worker_thread+0x228/0x438 kthread+0x104/0x1d4 ret_from_fork+0x10/0x20

Show More

In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: core: Fix ufshcd_abort_one racing issue When ufshcd_abort_one is racing with the completion ISR, the completed tag of the request's mq_hctx pointer will be set to NULL by ISR. Return success when request is completed by ISR because ufshcd_abort_one does not need to do anything. The racing flow is: Thread A ufshcd_err_handler step 1 ... ufshcd_abort_one ufshcd_try_to_abort_task ufshcd_cmd_inflight(true) ... In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: core: Fix ufshcd_abort_one racing issue When ufshcd_abort_one is racing with the completion ISR, the completed tag of the request's mq_hctx pointer will be set to NULL by ISR. Return success when request is completed by ISR because ufshcd_abort_one does not need to do anything. The racing flow is: Thread A ufshcd_err_handler step 1 ... ufshcd_abort_one ufshcd_try_to_abort_task ufshcd_cmd_inflight(true) step 3 ufshcd_mcq_req_to_hwq blk_mq_unique_tag rq->mq_hctx->queue_num step 5 Thread B ufs_mtk_mcq_intr(cq complete ISR) step 2 scsi_done ... __blk_mq_free_request rq->mq_hctx = NULL; step 4 Below is KE back trace. ufshcd_try_to_abort_task: cmd at tag 41 not pending in the device. ufshcd_try_to_abort_task: cmd at tag=41 is cleared. Aborting tag 41 / CDB 0x28 succeeded Unable to handle kernel NULL pointer dereference at virtual address 0000000000000194 pc : [0xffffffddd7a79bf8] blk_mq_unique_tag+0x8/0x14 lr : [0xffffffddd6155b84] ufshcd_mcq_req_to_hwq+0x1c/0x40 [ufs_mediatek_mod_ise] do_mem_abort+0x58/0x118 el1_abort+0x3c/0x5c el1h_64_sync_handler+0x54/0x90 el1h_64_sync+0x68/0x6c blk_mq_unique_tag+0x8/0x14 ufshcd_err_handler+0xae4/0xfa8 [ufs_mediatek_mod_ise] process_one_work+0x208/0x4fc worker_thread+0x228/0x438 kthread+0x104/0x1d4 ret_from_fork+0x10/0x20

Show More

In the Linux kernel, the following vulnerability has been resolved: vfio/pci: Init the count variable in collecting hot-reset devices The count variable is used without initialization, it results in mistakes in the device counting and crashes the userspace if the get hot reset info path is triggered.

In the Linux kernel, the following vulnerability has been resolved: ASoC: SOF: Intel: hda: fix null deref on system suspend entry When system enters suspend with an active stream, SOF core calls hw_params_upon_resume(). On Intel platforms with HDA DMA used to manage the link DMA, this leads to call chain of hda_dsp_set_hw_params_upon_resume() -> hda_dsp_dais_suspend() -> hda_dai_suspend() -> hda_ipc4_post_trigger() A bug is hit in hda_dai_suspend() as hda_link_dma_cleanup() is run firs ... In the Linux kernel, the following vulnerability has been resolved: ASoC: SOF: Intel: hda: fix null deref on system suspend entry When system enters suspend with an active stream, SOF core calls hw_params_upon_resume(). On Intel platforms with HDA DMA used to manage the link DMA, this leads to call chain of hda_dsp_set_hw_params_upon_resume() -> hda_dsp_dais_suspend() -> hda_dai_suspend() -> hda_ipc4_post_trigger() A bug is hit in hda_dai_suspend() as hda_link_dma_cleanup() is run first, which clears hext_stream->link_substream, and then hda_ipc4_post_trigger() is called with a NULL snd_pcm_substream pointer.

