Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: nfc: nci: add flush_workqueue to prevent uaf Our detector found a concurrent use-after-free bug when detaching an NCI device. The main reason for this bug is the unexpected scheduling between the used delayed mechanism (timer and workqueue). The race can be demonstrated below: Thread-1 Thread-2 | nci_dev_up() | nci_open_device() | __nci_request(nci_reset_req) | nci_send_cmd | queue_work(cmd_work) nci_unregister_device() | nci_close_device() | ... del_timer_sync(cmd_timer)[1] | ... | Worker nci_free_device() | nci_cmd_work() kfree(ndev)[3] | mod_timer(cmd_timer)[2] In short, the cleanup routine thought that the cmd_timer has already been detached by [1] but the mod_timer can re-attach the timer [2], even it is already released [3], resulting in UAF. This UAF is easy to trigger, crash trace by POC is like below [ 66.703713] ================================================================== [ 66.703974] BUG: KASAN: use-after-free in enqueue_timer+0x448/0x490 [ 66.703974] Write of size 8 at addr ffff888009fb7058 by task kworker/u4:1/33 [ 66.703974] [ 66.703974] CPU: 1 PID: 33 Comm: kworker/u4:1 Not tainted 5.18.0-rc2 #5 [ 66.703974] Workqueue: nfc2_nci_cmd_wq nci_cmd_work [ 66.703974] Call Trace: [ 66.703974] <TASK> [ 66.703974] dump_stack_lvl+0x57/0x7d [ 66.703974] print_report.cold+0x5e/0x5db [ 66.703974] ? enqueue_timer+0x448/0x490 [ 66.703974] kasan_report+0xbe/0x1c0 [ 66.703974] ? enqueue_timer+0x448/0x490 [ 66.703974] enqueue_timer+0x448/0x490 [ 66.703974] __mod_timer+0x5e6/0xb80 [ 66.703974] ? mark_held_locks+0x9e/0xe0 [ 66.703974] ? try_to_del_timer_sync+0xf0/0xf0 [ 66.703974] ? lockdep_hardirqs_on_prepare+0x17b/0x410 [ 66.703974] ? queue_work_on+0x61/0x80 [ 66.703974] ? lockdep_hardirqs_on+0xbf/0x130 [ 66.703974] process_one_work+0x8bb/0x1510 [ 66.703974] ? lockdep_hardirqs_on_prepare+0x410/0x410 [ 66.703974] ? pwq_dec_nr_in_flight+0x230/0x230 [ 66.703974] ? rwlock_bug.part.0+0x90/0x90 [ 66.703974] ? _raw_spin_lock_irq+0x41/0x50 [ 66.703974] worker_thread+0x575/0x1190 [ 66.703974] ? process_one_work+0x1510/0x1510 [ 66.703974] kthread+0x2a0/0x340 [ 66.703974] ? kthread_complete_and_exit+0x20/0x20 [ 66.703974] ret_from_fork+0x22/0x30 [ 66.703974] </TASK> [ 66.703974] [ 66.703974] Allocated by task 267: [ 66.703974] kasan_save_stack+0x1e/0x40 [ 66.703974] __kasan_kmalloc+0x81/0xa0 [ 66.703974] nci_allocate_device+0xd3/0x390 [ 66.703974] nfcmrvl_nci_register_dev+0x183/0x2c0 [ 66.703974] nfcmrvl_nci_uart_open+0xf2/0x1dd [ 66.703974] nci_uart_tty_ioctl+0x2c3/0x4a0 [ 66.703974] tty_ioctl+0x764/0x1310 [ 66.703974] __x64_sys_ioctl+0x122/0x190 [ 66.703974] do_syscall_64+0x3b/0x90 [ 66.703974] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 66.703974] [ 66.703974] Freed by task 406: [ 66.703974] kasan_save_stack+0x1e/0x40 [ 66.703974] kasan_set_track+0x21/0x30 [ 66.703974] kasan_set_free_info+0x20/0x30 [ 66.703974] __kasan_slab_free+0x108/0x170 [ 66.703974] kfree+0xb0/0x330 [ 66.703974] nfcmrvl_nci_unregister_dev+0x90/0xd0 [ 66.703974] nci_uart_tty_close+0xdf/0x180 [ 66.703974] tty_ldisc_kill+0x73/0x110 [ 66.703974] tty_ldisc_hangup+0x281/0x5b0 [ 66.703974] __tty_hangup.part.0+0x431/0x890 [ 66.703974] tty_release+0x3a8/0xc80 [ 66.703974] __fput+0x1f0/0x8c0 [ 66.703974] task_work_run+0xc9/0x170 [ 66.703974] exit_to_user_mode_prepare+0x194/0x1a0 [ 66.703974] syscall_exit_to_user_mode+0x19/0x50 [ 66.703974] do_syscall_64+0x48/0x90 [ 66.703974] entry_SYSCALL_64_after_hwframe+0x44/0x ---truncated---
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 6a2968aaf50c7a22fced77a5e24aa636281efca8 before 7d3232214ca4ea8f7d18df264c3b254aa8089d7f; affected 6a2968aaf50c7a22fced77a5e24aa636281efca8 before 9d243aff5f7e6b04e907c617426bbdf26e996ac8; affected 6a2968aaf50c7a22fced77a5e24aa636281efca8 before 1a1748d0dd0f0a98535c6baeef671c8722107639; affected 6a2968aaf50c7a22fced77a5e24aa636281efca8 before 5c63ad2b0a267a524c12c88acb1ba9c2d109a801; affected 6a2968aaf50c7a22fced77a5e24aa636281efca8 before 67677050cecbe0edfdd81cd508415e9636ba7c65; affected 6a2968aaf50c7a22fced77a5e24aa636281efca8 before 9ded5ae40f4fe37fcc28f36d76bf45df20be5432; affected 6a2968aaf50c7a22fced77a5e24aa636281efca8 before edd4600120641e1714e30112e69a548cfb68e067; affected 6a2968aaf50c7a22fced77a5e24aa636281efca8 before ef27324e2cb7bb24542d6cb2571740eefe6b00dc |
| Linux / Linux | affected 3.2; unaffected 0 before 3.2; unaffected 4.9.311 through 4.9.*; unaffected 4.14.276 through 4.14.*; unaffected 4.19.239 through 4.19.*; unaffected 5.4.190 through 5.4.*; unaffected 5.10.112 through 5.10.*; unaffected 5.15.35 through 5.15.*; unaffected 5.17.4 through 5.17.*; unaffected 5.18 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/7d3232214ca4ea8f7d18df264c3b254aa8089d7f
- https://git.kernel.org/stable/c/9d243aff5f7e6b04e907c617426bbdf26e996ac8
- https://git.kernel.org/stable/c/1a1748d0dd0f0a98535c6baeef671c8722107639
- https://git.kernel.org/stable/c/5c63ad2b0a267a524c12c88acb1ba9c2d109a801
- https://git.kernel.org/stable/c/67677050cecbe0edfdd81cd508415e9636ba7c65
- https://git.kernel.org/stable/c/9ded5ae40f4fe37fcc28f36d76bf45df20be5432
- https://git.kernel.org/stable/c/edd4600120641e1714e30112e69a548cfb68e067
- https://git.kernel.org/stable/c/ef27324e2cb7bb24542d6cb2571740eefe6b00dc
ADP enrichment
No English description supplied.
No references supplied.