Red Hat Security Advisory: kernel security update

Moderate

A null pointer dereference exists in the linux kernel, such that when sfb_init() fails qdisc is NULL, and it will cause gpf issue, leading to damage to the availability of the system.

CWE-476 - NULL Pointer Dereference

In the Linux kernel, the following vulnerability has been resolved: fs: fix UAF/GPF bug in nilfs_mdt_destroy In alloc_inode, inode_init_always() could return -ENOMEM if security_inode_alloc() fails, which causes inode->i_private uninitialized. Then nilfs_is_metadata_file_inode() returns true and nilfs_free_inode() wrongly calls nilfs_mdt_destroy(), which frees the uninitialized inode->i_private and leads to crashes(e.g., UAF/GPF). Fix this by moving security_inode_alloc just prior to this_cpu_inc(nr_inodes)

CWE-416 - Use After Free

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix user-after-free This uses l2cap_chan_hold_unless_zero() after calling __l2cap_get_chan_blah() to prevent the following trace: Bluetooth: l2cap_core.c:static void l2cap_chan_destroy(struct kref *kref) Bluetooth: chan 0000000023c4974d Bluetooth: parent 00000000ae861c08 ================================================================== BUG: KASAN: use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:191 [inline] BUG: KASAN: use-after-free in __mutex_lock_common kernel/locking/mutex.c:671 [inline] BUG: KASAN: use-after-free in __mutex_lock+0x278/0x400 kernel/locking/mutex.c:729 Read of size 8 at addr ffff888006a49b08 by task kworker/u3:2/389

In the Linux kernel, the following vulnerability has been resolved: mm: fix zswap writeback race condition The zswap writeback mechanism can cause a race condition resulting in memory corruption, where a swapped out page gets swapped in with data that was written to a different page. The race unfolds like this: 1. a page with data A and swap offset X is stored in zswap 2. page A is removed off the LRU by zpool driver for writeback in zswap-shrink work, data for A is mapped by zpool driver 3. user space program faults and invalidates page entry A, offset X is considered free 4. kswapd stores page B at offset X in zswap (zswap could also be full, if so, page B would then be IOed to X, then skip step 5.) 5. entry A is replaced by B in tree->rbroot, this doesn't affect the local reference held by zswap-shrink work 6. zswap-shrink work writes back A at X, and frees zswap entry A 7. swapin of slot X brings A in memory instead of B The fix: Once the swap page cache has been allocated (case ZSWAP_SWAPCACHE_NEW), zswap-shrink work just checks that the local zswap_entry reference is still the same as the one in the tree. If it's not the same it means that it's either been invalidated or replaced, in both cases the writeback is aborted because the local entry contains stale data. Reproducer: I originally found this by running `stress` overnight to validate my work on the zswap writeback mechanism, it manifested after hours on my test machine. The key to make it happen is having zswap writebacks, so whatever setup pumps /sys/kernel/debug/zswap/written_back_pages should do the trick. In order to reproduce this faster on a vm, I setup a system with ~100M of available memory and a 500M swap file, then running `stress --vm 1 --vm-bytes 300000000 --vm-stride 4000` makes it happen in matter of tens of minutes. One can speed things up even more by swinging /sys/module/zswap/parameters/max_pool_percent up and down between, say, 20 and 1; this makes it reproduce in tens of seconds. It's crucial to set `--vm-stride` to something other than 4096 otherwise `stress` won't realize that memory has been corrupted because all pages would have the same data.

CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition

In the Linux kernel, the following vulnerability has been resolved: wifi: ath9k: don't allow to overwrite ENDPOINT0 attributes A bad USB device is able to construct a service connection response message with target endpoint being ENDPOINT0 which is reserved for HTC_CTRL_RSVD_SVC and should not be modified to be used for any other services. Reject such service connection responses. Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

