Linux

In the Linux kernel, the following vulnerability has been resolved: iio: buffer: Fix file related error handling in IIO_BUFFER_GET_FD_IOCTL If we fail to copy the just created file descriptor to userland, we try to clean up by putting back 'fd' and freeing 'ib'. The code uses put_unused_fd() for the former which is wrong, as the file descriptor was already published by fd_install() which gets called internally by anon_inode_getfd(). This makes the error handling code leaving a half cleaned up file descriptor table around and a partially destructed 'file' object, allowing userland to play use-after-free tricks on us, by abusing the still usable fd and making the code operate on a dangling 'file->private_data' pointer. Instead of leaving the kernel in a partially corrupted state, don't attempt to explicitly clean up and leave this to the process exit path that'll release any still valid fds, including the one created by the previous call to anon_inode_getfd(). Simply return -EFAULT to indicate the error.Show less

In the Linux kernel, the following vulnerability has been resolved: mm: vmscan: remove deadlock due to throttling failing to make progress A soft lockup bug in kcompactd was reported in a private bugzilla with the following visible in dmesg; watchdog: BUG: soft lockup - CPU#33 stuck for 26s! [kcompactd0:479] watchdog: BUG: soft lockup - CPU#33 stuck for 52s! [kcompactd0:479] watchdog: BUG: soft lockup - CPU#33 stuck for 78s! [kcompactd0:479] watchdog: BUG: soft lockup - CPU#33 stuck for 104s! [kcompactd0:479] The machine had 256G of RAM with no swap and an earlier failed allocation indicated that node 0 where kcompactd was run was potentially unreclaimable; Node 0 active_anon:29355112kB inactive_anon:2913528kB active_file:0kB inactive_file:0kB unevictable:64kB isolated(anon):0kB isolated(file):0kB mapped:8kB dirty:0kB writeback:0kB shmem:26780kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 23480320kB writeback_tmp:0kB kernel_stack:2272kB pagetables:24500kB all_unreclaimable? yes Vlastimil Babka investigated a crash dump and found that a task migrating pages was trying to drain PCP lists; PID: 52922 TASK: ffff969f820e5000 CPU: 19 COMMAND: "kworker/u128:3" Call Trace: __schedule schedule schedule_timeout wait_for_completion __flush_work __drain_all_pages __alloc_pages_slowpath.constprop.114 __alloc_pages alloc_migration_target migrate_pages migrate_to_node do_migrate_pages cpuset_migrate_mm_workfn process_one_work worker_thread kthread ret_from_fork This failure is specific to CONFIG_PREEMPT=n builds. The root of the problem is that kcompact0 is not rescheduling on a CPU while a task that has isolated a large number of the pages from the LRU is waiting on kcompact0 to reschedule so the pages can be released. While shrink_inactive_list() only loops once around too_many_isolated, reclaim can continue without rescheduling if sc->skipped_deactivate == 1 which could happen if there was no file LRU and the inactive anon list was not low.Show less

In the Linux kernel, the following vulnerability has been resolved: perf: Fix list corruption in perf_cgroup_switch() There's list corruption on cgrp_cpuctx_list. This happens on the following path: perf_cgroup_switch: list_for_each_entry(cgrp_cpuctx_list) cpu_ctx_sched_in ctx_sched_in ctx_pinned_sched_in merge_sched_in perf_cgroup_event_disable: remove the event from the list Use list_for_each_entry_safe() to allow removing an entry during iteration.Show less

In the Linux kernel, the following vulnerability has been resolved: s390/cio: verify the driver availability for path_event call If no driver is attached to a device or the driver does not provide the path_event function, an FCES path-event on this device could end up in a kernel-panic. Verify the driver availability before the path_event function call.Show less

