In the Linux kernel, the following vulnerability has been resolved: btrfs: fix deadlock when cloning inline extents and using qgroups There are a few exceptional cases where cloning an inline extent needs to copy the inline extent data into a page of the destination inode. When this happens, we end up starting a transaction while having a dirty page for the destination inode and while having the range locked in the destination's inode iotree too. Because when reserving metadata space for a transaction we may need to flush existing delalloc in case there is not enough free space, we have a mechanism in place to prevent a deadlock, which was introduced in commit 3d45f221ce627d ("btrfs: fix deadlock when cloning inline extent and low on free metadata space"). However when using qgroups, a transaction also reserves metadata qgroup space, which can also result in flushing delalloc in case there is not enough available space at the moment. When this happens we deadlock, since flushing del...

In the Linux kernel, the following vulnerability has been resolved: usb: dwc3: gadget: Free gadget structure only after freeing endpoints As part of commit e81a7018d93a ("usb: dwc3: allocate gadget structure dynamically") the dwc3_gadget_release() was added which will free the dwc->gadget structure upon the device's removal when usb_del_gadget_udc() is called in dwc3_gadget_exit(). However, simply freeing the gadget results a dangling pointer situation: the endpoints created in dwc3_gadget_init_endpoints() have their dep->endpoint.ep_list members chained off the list_head anchored at dwc->gadget->ep_list. Thus when dwc->gadget is freed, the first dwc3_ep in the list now has a dangling prev pointer and likewise for the next pointer of the dwc3_ep at the tail of the list. The dwc3_gadget_free_endpoints() that follows will result in a use-after-free when it calls list_del(). This was caught by enabling KASAN and performing a driver unbind. The recent commit 568262bf5492 ("usb: dwc3: c...

In the Linux kernel, the following vulnerability has been resolved: ACPI: scan: Fix a memory leak in an error handling path If 'acpi_device_set_name()' fails, we must free 'acpi_device_bus_id->bus_id' or there is a (potential) memory leak.

In the Linux kernel, the following vulnerability has been resolved: kyber: fix out of bounds access when preempted __blk_mq_sched_bio_merge() gets the ctx and hctx for the current CPU and passes the hctx to ->bio_merge(). kyber_bio_merge() then gets the ctx for the current CPU again and uses that to get the corresponding Kyber context in the passed hctx. However, the thread may be preempted between the two calls to blk_mq_get_ctx(), and the ctx returned the second time may no longer correspond to the passed hctx. This "works" accidentally most of the time, but it can cause us to read garbage if the second ctx came from an hctx with more ctx's than the first one (i.e., if ctx->index_hw[hctx->type] > hctx->nr_ctx). This manifested as this UBSAN array index out of bounds error reported by Jakub: UBSAN: array-index-out-of-bounds in ../kernel/locking/qspinlock.c:130:9 index 13106 is out of range for type 'long unsigned int [128]' Call Trace: dump_stack+0xa4/0xe5 ubsan_epilogue+0x5/0x40 _...

In the Linux kernel, the following vulnerability has been resolved: nvmet-rdma: Fix NULL deref when SEND is completed with error When running some traffic and taking down the link on peer, a retry counter exceeded error is received. This leads to nvmet_rdma_error_comp which tried accessing the cq_context to obtain the queue. The cq_context is no longer valid after the fix to use shared CQ mechanism and should be obtained similar to how it is obtained in other functions from the wc->qp. [ 905.786331] nvmet_rdma: SEND for CQE 0x00000000e3337f90 failed with status transport retry counter exceeded (12). [ 905.832048] BUG: unable to handle kernel NULL pointer dereference at 0000000000000048 [ 905.839919] PGD 0 P4D 0 [ 905.842464] Oops: 0000 1 SMP NOPTI [ 905.846144] CPU: 13 PID: 1557 Comm: kworker/13:1H Kdump: loaded Tainted: G OE --------- - - 4.18.0-304.el8.x86_64 #1 [ 905.872135] RIP: 0010:nvmet_rdma_error_comp+0x5/0x1b [nvmet_rdma] [ 905.878259] Code: 19 4f c0 e8 89 b3 a5 f6 e9 5b e0...

