Linux

In the Linux kernel, the following vulnerability has been resolved: drm/vc4: kms: Add missing drm_crtc_commit_put Commit 9ec03d7f1ed3 ("drm/vc4: kms: Wait on previous FIFO users before a commit") introduced a global state for the HVS, with each FIFO storing the current CRTC commit so that we can properly synchronize commits. However, the refcounting was off and we thus ended up leaking the drm_crtc_commit structure every commit. Add a drm_crtc_commit_put to prevent the leakage.Show less

In the Linux kernel, the following vulnerability has been resolved: drm/vc4: kms: Clear the HVS FIFO commit pointer once done Commit 9ec03d7f1ed3 ("drm/vc4: kms: Wait on previous FIFO users before a commit") introduced a wait on the previous commit done on a given HVS FIFO. However, we never cleared that pointer once done. Since drm_crtc_commit_put can free the drm_crtc_commit structure directly if we were the last user, this means that it can lead to a use-after free if we were to duplicate the state, and that stale pointer would even be copied to the new state. Set the pointer to NULL once we're done with the wait so that we don't carry over a pointer to a free'd structure.Show less

In the Linux kernel, the following vulnerability has been resolved: drm/msm: Fix mmap to include VM_IO and VM_DONTDUMP In commit 510410bfc034 ("drm/msm: Implement mmap as GEM object function") we switched to a new/cleaner method of doing things. That's good, but we missed a little bit. Before that commit, we used to _first_ run through the drm_gem_mmap_obj() case where `obj->funcs->mmap()` was NULL. That meant that we ran: vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot); ...and _then_ we modified those mappings with our own. Now that `obj->funcs->mmap()` is no longer NULL we don't run the default code. It looks like the fact that the vm_flags got VM_IO / VM_DONTDUMP was important because we're now getting crashes on Chromebooks that use ARC++ while logging out. Specifically a crash that looks like this (this is on a 5.10 kernel w/ relevant backports but also seen on a 5.15 kernel): Unable to handle kernel paging request at virtual address ffffffc008000000 Mem abort info: ESR = 0x96000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 swapper pgtable: 4k pages, 39-bit VAs, pgdp=000000008293d000 [ffffffc008000000] pgd=00000001002b3003, p4d=00000001002b3003, pud=00000001002b3003, pmd=0000000000000000 Internal error: Oops: 96000006 [#1] PREEMPT SMP [...] CPU: 7 PID: 15734 Comm: crash_dump64 Tainted: G W 5.10.67 #1 [...] Hardware name: Qualcomm Technologies, Inc. sc7280 IDP SKU2 platform (DT) pstate: 80400009 (Nzcv daif +PAN -UAO -TCO BTYPE=--) pc : __arch_copy_to_user+0xc0/0x30c lr : copyout+0xac/0x14c [...] Call trace: __arch_copy_to_user+0xc0/0x30c copy_page_to_iter+0x1a0/0x294 process_vm_rw_core+0x240/0x408 process_vm_rw+0x110/0x16c __arm64_sys_process_vm_readv+0x30/0x3c el0_svc_common+0xf8/0x250 do_el0_svc+0x30/0x80 el0_svc+0x10/0x1c el0_sync_handler+0x78/0x108 el0_sync+0x184/0x1c0 Code: f8408423 f80008c3 910020c6 36100082 (b8404423) Let's add the two flags back in. While we're at it, the fact that we aren't running the default means that we _don't_ need to clear out VM_PFNMAP, so remove that and save an instruction. NOTE: it was confirmed that VM_IO was the important flag to fix the problem I was seeing, but adding back VM_DONTDUMP seems like a sane thing to do so I'm doing that too.Show less

In the Linux kernel, the following vulnerability has been resolved: drm/msm: Fix wait_fence submitqueue leak We weren't dropping the submitqueue reference in all paths. In particular, when the fence has already been signalled. Split out a helper to simplify handling this in the various different return paths.Show less

In the Linux kernel, the following vulnerability has been resolved: iwlwifi: Fix memory leaks in error handling path Should an error occur (invalid TLV len or memory allocation failure), the memory already allocated in 'reduce_power_data' should be freed before returning, otherwise it is leaking.Show less