In the Linux kernel, the following vulnerability has been resolved: mm: don't try to NUMA-migrate COW pages that have other uses Oded Gabbay reports that enabling NUMA balancing causes corruption with his Gaudi accelerator test load: "All the details are in the bug, but the bottom line is that somehow, this patch causes corruption when the numa balancing feature is enabled AND we don't use process affinity AND we use GUP to pin pages so our accelerator can DMA to/from system memory. Either disabling numa balancing, using process affinity to bind to specific numa-node or reverting this patch causes the bug to disappear" and Oded bisected the issue to commit 09854ba94c6a ("mm: do_wp_page() simplification"). Now, the NUMA balancing shouldn't actually be changing the writability of a page, and as such shouldn't matter for COW. But it appears it does. Suspicious. However, regardless of that, the condition for enabling NUMA faults in change_pte_range() is nonsensical. It uses "page_mapcount(page)" to decide if a COW page should be NUMA-protected or not, and that makes absolutely no sense. The number of mappings a page has is irrelevant: not only does GUP get a reference to a page as in Oded's case, but the other mappings migth be paged out and the only reference to them would be in the page count. Since we should never try to NUMA-balance a page that we can't move anyway due to other references, just fix the code to use 'page_count()'. Oded confirms that that fixes his issue. Now, this does imply that something in NUMA balancing ends up changing page protections (other than the obvious one of making the page inaccessible to get the NUMA faulting information). Otherwise the COW simplification wouldn't matter - since doing the GUP on the page would make sure it's writable. The cause of that permission change would be good to figure out too, since it clearly results in spurious COW events - but fixing the nonsensical test that just happened to work before is obviously the CorrectThing(tm) to do regardless.Show less

In the Linux kernel, the following vulnerability has been resolved: iommu: Fix potential use-after-free during probe Kasan has reported the following use after free on dev->iommu. when a device probe fails and it is in process of freeing dev->iommu in dev_iommu_free function, a deferred_probe_work_func runs in parallel and tries to access dev->iommu->fwspec in of_iommu_configure path thus causing use after free. BUG: KASAN: use-after-free in of_iommu_configure+0xb4/0x4a4 Read of size 8 at addr ffffff87a2f1acb8 by task kworker/u16:2/153 Workqueue: events_unbound deferred_probe_work_func Call trace: dump_backtrace+0x0/0x33c show_stack+0x18/0x24 dump_stack_lvl+0x16c/0x1e0 print_address_description+0x84/0x39c __kasan_report+0x184/0x308 kasan_report+0x50/0x78 __asan_load8+0xc0/0xc4 of_iommu_configure+0xb4/0x4a4 of_dma_configure_id+0x2fc/0x4d4 platform_dma_configure+0x40/0x5c really_probe+0x1b4/0xb74 driver_probe_device+0x11c/0x228 __device_attach_driver+0x14c/0x304 bus_for_each_drv+0x124/0x1b0 __device_attach+0x25c/0x334 device_initial_probe+0x24/0x34 bus_probe_device+0x78/0x134 deferred_probe_work_func+0x130/0x1a8 process_one_work+0x4c8/0x970 worker_thread+0x5c8/0xaec kthread+0x1f8/0x220 ret_from_fork+0x10/0x18 Allocated by task 1: ____kasan_kmalloc+0xd4/0x114 __kasan_kmalloc+0x10/0x1c kmem_cache_alloc_trace+0xe4/0x3d4 __iommu_probe_device+0x90/0x394 probe_iommu_group+0x70/0x9c bus_for_each_dev+0x11c/0x19c bus_iommu_probe+0xb8/0x7d4 bus_set_iommu+0xcc/0x13c arm_smmu_bus_init+0x44/0x130 [arm_smmu] arm_smmu_device_probe+0xb88/0xc54 [arm_smmu] platform_drv_probe+0xe4/0x13c really_probe+0x2c8/0xb74 driver_probe_device+0x11c/0x228 device_driver_attach+0xf0/0x16c __driver_attach+0x80/0x320 bus_for_each_dev+0x11c/0x19c driver_attach+0x38/0x48 bus_add_driver+0x1dc/0x3a4 driver_register+0x18c/0x244 __platform_driver_register+0x88/0x9c init_module+0x64/0xff4 [arm_smmu] do_one_initcall+0x17c/0x2f0 do_init_module+0xe8/0x378 load_module+0x3f80/0x4a40 __se_sys_finit_module+0x1a0/0x1e4 __arm64_sys_finit_module+0x44/0x58 el0_svc_common+0x100/0x264 do_el0_svc+0x38/0xa4 el0_svc+0x20/0x30 el0_sync_handler+0x68/0xac el0_sync+0x160/0x180 Freed by task 1: kasan_set_track+0x4c/0x84 kasan_set_free_info+0x28/0x4c ____kasan_slab_free+0x120/0x15c __kasan_slab_free+0x18/0x28 slab_free_freelist_hook+0x204/0x2fc kfree+0xfc/0x3a4 __iommu_probe_device+0x284/0x394 probe_iommu_group+0x70/0x9c bus_for_each_dev+0x11c/0x19c bus_iommu_probe+0xb8/0x7d4 bus_set_iommu+0xcc/0x13c arm_smmu_bus_init+0x44/0x130 [arm_smmu] arm_smmu_device_probe+0xb88/0xc54 [arm_smmu] platform_drv_probe+0xe4/0x13c really_probe+0x2c8/0xb74 driver_probe_device+0x11c/0x228 device_driver_attach+0xf0/0x16c __driver_attach+0x80/0x320 bus_for_each_dev+0x11c/0x19c driver_attach+0x38/0x48 bus_add_driver+0x1dc/0x3a4 driver_register+0x18c/0x244 __platform_driver_register+0x88/0x9c init_module+0x64/0xff4 [arm_smmu] do_one_initcall+0x17c/0x2f0 do_init_module+0xe8/0x378 load_module+0x3f80/0x4a40 __se_sys_finit_module+0x1a0/0x1e4 __arm64_sys_finit_module+0x44/0x58 el0_svc_common+0x100/0x264 do_el0_svc+0x38/0xa4 el0_svc+0x20/0x30 el0_sync_handler+0x68/0xac el0_sync+0x160/0x180 Fix this by setting dev->iommu to NULL first and then freeing dev_iommu structure in dev_iommu_free function.Show less