CWE-1285 - Improper Validation of Specified Index, Position, or Offset in Input

In the Linux kernel, the following vulnerability has been resolved: wifi: brcmfmac: slab-out-of-bounds read in brcmf_get_assoc_ies() Fix a slab-out-of-bounds read that occurs in kmemdup() called from brcmf_get_assoc_ies(). The bug could occur when assoc_info->req_len, data from a URB provided by a USB device, is bigger than the size of buffer which is defined as WL_EXTRA_BUF_MAX. Add the size check for req_len/resp_len of assoc_info. Found by a modified version of syzkaller. [ 46.592467][ T7] ================================================================== [ 46.594687][ T7] BUG: KASAN: slab-out-of-bounds in kmemdup+0x3e/0x50 [ 46.596572][ T7] Read of size 3014656 at addr ffff888019442000 by task kworker/0:1/7 [ 46.598575][ T7] [ 46.599157][ T7] CPU: 0 PID: 7 Comm: kworker/0:1 Tainted: G O 5.14.0+ #145 [ 46.601333][ T7] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 [ 46.604360][ T7] Workqueue: events brcmf_fweh_event_worker [ 46.605943][ T7] Call Trace: [ 46.606584][ T7] dump_stack_lvl+0x8e/0xd1 [ 46.607446][ T7] print_address_description.constprop.0.cold+0x93/0x334 [ 46.608610][ T7] ? kmemdup+0x3e/0x50 [ 46.609341][ T7] kasan_report.cold+0x79/0xd5 [ 46.610151][ T7] ? kmemdup+0x3e/0x50 [ 46.610796][ T7] kasan_check_range+0x14e/0x1b0 [ 46.611691][ T7] memcpy+0x20/0x60 [ 46.612323][ T7] kmemdup+0x3e/0x50 [ 46.612987][ T7] brcmf_get_assoc_ies+0x967/0xf60 [ 46.613904][ T7] ? brcmf_notify_vif_event+0x3d0/0x3d0 [ 46.614831][ T7] ? lock_chain_count+0x20/0x20 [ 46.615683][ T7] ? mark_lock.part.0+0xfc/0x2770 [ 46.616552][ T7] ? lock_chain_count+0x20/0x20 [ 46.617409][ T7] ? mark_lock.part.0+0xfc/0x2770 [ 46.618244][ T7] ? lock_chain_count+0x20/0x20 [ 46.619024][ T7] brcmf_bss_connect_done.constprop.0+0x241/0x2e0 [ 46.620019][ T7] ? brcmf_parse_configure_security.isra.0+0x2a0/0x2a0 [ 46.620818][ T7] ? __lock_acquire+0x181f/0x5790 [ 46.621462][ T7] brcmf_notify_connect_status+0x448/0x1950 [ 46.622134][ T7] ? rcu_read_lock_bh_held+0xb0/0xb0 [ 46.622736][ T7] ? brcmf_cfg80211_join_ibss+0x7b0/0x7b0 [ 46.623390][ T7] ? find_held_lock+0x2d/0x110 [ 46.623962][ T7] ? brcmf_fweh_event_worker+0x19f/0xc60 [ 46.624603][ T7] ? mark_held_locks+0x9f/0xe0 [ 46.625145][ T7] ? lockdep_hardirqs_on_prepare+0x3e0/0x3e0 [ 46.625871][ T7] ? brcmf_cfg80211_join_ibss+0x7b0/0x7b0 [ 46.626545][ T7] brcmf_fweh_call_event_handler.isra.0+0x90/0x100 [ 46.627338][ T7] brcmf_fweh_event_worker+0x557/0xc60 [ 46.627962][ T7] ? brcmf_fweh_call_event_handler.isra.0+0x100/0x100 [ 46.628736][ T7] ? rcu_read_lock_sched_held+0xa1/0xd0 [ 46.629396][ T7] ? rcu_read_lock_bh_held+0xb0/0xb0 [ 46.629970][ T7] ? lockdep_hardirqs_on_prepare+0x273/0x3e0 [ 46.630649][ T7] process_one_work+0x92b/0x1460 [ 46.631205][ T7] ? pwq_dec_nr_in_flight+0x330/0x330 [ 46.631821][ T7] ? rwlock_bug.part.0+0x90/0x90 [ 46.632347][ T7] worker_thread+0x95/0xe00 [ 46.632832][ T7] ? __kthread_parkme+0x115/0x1e0 [ 46.633393][ T7] ? process_one_work+0x1460/0x1460 [ 46.633957][ T7] kthread+0x3a1/0x480 [ 46.634369][ T7] ? set_kthread_struct+0x120/0x120 [ 46.634933][ T7] ret_from_fork+0x1f/0x30 [ 46.635431][ T7] [ 46.635687][ T7] Allocated by task 7: [ 46.636151][ T7] kasan_save_stack+0x1b/0x40 [ 46.636628][ T7] __kasan_kmalloc+0x7c/0x90 [ 46.637108][ T7] kmem_cache_alloc_trace+0x19e/0x330 [ 46.637696][ T7] brcmf_cfg80211_attach+0x4a0/0x4040 [ 46.638275][ T7] brcmf_attach+0x389/0xd40 [ 46.638739][ T7] brcmf_usb_probe+0x12de/0x1690 [ 46.639279][ T7] usb_probe_interface+0x2aa/0x760 [ 46.639820][ T7] really_probe+0x205/0xb70 [ 46.640342][ T7] __driver_probe_device+0 ---truncated---