Show More

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix too early release of tcx_entry Pedro Pinto and later independently also Hyunwoo Kim and Wongi Lee reported an issue that the tcx_entry can be released too early leading to a use after free (UAF) when an active old-style ingress or clsact qdisc with a shared tc block is later replaced by another ingress or clsact instance. Essentially, the sequence to trigger the UAF (one example) can be as follows: 1. A network na ... In the Linux kernel, the following vulnerability has been resolved: bpf: Fix too early release of tcx_entry Pedro Pinto and later independently also Hyunwoo Kim and Wongi Lee reported an issue that the tcx_entry can be released too early leading to a use after free (UAF) when an active old-style ingress or clsact qdisc with a shared tc block is later replaced by another ingress or clsact instance. Essentially, the sequence to trigger the UAF (one example) can be as follows: 1. A network namespace is created 2. An ingress qdisc is created. This allocates a tcx_entry, and &tcx_entry->miniq is stored in the qdisc's miniqp->p_miniq. At the same time, a tcf block with index 1 is created. 3. chain0 is attached to the tcf block. chain0 must be connected to the block linked to the ingress qdisc to later reach the function tcf_chain0_head_change_cb_del() which triggers the UAF. 4. Create and graft a clsact qdisc. This causes the ingress qdisc created in step 1 to be removed, thus freeing the previously linked tcx_entry: rtnetlink_rcv_msg() => tc_modify_qdisc() => qdisc_create() => clsact_init() [a] => qdisc_graft() => qdisc_destroy() => __qdisc_destroy() => ingress_destroy() [b] => tcx_entry_free() => kfree_rcu() // tcx_entry freed 5. Finally, the network namespace is closed. This registers the cleanup_net worker, and during the process of releasing the remaining clsact qdisc, it accesses the tcx_entry that was already freed in step 4, causing the UAF to occur: cleanup_net() => ops_exit_list() => default_device_exit_batch() => unregister_netdevice_many() => unregister_netdevice_many_notify() => dev_shutdown() => qdisc_put() => clsact_destroy() [c] => tcf_block_put_ext() => tcf_chain0_head_change_cb_del() => tcf_chain_head_change_item() => clsact_chain_head_change() => mini_qdisc_pair_swap() // UAF There are also other variants, the gist is to add an ingress (or clsact) qdisc with a specific shared block, then to replace that qdisc, waiting for the tcx_entry kfree_rcu() to be executed and subsequently accessing the current active qdisc's miniq one way or another. The correct fix is to turn the miniq_active boolean into a counter. What can be observed, at step 2 above, the counter transitions from 0->1, at step [a] from 1->2 (in order for the miniq object to remain active during the replacement), then in [b] from 2->1 and finally [c] 1->0 with the eventual release. The reference counter in general ranges from [0,2] and it does not need to be atomic since all access to the counter is protected by the rtnl mutex. With this in place, there is no longer a UAF happening and the tcx_entry is freed at the correct time.

Show More

In the Linux kernel, the following vulnerability has been resolved: cpufreq: amd-pstate: fix memory leak on CPU EPP exit The cpudata memory from kzalloc() in amd_pstate_epp_cpu_init() is not freed in the analogous exit function, so fix that. [ rjw: Subject and changelog edits ]

In the Linux kernel, the following vulnerability has been resolved: f2fs: don't set RO when shutting down f2fs Shutdown does not check the error of thaw_super due to readonly, which causes a deadlock like below. f2fs_ioc_shutdown(F2FS_GOING_DOWN_FULLSYNC) issue_discard_thread - bdev_freeze - freeze_super - f2fs_stop_checkpoint() - f2fs_handle_critical_error - sb_start_write - set RO - waiting - bdev_thaw - thaw_su ... In the Linux kernel, the following vulnerability has been resolved: f2fs: don't set RO when shutting down f2fs Shutdown does not check the error of thaw_super due to readonly, which causes a deadlock like below. f2fs_ioc_shutdown(F2FS_GOING_DOWN_FULLSYNC) issue_discard_thread - bdev_freeze - freeze_super - f2fs_stop_checkpoint() - f2fs_handle_critical_error - sb_start_write - set RO - waiting - bdev_thaw - thaw_super_locked - return -EINVAL, if sb_rdonly() - f2fs_stop_discard_thread -> wait for kthread_stop(discard_thread);

Show More

In the Linux kernel, the following vulnerability has been resolved: ALSA: hda: cs35l41: Possible null pointer dereference in cs35l41_hda_unbind() The cs35l41_hda_unbind() function clears the hda_component entry matching it's index and then dereferences the codec pointer held in the first element of the hda_component array, this is an issue when the device index was 0. Instead use the codec pointer stashed in the cs35l41_hda structure as it will still be valid.