In the Linux kernel, the following vulnerability has been resolved: parisc: Fix data TLB miss in sba_unmap_sg Rolf Eike Beer reported the following bug: [1274934.746891] Bad Address (null pointer deref?): Code=15 (Data TLB miss fault) at addr 0000004140000018 [1274934.746891] CPU: 3 PID: 5549 Comm: cmake Not tainted 5.15.4-gentoo-parisc64 #4 [1274934.746891] Hardware name: 9000/785/C8000 [1274934.746891] [1274934.746891] YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI [1274934.746891] PSW: 00001000000001001111111000001110 Not tainted [1274934.746891] r00-03 000000ff0804fe0e 0000000040bc9bc0 00000000406760e4 0000004140000000 [1274934.746891] r04-07 0000000040b693c0 0000004140000000 000000004a2b08b0 0000000000000001 [1274934.746891] r08-11 0000000041f98810 0000000000000000 000000004a0a7000 0000000000000001 [1274934.746891] r12-15 0000000040bddbc0 0000000040c0cbc0 0000000040bddbc0 0000000040bddbc0 [1274934.746891] r16-19 0000000040bde3c0 0000000040bddbc0 0000000040bde3c0 0000000000000007 [1274934.746891] r20-23 0000000000000006 000000004a368950 0000000000000000 0000000000000001 [1274934.746891] r24-27 0000000000001fff 000000000800000e 000000004a1710f0 0000000040b693c0 [1274934.746891] r28-31 0000000000000001 0000000041f988b0 0000000041f98840 000000004a171118 [1274934.746891] sr00-03 00000000066e5800 0000000000000000 0000000000000000 00000000066e5800 [1274934.746891] sr04-07 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [1274934.746891] [1274934.746891] IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000406760e8 00000000406760ec [1274934.746891] IIR: 48780030 ISR: 0000000000000000 IOR: 0000004140000018 [1274934.746891] CPU: 3 CR30: 00000040e3a9c000 CR31: ffffffffffffffff [1274934.746891] ORIG_R28: 0000000040acdd58 [1274934.746891] IAOQ[0]: sba_unmap_sg+0xb0/0x118 [1274934.746891] IAOQ[1]: sba_unmap_sg+0xb4/0x118 [1274934.746891] RP(r2): sba_unmap_sg+0xac/0x118 [1274934.746891] Backtrace: [1274934.746891] [<00000000402740cc>] dma_unmap_sg_attrs+0x6c/0x70 [1274934.746891] [<000000004074d6bc>] scsi_dma_unmap+0x54/0x60 [1274934.746891] [<00000000407a3488>] mptscsih_io_done+0x150/0xd70 [1274934.746891] [<0000000040798600>] mpt_interrupt+0x168/0xa68 [1274934.746891] [<0000000040255a48>] __handle_irq_event_percpu+0xc8/0x278 [1274934.746891] [<0000000040255c34>] handle_irq_event_percpu+0x3c/0xd8 [1274934.746891] [<000000004025ecb4>] handle_percpu_irq+0xb4/0xf0 [1274934.746891] [<00000000402548e0>] generic_handle_irq+0x50/0x70 [1274934.746891] [<000000004019a254>] call_on_stack+0x18/0x24 [1274934.746891] [1274934.746891] Kernel panic - not syncing: Bad Address (null pointer deref?) The bug is caused by overrunning the sglist and incorrectly testing sg_dma_len(sglist) before nents. Normally this doesn't cause a crash, but in this case sglist crossed a page boundary. This occurs in the following code: while (sg_dma_len(sglist) && nents--) { The fix is simply to test nents first and move the decrement of nents into the loop.Show less