In the Linux kernel, the following vulnerability has been resolved: usb: cdnsp: Fix a NULL pointer dereference in cdnsp_endpoint_init() In cdnsp_endpoint_init(), cdnsp_ring_alloc() is assigned to pep->ring and there is a dereference of it in cdnsp_endpoint_init(), which could lead to a NULL pointer dereference on failure of cdnsp_ring_alloc(). Fix this bug by adding a check of pep->ring. This bug was found by a static analyzer. The analysis employs differential checking to identify inconsistent security operations (e.g., checks or kfrees) between two code paths and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs. Note that, as a bug found by static analysis, it can be a false positive or hard to trigger. Multiple researchers have cross-reviewed the bug. Builds with CONFIG_USB_CDNSP_GADGET=y show no new warnings, and our static analyzer no longer warns about this code.Show less

In the Linux kernel, the following vulnerability has been resolved: serial: core: fix transmit-buffer reset and memleak Commit 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") converted serial core to use tty_port_close() but failed to notice that the transmit buffer still needs to be freed on final close. Not freeing the transmit buffer means that the buffer is no longer cleared on next open so that any ioctl() waiting for the buffer to drain might wait indefinitely (e.g. on termios changes) or that stale data can end up being transmitted in case tx is restarted. Furthermore, the buffer of any port that has been opened would leak on driver unbind. Note that the port lock is held when clearing the buffer pointer due to the ldisc race worked around by commit a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()"). Also note that the tty-port shutdown() callback is not called for console ports so it is not strictly necessary to free the buffer page after releasing the lock (cf. d72402145ace ("tty/serial: do not free trasnmit buffer page under port lock")).Show less

In the Linux kernel, the following vulnerability has been resolved: serial: liteuart: Fix NULL pointer dereference in ->remove() drvdata has to be set in _probe() - otherwise platform_get_drvdata() causes null pointer dereference BUG in _remove().Show less

In the Linux kernel, the following vulnerability has been resolved: serial: liteuart: fix use-after-free and memleak on unbind Deregister the port when unbinding the driver to prevent it from being used after releasing the driver data and leaking memory allocated by serial core.Show less

In the Linux kernel, the following vulnerability has been resolved: IB/hfi1: Fix leak of rcvhdrtail_dummy_kvaddr This buffer is currently allocated in hfi1_init(): if (reinit) ret = init_after_reset(dd); else ret = loadtime_init(dd); if (ret) goto done; /* allocate dummy tail memory for all receive contexts */ dd->rcvhdrtail_dummy_kvaddr = dma_alloc_coherent(&dd->pcidev->dev, sizeof(u64), &dd->rcvhdrtail_dummy_dma, GFP_KERNEL); if (!dd->rcvhdrtail_dummy_kvaddr) { dd_dev_err(dd, "cannot allocate dummy tail memory\n"); ret = -ENOMEM; goto done; } The reinit triggered path will overwrite the old allocation and leak it. Fix by moving the allocation to hfi1_alloc_devdata() and the deallocation to hfi1_free_devdata().Show less

In the Linux kernel, the following vulnerability has been resolved: HID: bigbenff: prevent null pointer dereference When emulating the device through uhid, there is a chance we don't have output reports and so report_field is null.Show less

In the Linux kernel, the following vulnerability has been resolved: can: sja1000: fix use after free in ems_pcmcia_add_card() If the last channel is not available then "dev" is freed. Fortunately, we can just use "pdev->irq" instead. Also we should check if at least one channel was set up.Show less

In the Linux kernel, the following vulnerability has been resolved: can: pch_can: pch_can_rx_normal: fix use after free After calling netif_receive_skb(skb), dereferencing skb is unsafe. Especially, the can_frame cf which aliases skb memory is dereferenced just after the call netif_receive_skb(skb). Reordering the lines solves the issue.Show less

In the Linux kernel, the following vulnerability has been resolved: can: m_can: m_can_read_fifo: fix memory leak in error branch In m_can_read_fifo(), if the second call to m_can_fifo_read() fails, the function jump to the out_fail label and returns without calling m_can_receive_skb(). This means that the skb previously allocated by alloc_can_skb() is not freed. In other terms, this is a memory leak. This patch adds a goto label to destroy the skb if an error occurs. Issue was found with GCC -fanalyzer, please follow the link below for details.Show less