In the Linux kernel, the following vulnerability has been resolved: ext4: fix slab-out-of-bounds in ext4_mb_find_good_group_avg_frag_lists() We can trigger a slab-out-of-bounds with the following commands: mkfs.ext4 -F /dev/$disk 10G mount /dev/$disk /tmp/test echo 2147483647 > /sys/fs/ext4/$disk/mb_group_prealloc echo test > /tmp/test/file && sync ================================================================== BUG: KASAN: slab-out-of-bounds in ext4_mb_find_good_group_avg_ ... In the Linux kernel, the following vulnerability has been resolved: ext4: fix slab-out-of-bounds in ext4_mb_find_good_group_avg_frag_lists() We can trigger a slab-out-of-bounds with the following commands: mkfs.ext4 -F /dev/$disk 10G mount /dev/$disk /tmp/test echo 2147483647 > /sys/fs/ext4/$disk/mb_group_prealloc echo test > /tmp/test/file && sync ================================================================== BUG: KASAN: slab-out-of-bounds in ext4_mb_find_good_group_avg_frag_lists+0x8a/0x200 [ext4] Read of size 8 at addr ffff888121b9d0f0 by task kworker/u2:0/11 CPU: 0 PID: 11 Comm: kworker/u2:0 Tainted: GL 6.7.0-next-20240118 #521 Call Trace: dump_stack_lvl+0x2c/0x50 kasan_report+0xb6/0xf0 ext4_mb_find_good_group_avg_frag_lists+0x8a/0x200 [ext4] ext4_mb_regular_allocator+0x19e9/0x2370 [ext4] ext4_mb_new_blocks+0x88a/0x1370 [ext4] ext4_ext_map_blocks+0x14f7/0x2390 [ext4] ext4_map_blocks+0x569/0xea0 [ext4] ext4_do_writepages+0x10f6/0x1bc0 [ext4] [...] ================================================================== The flow of issue triggering is as follows: // Set s_mb_group_prealloc to 2147483647 via sysfs ext4_mb_new_blocks ext4_mb_normalize_request ext4_mb_normalize_group_request ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc ext4_mb_regular_allocator ext4_mb_choose_next_group ext4_mb_choose_next_group_best_avail mb_avg_fragment_size_order order = fls(len) - 2 = 29 ext4_mb_find_good_group_avg_frag_lists frag_list = &sbi->s_mb_avg_fragment_size[order] if (list_empty(frag_list)) // Trigger SOOB! At 4k block size, the length of the s_mb_avg_fragment_size list is 14, but an oversized s_mb_group_prealloc is set, causing slab-out-of-bounds to be triggered by an attempt to access an element at index 29. Add a new attr_id attr_clusters_in_group with values in the range [0, sbi->s_clusters_per_group] and declare mb_group_prealloc as that type to fix the issue. In addition avoid returning an order from mb_avg_fragment_size_order() greater than MB_NUM_ORDERS(sb) and reduce some useless loops.