In the Linux kernel, the following vulnerability has been resolved: net: ieee802154: at86rf230: Stop leaking skb's Upon error the ieee802154_xmit_complete() helper is not called. Only ieee802154_wake_queue() is called manually. In the Tx case we then leak the skb structure. Free the skb structure upon error before returning when appropriate. As the 'is_tx = 0' cannot be moved in the complete handler because of a possible race between the delay in switching to STATE_RX_AACK_ON and a new interrupt, we introduce an intermediate 'was_tx' boolean just for this purpose. There is no Fixes tag applying here, many changes have been made on this area and the issue kind of always existed.Show less

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: nSVM: fix potential NULL derefernce on nested migration Turns out that due to review feedback and/or rebases I accidentally moved the call to nested_svm_load_cr3 to be too early, before the NPT is enabled, which is very wrong to do. KVM can't even access guest memory at that point as nested NPT is needed for that, and of course it won't initialize the walk_mmu, which is main issue the patch was addressing. Fix this for real.Show less

In the Linux kernel, the following vulnerability has been resolved: scsi: pm8001: Fix use-after-free for aborted SSP/STP sas_task Currently a use-after-free may occur if a sas_task is aborted by the upper layer before we handle the I/O completion in mpi_ssp_completion() or mpi_sata_completion(). In this case, the following are the two steps in handling those I/O completions: - Call complete() to inform the upper layer handler of completion of the I/O. - Release driver resources associated with the sas_task in pm8001_ccb_task_free() call. When complete() is called, the upper layer may free the sas_task. As such, we should not touch the associated sas_task afterwards, but we do so in the pm8001_ccb_task_free() call. Fix by swapping the complete() and pm8001_ccb_task_free() calls ordering.Show less

In the Linux kernel, the following vulnerability has been resolved: scsi: pm8001: Fix use-after-free for aborted TMF sas_task Currently a use-after-free may occur if a TMF sas_task is aborted before we handle the IO completion in mpi_ssp_completion(). The abort occurs due to timeout. When the timeout occurs, the SAS_TASK_STATE_ABORTED flag is set and the sas_task is freed in pm8001_exec_internal_tmf_task(). However, if the I/O completion occurs later, the I/O completion still thinks that the sas_task is available. Fix this by clearing the ccb->task if the TMF times out - the I/O completion handler does nothing if this pointer is cleared.Show less

