Gaosheng Cui 0152e7758c audit: fix possible soft lockup in __audit_inode_child()
[ Upstream commit b59bc6e37237e37eadf50cd5de369e913f524463 ]

Tracefs or debugfs maybe cause hundreds to thousands of PATH records,
too many PATH records maybe cause soft lockup.

For example:
  1. CONFIG_KASAN=y && CONFIG_PREEMPTION=n
  2. auditctl -a exit,always -S open -k key
  3. sysctl -w kernel.watchdog_thresh=5
  4. mkdir /sys/kernel/debug/tracing/instances/test

There may be a soft lockup as follows:
  watchdog: BUG: soft lockup - CPU#45 stuck for 7s! [mkdir:15498]
  Kernel panic - not syncing: softlockup: hung tasks
  Call trace:
   dump_backtrace+0x0/0x30c
   show_stack+0x20/0x30
   dump_stack+0x11c/0x174
   panic+0x27c/0x494
   watchdog_timer_fn+0x2bc/0x390
   __run_hrtimer+0x148/0x4fc
   __hrtimer_run_queues+0x154/0x210
   hrtimer_interrupt+0x2c4/0x760
   arch_timer_handler_phys+0x48/0x60
   handle_percpu_devid_irq+0xe0/0x340
   __handle_domain_irq+0xbc/0x130
   gic_handle_irq+0x78/0x460
   el1_irq+0xb8/0x140
   __audit_inode_child+0x240/0x7bc
   tracefs_create_file+0x1b8/0x2a0
   trace_create_file+0x18/0x50
   event_create_dir+0x204/0x30c
   __trace_add_new_event+0xac/0x100
   event_trace_add_tracer+0xa0/0x130
   trace_array_create_dir+0x60/0x140
   trace_array_create+0x1e0/0x370
   instance_mkdir+0x90/0xd0
   tracefs_syscall_mkdir+0x68/0xa0
   vfs_mkdir+0x21c/0x34c
   do_mkdirat+0x1b4/0x1d4
   __arm64_sys_mkdirat+0x4c/0x60
   el0_svc_common.constprop.0+0xa8/0x240
   do_el0_svc+0x8c/0xc0
   el0_svc+0x20/0x30
   el0_sync_handler+0xb0/0xb4
   el0_sync+0x160/0x180

Therefore, we add cond_resched() to __audit_inode_child() to fix it.

Fixes: 5195d8e217a7 ("audit: dynamically allocate audit_names when not enough space is in the names array")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-19 12:22:39 +02:00
2023-08-30 16:18:18 +02:00
2023-09-19 12:22:35 +02:00
2023-07-23 13:47:17 +02:00
2021-10-18 20:22:03 -10:00
2023-09-06 21:28:41 +01:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Description
No description provided
Readme 5.7 GiB
Languages
C 97.6%
Assembly 1%
Shell 0.5%
Python 0.3%
Makefile 0.3%