In the Linux kernel, the following vulnerability has been resolved: f2fs: compress: fix race condition of overwrite vs truncate pos_fsstress testcase complains a panic as belew: ------------[ cut here ]------------ kernel BUG at fs/f2fs/compress.c:1082! invalid opcode: 0000 [#1] SMP PTI CPU: 4 PID: 2753477 Comm: kworker/u16:2 Tainted: G OE 5.12.0-rc1-custom #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 Workqueue: writeback wb_workfn (flush-252:16) RIP: 0010:prepare_compress_overwrite+0x4c0/0x760 [f2fs] Call Trace: f2fs_prepare_compress_overwrite+0x5f/0x80 [f2fs] f2fs_write_cache_pages+0x468/0x8a0 [f2fs] f2fs_write_data_pages+0x2a4/0x2f0 [f2fs] do_writepages+0x38/0xc0 __writeback_single_inode+0x44/0x2a0 writeback_sb_inodes+0x223/0x4d0 __writeback_inodes_wb+0x56/0xf0 wb_writeback+0x1dd/0x290 wb_workfn+0x309/0x500 process_one_work+0x220/0x3c0 worker_thread+0x53/0x420 kthread+0x12f/0x150 ret_from_fork+0x22/0x30 The root cause is truncat...

In the Linux kernel, the following vulnerability has been resolved: nbd: Fix NULL pointer in flush_workqueue Open /dev/nbdX first, the config_refs will be 1 and the pointers in nbd_device are still null. Disconnect /dev/nbdX, then reference a null recv_workq. The protection by config_refs in nbd_genl_disconnect is useless. [ 656.366194] BUG: kernel NULL pointer dereference, address: 0000000000000020 [ 656.368943] #PF: supervisor write access in kernel mode [ 656.369844] #PF: error_code(0x0002) - not-present page [ 656.370717] PGD 10cc87067 P4D 10cc87067 PUD 1074b4067 PMD 0 [ 656.371693] Oops: 0002 [#1] SMP [ 656.372242] CPU: 5 PID: 7977 Comm: nbd-client Not tainted 5.11.0-rc5-00040-g76c057c84d28 #1 [ 656.373661] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014 [ 656.375904] RIP: 0010:mutex_lock+0x29/0x60 [ 656.376627] Code: 00 0f 1f 44 00 00 55 48 89 fd 48 83 05 6f d7 fe 08 01 e8 7a c3 f...

In the Linux kernel, the following vulnerability has been resolved: usb: typec: ucsi: Retrieve all the PDOs instead of just the first 4 commit 4dbc6a4ef06d ("usb: typec: ucsi: save power data objects in PD mode") introduced retrieval of the PDOs when connected to a PD-capable source. But only the first 4 PDOs are received since that is the maximum number that can be fetched at a time given the MESSAGE_IN length limitation (16 bytes). However, as per the PD spec a connected source may advertise up to a maximum of 7 PDOs. If such a source is connected it's possible the PPM could have negotiated a power contract with one of the PDOs at index greater than 4, and would be reflected in the request data object's (RDO) object position field. This would result in an out-of-bounds access when the rdo_index() is used to index into the src_pdos array in ucsi_psy_get_voltage_now(). With the help of the UBSAN -fsanitize=array-bounds checker enabled this exact issue is revealed when connecting to ...

In the Linux kernel, the following vulnerability has been resolved: iio: core: fix ioctl handlers removal Currently ioctl handlers are removed twice. For the first time during iio_device_unregister() then later on inside iio_device_unregister_eventset() and iio_buffers_free_sysfs_and_mask(). Double free leads to kernel panic. Fix this by not touching ioctl handlers list directly but rather letting code responsible for registration call the matching cleanup routine itself.