In the Linux kernel, the following vulnerability has been resolved: nvme: fix a possible use-after-free in controller reset during load Unlike .queue_rq, in .submit_async_event drivers may not check the ctrl readiness for AER submission. This may lead to a use-after-free condition that was observed with nvme-tcp. The race condition may happen in the following scenario: 1. driver executes its reset_ctrl_work 2. -> nvme_stop_ctrl - flushes ctrl async_event_work 3. ctrl sends AEN which is received by the host, which in turn schedules AEN handling 4. teardown admin queue (which releases the queue socket) 5. AEN processed, submits another AER, calling the driver to submit 6. driver attempts to send the cmd ==> use-after-free In order to fix that, add ctrl state check to validate the ctrl is actually able to accept the AER submission. This addresses the above race in controller resets because the driver during teardown should: 1. change ctrl state to RESETTING 2. flush async_event_work (as well as other async work elements) So after 1,2, any other AER command will find the ctrl state to be RESETTING and bail out without submitting the AER.Show less

In the Linux kernel, the following vulnerability has been resolved: nvme-tcp: fix possible use-after-free in transport error_recovery work While nvme_tcp_submit_async_event_work is checking the ctrl and queue state before preparing the AER command and scheduling io_work, in order to fully prevent a race where this check is not reliable the error recovery work must flush async_event_work before continuing to destroy the admin queue after setting the ctrl state to RESETTING such that there is no race .submit_async_event and the error recovery handler itself changing the ctrl state.Show less

In the Linux kernel, the following vulnerability has been resolved: nvme-rdma: fix possible use-after-free in transport error_recovery work While nvme_rdma_submit_async_event_work is checking the ctrl and queue state before preparing the AER command and scheduling io_work, in order to fully prevent a race where this check is not reliable the error recovery work must flush async_event_work before continuing to destroy the admin queue after setting the ctrl state to RESETTING such that there is no race .submit_async_event and the error recovery handler itself changing the ctrl state.Show less

In the Linux kernel, the following vulnerability has been resolved: iwlwifi: fix use-after-free If no firmware was present at all (or, presumably, all of the firmware files failed to parse), we end up unbinding by calling device_release_driver(), which calls remove(), which then in iwlwifi calls iwl_drv_stop(), freeing the 'drv' struct. However the new code I added will still erroneously access it after it was freed. Set 'failure=false' in this case to avoid the access, all data was already freed anyway.Show less

In the Linux kernel, the following vulnerability has been resolved: vsock: remove vsock from connected table when connect is interrupted by a signal vsock_connect() expects that the socket could already be in the TCP_ESTABLISHED state when the connecting task wakes up with a signal pending. If this happens the socket will be in the connected table, and it is not removed when the socket state is reset. In this situation it's common for the process to retry connect(), and if the connection is successful the socket will be added to the connected table a second time, corrupting the list. Prevent this by calling vsock_remove_connected() if a signal is received while waiting for a connection. This is harmless if the socket is not in the connected table, and if it is in the table then removing it will prevent list corruption from a double add. Note for backporting: this patch requires d5afa82c977e ("vsock: correct removal of socket from the list"), which is in all current stable trees except 4.9.y.Show less