Show More

In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix NULL pointer dereference in ocfs2_journal_dirty() bdev->bd_super has been removed and commit 8887b94d9322 change the usage from bdev->bd_super to b_assoc_map->host->i_sb. This introduces the following NULL pointer dereference in ocfs2_journal_dirty() since b_assoc_map is still not initialized. This can be easily reproduced by running xfstests generic/186, which simulate no more credits. [ 134.351592] BUG: kernel ... In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix NULL pointer dereference in ocfs2_journal_dirty() bdev->bd_super has been removed and commit 8887b94d9322 change the usage from bdev->bd_super to b_assoc_map->host->i_sb. This introduces the following NULL pointer dereference in ocfs2_journal_dirty() since b_assoc_map is still not initialized. This can be easily reproduced by running xfstests generic/186, which simulate no more credits. [ 134.351592] BUG: kernel NULL pointer dereference, address: 0000000000000000 ... [ 134.355341] RIP: 0010:ocfs2_journal_dirty+0x14f/0x160 [ocfs2] ... [ 134.365071] Call Trace: [ 134.365312] <TASK> [ 134.365524] ? __die_body+0x1e/0x60 [ 134.365868] ? page_fault_oops+0x13d/0x4f0 [ 134.366265] ? __pfx_bit_wait_io+0x10/0x10 [ 134.366659] ? schedule+0x27/0xb0 [ 134.366981] ? exc_page_fault+0x6a/0x140 [ 134.367356] ? asm_exc_page_fault+0x26/0x30 [ 134.367762] ? ocfs2_journal_dirty+0x14f/0x160 [ocfs2] [ 134.368305] ? ocfs2_journal_dirty+0x13d/0x160 [ocfs2] [ 134.368837] ocfs2_create_new_meta_bhs.isra.51+0x139/0x2e0 [ocfs2] [ 134.369454] ocfs2_grow_tree+0x688/0x8a0 [ocfs2] [ 134.369927] ocfs2_split_and_insert.isra.67+0x35c/0x4a0 [ocfs2] [ 134.370521] ocfs2_split_extent+0x314/0x4d0 [ocfs2] [ 134.371019] ocfs2_change_extent_flag+0x174/0x410 [ocfs2] [ 134.371566] ocfs2_add_refcount_flag+0x3fa/0x630 [ocfs2] [ 134.372117] ocfs2_reflink_remap_extent+0x21b/0x4c0 [ocfs2] [ 134.372994] ? inode_update_timestamps+0x4a/0x120 [ 134.373692] ? __pfx_ocfs2_journal_access_di+0x10/0x10 [ocfs2] [ 134.374545] ? __pfx_ocfs2_journal_access_di+0x10/0x10 [ocfs2] [ 134.375393] ocfs2_reflink_remap_blocks+0xe4/0x4e0 [ocfs2] [ 134.376197] ocfs2_remap_file_range+0x1de/0x390 [ocfs2] [ 134.376971] ? security_file_permission+0x29/0x50 [ 134.377644] vfs_clone_file_range+0xfe/0x320 [ 134.378268] ioctl_file_clone+0x45/0xa0 [ 134.378853] do_vfs_ioctl+0x457/0x990 [ 134.379422] __x64_sys_ioctl+0x6e/0xd0 [ 134.379987] do_syscall_64+0x5d/0x170 [ 134.380550] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 134.381231] RIP: 0033:0x7fa4926397cb [ 134.381786] Code: 73 01 c3 48 8b 0d bd 56 38 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 8d 56 38 00 f7 d8 64 89 01 48 [ 134.383930] RSP: 002b:00007ffc2b39f7b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 134.384854] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fa4926397cb [ 134.385734] RDX: 00007ffc2b39f7f0 RSI: 000000004020940d RDI: 0000000000000003 [ 134.386606] RBP: 0000000000000000 R08: 00111a82a4f015bb R09: 00007fa494221000 [ 134.387476] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 134.388342] R13: 0000000000f10000 R14: 0000558e844e2ac8 R15: 0000000000f10000 [ 134.389207] </TASK> Fix it by only aborting transaction and journal in ocfs2_journal_dirty() now, and leave ocfs2_abort() later when detecting an aborted handle, e.g. start next transaction. Also log the handle details in this case.

Show More

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix a potential use-after-free in bpf_link_free() After commit 1a80dbcb2dba, bpf_link can be freed by link->ops->dealloc_deferred, but the code still tests and uses link->ops->dealloc afterward, which leads to a use-after-free as reported by syzbot. Actually, one of them should be sufficient, so just call one of them instead of both. Also add a WARN_ON() in case of any problematic implementation.

