In the Linux kernel, the following vulnerability has been resolved: tty: tty_buffer: Fix the softlockup issue in flush_to_ldisc When runnin…
In the Linux kernel, the following vulnerability has been resolved: tty: tty_buffer: Fix the softlockup issue in flush_to_ldisc When running ltp testcase(ltp/testcases/kernel/pty/pty04.c) with arm64, there is a soft lockup, which look like this one: Workqueue: events_unbound flush_to_ldisc Call trace: dump_backtrace+0x0/0x1ec show_stack+0x24/0x30 dump_stack+0xd0/0x128 panic+0x15c/0x374 watchdog_timer_fn+0x2b8/0x304 __run_hrtimer+0x88/0x2c0 __hrtimer_run_queues+0xa4/0x120 hrtimer_interrupt+0xfc/0x270 arch_timer_handler_phys+0x40/0x50 handle_percpu_devid_irq+0x94/0x220 __handle_domain_irq+0x88/0xf0 gic_handle_irq+0x84/0xfc el1_irq+0xc8/0x180 slip_unesc+0x80/0x214 [slip] tty_ldisc_receive_buf+0x64/0x80 tty_port_default_receive_buf+0x50/0x90 flush_to_ldisc+0xbc/0x110 process_one_work+0x1d4/0x4b0 worker_thread+0x180/0x430 kthread+0x11c/0x120 In the testcase pty04, The first process call the write syscall to send data to the pty master. At the same time, the workqueue will do the flush_to_ldisc to pop data in a loop until there is no more data left. When the sender and workqueue running in different core, the sender sends data fastly in full time which will result in workqueue doing work in loop for a long time and occuring softlockup in flush_to_ldisc with kernel configured without preempt. So I add need_resched check and cond_resched in the flush_to_ldisc loop to avoid it.
The product has a loop body or loop condition that contains a control element that directly or indirectly consumes platform resources, e.g. messaging, sessions, locks, or file descriptors.
https://cwe.mitre.org/data/definitions/1050.html →Open in CWE collection →The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.
https://cwe.mitre.org/data/definitions/667.html →Open in CWE collection →The adversary triggers and exploits a deadlock condition in the target software to cause a denial of service. A deadlock can occur when two or more competing actions are waiting for each other to finish, and thus neither ever does. Deadlock conditions can be difficult to detect.
https://capec.mitre.org/data/definitions/25.html →Open in CAPEC collection →The adversary targets a race condition occurring when multiple processes access and manipulate the same resource concurrently, and the outcome of the execution depends on the particular order in which the access takes place. The adversary can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance, a race condition can occur while accessing a file: the adversary can trick the system by replacing the original file with their version and cause the system to read the malicious file.
https://capec.mitre.org/data/definitions/26.html →Open in CAPEC collection →This attack leverages the use of symbolic links (Symlinks) in order to write to sensitive files. An attacker can create a Symlink link to a target file not otherwise accessible to them. When the privileged program tries to create a temporary file with the same name as the Symlink link, it will actually write to the target file pointed to by the attackers' Symlink link. If the attacker can insert malicious content in the temporary file they will be writing to the sensitive file by using the Symlink. The race occurs because the system checks if the temporary file exists, then creates the file. The attacker would typically create the Symlink during the interval between the check and the creation of the temporary file.
https://capec.mitre.org/data/definitions/27.html →Open in CAPEC collection →| Product | Vendor | Status |
|---|---|---|
| kernel | Tracked | |
| kernel | Tracked | |
| kernel | Tracked | |
| kernel-rt | Tracked | |
| linux | Tracked | |
| linux | Tracked | |
| linux | Tracked | |
| linux | Tracked | |
| linux | Tracked | |
| linux | Tracked | |
| linux | Tracked | |
| linux | Tracked | |
| linux | Tracked | |
| linux | Tracked | |
| linux | Tracked | |
| linux | Tracked | |
| linux | Tracked | |
| linux | Tracked | |
| linux | Tracked | |
| linux | Tracked |