CWE-125 - Out-of-bounds Read

In the Linux kernel, the following vulnerability has been resolved: mt76: mt7921: fix kernel panic by accessing unallocated eeprom.data The MT7921 driver no longer uses eeprom.data, but the relevant code has not been removed completely since commit 16d98b548365 ("mt76: mt7921: rely on mcu_get_nic_capability"). This could result in potential invalid memory access. To fix the kernel panic issue in mt7921, it is necessary to avoid accessing unallocated eeprom.data which can lead to invalid memory access. Furthermore, it is possible to entirely eliminate the mt7921_mcu_parse_eeprom function and solely depend on mt7921_mcu_parse_response to divide the RxD header. [2.702735] BUG: kernel NULL pointer dereference, address: 0000000000000550 [2.702740] #PF: supervisor write access in kernel mode [2.702741] #PF: error_code(0x0002) - not-present page [2.702743] PGD 0 P4D 0 [2.702747] Oops: 0002 [#1] PREEMPT SMP NOPTI [2.702755] RIP: 0010:mt7921_mcu_parse_response+0x147/0x170 [mt7921_common] [2.702758] RSP: 0018:ffffae7c00fef828 EFLAGS: 00010286 [2.702760] RAX: ffffa367f57be024 RBX: ffffa367cc7bf500 RCX: 0000000000000000 [2.702762] RDX: 0000000000000550 RSI: 0000000000000000 RDI: ffffa367cc7bf500 [2.702763] RBP: ffffae7c00fef840 R08: ffffa367cb167000 R09: 0000000000000005 [2.702764] R10: 0000000000000000 R11: ffffffffc04702e4 R12: ffffa367e8329f40 [2.702766] R13: 0000000000000000 R14: 0000000000000001 R15: ffffa367e8329f40 [2.702768] FS: 000079ee6cf20c40(0000) GS:ffffa36b2f940000(0000) knlGS:0000000000000000 [2.702769] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [2.702775] CR2: 0000000000000550 CR3: 00000001233c6004 CR4: 0000000000770ee0 [2.702776] PKRU: 55555554 [2.702777] Call Trace: [2.702782] mt76_mcu_skb_send_and_get_msg+0xc3/0x11e [mt76 <HASH:1bc4 5>] [2.702785] mt7921_run_firmware+0x241/0x853 [mt7921_common <HASH:6a2f 6>] [2.702789] mt7921e_mcu_init+0x2b/0x56 [mt7921e <HASH:d290 7>] [2.702792] mt7921_register_device+0x2eb/0x5a5 [mt7921_common <HASH:6a2f 6>] [2.702795] ? mt7921_irq_tasklet+0x1d4/0x1d4 [mt7921e <HASH:d290 7>] [2.702797] mt7921_pci_probe+0x2d6/0x319 [mt7921e <HASH:d290 7>] [2.702799] pci_device_probe+0x9f/0x12a

CWE-476 - NULL Pointer Dereference

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: check S1G action frame size Before checking the action code, check that it even exists in the frame.

In the Linux kernel, the following vulnerability has been resolved: crypto: seqiv - Handle EBUSY correctly As it is seqiv only handles the special return value of EINPROGERSS, which means that in all other cases it will free data related to the request. However, as the caller of seqiv may specify MAY_BACKLOG, we also need to expect EBUSY and treat it in the same way. Otherwise backlogged requests will trigger a use-after-free.

CWE-416 - Use After Free

A use-after-free vulnerability exists in the linux kernel such that the buffer release sequence in the deferred receive path. The code freed the RQ buffer first and only then cleared the context pointer under the lock.

CWE-416 - Use After Free