In the Linux kernel, the following vulnerability has been resolved: ionic: fix kernel panic in XDP_TX action In the XDP_TX path, ionic driver sends a packet to the TX path with rx page and corresponding dma address. After tx is done, ionic_tx_clean() frees that page. But RX ring buffer isn't reset to NULL. So, it uses a freed page, which causes kernel panic. BUG: unable to handle page fault for address: ffff8881576c110c PGD 773801067 P4D 773801067 PUD 87f086067 PMD 87efca067 PTE 800ffffea893e ... In the Linux kernel, the following vulnerability has been resolved: ionic: fix kernel panic in XDP_TX action In the XDP_TX path, ionic driver sends a packet to the TX path with rx page and corresponding dma address. After tx is done, ionic_tx_clean() frees that page. But RX ring buffer isn't reset to NULL. So, it uses a freed page, which causes kernel panic. BUG: unable to handle page fault for address: ffff8881576c110c PGD 773801067 P4D 773801067 PUD 87f086067 PMD 87efca067 PTE 800ffffea893e060 Oops: Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN NOPTI CPU: 1 PID: 25 Comm: ksoftirqd/1 Not tainted 6.9.0+ #11 Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021 RIP: 0010:bpf_prog_f0b8caeac1068a55_balancer_ingress+0x3b/0x44f Code: 00 53 41 55 41 56 41 57 b8 01 00 00 00 48 8b 5f 08 4c 8b 77 00 4c 89 f7 48 83 c7 0e 48 39 d8 RSP: 0018:ffff888104e6fa28 EFLAGS: 00010283 RAX: 0000000000000002 RBX: ffff8881576c1140 RCX: 0000000000000002 RDX: ffffffffc0051f64 RSI: ffffc90002d33048 RDI: ffff8881576c110e RBP: ffff888104e6fa88 R08: 0000000000000000 R09: ffffed1027a04a23 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881b03a21a8 R13: ffff8881589f800f R14: ffff8881576c1100 R15: 00000001576c1100 FS: 0000000000000000(0000) GS:ffff88881ae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff8881576c110c CR3: 0000000767a90000 CR4: 00000000007506f0 PKRU: 55555554 Call Trace: <TASK> ? __die+0x20/0x70 ? page_fault_oops+0x254/0x790 ? __pfx_page_fault_oops+0x10/0x10 ? __pfx_is_prefetch.constprop.0+0x10/0x10 ? search_bpf_extables+0x165/0x260 ? fixup_exception+0x4a/0x970 ? exc_page_fault+0xcb/0xe0 ? asm_exc_page_fault+0x22/0x30 ? 0xffffffffc0051f64 ? bpf_prog_f0b8caeac1068a55_balancer_ingress+0x3b/0x44f ? do_raw_spin_unlock+0x54/0x220 ionic_rx_service+0x11ab/0x3010 [ionic 9180c3001ab627d82bbc5f3ebe8a0decaf6bb864] ? ionic_tx_clean+0x29b/0xc60 [ionic 9180c3001ab627d82bbc5f3ebe8a0decaf6bb864] ? __pfx_ionic_tx_clean+0x10/0x10 [ionic 9180c3001ab627d82bbc5f3ebe8a0decaf6bb864] ? __pfx_ionic_rx_service+0x10/0x10 [ionic 9180c3001ab627d82bbc5f3ebe8a0decaf6bb864] ? ionic_tx_cq_service+0x25d/0xa00 [ionic 9180c3001ab627d82bbc5f3ebe8a0decaf6bb864] ? __pfx_ionic_rx_service+0x10/0x10 [ionic 9180c3001ab627d82bbc5f3ebe8a0decaf6bb864] ionic_cq_service+0x69/0x150 [ionic 9180c3001ab627d82bbc5f3ebe8a0decaf6bb864] ionic_txrx_napi+0x11a/0x540 [ionic 9180c3001ab627d82bbc5f3ebe8a0decaf6bb864] __napi_poll.constprop.0+0xa0/0x440 net_rx_action+0x7e7/0xc30 ? __pfx_net_rx_action+0x10/0x10

Show More

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_inner: validate mandatory meta and payload Check for mandatory netlink attributes in payload and meta expression when used embedded from the inner expression, otherwise NULL pointer dereference is possible from userspace.

In the Linux kernel, the following vulnerability has been resolved: drm/mst: Fix NULL pointer dereference at drm_dp_add_payload_part2 [Why] Commit: - commit 5aa1dfcdf0a4 ("drm/mst: Refactor the flow for payload allocation/removement") accidently overwrite the commit - commit 54d217406afe ("drm: use mgr->dev in drm_dbg_kms in drm_dp_add_payload_part2") which cause regression. [How] Recover the original NULL fix and remove the unnecessary input parameter 'state' for drm_dp_add_payload_part2(). ... In the Linux kernel, the following vulnerability has been resolved: drm/mst: Fix NULL pointer dereference at drm_dp_add_payload_part2 [Why] Commit: - commit 5aa1dfcdf0a4 ("drm/mst: Refactor the flow for payload allocation/removement") accidently overwrite the commit - commit 54d217406afe ("drm: use mgr->dev in drm_dbg_kms in drm_dp_add_payload_part2") which cause regression. [How] Recover the original NULL fix and remove the unnecessary input parameter 'state' for drm_dp_add_payload_part2(). (cherry picked from commit 4545614c1d8da603e57b60dd66224d81b6ffc305)

Show More

In the Linux kernel, the following vulnerability has been resolved: crypto: qat - Fix ADF_DEV_RESET_SYNC memory leak Using completion_done to determine whether the caller has gone away only works after a complete call. Furthermore it's still possible that the caller has not yet called wait_for_completion, resulting in another potential UAF. Fix this by making the caller use cancel_work_sync and then freeing the memory safely.

In the Linux kernel, the following vulnerability has been resolved: ipv6: sr: fix memleak in seg6_hmac_init_algo seg6_hmac_init_algo returns without cleaning up the previous allocations if one fails, so it's going to leak all that memory and the crypto tfms. Update seg6_hmac_exit to only free the memory when allocated, so we can reuse the code directly.