In the Linux kernel, the following vulnerability has been resolved: KVM: nVMX: Always make an attempt to map eVMCS after migration When enlightened VMCS is in use and nested state is migrated with vmx_get_nested_state()/vmx_set_nested_state() KVM can't map evmcs page right away: evmcs gpa is not 'struct kvm_vmx_nested_state_hdr' and we can't read it from VP assist page because userspace may decide to restore HV_X64_MSR_VP_ASSIST_PAGE after restoring nested state (and QEMU, for example, does exactly that). To make sure eVMCS is mapped /vmx_set_nested_state() raises KVM_REQ_GET_NESTED_STATE_PAGES request. Commit f2c7ef3ba955 ("KVM: nSVM: cancel KVM_REQ_GET_NESTED_STATE_PAGES on nested vmexit") added KVM_REQ_GET_NESTED_STATE_PAGES clearing to nested_vmx_vmexit() to make sure MSR permission bitmap is not switched when an immediate exit from L2 to L1 happens right after migration (caused by a pending event, for example). Unfortunately, in the exact same situation we still need to have eV...

In the Linux kernel, the following vulnerability has been resolved: KVM: VMX: Disable preemption when probing user return MSRs Disable preemption when probing a user return MSR via RDSMR/WRMSR. If the MSR holds a different value per logical CPU, the WRMSR could corrupt the host's value if KVM is preempted between the RDMSR and WRMSR, and then rescheduled on a different CPU. Opportunistically land the helper in common x86, SVM will use the helper in a future commit.

In the Linux kernel, the following vulnerability has been resolved: drm/i915: Fix crash in auto_retire The retire logic uses the 2 lower bits of the pointer to the retire function to store flags. However, the auto_retire function is not guaranteed to be aligned to a multiple of 4, which causes crashes as we jump to the wrong address, for example like this: 2021-04-24T18:03:53.804300Z WARNING kernel: [ 516.876901] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI 2021-04-24T18:03:53.804310Z WARNING kernel: [ 516.876906] CPU: 7 PID: 146 Comm: kworker/u16:6 Tainted: G U 5.4.105-13595-g3cd84167b2df #1 2021-04-24T18:03:53.804311Z WARNING kernel: [ 516.876907] Hardware name: Google Volteer2/Volteer2, BIOS Google_Volteer2.13672.76.0 02/22/2021 2021-04-24T18:03:53.804312Z WARNING kernel: [ 516.876911] Workqueue: events_unbound active_work 2021-04-24T18:03:53.804313Z WARNING kernel: [ 516.876914] RIP: 0010:auto_retire+0x1/0x20 2021-04-24T18:03:53.804314Z WARNING kernel: [ 516....

[REJECTED CVE] In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: Make global sysctls readonly in non-init netns The Linux kernel CVE team has assigned CVE-2021-46975 to this issue.

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix masking negation logic upon negative dst register The negation logic for the case where the off_reg is sitting in the dst register is not correct given then we cannot just invert the add to a sub or vice versa. As a fix, perform the final bitwise and-op unconditionally into AX from the off_reg, then move the pointer from the src to dst and finally use AX as the source for the original pointer arithmetic operation such that the inversion yields a correct result. The single non-AX mov in between is possible given constant blinding is retaining it as it's not an immediate based operation.

In the Linux kernel, the following vulnerability has been resolved: net: qrtr: Avoid potential use after free in MHI send It is possible that the MHI ul_callback will be invoked immediately following the queueing of the skb for transmission, leading to the callback decrementing the refcount of the associated sk and freeing the skb. As such the dereference of skb and the increment of the sk refcount must happen before the skb is queued, to avoid the skb to be used after free and potentially the sk to drop its last refcount..