In the Linux kernel, the following vulnerability has been resolved: ipv6: mcast: use rcu-safe version of ipv6_get_lladdr() Some time ago 8965779d2c0e ("ipv6,mcast: always hold idev->lock before mca_lock") switched ipv6_get_lladdr() to __ipv6_get_lladdr(), which is rcu-unsafe version. That was OK, because idev->lock was held for these codepaths. In 88e2ca308094 ("mld: convert ifmcaddr6 to RCU") these external locks were removed, so we probably need to restore the original rcu-safe call. Otherwise, we occasionally get a machine crashed/stalled with the following in dmesg: [ 3405.966610][T230589] general protection fault, probably for non-canonical address 0xdead00000000008c: 0000 [#1] SMP NOPTI [ 3405.982083][T230589] CPU: 44 PID: 230589 Comm: kworker/44:3 Tainted: G O 5.15.19-cloudflare-2022.2.1 #1 [ 3405.998061][T230589] Hardware name: SUPA-COOL-SERV [ 3406.009552][T230589] Workqueue: mld mld_ifc_work [ 3406.017224][T230589] RIP: 0010:__ipv6_get_lladdr+0x34/0x60 [ 3406.025780][T230589] Code: 57 10 48 83 c7 08 48 89 e5 48 39 d7 74 3e 48 8d 82 38 ff ff ff eb 13 48 8b 90 d0 00 00 00 48 8d 82 38 ff ff ff 48 39 d7 74 22 <66> 83 78 32 20 77 1b 75 e4 89 ca 23 50 2c 75 dd 48 8b 50 08 48 8b [ 3406.055748][T230589] RSP: 0018:ffff94e4b3fc3d10 EFLAGS: 00010202 [ 3406.065617][T230589] RAX: dead00000000005a RBX: ffff94e4b3fc3d30 RCX: 0000000000000040 [ 3406.077477][T230589] RDX: dead000000000122 RSI: ffff94e4b3fc3d30 RDI: ffff8c3a31431008 [ 3406.089389][T230589] RBP: ffff94e4b3fc3d10 R08: 0000000000000000 R09: 0000000000000000 [ 3406.101445][T230589] R10: ffff8c3a31430000 R11: 000000000000000b R12: ffff8c2c37887100 [ 3406.113553][T230589] R13: ffff8c3a39537000 R14: 00000000000005dc R15: ffff8c3a31431000 [ 3406.125730][T230589] FS: 0000000000000000(0000) GS:ffff8c3b9fc80000(0000) knlGS:0000000000000000 [ 3406.138992][T230589] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 3406.149895][T230589] CR2: 00007f0dfea1db60 CR3: 000000387b5f2000 CR4: 0000000000350ee0 [ 3406.162421][T230589] Call Trace: [ 3406.170235][T230589] <TASK> [ 3406.177736][T230589] mld_newpack+0xfe/0x1a0 [ 3406.186686][T230589] add_grhead+0x87/0xa0 [ 3406.195498][T230589] add_grec+0x485/0x4e0 [ 3406.204310][T230589] ? newidle_balance+0x126/0x3f0 [ 3406.214024][T230589] mld_ifc_work+0x15d/0x450 [ 3406.223279][T230589] process_one_work+0x1e6/0x380 [ 3406.232982][T230589] worker_thread+0x50/0x3a0 [ 3406.242371][T230589] ? rescuer_thread+0x360/0x360 [ 3406.252175][T230589] kthread+0x127/0x150 [ 3406.261197][T230589] ? set_kthread_struct+0x40/0x40 [ 3406.271287][T230589] ret_from_fork+0x22/0x30 [ 3406.280812][T230589] </TASK> [ 3406.288937][T230589] Modules linked in: ... [last unloaded: kheaders] [ 3406.476714][T230589] ---[ end trace 3525a7655f2f3b9e ]---Show less

In the Linux kernel, the following vulnerability has been resolved: cfg80211: fix race in netlink owner interface destruction My previous fix here to fix the deadlock left a race where the exact same deadlock (see the original commit referenced below) can still happen if cfg80211_destroy_ifaces() already runs while nl80211_netlink_notify() is still marking some interfaces as nl_owner_dead. The race happens because we have two loops here - first we dev_close() all the netdevs, and then we destroy them. If we also have two netdevs (first one need only be a wdev though) then we can find one during the first iteration, close it, and go to the second iteration -- but then find two, and try to destroy also the one we didn't close yet. Fix this by only iterating once.Show less

In the Linux kernel, the following vulnerability has been resolved: net: dsa: lantiq_gswip: fix use after free in gswip_remove() of_node_put(priv->ds->slave_mii_bus->dev.of_node) should be done before mdiobus_free(priv->ds->slave_mii_bus).Show less

In the Linux kernel, the following vulnerability has been resolved: mctp: fix use after free Clang static analysis reports this problem route.c:425:4: warning: Use of memory after it is freed trace_mctp_key_acquire(key); ^~~~~~~~~~~~~~~~~~~~~~~~~~~ When mctp_key_add() fails, key is freed but then is later used in trace_mctp_key_acquire(). Add an else statement to use the key only when mctp_key_add() is successful.Show less