Known Vulnerabilities
CVE-2021-47522
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.
CVE-2021-47521
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.
CVE-2021-47520
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.
CVE-2021-47518
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()).
CVE-2021-47516
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 }
CVE-2021-47515
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.
CVE-2021-47511
In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: oss: Fix negative period/buffer sizes The period size calculation in OSS layer may receive a negative value as an error, but the code there assumes only the positive values and handle them with size_t. Due to that, a too big value may be passed to the lower layers. This patch changes the code to handle with ssize_t and adds the proper error checks appropriately.
CVE-2021-47509
In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: oss: Limit the period size to 16MB Set the practical limit to the period size (the fragment shift in OSS) instead of a full 31bit; a too large value could lead to the exhaust of memory as we allocate temporary buffers of the period size, too. As of this patch, we set to 16MB limit, which should cover all use cases.
CVE-2021-47507
In the Linux kernel, the following vulnerability has been resolved: nfsd: Fix nsfd startup race (again) Commit bd5ae9288d64 ("nfsd: register pernet ops last, unregister first") has re-opened rpc_pipefs_event() race against nfsd_net_id registration (register_pernet_subsys()) which has been fixed by commit bb7ffbf29e76 ("nfsd: fix nsfd startup race triggering BUG_ON"). Restore the order of register_pernet_subsys() vs register_cld_notifier(). Add WARN_ON() to prevent a future regression. Crash info: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000012 CPU: 8 PID: 345 Comm: mount Not tainted 5.4.144-... #1 pc : rpc_pipefs_event+0x54/0x120 [nfsd] lr : rpc_pipefs_event+0x48/0x120 [nfsd] Call trace: rpc_pipefs_event+0x54/0x120 [nfsd] blocking_notifier_call_chain rpc_fill_super get_tree_keyed rpc_fs_get_tree vfs_get_tree do_mount ksys_mount __arm64_sys_mount el0_svc_handler el0_svc
CVE-2021-47505
In the Linux kernel, the following vulnerability has been resolved: aio: fix use-after-free due to missing POLLFREE handling signalfd_poll() and binder_poll() are special in that they use a waitqueue whose lifetime is the current task, rather than the struct file as is normally the case. This is okay for blocking polls, since a blocking poll occurs within one task; however, non-blocking polls require another solution. This solution is for the queue to be cleared before it is freed, by sending a POLLFREE notification to all waiters. Unfortunately, only eventpoll handles POLLFREE. A second type of non-blocking poll, aio poll, was added in kernel v4.18, and it doesn't handle POLLFREE. This allows a use-after-free to occur if a signalfd or binder fd is polled with aio poll, and the waitqueue gets freed. Fix this by making aio poll handle POLLFREE. A patch by Ramji Jiyani <[email protected]> (https://lore.kernel.org/r/[email protected]) tried to do this by making aio_poll_wake() always complete the request inline if POLLFREE is seen. However, that solution had two bugs. First, it introduced a deadlock, as it unconditionally locked the aio context while holding the waitqueue lock, which inverts the normal locking order. Second, it didn't consider that POLLFREE notifications are missed while the request has been temporarily de-queued. The second problem was solved by my previous patch. This patch then properly fixes the use-after-free by handling POLLFREE in a deadlock-free way. It does this by taking advantage of the fact that freeing of the waitqueue is RCU-delayed, similar to what eventpoll does.
CVE-2021-47500
In the Linux kernel, the following vulnerability has been resolved: iio: mma8452: Fix trigger reference couting The mma8452 driver directly assigns a trigger to the struct iio_dev. The IIO core when done using this trigger will call `iio_trigger_put()` to drop the reference count by 1. Without the matching `iio_trigger_get()` in the driver the reference count can reach 0 too early, the trigger gets freed while still in use and a use-after-free occurs. Fix this by getting a reference to the trigger before assigning it to the IIO device.
CVE-2021-47499
In the Linux kernel, the following vulnerability has been resolved: iio: accel: kxcjk-1013: Fix possible memory leak in probe and remove When ACPI type is ACPI_SMO8500, the data->dready_trig will not be set, the memory allocated by iio_triggered_buffer_setup() will not be freed, and cause memory leak as follows: unreferenced object 0xffff888009551400 (size 512): comm "i2c-SMO8500-125", pid 911, jiffies 4294911787 (age 83.852s) hex dump (first 32 bytes): 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 20 e2 e5 c0 ff ff ff ff ........ ....... backtrace: [<0000000041ce75ee>] kmem_cache_alloc_trace+0x16d/0x360 [<000000000aeb17b0>] iio_kfifo_allocate+0x41/0x130 [kfifo_buf] [<000000004b40c1f5>] iio_triggered_buffer_setup_ext+0x2c/0x210 [industrialio_triggered_buffer] [<000000004375b15f>] kxcjk1013_probe+0x10c3/0x1d81 [kxcjk_1013] Fix it by remove data->dready_trig condition in probe and remove.