In the Linux kernel, the following vulnerability has been resolved: ovl: fix leaked dentry Since commit 6815f479ca90 ("ovl: use only uppermetacopy state in ovl_lookup()"), overlayfs doesn't put temporary dentry when there is a metacopy error, which leads to dentry leaks when shutting down the related superblock: overlayfs: refusing to follow metacopy origin for (/file0) ... BUG: Dentry (____ptrval____){i=3f33,n=file3} still in use (1) [unmount of overlay overlay] ... WARNING: CPU: 1 PID: 432 at umount_check.cold+0x107/0x14d CPU: 1 PID: 432 Comm: unmount-overlay Not tainted 5.12.0-rc5 #1 ... RIP: 0010:umount_check.cold+0x107/0x14d ... Call Trace: d_walk+0x28c/0x950 ? dentry_lru_isolate+0x2b0/0x2b0 ? __kasan_slab_free+0x12/0x20 do_one_tree+0x33/0x60 shrink_dcache_for_umount+0x78/0x1d0 generic_shutdown_super+0x70/0x440 kill_anon_super+0x3e/0x70 deactivate_locked_super+0xc4/0x160 deactivate_super+0xfa/0x140 cleanup_mnt+0x22e/0x370 __cleanup_mnt+0x1a/0x30 task_work_run+0x139/0x210 do_ex...

In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix unconditional security_locked_down() call Currently, the lockdown state is queried unconditionally, even though its result is used only if the PERF_SAMPLE_REGS_INTR bit is set in attr.sample_type. While that doesn't matter in case of the Lockdown LSM, it causes trouble with the SELinux's lockdown hook implementation. SELinux implements the locked_down hook with a check whether the current task's type has the corresponding "lockdown" class permission ("integrity" or "confidentiality") allowed in the policy. This means that calling the hook when the access control decision would be ignored generates a bogus permission check and audit record. Fix this by checking sample_type first and only calling the hook when its result would be honored.

In the Linux kernel, the following vulnerability has been resolved: bus: mhi: pci_generic: Remove WQ_MEM_RECLAIM flag from state workqueue A recent change created a dedicated workqueue for the state-change work with WQ_HIGHPRI (no strong reason for that) and WQ_MEM_RECLAIM flags, but the state-change work (mhi_pm_st_worker) does not guarantee forward progress under memory pressure, and will even wait on various memory allocations when e.g. creating devices, loading firmware, etc... The work is then not part of a memory reclaim path... Moreover, this causes a warning in check_flush_dependency() since we end up in code that flushes a non-reclaim workqueue: [ 40.969601] workqueue: WQ_MEM_RECLAIM mhi_hiprio_wq:mhi_pm_st_worker [mhi] is flushing !WQ_MEM_RECLAIM events_highpri:flush_backlog [ 40.969612] WARNING: CPU: 4 PID: 158 at kernel/workqueue.c:2607 check_flush_dependency+0x11c/0x140 [ 40.969733] Call Trace: [ 40.969740] __flush_work+0x97/0x1d0 [ 40.969745] ? wake_up_proc...

In the Linux kernel, the following vulnerability has been resolved: bus: mhi: core: Fix invalid error returning in mhi_queue mhi_queue returns an error when the doorbell is not accessible in the current state. This can happen when the device is in non M0 state, like M3, and needs to be waken-up prior ringing the DB. This case is managed earlier by triggering an asynchronous M3 exit via controller resume/suspend callbacks, that in turn will cause M0 transition and DB update. So, since it's not an error but just delaying of doorbell update, there is no reason to return an error. This also fixes a use after free error for skb case, indeed a caller queuing skb will try to free the skb if the queueing fails, but in that case queueing has been done.

In the Linux kernel, the following vulnerability has been resolved: s390/zcrypt: fix zcard and zqueue hot-unplug memleak Tests with kvm and a kmemdebug kernel showed, that on hot unplug the zcard and zqueue structs for the unplugged card or queue are not properly freed because of a mismatch with get/put for the embedded kref counter. This fix now adjusts the handling of the kref counters. With init the kref counter starts with 1. This initial value needs to drop to zero with the unregister of the card or queue to trigger the release and free the object.