In the Linux kernel, the following vulnerability has been resolved: drm/drm_file: Fix pid refcounting race <[email protected]>, Maxime Ripard <[email protected]>, Thomas Zimmermann <[email protected]> filp->pid is supposed to be a refcounted pointer; however, before this patch, drm_file_update_pid() only increments the refcount of a struct pid after storing a pointer to it in filp->pid and dropping the dev->filelist_mutex, making the following race possible: process A ... In the Linux kernel, the following vulnerability has been resolved: drm/drm_file: Fix pid refcounting race <[email protected]>, Maxime Ripard <[email protected]>, Thomas Zimmermann <[email protected]> filp->pid is supposed to be a refcounted pointer; however, before this patch, drm_file_update_pid() only increments the refcount of a struct pid after storing a pointer to it in filp->pid and dropping the dev->filelist_mutex, making the following race possible: process A process B ========= ========= begin drm_file_update_pid mutex_lock(&dev->filelist_mutex) rcu_replace_pointer(filp->pid, <pid B>, 1) mutex_unlock(&dev->filelist_mutex) begin drm_file_update_pid mutex_lock(&dev->filelist_mutex) rcu_replace_pointer(filp->pid, <pid A>, 1) mutex_unlock(&dev->filelist_mutex) get_pid(<pid A>) synchronize_rcu() put_pid(<pid B>) *** pid B reaches refcount 0 and is freed here *** get_pid(<pid B>) *** UAF *** synchronize_rcu() put_pid(<pid A>) As far as I know, this race can only occur with CONFIG_PREEMPT_RCU=y because it requires RCU to detect a quiescent state in code that is not explicitly calling into the scheduler. This race leads to use-after-free of a "struct pid". It is probably somewhat hard to hit because process A has to pass through a synchronize_rcu() operation while process B is between mutex_unlock() and get_pid(). Fix it by ensuring that by the time a pointer to the current task's pid is stored in the file, an extra reference to the pid has been taken. This fix also removes the condition for synchronize_rcu(); I think that optimization is unnecessary complexity, since in that case we would usually have bailed out on the lockless check above.

Show More

In the Linux kernel, the following vulnerability has been resolved: media: v4l: async: Properly re-initialise notifier entry in unregister The notifier_entry of a notifier is not re-initialised after unregistering the notifier. This leads to dangling pointers being left there so use list_del_init() to return the notifier_entry an empty list.

In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: WARN on vNMI + NMI window iff NMIs are outright masked When requesting an NMI window, WARN on vNMI support being enabled if and only if NMIs are actually masked, i.e. if the vCPU is already handling an NMI. KVM's ABI for NMIs that arrive simultanesouly (from KVM's point of view) is to inject one NMI and pend the other. When using vNMI, KVM pends the second NMI simply by setting V_NMI_PENDING, and lets the CPU do th ... In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: WARN on vNMI + NMI window iff NMIs are outright masked When requesting an NMI window, WARN on vNMI support being enabled if and only if NMIs are actually masked, i.e. if the vCPU is already handling an NMI. KVM's ABI for NMIs that arrive simultanesouly (from KVM's point of view) is to inject one NMI and pend the other. When using vNMI, KVM pends the second NMI simply by setting V_NMI_PENDING, and lets the CPU do the rest (hardware automatically sets V_NMI_BLOCKING when an NMI is injected). However, if KVM can't immediately inject an NMI, e.g. because the vCPU is in an STI shadow or is running with GIF=0, then KVM will request an NMI window and trigger the WARN (but still function correctly). Whether or not the GIF=0 case makes sense is debatable, as the intent of KVM's behavior is to provide functionality that is as close to real hardware as possible. E.g. if two NMIs are sent in quick succession, the probability of both NMIs arriving in an STI shadow is infinitesimally low on real hardware, but significantly larger in a virtual environment, e.g. if the vCPU is preempted in the STI shadow. For GIF=0, the argument isn't as clear cut, because the window where two NMIs can collide is much larger in bare metal (though still small). That said, KVM should not have divergent behavior for the GIF=0 case based on whether or not vNMI support is enabled. And KVM has allowed simultaneous NMIs with GIF=0 for over a decade, since commit 7460fb4a3400 ("KVM: Fix simultaneous NMIs"). I.e. KVM's GIF=0 handling shouldn't be modified without a *really* good reason to do so, and if KVM's behavior were to be modified, it should be done irrespective of vNMI support.

Show More