In the Linux kernel, the following vulnerability has been resolved: nfc: fix potential NULL pointer deref in nfc_genl_dump_ses_done The done() netlink callback nfc_genl_dump_ses_done() should check if received argument is non-NULL, because its allocation could fail earlier in dumpit() (nfc_genl_dump_ses()).Show less

In the Linux kernel, the following vulnerability has been resolved: ethtool: do not perform operations on net devices being unregistered There is a short period between a net device starts to be unregistered and when it is actually gone. In that time frame ethtool operations could still be performed, which might end up in unwanted or undefined behaviours[1]. Do not allow ethtool operations after a net device starts its unregistration. This patch targets the netlink part as the ioctl one isn't affected: the reference to the net device is taken and the operation is executed within an rtnl lock section and the net device won't be found after unregister. [1] For example adding Tx queues after unregister ends up in NULL pointer exceptions and UaFs, such as: BUG: KASAN: use-after-free in kobject_get+0x14/0x90 Read of size 1 at addr ffff88801961248c by task ethtool/755 CPU: 0 PID: 755 Comm: ethtool Not tainted 5.15.0-rc6+ #778 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/014 Call Trace: dump_stack_lvl+0x57/0x72 print_address_description.constprop.0+0x1f/0x140 kasan_report.cold+0x7f/0x11b kobject_get+0x14/0x90 kobject_add_internal+0x3d1/0x450 kobject_init_and_add+0xba/0xf0 netdev_queue_update_kobjects+0xcf/0x200 netif_set_real_num_tx_queues+0xb4/0x310 veth_set_channels+0x1c3/0x550 ethnl_set_channels+0x524/0x610Show less

In the Linux kernel, the following vulnerability has been resolved: nfp: Fix memory leak in nfp_cpp_area_cache_add() In line 800 (#1), nfp_cpp_area_alloc() allocates and initializes a CPP area structure. But in line 807 (#2), when the cache is allocated failed, this CPP area structure is not freed, which will result in memory leak. We can fix it by freeing the CPP area when the cache is allocated failed (#2). 792 int nfp_cpp_area_cache_add(struct nfp_cpp *cpp, size_t size) 793 { 794 struct nfp_cpp_area_cache *cache; 795 struct nfp_cpp_area *area; 800 area = nfp_cpp_area_alloc(cpp, NFP_CPP_ID(7, NFP_CPP_ACTION_RW, 0), 801 0, size); // #1: allocates and initializes 802 if (!area) 803 return -ENOMEM; 805 cache = kzalloc(sizeof(*cache), GFP_KERNEL); 806 if (!cache) 807 return -ENOMEM; // #2: missing free 817 return 0; 818 }Show less

In the Linux kernel, the following vulnerability has been resolved: seg6: fix the iif in the IPv6 socket control block When an IPv4 packet is received, the ip_rcv_core(...) sets the receiving interface index into the IPv4 socket control block (v5.16-rc4, net/ipv4/ip_input.c line 510): IPCB(skb)->iif = skb->skb_iif; If that IPv4 packet is meant to be encapsulated in an outer IPv6+SRH header, the seg6_do_srh_encap(...) performs the required encapsulation. In this case, the seg6_do_srh_encap function clears the IPv6 socket control block (v5.16-rc4 net/ipv6/seg6_iptunnel.c line 163): memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); The memset(...) was introduced in commit ef489749aae5 ("ipv6: sr: clear IP6CB(skb) on SRH ip4ip6 encapsulation") a long time ago (2019-01-29). Since the IPv6 socket control block and the IPv4 socket control block share the same memory area (skb->cb), the receiving interface index info is lost (IP6CB(skb)->iif is set to zero). As a side effect, that condition triggers a NULL pointer dereference if commit 0857d6f8c759 ("ipv6: When forwarding count rx stats on the orig netdev") is applied. To fix that issue, we set the IP6CB(skb)->iif with the index of the receiving interface once again.Show less